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Date: Mon, 17 Dec 1990 15:10:14 -0500 (EST)
Subject: SPACE Digest V12 #675

SPACE Digest                                     Volume 12 : Issue 675

Today's Topics:
        SOLAR TERRESTRIAL FORECAST AND REVIEW

Administrivia:

    Submissions to the SPACE Digest/sci.space should be mailed to
  [e-mail].  Other mail, esp. [un]subscription notices,
  should be sent to [e-mail], or, if urgent, to
             [e-mail]

----------------------------------------------------------------------

Date:    Mon, 10 Dec 90 01:00:02 MST
From: [e-mail] (Cary Oler)
Subject: SOLAR TERRESTRIAL FORECAST AND REVIEW
X-St-Vmsmail-To: ST%"[e-mail]"

/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\

Please Note:

     The document "Understanding Solar Terrestrial Reports" will be
ready for distribution this week.  The document will be posted over the
various nets in several parts.  Hopefully, those of you who requested the
report will receive the full document over the nets.  This route has been
chosen because of the overwhelming number of requests which have been
received for this document.  If any of you fail to receive the document
within the next two weeks, feel free to request it directly from
[e-mail].

/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\


                ---  SOLAR TERRESTRIAL FORECAST AND REVIEW  ---
                       December 09 to December 18, 1990

                Report Based In-Part from Data Obtained from the
                       Space Environment Services Center
                               Boulder Colorado

                                   --------


SOLAR TERRESTRIAL REVIEW FOR 02 DECEMBER TO 08 DECEMBER.

     Solar activity this week again ranged from low to high.  The most
significant event was the major class M6.6/1F flare of 04 December which
originated from Region 6397.  This region was unusually active early in the
week.  It unexpectedly produced this major flare when magnetic gradients
within the region were observed as being relatively weak.  It was also
responsible for several M-class events and numerous C-class flares.  The major
flare of 04 December occurred at 02:03 UT and lasted a respectable 39 minutes.
It had no terrestrial impacts, due to its distant location (N08E56), lack
of emissions and absence of sweep frequency events.

     The solar flux continued a steady climb this week with the return of
numerous regions.  At the present time (09 December), there are 15 active
regions on the sun, four of which are showing signs of increased spot growth
and flaring.

     Region 6397, which produced the major flare earlier in the week,
stabilized during the week and is now beginning to show increased signs of
instability.  At 09:28 UT on 09 December, this region produced a class
M1.0/1F impulsive flare at a location of N09W11.  This region is also
exhibiting signs of increased magnetic complexity, although it is still rated
as a bipolar beta-type spot group.

     Aside from Region 6397, the only other region to produce any significant
minor flaring was Region 6410, which spawned a class M2.8/1N flare at 08:21
UT.  This flare borders as a long-duration event, maintaining energy output
for 65 minutes.  However, it's location (N02E79) will prevent it from
having any geophysical impacts on the earth.  This flare is suspected of
producing a moderate-duration, moderate-intensity SID/SWF.  However, this has
not yet been confirmed.

     The background X-ray flux, which is (among other things) an indicator of
the intensity of solar activity, has increased over the week with the
appearance of the numerous new solar regions.  It is currently holding at an
X-ray level of C1.5.

     Geomagnetic and auroral activity this week was notably low.  The only
exception to this was on 04 December when geomagnetic activity increased to
unsettled levels over most latitudes.  High latitudes experienced a few brief
periods of minor storming.  But other than that, activity remained relatively
low.  Auroral activity was visible over high latitudes and northerly middle
latitudes on the evening of 04 December, but returned to generally
non-visible levels for the remainder of the week.

     HF radio propagation conditions were normal to above normal this week,
due in part to increased ionospheric ionization and low geomagnetic activity.
MUF's experienced a respectable increase over the last week and are now
approaching (and exceeding over some paths) 50 MHz.

