Software Vault: The Gold Collection/Software Vault - The Gold Collection (American Databankers) (1993).ISO/cdr17/weathe31.zip/WEATHER.DOC

Text File | 1993-05-03 | 68KB | 1,228 lines

                              WeatherGraphix
                   Interactive Weather Analysis System
                       (c) 1992, 1993 Tim Vasquez
           Tim Vasquez, 3222 Kingswood Drive, Garland, TX 75040
 CompuServe 71611,2267 -- Internet [e-mail] -- Genie
                               T.VASQUEZ1


*** IMPORTANT!
    See READ.ME for important changes to this version!



I.  INTRODUCTION

    WeatherGraphix (formerly Weather Pro and RadarScan) is a full color
EGA/VGA-graphics program which plots high-resolution weather graphic
charts.  It gets its information from National Weather Service data that
you capture on any database you prefer -- no longer are you tied to a
specific system (with extra costs) just to get maps.  You use the program
offline, at your leisure, saving you time and money.
    WeatherGraphix is -not- a cute toy.  It's a slick tool, and it's about
the best one in existence for pilots, amateur weather persons, storm
spotters, storm chasers, and just about anyone who wants to have the upper
hand on the Weather Channel.  It offers some features that are comparable
to those seen in weather forecasting centers and on weather briefing
terminals used by the major airlines.
    The high-resolution base map of North America is the big plus.  It's
plotted in the polar stereographic projection, and on it, you have
complete control over zooming and panning!  You can even get into the
geography database and modify it, say to enhance the coastline, or add
highways, county lines, and air routes.  Weather Pro offers complete
coverage and support for the United States, Canada, and Alaska -- it is
guaranteed to work for users living in each of these regions.
    There is another file, too, which contains modifiable cities and towns
you can overlay with a keystroke -- perfect to determine whether
Northville Municipal Airfield is getting hit by a storm or just to see if
it's raining over at Grandma's place.
    The radar plotting ability is the major strength of the program.  It
produces charts that are strikingly similar in form to those received by
National Weather Service forecasters over AFOS circuits.  You don't get a
dinky, vague CGA chart -- you get a full-color, almost broadcast-quality
radar composite for the contiguous United States (Canadian radar data is
not supported).  At your option, WeatherGraphix will overlay maximum tops,
bow echoes, hook echoes, line-echo wave patterns, BWERs, WERs, and other
significant storm features.  It will even outline the exact coordinates of
severe squall lines!  As you can imagine, it does away with those warped
"teletype"-style radar dot maps available on many databases.  If you've
used one of them, you know how difficult it is to locate a city accurately
or plot straight-line routes.
    WeatherGraphix masters surface analysis on the PC.  It adds sky
condition, temperature, dewpoint, sea level pressure, and wind data from
hourly surface reports in the form of standard plots.  You don't get
large, oversized plots, which plague many specialized weather graphics
maps seen on professional databases.  You get a small, meteorologically
useful density of data, perfect for examing small-scale (mesoscale)
conditions, along with the option to either plot ALL reports or let the
computer reduce clutter.  You can also instruct WeatherGraphix to plot the
surface wind only, without the other data, to get an idea of the surface
wind field.  You can't beat it for planning a flight or a trip.  Fronts
and disturbances will stand out perfectly.
    Rawinsonde data can be imported into WeatherGraphix.  From this
information you can plot constant pressure charts with raw data, create
height contours, make your own customized 500- millibar vorticity maps,
and even evaluate shear over a storm threat region!
    WeatherGraphix decodes FDHI/FDLO upper-air reports, widely used by
pilots, to plot upper air wind charts.  You choose which level and valid
time you want, and WeatherGraphix selects the correct data set.  Like the
surface chart, it draws a network of standard station plots.  The results
are sharp.  And users who don't have access to rawinsonde data can analyze
the FD maps just as if it was rawinsonde data (with some obvious
limitations).
    Compositing is a state-of-the-art word in many forecast offices today.
 It means being able to overlay radically different types of data on one
another, and it's a key concept in the National Weather Service's new
AWIPS (Advanced Weather Interactive Processing) computer system.
WeatherGraphix brings this power to your desk, and adds ADAP-type
diagnostic analysis of all levels.  For example, you can plot the color
radar chart and then overlay surface data on it, perhaps to find out if
that front is driving the storms or not, or what the winds in a rain area
are.  Then you might want to zoom in really close for a better look at the
mesoscale composite, and allow WeatherGraphix to fill in more data in that
area.  Or you can overlay the upper-level winds on the squall line to see
how the storms will be steered.  Or check the moisture convergence at the
surface to see just how the storms are being fueled.
    And it's fast.  On my Gateway 386/25, the North American base map
plots in four seconds.  Take a huge 150,000-byte weather data file.
Sifting through this mountain of information, WeatherGraphix plots surface
observations in 12 seconds.  Upper-level wind data takes about 7 seconds.
Radar height data plots in 8 to 17 seconds.  Radar decoding takes anywhere
from 8 to 30 seconds.
    The catch?  You have to get the data yourself.  To save time and
effort, many terminal programs will let you design a script to automate
the process.
    Where do you get the data?  YOU decide!  For example, on CompuServe,
aviation weather is part of the basic services -- $8 a month, with no
connect charges.  Pilots can use DUAT and Weathermation, which are free.
WeatherGraphix will sink its teeth into almost ANY raw data from ANY
database -- if it can't, I'll try to adapt it for that system.
    Without a doubt, WeatherGraphix is one of the most powerful, flexible
tools available to amateur forecasters, pilots, and students.


II.  REQUIREMENTS

   WeatherGraphix requires a PC or 100% compatible with at least EGA (640 x
350 x 16) graphics.  VGA (640 x 480 x 16) is preferred,  however.  A 286
(AT) or higher grade computer is recommended to avoid slow performance.  A
hard drive will also speed things up somewhat.  You will also need 700K of
empty space, minimum, to install the program in your WeatherGraphix
directory, so a hard drive is recommended.
    The final requirement is a source of weather reports.  You wil need
either FDHI/FDLO reports, surface aviation reports, SD radar data, and/or
rawinsonde (TTAA/TTBB/PPBB) data.  The data source should NOT modify the
original reports in any way (no "decoded" reports, for example!).
CompuServe, AccuWeather, Contel DUAT, and Weathermation are examples of
data sources which have been successfully tested with WeatherGraphix.


III.  TERMS OF USE

    There are two versions of WeatherGraphix, a demo version and a
registered version.  Each have different terms of use.

A. Demo Version ---- If you're on any BBSs, feel free to upload and
freely distribute the demo version, WEATHER.ZIP, which is available on
CompuServe as WEATHE.ZIP.  It is also enclosed on the registered program
disk as "WXDEMO.ZIP", and may be uploaded intact.  My only restrictions --
you may not tamper with the content of that file in any way, nor can you
sell the file for profit or include it as part of another package.

B. Registered Version ---- You may not upload or distribute any portion of the
registered version whatsoever.  It is protected under Title 17, USC and
international copyright laws.  Unauthorized distribution of any part of it
constitutes copyright infringement.  I am involved extensively in
meteorology and will quickly be able to track down unauthorized copies of
this program.  With countless hours invested in this system I will not
hesistate to follow up on and take action if I suspect copyright
infringement.

