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1992-02-18
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The SELS log is compiled and issued daily by the National Severe Storms
Forecast Center at Kansas City, MO. It lists reports of severe and
near-severe weather that they receive (either directly or intercepted)
from around the 48 contiguous states. Although the events listed are
in a semi-ordered form, tornadoes are *always* listed first. Here's
a sample entry decoded:
ZCZC MKCSTADTS
WWUS60 KMKC 081017
NSSFC TORNADO AND SEVERE THUNDERSTORM REPORTS
PRELIMINARY LIST - INTERNAL DISSEMINATION ONLY
FOR 06CST SUN MAY 7 1989 THRU 06CST MON MAY 8 1989
EVENT LOCATION REMARKS (CST) TIME
1 A 75 NW PALO PINTO CO TX (15 WSW MWL) ( ----- ) 7/0618
DIME SIZE HAIL RPTD AT POSSUM KINGDOM FTW/SVS 3273 9833
RESERVOIR.
Event Number: 1
Event: "A" - Hail measured at .75 inches (3/4 of an inch) in diameter.
Location: Northwest Pala Pinto County, TX. Specifically 15 miles west-
southwest of MWL (Mineral Wells, TX).
Weather watch: ( ----- ) This event did not occur inside a weather watch.
DATE/TIME: 07/0618 OCCURRED ON THE 7TH OF THE MONTH AT 0618 CST.
Details: Dime sized hail reported at Possum Kingdom Reservoir.
Source: FTW/SVS NSSFC learned about this from a Severe Weather Statement
(SVS) issued by the National Weather Service at Ft. Worth, TX (FTW).
Initial start: The hail began at 32.73 degrees north, 98.33 degrees west.
Had there been a weather watch, it would have been listed as either
WT (tornado) or WS (severe thunderstorm) and followed by the box number.
Here are some of the more common report abbreviations:
*TORN Tornado (always has asterisk to catch your eye)
A nnn Hailstones and diameter in inches. 475 would be 4 and 3/4 inches.
WDMG Wind damage (usually has description of damage)
G nnn Wind gust and speed in knots.
TURB Turbulence (usually has altitude and severity of event)
----------------------------------------------------------------------------
----------------------------------------------------------------------------
The tornado statistics are issued by NSSFC from once per month in the slow
season to once per day when things are really cooking. Let's look at the
headers (as I rewrite them):
MONTH N U M B E R O F T O R N A D O E S
....1989.... ...1988... ..1987.. D E A T H S KILLERS
PRELIM FINAL RUFF SMTH RUFF SMTH 86 NORM 89 88 87 86 NORM 89 NORM
JAN 17 13 19 17 9 6 2 14 0 5 0 0 3 0 3
FEB 27 18 1 4 23 19 37 20 0 0 6 2 6 0 0
MAR 61 X 29 28 41 38 95 51 1 1 1 6 8 1 1
. . . . . . . . . . . . . . .
. . . . . . . . . . . . . . .
. . . . . . . . . . . . . . .
298 31 806 701 805 656 961 780 3 32 59 15 88 2 18
RUFF THRU MAY 6....298 VS 124 IN 1988 CURRENT 0732C MAY 7 1989
SMOOTH THRU FEB.... 31 VS 21 IN 1988 VS 34 NORMAL...
The statistics are broken down by month and contain data for the last four
years and average data. In the 1989 columns under "NUMBER OF TORNADOES"
there were 17 reported tornadoes in January (PRELIM). After removing any
erroneous and duplicate reports this number dropped to only 13 under the
FINAL category. The "X" in the FINAL category for March indicates that
they have not completed sifting through the reports for that month yet.
The 1988 and 1987 RUFF and SMTH (rough and smooth) colums function the
same as the PRELIM/FINAL columns respectively. The "86" column represents
the FINAL (or smoothed) number of tornadoes for 1986. The NORM column is
the average (mean or "normal") number of tornadoes from about 1950 through
present. The DEATHS columns are simply the number of people killed by
month for the years 89 through 86 and the average killed (1950 - 1989) per
month. The KILLERS columns represent killer tornado events for the
current year and the average between 1950 and the current year (1989).
A tornado is counted as a killer if one or more persons were killed.
If 100 people were killed by a single tornado it would be counded as one
killer event. Multiple killer tornadoes on the same day are counted as
separate events. The last lines are the totals for the columns and a
simplified re-cap. For example, there were 289 preliminary (RUFF)
reports of tornadoes this year through May 6th, versus 124 for the same
period in 1988 (interesting huh !). The same comparison is given for
the FINAL (smooth) data but only for the period where complete data is
available (in this case only through February). Although some reports
are listed as FINAL, this does not mean these figures are cast in stone.
Sometimes it's months or years until NSSFC receives reports of tornadoes.
Consider tree damage in a deeply wooded national park. It might not be
until some hikers discover the damage that a report is ever made.