     VHF propagation has been good this week, with increased prospects for DX
on the lower-frequency VHF bands (ie. near 50 MHz).  There have been no
significant opportunities for auroral communications this week, however
several SID's (particularly the one accompanying the major flare of 04
December) were capable of enhancing VHF propagation over the sunlit portions
of the earth.


SHORT TERM SOLAR TERRESTRIAL FORECAST

     Solar activity is expected to reach its peak during this week.  The
solar flux is expected to peak somewhere near 245-250.  The sunspot number
(currently 288) could break 300 before the week ends.  Old Region 6368, which
contained a complex beta-gamma-delta magnetic configuration, is due to return
between 11 December and 12 December.  This region was extensive in area, but
exhibited signs of decay and stabilization before it passed out of view
several weeks ago.  Models currently suggest that this region has probably
detensified and returned to a relatively stable, less extensive and less
threatening configuration.  Remnants of this region should rotate back into
view between 11 and 12 December, which should produce a notable increase in
the solar flux.

     There is a slight possibility that old Region 6368 has maintained its
extensive size and magnetic complexity.  Should this be true, flare activity
could increase further over the coming week.  This is, however, going against
what most of the models suggest.

     Geomagnetic activity is expected to remain mostly quiet until later in
the week, near 15 or 16 December, when activity is expected to increase to
mostly unsettled levels.  By near 19 December, activity should again return
to quiet levels.  Auroral activity should likewise increase near 16 December,
peaking near 17 December.  Periods of moderate activity are likely over high
latitudes during this time.  Middle latitudes will likely only witness periods
of low activity on these dates, with a risk of sporadic moderate activity.

     HF radio propagation conditions should be above normal this week, with
significant possibilities for DX existing until near 15 December when
decreased ionization and increased geomagnetic activity will hamper attempts
at DX over many latitudes.  There is a risk for brief flare-related short-
wave-fades (SWF's) this week, due to the number of M-class flare-capable
regions existing on the solar disk.  The frequency of SWF's may increase if
old Region 6368 returns with a complex configuration.  Overall, this week
looks like one of the better opportunities for HF DX.

     VHF propagation conditions should be normal to above normal this week.
The prospects for VHF DX are increased, particularly for those who work the
lower VHF bands near 50 MHz.  Daily MUF's are approaching 50 MHz at the
present time and may be exceeding 50 MHz over some paths, providing potential
openings on frequencies at and above 50 MHz.  There is also a moderate
possibility for flare-related VHF enhancements which might permit isolated
periods of VHF DX.


SUMMARY OF ALL ACTIVE REGIONS VISIBLE ON THE SOLAR DISK AS OF 10 DECEMBER

Region #   Location   LO   Area   Class   LL    Spots     Magnetic Type
--------   --------  ---   ----   -----   --    -----     -------------
  6385      S15W86   208   0090    HSX    01     001      ALPHA
  6387      S25W67   189   0720    DAI    10     017      BETA
  6390      N35W54   176   0030    BXO    03     002      BETA
  6395      N18W26   148   0660    DAI    10     031      BETA
  6397      N10W21   143   1020    DKO    10     023      BETA
  6398      N14W43   165   0570    DAO    10     018      BETA
  6399      N22W40   162   0000    AXX    00     001      ALPHA
  6402      S11W53   175   0240    DAO    10     015      BETA
  6404      S18W14   136   0450    DAO    09     011      BETA
  6406      S27E18   104   0030    BXO    05     004      BETA
  6407      S15W74   196   0240    CSO    09     005      BETA
  6408      N25E45   077   0030    BXO    04     002      BETA
  6409      N28E65   057   0210    HAX    01     001      ALPHA
  6410      N05E71   051   0720    DAO    07     006      BETA
  6411      S24E61   061   0000    AXX    00     001      ALPHA

NOTES:  Area is in million square kilometers.  Angular extent (LL) and solar
longitude (LO) are in degree's.  For more information regarding the terminology
used above, request the Glossary of Solar Terrestrial Terms from:
"[e-mail]".