C. Liability ---- THE WEATHERGRAPHIX SYSTEM IS PROVIDED WITHOUT
WARRANTY OF ANY KIND, EXPRESSED OR IMPLIED.  The author makes no claims or
representation as to its accuracy, reliability, or fitness for a
particular purpose.  The author disavows any liability connected with this
program and documentation, and the user assumes all risks from the
application and use of it.
   In other words, you use it at your own risk!
   It would be great if I could guarantee this program to work 100%, but
this would quickly make it a full-time project for me.  Instead of doing
that, I'd rather provide a program that works 99% of the time, for a lower
price.
   If you need guaranteed precision and reliability, I will gladly point
you toward the thousand-dollar-plus packages and systems produced for the
weather industry by companies such as Kavouras and Alden.  Their data
invariably goes through highly specialized human and computerized quality
control checks that assure you of top-notch accuracy.
   Although I will try to snuff out all errors and release corrected
updates, you should use WeatherGraphix with caution and common sense. This
especially goes for you pilots, whose lives depend on the weather -- you
already know that you're required to get a formal weather briefing before
takeoff.  WeatherGraphix, unfortunately, doesn't constitute one.
Unformatted weather reports severely test the limitations of any
processing method, and since this is a spare-time project for me, I
haven't had the time to explore every last data error that could cause
this program to malfunction.

D. Improvements ---- If you have any comments, suggestions, or
questions, you may send them to the address listed above.  For a quicker
response, write to me at the computer addresses shown.


IV.  REGISTERING A COPY

   A registered copy of WeatherGraphix is $45.
   "Forty five dollars?!" you say.  "For that much, I'd better get something
good!"
   Well, here's what you get.

A. The Program ---- You get the full-fledged program, of course.  It allows
you to zoom and roam around in different regions, giving you a tremendous
leap in the number of stations and analysis resolution available to you.
you can access.  See the enclosed file, SAMPLE.GIF, using a graphics
viewing program to get a look at what you'll be in for!

B. Documentation ---- You get this documentation file in the form of a desktop
published manual.  AND you get a guide to weather forecasting and
thunderstorms, just in case you're wondering what drives the jet streams
or what "short waves" are.

C. Improvements ---- You get a say in what you'd like to see in future
updates.  This program has constantly been improving due to the
suggestions of many die-hard users.

D. Updates! ---- You get FREE UPDATES.  You can update your program
using the new demo versions which are routinely posted in CompuServe's
AVSIG forum and distributed elsewhere.  I want to make sure that you never
have to re-register just to upgrade your copy!  For example, the people
who ordered the prehistoric version of this program (RadarScan) are
updating their registered program right now with this package.
   If you're registered and can't find a demo, all you have to do is mail
me a disk and a SASE disk mailer and I'll burn you off a copy, no charge.
This policy also protects you from future price increases.  Sound good?

E. How to Register ---- To register, just send a check or money order for $45
to  Tim Vasquez at the address listed at the beginning of this manual.  Your
package will be sent to you first-class U.S. mail (postage is included).


V.  OPERATION

   Here's a brief outline of what it takes to use WeatherGraphix.  Once
you get familiar with the process, you can build batch and script files
which automate the entire process to your own specifications.  And with
the right software, you can even let your PC dial up and display a new
chart every hour -- automatically!

A. Capture the data -- Before you get the data, turn on your "capture" or
"disk log" function to capture the raw radar reports.  Reports are stored
in two separate files.
   Store surface data (surface observations, radar, forecasts, plain
language, etc) in DATA.SFC in the WeatherGraphix directory.  This name can
be changed as will be shown later.
   You must store rawinsonde and winds aloft information (FDLO/FDHI) in a
seperate file -- DATA.UPR, which is stored in the WeatherGraphix
directory.  This filename may also be renamed.  The reason this
information is stored separately is because upper-air data only changes
once every 12 hours, as opposed to hourly for surface and radar data.
This will save you time and effort when making multiple captures in the
same day.
   Important!  Make sure existing files are deleted first (unless you plan
to use old data, for example, the latest upper air file, and you don't
plan to add anything to it).  Some terminal programs may append data to
the end of a file if it already exists, and this WILL eventually cause you
problems.  So make sure that your "disk log" or "capture" command is
configured to destroy or overwrite any existing file.

B. Access the data ----  Using any quality terminal communications program
log into your database and capture one or all of the following.  It
doesn't matter what order the reports are in, as long as they aren't
modified.  WeatherGraphix will ignore all extraneous text, so you don't
need to edit the captured file.

     Retrieve one or all of the following:

 1.  Current radar observations (SD reports).  This may take about 1 to 2
minutes at 2400 baud.  You can select certain regions only, but your map
may be incomplete as a result.  On CompuServe, use the command "SD @ALL".
On Accu-Data, use the command "RADU * 1".  See the data vendor's guide for
further help.

 2.  Current surface observations (the common airways format).  There are
over 2000 stations in the United States and Canada, and this amount of
data may take 6 minutes at 2400 baud to download.  If this is too long,
you may just want to select certain states, and a handful of
representative stations elsewhere.  On CompuServe, use the command "SA
@ALL", or "SA TX,OK,LA", etc, to get specific areas.  On Accu-Data, use
the command "HRU * 1".  See the data vendor's guide for further help.
   Be sure that you get, at the minimum, the latest hourly reports, not
just "special" observations.  WeatherGraphix does not plot special
observations.  Weathermation, for example, will ignore a station's hourly
if a special observation has been taken recently; you can correct this by
specifying a parameter of one-hour's worth of data.

 3.  The latest FDLO/FDHI winds aloft data for the United States.  This
may take about 3 minutes.

 4.  The latest rawinsonde reports for North America.  These are NOT
available on CompuServe, DUAT, Weathermation, etc.  They must be RAW
reports, not processed or "decoded".  An example of usable reports is "UPU
72,74,71" on Accu-Data.  Blocks 72xxx and 74xxx are the contiguous United
States, 70xxx is Alaska, 71xxx is Canada.  You can select whichever blocks
are must useful for your needs.  Capturing all of North America will take
about 10 minutes at 2400 baud.  Rawinsonde reports must be stored only in
the file "DATA.UPR" in the WeatherGraphix directory.

   One factor that will affect your data gathering activities is the time.
 Radar and surface reports are filed at opposite times of the hour, and
are stored in "batches".  This means that if you're not careful, you could
get a potpourri of data times which will reduce the number of usable
reports for WeatherGraphix.  Radar reports are filed at :25 past the hour
and surface observations at :55 past the hour.  Accordingly, you  should
allow for the data to come in.  WeatherGraphix checks report times
carefully, and will throw out observations that don't conform to a single
time.

C. Run WeatherGraphix ---- Exit the telecommunications program, change the
current directory to the WeatherGraphix directory, and enter WEATHER to
run WeatherGraphix.
   If you did not save your surface data to DATA.SFC, append the desired
filename to the command, for example, WEATHER 08JUN92.22Z .  You may also
append an upper air file to the surface file if data was not saved to
"DATA.UPR", for example "WEATHER 08JUN92.22Z 08JUN92.RAW".  But if you
specify an upper air file, you must also specify a surface file, even if
it's the default file.
   If you do not have a VGA card (only EGA), or desire an EGA map, append
/E to the end of the startup command (for example, enter WEATHER
08JUN92.22Z /E).