H-ALPHA PLAGES WITHOUT SPOTS.  LOCATIONS VALID AS OF 24:00 UT ON 09 DECEMBER.

REGION           LOCATION            LO             COMMENTS (IF ANY)
------           --------            ---      -------------------------------
 6401             S33W76             198
 6403             S23W47             169                  NONE
 6405             S11E17             105


ACTIVE REGIONS DUE TO RETURN BETWEEN 10 AND 12 DECEMBER

Region   Latitude  Longitude (Helio.)
------   --------  ---------
 6368      N18        025

NOTES:
       For definitions regarding the above, request the "Glossary of Solar
Terrestrial Terms" from "[e-mail]".



GRAPHICAL ANALYSIS OF RECENT GEOMAGNETIC ACTIVITY - BOULDER COLORADO

                  Cumulative Geomagnetic Activity History
             Peak Geomagnetic Activity during the past 87 hours
     _________________________________________________________________
    |  EXTREMELY SEVERE |        |        |        |     | VERY HIGH! |
    | VERY SEVERE STORM |        |        |        |     | HIGH       |
    |      SEVERE STORM |        |        |        |     | MODERATE   |
    |       MAJOR STORM |        |        |        |     | MODERATE   |
    |       MINOR STORM |        |        |        |     | LOW        |
    |       VERY ACTIVE |        |        |   *    |     | NONE - LOW |
    |            ACTIVE |  *     |        | * ***  |     | NONE       |
    |         UNSETTLED | *****  | *  **  | ***** *|*  **| NONE       |
    |             QUIET |********|******  |********|*****| NONE       |
    |        VERY QUIET |********|********|********|*****| NONE       |
    |-------------------|--------|--------|--------|-----|------------|
    | Geomagnetic Field |  Thu.  |  Fri.  |  Sat.  | Sun.|  Anomaly   |
    |    Conditions     |    Given in 3-hour intervals   | Intensity  |
    |_________________________________________________________________|

NOTES:
       This graph ONLY depicts geomagnetic conditions observed at Boulder,
Colorado for the past 87 hours.  Conditions to the north of Boulder will
generally have slightly higher activity than Boulder, while conditions to the
south of Boulder will likely have lower activity than those depicted here.
However, the plots should present a good approximate average of planetary
geomagnetic conditions.
       For information regarding the interpretation and/or use of these charts,
send a request for the document "Understanding Solar Terrestrial Reports" to:
[e-mail].


PLANETARY 10-DAY GEOMAGNETIC ACTIVITY OUTLOOK (09 DECEMBER - 18 DECEMBER)

    ________________________________________________________________________
   |  EXTREMELY SEVERE |   |   |   |   |   |   |   |   |   |   | VERY HIGH! |
   | VERY SEVERE STORM |   |   |   |   |   |   |   |   |   |   | HIGH       |
   |      SEVERE STORM |   |   |   |   |   |   |   |   |   |   | MODERATE   |
   |       MAJOR STORM |   |   |   |   |   |   |   |   |   |   | MODERATE   |
   |       MINOR STORM |   |   |   |   |   |   |   |   |   |   | LOW        |
   |       VERY ACTIVE |   |   |   |   |   |   |   |   |   |   | NONE - LOW |
   |            ACTIVE |   |   |   |   |   |   |   |   |   | * | NONE       |
   |         UNSETTLED |   |   |   |   |   | * | **|***|***|***| NONE       |
   |             QUIET |***|***|***|***|***|***|***|***|***|***| NONE       |
   |        VERY QUIET |***|***|***|***|***|***|***|***|***|***| NONE       |
   |-------------------|---|---|---|---|---|---|---|---|---|---|------------|
   | Geomagnetic Field |Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun|Mon|Tue|  Anomaly   |
   |    Conditions     |       Given in 8-hour intervals       | Intensity  |
   |________________________________________________________________________|

NOTES:
       Predicted geomagnetic activity is based heavily on recurrent phenomena.
Transient energetic solar events cannot be predicted reliably over periods in
excess of several days.  Hence, there may be some deviations from the
predictions due to the unpredictable transient solar component.


GRAPHICAL ANALYSIS OF SOLAR ACTIVITY OVER THE PAST 60 DAYS

                   Cumulative Graphical Analysis of
                           Solar Activity
    ____________________________________________________________
245|                                                            | MOD.
237|            F = Major Flare(s)                              | MOD.
230|    *                                                     **| MOD.
222|    **                               *                  ****| MOD.
214|   ***  *                  *         *                 *****| MOD.
207|  ****  *                  **      ***                 *****| MOD.
199|******  *F                 ***    *****               F*****| MOD.
191|*********F                ******* ******             *F*****| MOD.
184|*********F*               ***************            *F*****| LOW
176|*********F*               ******************       ***F*****| LOW
168|*********F**             ********************   * ****F*****| LOW
161|*********F*** * *        *********************  ******F*****| LOW
153|*********F******* **    **********************F*******F*****| LOW
145|*********F********** * ***********************F*******F*****| LOW
138|*********F************************************F*******F*****| LOW
    ------------------------------------------------------------
               Cumulative 60 day Solar Activity Record
                   Start Date:  October 11, 1990

NOTES:
       Left-hand column digits represent the 10.7 cm solar radio flux obtained
from Ottawa.  The right-hand column describes the relative solar activity for
that period based on the average number of major and minor flares that can be
expected for related solar flux values.  Plot lines labeled with the letter "F"
represent days where at least one major flare occurred (ie. class M5 or greater
flare).


GRAPHICAL 20-DAY SOLAR ACTIVITY PREDICTION

                           Solar Activity
 _________________________________________________________________
| 250 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| 243 |  |  |**|**|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| 236 |**|**|  |  |**|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| 229 |  |  |  |  |  |**|  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| 223 |  |  |  |  |  |  |**|**|  |  |  |  |  |  |  |  |  |  |  |  |
| 216 |  |  |  |  |  |  |  |  |**|**|  |  |  |  |  |  |  |  |  |  |
| 209 |  |  |  |  |  |  |  |  |  |  |**|  |  |  |  |  |  |  |  |  |
| 202 |  |  |  |  |  |  |  |  |  |  |  |**|  |  |  |  |  |  |  |  |
| 195 |  |  |  |  |  |  |  |  |  |  |  |  |**|  |  |  |  |  |  |  |
| 188 |  |  |  |  |  |  |  |  |  |  |  |  |  |**|  |  |  |  |  |  |
| 181 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |**|  |  |  |  |  |
| 174 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| 168 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |**|  |  |  |  |
| 161 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |**|  |  |**|
| 154 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |**|**|  |
| 146 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|-----|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|
|Solar|09|10|11|12|13|14|15|16|17|18|19|20|21|22|23|24|25|26|27|28|
|Flux |                        December                           |
 -----------------------------------------------------------------


HF RADIO SIGNAL PROPAGATION PREDICTIONS (09 DECEMBER - 18 DECEMBER)

                              High Latitude Paths
            ________________________________________________________
           | EXTREMELY GOOD |   |   |   |   |   |   |   |   |   |   |
           |      VERY GOOD |   |   |   |   |   |   |   |   |   |   |
           |           GOOD |   |  *|* *|* *|  *|* *|***|   |   |   |
           |           FAIR |***|** | * | * |** | * |   |***|***|* *|
           |           POOR |   |   |   |   |   |   |   |   |   | * |
           |      VERY POOR |   |   |   |   |   |   |   |   |   |   |
           | EXTREMELY POOR |   |   |   |   |   |   |   |   |   |   |
           |----------------|---|---|---|---|---|---|---|---|---|---|
           |  PROPAGATION   |Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun|Mon|Tue|
           |    QUALITY     |     Given in 8-Hour UT Intervals      |
            --------------------------------------------------------