VI.  INSIDE THE PROGRAM

   Once you run the program, you will see a map of the United States,
Mexico, and Canada.  Then the program accesses weather data.
   When it's done, it does not magically display a map.  You must tell the
computer what you want to see, using the commands listed below.
   To access the menu, use the cursor keys and the enter key.
   You can also use hotkeys.  You'll notice that each menu selection has a
certain letter underlined.  If you press this underlined letter on your
keyboard, the menu selection will be activated.
   The bottom title bar contains some useful information.  The active
surface filename is shown after the "S:", while the active upper-air
filename is shown under "U:".  WeatherGraphix uses these two separate
files since the surface data changes hourly, while the upper-air data is
usually current for 12 hours, thus saving headaches in capturing data.
   The figure after the "M" tells you how much memory is free, in bytes.
Anything over 50,000 is more than enough for WeatherGraphix.
   Always look at the very bottom line when you run the program, because
it tells you what the program is doing.  WeatherGraphix will never "leave
you hanging".  Check out this line before you start trying to activate
menus.


A. Active Level Commands ---- The leftmost title on the top bar shows the
active level in the atmosphere.  It is preceded by an "S:", because the hotkey
for this menu is always "S" no matter which level is loaded.  When you
start the program, it shows "SFC", which means any data you plot or
analyze will be surface data.  If you access rawinsonde data, you can
change the level so that it reads "500 MB", "700 MB", etc, which are
different atmospheric heights.


1. DATA PLOT (FILTERED)
   Plots raw station reports on the map, using standard meteorological
"station plots".  It shows the conditions at various observing sites
across the map.  The "filter" feature  option checks if two stations are
too close together -- if so, only one of the stations will be plotted.
This process is called "anti-crowding", and gives you an easy-to-read map
at any zoom setting.

2. DATA PLOT (ALL SITES)
   Again, this plots raw reports on the map using standard meteorological
"station plots".  The only difference is that ALL sites are plotted,
regardless of how close they are to each other.  It could cause your map
to become cluttered unless you zoom in closer.  However, if you're already
zoomed close on a state, you may prefer having the additional stations
plotted by using this command.

3. TEMPERATURES
   This is a quick option to display the temperatures across the map region.
It makes it easy for "non-weather" viewers to see what is happening.

4. WIND FIELD
   Plots the surface wind field, as observed at the various meteorological
stations.  Note that this does not use anti-crowding to reduce clutter.
ALL stations will be plotted regardless of settings.  You can also get a
detailed, gridded wind field by selecting "Analyze, Wind Grid" from the
top bar.

5. CHANGE LEVELS
   If you have any upper-air data stored in DATA.UPR (or equivalent
filename), you can access this information by changing levels.  You will
be prompted for whether you want to see SFC, 925, 850, 700, or 500
millibar data, which require rawinsonde data to be stored in DATA.UPR.
The 925 mb level is approximately 3,000 feet; the 850 mb level is
approximately 5,000 feet; the 700 mb level is approximately 10,000 feet;
and the 500 mb level is approximately 18,000 feet.
   You may also select FD to access the FDLO/FDHI reports stored in
DATA.UPR or its equivalent filename (follow the instructions to select the
desired data).
   Any further data plots or analysis you do will be ONLY for that level
-- to get surface analysis again, you will need to "change levels" back to
SFC.


B. Radar Commands ---- Radar information is stored in the hourly surface file
(DATA.SFC or its equivalent).  This data must consist of unformatted SD
alphanumeric radar reports.

1. ECHO COMPOSITE
   Overlays radar echoes.  The echoes are plotted in either squares or
bubbles according to the program configuration; bubbles are slightly
faster and use less disk space, but squares are more precise.

2. RADAR HEIGHTS
   Overlays maximum echo heights, bounded weak echo regions (BWERs), weak
echo regions (WERs), line echo wave patterns (LEWPs), bow echoes, hook
echoes, and hail indications.  LEWP coordinates will be plotted on the map
using the color specified for the city overlay.  If minimum height
criteria is specified in the configuration, then all storm tops below that
height will not be plotted.
      Important!  If the map is too cluttered or has too many radar
echoes, some radar height data will not be plotted.  This is to avoid
making the map illegible.


3. UNDO RADAR (U)
   This command will remove the radar echoes without disturbing other
information on the map.  Note that if you configure the color settings so
that any text or graphics have the same color as a radar echo, it will be
erased, too.

C. Analysis Commands (All Levels)
   Analysis -- what is it?  It is the process of allowing the computer to
interpret the data, by plotting lines, gridded data, or outlines.  This
information is not definitive -- in some cases, you may be able to do a
more accurate analysis if you do it by hand.  The computer has to contend
with bad reports, unusual mathematical fields, and its inherent inability
to make inferences from the data, all of which limit its accuracy.  You
should always overlay the raw data when possible so that you can compare
what the computer is seeing to the real atmosphere.
   WeatherGraphix requires you to have at least several reporting stations
in your selected area, since an analysis can't be generated magically.
Remember that the fewer the stations, the more unreliable the analysis.
Also, the further away from the weather stations you are (such as over the
ocean), the more unreliable the analysis.  Offshore lows will usually
appear to be right on the coast for this reason (since there are no data
points in the ocean to place a low).  With tighter zooms, the increase in
data resolution will give you improved analysis detail in the region
selected.

1. SEA LEVEL PRESSURE (Surface Only)
   Plots isopleths of sea-level pressure (isobars) in tens and units of a
millibar.  It is most accurate for tracking highs, lows, and weather
systems.  Sea-level pressure contains corrections for temperatures at each
station, so it is very useful when looking at the big picture.

2. HEIGHT (Rawinsonde Only)
   Isopleths lines of equal geopotential height (height contours) of the
constant pressure level which is active.  This is similar to a "pressure"
map of the atmosphere aloft -- low heights are similar to low pressure at
that level, while high heights are like high pressure.  At 700 mb and
above (500 mb, etc), the wind tends to parallel the contours.
   At the 500 mb level, contours are labelled in hundreds and tens of
meters, plus 5000 (e.g. 76 equals 5760 geopotential meters).  At 700 mb,
contours are in hundreds and tens of meters, plus whatever puts it in the
2500-3500 range (e.g. 94 equals 2940 meters).  At 850 mb, contours are in
hundreds and tens of meters, plus 1000 meters (.e.g. 46 equals 1460
meters).  At 925 mb, contours are in hundreds and tens of meters (e.g. 76
equals 760 meters).  At 1000 mb, contours are in hundreds and tens of
meters (e.g. 12 equals 120 meters).

3. TEMPERATURE
   Plots isotherms (lines of equal temperature) in degrees Fahrenheit at the
surface, or Celsius aloft.

4. DEWPOINT
   Plots isodrosotherms (lines of equal surface dewpoint) in degrees
Fahrenheit at the surface, or Celsius aloft.  Dewpoint temperatures show
you most accurately the true amount of water vapor available to weather
and storm systems.