                             Middle Latitude Paths
            ________________________________________________________
           | EXTREMELY GOOD |   |   |   |   |   |   |   |   |   |   |
           |      VERY GOOD |***|***|***|***|***|***|* *|  *|   |   |
           |           GOOD |   |   |   |   |   |   | * |** |***|* *|
           |           FAIR |   |   |   |   |   |   |   |   |   | * |
           |           POOR |   |   |   |   |   |   |   |   |   |   |
           |      VERY POOR |   |   |   |   |   |   |   |   |   |   |
           | EXTREMELY POOR |   |   |   |   |   |   |   |   |   |   |
           |----------------|---|---|---|---|---|---|---|---|---|---|
           |  PROPAGATION   |Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun|Mon|Tue|
           |    QUALITY     |     Given in 8-Hour UT Intervals      |
            --------------------------------------------------------

                                Low Latitude Paths
            ________________________________________________________
           | EXTREMELY GOOD |   |   |   |   |   |   |   |   |   |   |
           |      VERY GOOD |***|***|***|***|***|***|***|* *|  *|   |
           |           GOOD |   |   |   |   |   |   |   | * |** |***|
           |           FAIR |   |   |   |   |   |   |   |   |   |   |
           |           POOR |   |   |   |   |   |   |   |   |   |   |
           |      VERY POOR |   |   |   |   |   |   |   |   |   |   |
           | EXTREMELY POOR |   |   |   |   |   |   |   |   |   |   |
           |----------------|---|---|---|---|---|---|---|---|---|---|
           |  PROPAGATION   |Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun|Mon|Tue|
           |    QUALITY     |     Given in 8-Hour UT Intervals      |
            --------------------------------------------------------

NOTES:
       High latitudes >= 55       degree's north latitude
     Middle latitudes >= 40 < 55  degree's north latitude
        Low latitudes  < 40       degree's north latitude



POTENTIAL VHF DX PROPAGATION PREDICTIONS (09 DECEMBER - 18 DECEMBER)
   INCLUDES SID AND AURORAL BACKSCATTER ENHANCEMENT PREDICTIONS

                   HIGH LATITUDES
 __________________________________________________      ___________________
|  SIGNAL  | Given in 8 hour local time intervals  |    |  SID ENHANCEMENT  |
| QUALITY  |Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun|Mon|Tue|    |S|M|T|W|T|F|S|S|M|T|
|__________|___|___|___|___|___|___|___|___|___|___|    |-|-|-|-|-|-|-|-|-|-|
| VERY GOOD|   |   |   |   |   |   |   |   |   |   |  0%|*|*|*|*|*|*|*|*|*|*|
|ABOVE NORM|   |   |   |   |   |   |   |   |   |   | 20%|*|*|*|*|*|*|*|*|*|*|
|    NORMAL|***|***|***|***|***|***|***|***|* *|* *| 40%| | | | | | | | | | |
|BELOW NORM|   |   |   |   |   |   |   |   | * | * | 60%| | | | | | | | | | |
| VERY POOR|   |   |   |   |   |   |   |   |   |   | 80%| | | | | | | | | | |
|  BLACKOUT|   |   |   |   |   |   |   |   |   |   |100%| | | | | | | | | | |
|==========|===|===|===|===|===|===|===|===|===|===|    |-------------------|
|     100% |   |   |   |   |   |   |   |   |   |   |100%| | | | | | | | | | |
|      80% |   |   |   |   |   |   |   |   |   |   | 80%| | | | | | | | | | |
|      60% |   |   |   |   |   |   |   |   |   |   | 60%| | | | | | | | | | |
|      40% |   |   |   |   |   |   |   |   |* *|* *| 40%| | | | | | | | |*|*|
|      20% | **| **| **| **| **| **| **|***|***|***| 20%| | | | | | | |*|*|*|
|       0% |***|***|***|***|***|***|***|***|***|***|  0%|*|*|*|*|*|*|*|*|*|*|
|----------+---|---|---|---|---|---|---|---|---|---|    |-|-|-|-|-|-|-|-|-|-|
|CHANCE OF |Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun|Mon|Tue|    |S|M|T|W|T|F|S|S|M|T|
|  VHF DX  | Given in 8 hour local time intervals  |    |AURORAL BACKSCATTER|
|__________|_______________________________________|    |___________________|


                  MIDDLE LATITUDES
 __________________________________________________      ___________________
|  SIGNAL  | Given in 8 hour local time intervals  |    |  SID ENHANCEMENT  |
| QUALITY  |Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun|Mon|Tue|    |S|M|T|W|T|F|S|S|M|T|
|__________|___|___|___|___|___|___|___|___|___|___|    |-|-|-|-|-|-|-|-|-|-|
| VERY GOOD|   |   |   |   |   |   |   |   |   |   |  0%|*|*|*|*|*|*|*|*|*|*|
|ABOVE NORM| * | * | * | * | * |   |   |   |   |   | 20%|*|*|*|*|*|*|*|*|*|*|
|    NORMAL|* *|* *|* *|* *|* *|***|***|***|* *|* *| 40%|*|*|*|*|*|*|*|*|*|*|
|BELOW NORM|   |   |   |   |   |   |   |   | * | * | 60%|*|*|*|*|*| | | | | |
| VERY POOR|   |   |   |   |   |   |   |   |   |   | 80%| | | | | | | | | | |
|  BLACKOUT|   |   |   |   |   |   |   |   |   |   |100%| | | | | | | | | | |
|==========|===|===|===|===|===|===|===|===|===|===|    |-------------------|
|     100% |   |   |   |   |   |   |   |   |   |   |100%| | | | | | | | | | |
|      80% |   |   |   |   |   |   |   |   |   |   | 80%| | | | | | | | | | |
|      60% |   |   |   |   |   |   |   |   |   |   | 60%| | | | | | | | | | |
|      40% | * | * | * | * | * |   |   |   |   |   | 40%| | | | | | | | | | |
|      20% | **| **| **| **| **| **| **|***|***|***| 20%| | | | | | | |*|*|*|
|       0% |***|***|***|***|***|***|***|***|***|***|  0%|*|*|*|*|*|*|*|*|*|*|
|----------+---|---|---|---|---|---|---|---|---|---|    |-|-|-|-|-|-|-|-|-|-|
|CHANCE OF |Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun|Mon|Tue|    |S|M|T|W|T|F|S|S|M|T|
|  VHF DX  | Given in 8 hour local time intervals  |    |AURORAL BACKSCATTER|
|__________|_______________________________________|    |___________________|

                    LOW LATITUDES
 __________________________________________________      ___________________
|  SIGNAL  | Given in 8 hour local time intervals  |    |  SID ENHANCEMENT  |
| QUALITY  |Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun|Mon|Tue|    |S|M|T|W|T|F|S|S|M|T|
|__________|___|___|___|___|___|___|___|___|___|___|    |-|-|-|-|-|-|-|-|-|-|
| VERY GOOD|   |   |   |   |   |   |   |   |   |   |  0%|*|*|*|*|*|*|*|*|*|*|
|ABOVE NORM| * | * | * | * | * | * |   |   |   |   | 20%|*|*|*|*|*|*|*|*|*|*|
|    NORMAL|* *|* *|* *|* *|* *|* *|***|***|***|***| 40%|*|*|*|*|*|*|*|*|*|*|
|BELOW NORM|   |   |   |   |   |   |   |   |   |   | 60%|*|*|*|*|*| | | | | |
| VERY POOR|   |   |   |   |   |   |   |   |   |   | 80%| | | | | | | | | | |
|  BLACKOUT|   |   |   |   |   |   |   |   |   |   |100%| | | | | | | | | | |
|==========|===|===|===|===|===|===|===|===|===|===|    |-------------------|
|     100% |   |   |   |   |   |   |   |   |   |   |100%| | | | | | | | | | |
|      80% |   |   |   |   |   |   |   |   |   |   | 80%| | | | | | | | | | |
|      60% |   |   |   |   |   |   |   |   |   |   | 60%| | | | | | | | | | |
|      40% | * | * | * | * | * | * | * | * | * | * | 40%| | | | | | | | | | |
|      20% | **| **| **| **| **| **| **| **| **| **| 20%| | | | | | | | | | |
|       0% |***|***|***|***|***|***|***|***|***|***|  0%|*|*|*|*|*|*|*|*|*|*|
|----------+---|---|---|---|---|---|---|---|---|---|    |-|-|-|-|-|-|-|-|-|-|
|CHANCE OF |Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun|Mon|Tue|    |S|M|T|W|T|F|S|S|M|T|
|  VHF DX  | Given in 8 hour local time intervals  |    |AURORAL BACKSCATTER|
|__________|_______________________________________|    |___________________|