5. DEWPOINT DEPRESSION
   Analyzes the spread between the surface temperature and surface dewpoint,
in degrees Fahrenheit (surface) or degrees Celsius (aloft).  This shows
you the amount of saturation of the air mass, similar to relative
humidity, and can be useful for locating potential fog and cloud areas.

6. RELATIVE HUMIDITY
   Analyzes the relative humidity, in percent.  Areas of 90 percent or
greater are generally prone to fog and stratus clouds.

7. CONVERGENCE
 Analyzes the vector convergence of the wind field, using arbitrary units.
 Blue regions indicate divergent areas, where surface air is spreading
apart, and red regions indicate convergent areas, where air is coming
together.  Convergent areas at the surface often result in upward vertical
motion, and are favorable to the development of low cloud decks and
precipitation.  Divergent areas at 500 mb may sometimes indicate
divergence at higher levels (300 mb, etc), which in turn indicates that
surface pressure falls and cyclogenesis are possible.

8. VORTICITY
   Analyzes the relative horizontal vorticity of the wind field, using
arbitrary units.  Blue regions indicate negative vorticity (anticyclonic)
areas, and red regions indicate positive vorticity (cyclonic) areas.
Surface vorticity has some use in finding surface lows -- to determine
vertical motion through vorticity advection, you may NOT use surface
vorticity.  Instead, you need to get rawinsonde data, and analyze the
vorticity at 500 mb.  You MAY use FDLO/HI data for 18,000 feet, but
remember that FD reports are not observed data -- the results may be
excessively smoothed over or distorted by the numerical forecast models
which create the FD reports.

9. WIND GRID
   Displays a uniform gridded wind field across the region, determined by
breaking all the wind reports into their X and Y components, filtering the
results, and mapping the information to a grid.  This is very helpful in
visualizing the winds across the area of interest, and can be highly
accurate in locating lows and highs (often more accurate than
computer-generated isobars).  The wind shaft is pointed upwind, i.e. the
wind arrow as a whole "points" downwind.  Gridpoints with dots and no wind
shaft indicate winds are calm or less than 3 knots.
   A dense grid is provided at the surface, since the resolution can
support a detailed grid fiend.  However, a light grid is used at levels
aloft.  The use of dense and light grids is automatic and cannot be
changed.


D. Analysis Commands (Surface Only)
   There are more analysis options provided for surface data.  Some of these
include:

1. SURFACE MOISTURE CONVERGENCE
 Analyzes the product of the vector convergence of the wind field and the
surface mixing ratio (extracted from dewpoint).  In other words, it tells
you where "moisture is piling up".  Blue areas indicate regions of
moisture divergence, and red areas outline moisture convergence zones.  It
is a very helpful tool in locating regions where severe thunderstorms are
favorable, especially when the area moves very slowly.  Tornadic storms
have often been observed to have a moisture convergence center to their
southeast.

2. ALTIMETER SETTING
 Analyzes the altimeter setting in tenths and hundredths of an inch.  It
gives isobars, however they are skewed due to temperature deviations at
various stations.  Pilots can use it to see the QNH pressures along the
route of flight.

3. WIND CHILL
 Analyzes the wind chill in degrees Fahrenheit.

4. HEAT INDEX
 Analyzes the heat index in degrees Fahrenheit.  (This feature has not
been fully tested yet).

5. WEATHER DEPICTION
 A weather depiction will give you a chart outlining areas of MVFR
(marginal visual flight rules) and IFR (instrument flight rules).  MVFR
encompasses conditions of ceilings less than 3000 feet and/or visibility
less than 5 miles.  If a ceiling of less than 1000 feet and/or a
visibility of less than 3 miles is present, the spot is considered to be
in IFR conditions.  A ceiling of less than 500 feet and/or 1 mile is
considered LIFR (low instrument flight rules).
   The floodfill shading of the IFR areas will erase any data underneath.
This occurs due to programming limitations.  It is suggested that you call
up a weather depiction before you add other information.
   For the non-aviation people, MVFR can be considered low overcast
weather, IFR very low overcast, and LIFR bad weather.

6. PRECIPITATION
 Outlines areas of rain and snow, based solely on surface weather reports.
 You can use this to refine the radar display, or substitute for it if it
is not available.  It also shows the delineation between rain and snow --
where they overlap, a mixed bag of weather is occurring.


E. Map Commands ---- These commands have nothing to do with the data.  They
are solely for the purpose of moving the map, adjusting the window, and
showing you information such as the location of weather stations and
cities.  Note that unregistered copies of the program are unable to zoom
or pan -- they are permanently locked onto the wide-screen United States
map.

1. ZOOM CENTER
 Centers the map on any station in the WEATHER.STN database.  You will be
asked for the 3- letter identifier of the station that you want to center
on, and then you will be prompted for a map width in miles.

2. CLEAN MAP
 Plots a clean basemap without moving or rezooming the image.  Cleans the
slate, so to speak.  This is useful when you have accidentally overlaid an
unwanted field on the map.  It also cleans the auto-composite slate (to be
discussed shortly), erasing memorized dataset choices.

3. OVERLAY CITIES
 Overlays cities and towns contained within WEATHER.CTY.  The overlay
always uses an automatic anti-crowding algorithm to prevent the cities
from cluttering each other, so some towns might temporarily disappear on
wide zooms.

4. STATION ID OVERLAY
 Overlays on the map the identifiers of ALL stations in WEATHER.STN,
regardless of if they are reporting weather.  This will help you customize
your WEATHER.STN file, locate weather stations that don't report data, and
help you find the identifier of a weather report in order to do an
observation request.

5. CENTER ON UNITED STATES
 Deselects any zoom settings and starts you out with a national map of the
United States.

6. MANUAL ZOOM (Page Up/Page Down)
 Manually zooms in and out of the map.  This will help adjust your zoom.

7. MANUAL PAN (Cursor Keys)
 Moves east, west, north, or south around the region.  It will help adjust
your map frame.

8. BASE MAP (B)
 Simply overlays the base map without clearing the screen.  This is
helpful if you can't see state borders for some reason.


F. Other Commands ---- There are a number of miscellaneous commands available
for your use.  These include:

1. REQUEST OBSERVATION
 This is a powerful tool which lets you request the full surface weather
observation from any site in your DATA.SFC (or equivalent) file.  You need
not have the SFC level active.  Just type in the 3- letter identifier
(such as "DEN", "BOS", etc), and the bottom window will show you a small
clip of the file, containing the requested report.  Type in another
identifier to see other stations.  If you don't have a list of
identifiers, simply print the WEATHER.STN file, or overlay Station ID's in
the Map menu.  When you're done, just hit return and the windows will
disappear.

2. READ RAW DATA
 Lets you scan through the raw data, in order to read bulletins, raw
reports, forecasts, etc.  You can also search by keywords (proper upper or
lower case is important).

3. PROGRAM CONFIGURATION
 This will place you in a menu where you can specify your desired program
preferences.  They will automatically take effect every time you run
WeatherGraphix.  Certain options may require you to restart WeatherGraphix
before they take effect.
   Hit the space bar to flip between the various pages in the
configuration module.