NOTES:
      These VHF DX prediction charts are defined for the 50 MHz to 220 MHz
bands.  They are based primarily on phenomena which can affect VHF DX
propagation globally.  They should be used only as a guide to potential
DX conditions on VHF bands.  Latitudinal boundaries are the same as those for
the HF predictions charts.  For more information, request the document
"Understanding Solar Terrestrial Reports" from: "[e-mail]".


AURORAL ACTIVITY PREDICTIONS (09 DECEMBER - 18 DECEMBER)

                            High Latitude Locations
            ________________________________________________________
           | EXTREMELY HIGH |   |   |   |   |   |   |   |   |   |   |
           |      VERY HIGH |   |   |   |   |   |   |   |   |   |   |
           |           HIGH |   |   |   |   |   |   |   |   |   |   |
           |       MODERATE |   |   |   |   |   |   |   |   |   | * |
           |            LOW |   |   |   |   | * |   |   | * |***|***|
           |    NOT VISIBLE |***|***|***|***|***|***|***|***|***|***|
           |----------------|---|---|---|---|---|---|---|---|---|---|
           |    AURORAL     |Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun|Mon|Tue|
           |   INTENSITY    |  Eve.Twilight/Midnight/Morn.Twilight  |
            --------------------------------------------------------

                          Middle Latitude Locations
            ________________________________________________________
           | EXTREMELY HIGH |   |   |   |   |   |   |   |   |   |   |
           |      VERY HIGH |   |   |   |   |   |   |   |   |   |   |
           |           HIGH |   |   |   |   |   |   |   |   |   |   |
           |       MODERATE |   |   |   |   |   |   |   |   |   | * |
           |            LOW |   |   |   |   |   |   |   | * |***|***|
           |    NOT VISIBLE |***|***|***|***|***|***|***|***|***|***|
           |----------------|---|---|---|---|---|---|---|---|---|---|
           |    AURORAL     |Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun|Mon|Tue|
           |   INTENSITY    |  Eve.Twilight/Midnight/Morn.Twilight  |
            --------------------------------------------------------

                             Low Latitude Locations
            ________________________________________________________
           | EXTREMELY HIGH |   |   |   |   |   |   |   |   |   |   |
           |      VERY HIGH |   |   |   |   |   |   |   |   |   |   |
           |           HIGH |   |   |   |   |   |   |   |   |   |   |
           |       MODERATE |   |   |   |   |   |   |   |   |   |   |
           |            LOW |   |   |   |   |   |   |   |   |   |   |
           |    NOT VISIBLE |***|***|***|***|***|***|***|***|***|***|
           |----------------|---|---|---|---|---|---|---|---|---|---|
           |    AURORAL     |Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun|Mon|Tue|
           |   INTENSITY    |  Eve.Twilight/Midnight/Morn.Twilight  |
            --------------------------------------------------------

NOTE:
     For more information regarding these charts, send a request for the
document, "Understanding Solar Terrestrial Reports" to: [e-mail].


**  End of Report  **

------------------------------

End of SPACE Digest V12 #675
*******************