4. NEW DATA SET
 Press this to switch to a different observation time in your data file.
For example, if you are currently looking at 1355Z observations and want
to see 1755Z reports, enter 18 for a surface time (1755 is actually the
18Z observation).  If you leave it blank, the computer will determine the
best time to use.
   You will then be prompted for a radar report time.  Use an entry of 22
to get 2235Z reports, or leave blank to let the computer figure it out.
You cannot switch data files within the program.


G. Quit ---- Exits the program and returns you to MS-DOS.


VII. SURFACE

   WeatherGraphix plots surface data in internationally standardized
station plots.  The circle or square over the station is shaded according
to the amount of cloud cover.  If you see a square, this indicates that
the station is a computerized site, and the observation should be taken
with a grain of salt.  A cross indicates a computerized weather station
that doesn't take sky condition reports.
   A wind shaft extends away INTO the wind, and has feathers -- each long
feather indicates 10 knots (11.5 mph), and each short feather indicates 5
knots (6 mph). If there is no feather, a circle is plotted around the
station, indicating calm winds.
   Above and to the left of the circle is the temperature in degrees
Fahrenheit.  Below the temperature is the dewpoint in degrees Fahrenheit
-- this is a direct indicator of the amount of moisture in the air.  If
you subtract the dewpoint from the temperature, this gives you the
dewpoint depression, which is indicative of the relative humidity of the
air (the less the dewpoint depression, the greater the relative humidity).
   Dewpoint per se is an accurate measure of how much energy is available
to a weather system, while the dewpoint depression and relative humidity
tells how humid the air is and whether fog or low clouds are possible.
   If weather is occurring, a special data group is inserted between the
temperature and dewpoint.  It starts out with a number describing the
visibility in statute miles (10 = ten miles, 21/2 = two and a half miles,
etc).  The letters indicate the type of weather that is occurring.  They
can be decoded as follows: T thunder, R rain, W shower, S snow, A hail, IP
ice pellets (sleet), L drizzle, Z freezing precipitation, F fog, H haze, K
smoke, BD blowing dust, BN blowing sand, IC ice crystals.  If a + is
present, this indicates that the preceding weather type is intense, a -
indicates it is weak, and nothing indicates moderate. V may be appended to
the visibility number, indicating that the visibility is fluctuating
(variable).
   Pressure is located above and to the right of the station circle.  What
it means depends on whether SLP (sea level pressure) or ALSTG (altimeter
setting) is selected.  Sea-level pressure is usually the best parameter
for general weather browsing. If the configuration file specifies that
pressures will be plotted in sea-level pressure, then it will be plotted
in tens, hundreds, and units of a millibar. If the group is above "500",
stick a 9 before it; if below, stick a 10 before it.  Then move the
decimal place between the last and second-to-last digit.  For example, 983
is 998.3 mb, 046 is 1004.6 mb, and 423 is 1042.3 mb.  Sea-level pressure
filters out extremes in pressure due to temperature swings and is more
accurate for large-scale analysis, but it's only available at 90% of
weather stations.
   If the configuration specifies that altimeter setting will be plotted,
pressure will appear in units, tenths, and hundredths of an inch.  If the
group is above "500", stick a 2 before it; if below, stick a 3 before it.
Then move the decimal place to the middle.  For example, 983 equals 29.83
inches, 844 is 28.84 inches, and 043 is 30.43 inches.  Altimeter setting
is a true barometer reading, is available at almost every weather station,
and is used by pilots to set altimeters.  It fluctuates markedly with
temperature.
   Finally, if a ceiling is present at a station, its height and method of
measurement are plotted in the lower right corner of the station.  A
ceiling is the lowest layer of cloud which occupies 6/10ths or more of the
sky (assuming it is visually present behind lower layers).  The
alphabetical prefix indicates the method of measurement (E-Estimated,
M-Measured, B-Balloon, A-Aircraft, W-Vertical Visibility).  The remaining
digits are the height in hundreds of feet (M31 = measured ceiling 3100
feet, etc).  If the station shows broken or overcast skies yet there is no
ceiling shown, this means that the layers are thin and no ceiling is
present.


VIII. UPPER AIR

   Once you select winds aloft from the main menu and enter appropriate
data, WeatherGraphix will search the data files for FDLO/FDHI reports.
The more reports there are, the more complete the map will be.
   Similar to the surface wind plots, the shaft points INTO the wind.
Each triangular feather means 50 knots (56 mph), each long feather means
10 knots (11.5 mph), and each short one indicates 5 knots (6 mph).
   This data is not only useful to pilots.  The amateur forecaster can
look at the patterns to find jet streams (which are closely associated
with frontal activity), along with waves in the upper-level winds.  When
the flow between 20 and 30 thousand feet is predominantly west-to-east,
this is called a zonal flow, meaning that systems tend to be dry and move
rapidly.  However, a flow with numerous dips and rises north and south is
called meridional, or low-zonal. Such a pattern suggests considerable
transport of energy and moisture northward and destabilizing cold air
southward, meaning systems across the country tend to be slow and intense.


IX. RADAR

   When WeatherGraphix plots a radar depiction is plotted, it sifts
through the U.S. weather radar network reports and squeezes out all
possible data.  Its main source of information is from MDR (manually
digitized radar) code and polar-coordinate cell reports in the report.
Outlined echo areas in the report are not used since they are chunky and
often duplicate the MDR data.
   The decoding process does take a little time; it is this process, not
the graphics, that makes it so slow.
   MDR data is a numerical code which describes intensity levels within a
20-mile Cartesian grid (variable with latitude) overlaid on the radar
sweep area.  Using MDR data, WeatherGraphix builds the best possible image
by painting a "base map" of light precipitation, then discretely painting
higher intensities on top.
   The FAA (Federal Aviation Administration) operates a network of long
range air-traffic control radars across the western United States.
WeatherGraphix is capable of decoding this data, too.
   Since a single, small radar echo can straddle a grid border, the MDR
code may take more grid boxes than neccessary to define it.  This makes
radar echoes somewhat larger than they really are, an effect known as
"blooming".  Although radar operators try to reduce this, it is an
inherent drawback of gridding radar echoes and may be reflected by
WeatherGraphix.

A. Radar Sites ---- Reporting locations which have contributed data to the
echo chart are identified in WeatherGraphix (depending on the
configuration setting) using a mark or an abbreviation, precisely centered
on the radar site.  It will appear as follows:

 +  -- The site is reporting echoes, which have been plotted (the National
Meteorological Center doesn't do THIS for you!).
 NE -- PPINE, Plan Position Indicator No Echoes.  The radar is not
detecting any echoes.
 NA -- PPINA, Plan Position Indicator Not Available.  The radar is off,
but is otherwise working fine.  The radar operator may be out doing lunch.
 OM -- PPIOM, Plan Position Indicator Out for Maintenance.  The Maytag man
is probably on call.
 NS -- PPINS, Plan Position Indicator No Significant echoes.  Echoes are
very small (cover only 20% or less of the grid box) and do not exceed VIP
1.  Sort of a "why bother" code.
 DE -- PPIDE, Plan Position Indicator Duplicate Echo.  Although the site
is detecting echoes, a sister radar is reporting them, so no report will
be made.  Used by the FAA air traffic control centers where the
meteorologist sees several radar displays at once and can spot potential
duplication of data.

B. Echo Intensity ---- All radars contain VIP (intensity) circuitry which
shows the reflective strength of different parts of the echo pattern.
Weather pro extracts this from the observation and assigns different
colors to the spot.  It's important to remember that most radar dishes are
elevated about half a degree to eliminate ground clutter, so the
depictions always show precipitation at about 1 mile high -- not
neccessarily what's occurring at the surface.  If a surface station is
reporting no weather under a strong intensity level, you can bet it's a
matter of time before they get clobbered.
   Radar intensities are directly proportional to the amount of rainwater
contained within the cloud (radar does not detect cloud droplets).  At
high intensity levels, it can be inferred that a strong convective process
is occurring, which often means hail.  However, the presence of hail means
that less rainfall is occurring than otherwise might be indicated, and
it's not even known if the hail is in fact reaching the ground, so you can
never really tell exactly what's going on with such intense readings.

C. Radar Heights ---- If heights are desired, WeatherGraphix will sort
through the radar reports.  It will find significant cloud top heights and
plot these on top of the image.  It also looks for important radar
signatures such as hail, line-echo wave patterns (LEWPs, a dangerous
squall line pattern), bounded weak echo regions (BWERs, also known as
"vaults" which indicate tornadogenesis), bow echoes, and tornadic hook
echoes.  It plots the precise location of these features on top of the
color map.
   Where does this data come from?  By tilting the radar antenna, the
radar operator can construct a cross section of the thunderstorm on a
special display (which is never seen outside the radar station).  From
this, the height of the storm can be determined.
   The operator encodes the information on the outgoing report.  On raw
reports and in WeatherGraphix, echo tops are indicated in hundreds of feet
MSL (above mean sea level).  The tops have a direct relation to the amount
of energy available to the storm, but this does not imply that the storm
releases it destructively.
   For example, we might think a 70,000 foot storm would create death and
destruction, but weak "popcorn" storms seen in the southern U.S. during
the middle of summer sometimes reach these heights without any significant
severe weather.
      As a general guide, this table will indicate the usual content of
storms based on echo height, but it's not a book of rules:

 HEIGHT (ft) TYPICAL DESCRIPTION
 20,000 Normal minimum for a rainshower to become a thunderstorm
 30,000 Normal height of summertime popcorn thunderstorms
 40,000 Strong thunderstorm with heavy rain and isolated severe wx
 50,000 Storm often contains hail, heavy rains, high wind
 60,000 Normal height of springtime tornadic storms, Great Plains


X. CONFIGURATION

   The program's configuration values can be modified by selecting the
appropriate keystroke from the main menu.  This section will list only
some selections that will be of interest to you if you're evaluating the
program.

A. Data Default File (Surface and Upper Air)
 Indicates where the program will get data if you type WEATHER to run it
without a filename.  This is normally DATA.SFC and DATA.UPR, but can be
modified.  You may path out of the WeatherGraphix directory to access the
datafile (e.g. C:\DATA\14JUN92.04Z).

B. Plot All Radar Echoes During Startup
 Tells WeatherGraphix whether to auto-plot radar echoes when you execute
the program.  If you have a slow computer, setting this to "no" will speed
things up considerably.

C. Plot Echo Squares or Bubbles
 Bubbles are faster, but squares are more precise.  Try both to see what
you prefer.

D. Plot Basemap On Startup
 Slower users may prefer to select "no".  This simply determines whether a
map is plotted once the program is started.

E. Always Plot User-Defined Geography
 If "yes" is selected, WeatherGraphix will include customized geography
patterns (highways, roads, airways, county lines, etc) on all images.

F. Always Plot User-Defined Cities
 If "yes" is selected, the program will always include cities and towns
from WEATHER.CTY on the map.

G. Plot ALSTG Instead of SLP
 Tells WeatherGraphix whether to plot altimeter setting or sea-level
pressure on the surface data plot.

H. Overlay Basemap After Plotting Radar
 This option will force WeatherGraphixfessional to overlay the base map
after plotting radar echoes.  If you don't like having state borders
hidden, this option is for you.  If the base map plots slow on your
system, this option may not be for you.

I. Auto-Composite Mode
 If auto-composite mode is activated, whenever you build a weather map
(from echoes, heights, surface data, etc), WeatherGraphix will memorize
your choices.  Whenever you move or zoom the map, the selected data will
automatically be plotted on the new map, saving you keystrokes.  To erase
memorized settings, use the Replot command.  The only way to disable
auto-composite mode is to revert the configuration setting.
Auto-composite mode is not recommended for slower computers, especially
for radar echo plots.  Auto-composite will not memorize winds-aloft
settings or contours.


XI. CUSTOMIZING THE PROGRAM

   With a little experience with MS-DOS and a bit of spare time, you can
configure WeatherGraphix for your own setup.  Whether you run an amateur
weather station, fly cross-country, or monitor weather for a company,
WeatherGraphix's small details can be tailored to your specifications.

A. Batch Files ----  WeatherGraphix will allow you to use batch files to
automate the entire process.  You may even automate the system completely,
having the computer dial up radar maps every hour, but this requires a
memory-resident (TSR) time-delay program -- fortunately there are such
programs available within CompuServe forums.  Such a program will have to
be able to invoke the batch file automatically and initiate appropriate
keystrokes to quit the program.
   If you have a telecommunications program such as Procomm or QModem, you
can write scripts which automatically log into your favorite weather
database and retrieve the radar data.  Then you can link the
telecommunications program with WeatherGraphix by using a "batch" file.
Batch files simulate keyboard entries at the DOS prompt, so you can use it
to invoke the telecommunications program with its script, then run
WeatherGraphix immediately.
   There are many scripts for WeatherGraphix which may be available on
CompuServe in the AVSIG forum, Library 1.  Unfortunately I can't act as a
go-between to get them for you.  If you need one, a CompuServe account is
rather cheap.
   Here's an example of a batch file which automates WeatherGraphix using
QModem.  It's assumed that you already have created a script in QModem
using their auto-script feature, and that you save data to
C:\WEATHER\DATA.SFC.  It's also helpful to go into C:\AUTOEXEC.BAT to make
sure that a PATH command is specified to the directory GETWX.BAT resides
in -- this way, you can call up the procedure from any directory.

 Filename: GETWX.BAT
 ======================
 ECHO OFF
 C:
 CD \QMODEM
 QMODEM /S=SCRIPT.SCR
 C:
 CD \RADAR
 WEATHER

   It's not my purpose to give you a DOS tutorial, so for more information
please consult your DOS User's Guide.

B. Master Station Database ---- The file WEATHER.STN contains a listing of
stations used by WeatherGraphix in locating radar and observing sites.  It
is in a new format which is not compatible with earlier versions of
Weather Graphix (Weather Pro and RadarScan).
   The information in this file is used to plot the observations and radar
echoes.  You can add or delete stations as you like to modify the density
and coverage of reports in desired regions.  Be sure to use only an ASCII
editor such as MS-DOS EDIT to modify this file.
   Columns 1-3 contain the three-digit identifier of the observing
station.  This MUST be in uppercase and must match the exact identifier
used in the surface and/or radar reports.
   Columns 5-9 contain the WMO (World Meteorological Organization) 5-digit
identifier for the station.  This is only neccessary for processing
rawinsonde reports.
   Columns 11-12 contain the latitude of the station in degrees.
   Columns 13-14 contain the latitude of the station in minutes.  Fill
unused columns with zeroes (e.g. encode 8 minutes as "08").
   Columns 16-18 contain the longitude of the station in degrees.
Remember to fill any unused columns with zeros (e.g. "98" degrees should
be "098".
   Columns 19-20 contain the longitude of the station in minutes.  Encode
4 minutes as "04".
   Columns 22-25 contain the elevation of the station in meters.  This is
only neccessary for rawinsonde stations.
   Column 27: If a "C" is present in this column, it indicates that the
temperature and dewpoint in the surface weather report will be in degrees
Celsius, not Fahrenheit.  This usually implies a Canadian station.
   Column 29: If a "S" is present in this column, it indicates that the
station's surface report should be ignored.  Perhaps the station's radar
report is neccessary, but the surface report is not needed.
   Columns 31-32 contain the two-letter identifier of the state or
province where the station is located.  It's for informational use only.
   Columns 35-75 contain the name of the observing site.  Again, it's only
for informational use.  The program doesn't care what you put here.
   If you use the "Data Plot, Filtered" command religiously and there is a
specific station you have a preference for seeing, simply move it to the
first line in the state or to the beginning of the file.  Station plots
are plotted on a first-in-WEATHER.STN, first-plotted basis, so if you move
your station to line 1, you can rest assured it will ALWAYS get plotted.
   If you wish to make adjustments to a preset zoom window, you can
"bogus" this file by inputting a fake weather station, determining the
desired latitude and longitude, and specifying it in the configuration
file.  Be sure that you don't use the identifier of an existing station;
QQQ would be a safe one.
   You may not have more than 900 stations in this file.  To make sure you
aren't reaching this limit, you can use the MS-DOS editor to see if the
line count on the file has exceeded 900.

C. Cities ---- All user-defined cities are used only for overlaying,
not for locating data.  They're there simply for grins and giggles.  You
can modify them in WEATHER.CTY.  Use any ASCII editor such as MS-DOS EDIT
to modify this file.
   The sample file contains representative stations in the central United
States.  You can delete or modify this file as much as you like, but do
not eliminate it, otherwise you may have problems.  The leftmost three
columns contain the identifier of the city to be plotted.  You can do like
I do -- identify airfields by their standard three-letter code, and
identify towns and cities by an arbitrary two-letter system.
   The city identifier is located in columns 1-3.
   The city name is located in columns 6-29 (for your own use only).
   Columns 30-31 contain the latitude in degrees, and columns 33-34
contain the latitude in minutes.
   Columns 36-38 contain the longitude in degrees, and columns 40-41
contain the longitude in minutes.
   If there are any unused numerical columns, fill them with zeroes (i.e.
write 79 degrees longitude as '079').
   See the file itself for examples.  You may NOT have more than 250
cities in this database.

D. Geography ---- All geography can be modified by registered users.
There are two geography sets -- the North American "map" set, and the
user-defined geography set, both contained within the single file
WEATHER.PLT.  Load the file into an ASCII editor (such as MS-DOS EDIT) to
see the instructions for modifying it.
   Note -- unregistered users do not have this file.


XII. TROUBLESHOOTING

   WeatherGraphix contains many algorithms which are designed to catch
human errors made by those disseminating the radar reports.  While it
succeeds in dodging most of them, you may find a few that slip through the
cracks.  So if you see an echo height of 90,000 feet or a hook echo over
Idaho, you might want to browse through the raw text file and see what is
happening.
   You can also use a true ASCII editor (such as MS-DOS EDIT) to correct
any deficiencies in the data that you see.  Or, of course, you can just
ignore it.

 Q. My computer goes berserk when it runs the program.
 A. Do you have a VGA card?  If not, enable the EGA option by appending /E
to WEATHER (the startup command).  This will force WeatherGraphix into 640
x 350 mode.  WeatherGraphix will not run on a CGA computer.

 Q. The program reads the data file, but no data plots (or some of it
plots strangely).  What's the deal?
 A. Be ABSOLUTELY sure that your data source does not reformat the reports
in some manner.  Also check to make sure that your terminal program is in
a standard configuration and does not strip characters/linefeeds or
transpose character sets.  If you have further trouble send me a note.

 Q. WeatherGraphix runs strangely and aborts.
 A. Make sure that you have all WeatherGraphix files residing within the
same directory and that you CHANGE DIRECTORY to it before running WEATHER.
 WeatherGraphix will not run if called from another directory.
   If this isn't the problem, remove unneeded TSR (memory resident)
programs as Wx Pro requires a considerable amount of the 640K memory space
normally available -- look into using a memory manager program.

 Q. Why do the echo squares look so jagged and crooked?
 A. This is how they are mapped -- you're not seeing an error!  When
looking at the national map, the Cartesian coordinate grid that the
squares use tends to be slightly rotated from the map grid.  This gives it
the weird appearance.  Try centering the map over the east coast, and
you'll see the MDR grid much more easily.

 Q. WeatherGraphix doesn't plot any data or some plots are clearly
erroneous.
 A. BE SURE that your data source and capture utility does not "tamper"
with the content of the raw reports.  Even something as simple as
stripping the equal signs (end of report markers) off the ends of the
observations or adding extra characters will cause problems with the
program.  It would be nice if the program had pure "fuzzy logic" to handle
these situations, but such is not the case.  Fortunately, I haven't seen
any data sources yet which do this.  If you do encounter problems, contact
me, or write yourself a utility which will preprocess the raw data.  If
you have found the offending station and it is clearly not a one-time
coding error, send me an exact copy of it and I will try to adjust the
program to handle it.

 Q. My customized cities and geography doesn't plot.
 A. You've either not inputted the data correctly, or you're using a
non-true ASCII editor.  If you're in doubt, ALWAYS use the MS-DOS EDIT
command.  If you've already messed up your file, you will need to delete
all your entries to strip out the invisible control codes and et cetera.

 Q. How can I send the chart to my printer?
 A. There are so many printer models and "printing languages" out nowadays
that I decided to wait on any built-in print feature.  You're much better
off using a TSR (memory resident) program which you can load before
running WeatherGraphix.  When you press a certain key, such a program will
dump the screen image to the printer.  Try the MS-DOS GRAPHICS command
(read about it in your user's manual), and if this doesn't work suitably,
access one from many available on CompuServe.

 Q. The chart contains too much data!
 A. If you store, say, 1935Z data in a file, ensure that there is no 1935Z
data there from another day.  WeatherGraphix cannot tell the two reports
apart, and you may get some strange looking maps.  You can avoid this by
setting up your telecommunications program to destroy any existing capture
file before opening one with the same name.

 Q. Why is the "system time" printed on the chart and not the date of the
data?
 A. WeatherGraphix has no way of knowing whether the data is current or
historical since this information isn't contained in the file, and the
file date can be ambiguous.  So it can't really put a date on the chart
for sure.  But the computer's clock date is listed on the map to help you
out in case you make printouts and need to refer to them later.

 Q. Tell me about the precision of WeatherGraphix.
 A. The image is only as accurate as the raw data and technical
limitations of the weather radar network and of WeatherGraphix's
interpretation scheme.  However, WeatherGraphix uses precision in handling
the data.  All coordinates are transformed mathematically through the
polar stereographic projection formula, so placement error is nominal and
is subject to the precision of the data.

 Q. Are the radar echoes located accurately?
 A. The national MDR grid is based on the LFM-I grid, the same one used by
the National Meteorological Center's Cray supercomputers.  Unfortunately,
I don't have their mathematical formula for translating Cartesian MDR
coordinates to lat/long.  I've tested some of my own formulas -- they come
close but don't meet my standards of precision.  Therefore, all echoes are
vector-mapped from the radar site using MM as the center location without
any gridbox offset. Accordingly, the vector direction is adjusted to
account for the MDR-north declination across the United States.  Overall,
the maximum position error of all echoes relative to the real-world is
subject to the limitations of the MDR grid (about 20 nautical miles), plus
the deviation of vector-mapping instead of using a mathematical MDR grid
(about 10 more miles).  It is fairly accurate, and the method
interestingly removes much of the "blockiness" from the map.

 Q. Do you foresee any peace in Yugoslavia?  What about the Middle East?
 A. I thought were talking about weather here!

 Q. Oh -- well how do I update my copy if a new version comes along?


XIV. UPDATING YOUR COPY

   I've made it easy for you to update your registered copy.
   Whenever I release updates to WeatherGraphix, I'll make them available
on CompuServe in the form of a demo program.  You should be able to find a
copy in the AVSIG or IBMAPP forum.  All you have to do is download this
file and unzip it in a temporary directory.  Then read the READ.ME file
contained in that update for updating instructions.
   When you run the program, the new WeatherGraphix will look at the
WeatherGraphix data files on your disk.  If you have an intact, registered
copy of WeatherGraphix, the program will recognize that you are registered
and will disable its demo mode.  If everything looks good, you may want to
back up your directory on a disk and install from that disk if you later
have trouble.
   The documentation also contains information on updating directly from
me.  When you send a SASE disk mailer and a blank disk, I will update you
for no charge.  Since I'm not a full-time business I can't guarantee that
this policy will last forever, but I'll try as long as I can.


XV. IN THE WORKS?

   Ask any WeatherGraphix user, and he or she will tell you that the
program has had a long and successful history of improvements and
enhancements.  When you register, you jump on the bandwagon and get access
to these features that are continuously being developed.  As more features
are developed, price increases are possible.  So if you're already
registered, you have your security blanket.
   The most immediate ideas for near-term improvements include SKEW-T
soundings, hodographs, vertical cross sections, and isentropic analysis.
   One idea considered for WeatherGraphix includes time-lapse
animation.  This is very graphics-intensive and I'll probably have to
obtain some machine-code routines to do this.  It's going to take work.
   Another feature that I hope to add is automatic data-source dialing.
This is something I could even use myself, but writing routines to control
telecommunications ports has proven more complicated than I thought.
Besides, you can imagine the complications in the different data access
protocols used by the countless weather databases in existence today.  The
purpose of WeatherGraphix was to let you use data from ANY source --
automatic source dialing would be a step away from this goal.
   You might also expect improvements in the surface and upper air
plotting.  Maybe vectors and components, too, for you pilots.
   I'll be looking at compositing of satellite data (with zooms, moves,
etc).  The only question here is "will the typical user really access all
this stuff"?
   Also being considered are enhancements to plot AIRMETS, SIGMETS, and
watches and warnings.
   Thanks to CompuServe users Robert Kelsoe, Dick Zeitlin, and Scott Dyer
for beta testing the basic version of WeatherGraphixfessional.  A
-special- thanks to Patrick Rudolph for his extensive testing and
suggestion for the title of "WeatherGraphix".



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   WEATHER DATA SOURCES
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   There are many ways that you can access data for WeatherGraphix.

 CompuServe ----  This is one of the largest consumer databases in
existence.  It offers news, reference services, special interest forums,
software download libraries, and the list goes on.
   In terms of weather, it offers a respectable variety of weather
information, allowing you to access all types of National Weather Service
data, except for National Meteorological Center products and
rawinsonde/synoptic reports.  It offers raw surface reports for the United
States and Canada, radar reports, FDLO/HI winds aloft, forecast
discussions (not listed, but accessible if you use the FE command within
the weather section), and many other products.
   If you subscribe to CompuServe and have the Basic Service plan (which
charges you a slightly higher monthly minimum), you get the entire weather
service for $9 a month, free of connect time in most larger towns and
cities.  It's a bargain that should be looked into, although the service
has been occasionally plagued by slow response time and nonavailability
during peak weather periods.
   You can also contact me on CompuServe through EMail 71611,2267, or
better yet, chat with me on AVSIG (Aviation Forum), Section 1 (Weather),
about the program.
   For more information, call [phone] or obtain a Membership
package at any software store.

 Contel DUAT ---- The DUAT weather service is a government-contracted
system for pilots which is famous in aviation circles since it is free and
accessable through an 800 number.
   It is a very good data service, but pilots and users have asked me if
there are any shortcuts for downloading the entire United States.
Unfortunately, there are none.  You should develop a script in your
telecommunications program to access the desired data, or obtain one from
the AVSIG forum, Library 1, on CompuServe, or in the Genie Science-Weather
Bulletin Board.
   As of April 1993, there have been indications that DUAT may be axed due
to budget cuts.  Stay tuned.
   Contel DUAT is accessed by modem at [phone].

 DTC DUAT ---- This is another contractor's (Data Transformation
Company's) version of DUAT.  It can be accessed by modem at [phone].

 Weathermation ---- Pilots in Wisconsin can access an open weather
system at 1200 baud.  This system is run by the Wisconsin Department of
Transportation.  Since there are only a few nodes at each site,
Weathermation should not be used except by pilots.  One number is (608)
326-6076.

 GEnie ---- This database offers no information for WeatherPro,
however, there is a large group of weather hobbyists running a bulletin
board, along with WeatherGraphix support.  My address on GEnie is
T.VASQUEZ1.
   Genie costs $5 per hour, as long as you don't download files, or access
during the daytime.  To subscribe, call modem [phone], half-duplex,
and upon connection, type HHH.  At the U# prompt, enter XTX99410,GENIE,
and hit return.

 Accu-Data ---- Among the most respectable "complete" weather systems is
Accu-Data, run by Accu-Weather of State College, Pennsylvania.  It gives
access to every weather product imaginable.  The hobbyist rate runs about
$16 per hour during off-peak hours (long distance call required).  Call
(814) 234- 9601 x 400, or [phone] for more information.

 Weather Network, Inc. ---- I haven't personally tried this system, so I can't
say what it offers.  It is a "complete weather system".  Their vital
stats: 568 Manzanita Ave., Suite 1, Chico, CA 95926.  [phone].
WeatherGraphix has been modified to accept their surface data.