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  5.           Tue, 19 Feb 91 01:36:52 -0500 (EST)
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  9. From: space-request+@Andrew.CMU.EDU
  10. To: space+@Andrew.CMU.EDU
  11. Date: Tue, 19 Feb 91 01:36:45 -0500 (EST)
  12. Subject: SPACE Digest V13 #174
  13.  
  14. SPACE Digest                                     Volume 13 : Issue 174
  15.  
  16. Today's Topics:
  17.         SOLAR TERRESTRIAL FORECAST AND REVIEW
  18.  
  19. Administrivia:
  20.  
  21.     Submissions to the SPACE Digest/sci.space should be mailed to
  22.   space+@andrew.cmu.edu.  Other mail, esp. [un]subscription requests,
  23.   should be sent to space-request+@andrew.cmu.edu, or, if urgent, to
  24.              tm2b+@andrew.cmu.edu
  25.  
  26. ----------------------------------------------------------------------
  27.  
  28. X-Delivery-Notice:  SMTP MAIL FROM does not correspond to sender.
  29. Date:    Mon, 18 Feb 91 02:32:22 MST
  30. From: std_oler%HG.ULeth.CA@vma.cc.cmu.edu (Cary Oler)
  31. Subject: SOLAR TERRESTRIAL FORECAST AND REVIEW
  32. X-St-Vmsmail-To: st%"space+@andrew.cmu.edu"
  33.  
  34.                 ---  SOLAR TERRESTRIAL FORECAST AND REVIEW  ---
  35.                        February 17 to February 26, 1991
  36.  
  37.                 Report Based In-Part from Data Obtained from the
  38.                        Space Environment Services Center
  39.                                Boulder Colorado
  40.  
  41.                                    --------
  42.  
  43.  
  44. SOLAR TERRESTRIAL REVIEW FOR 10 FEBRUARY TO 16 FEBRUARY.
  45.  
  46.      Solar activity over the past week has been mostly low.  A low-level
  47. M-class flare erupted early in the week (11 Feb) from Region 6487.  This
  48. region exhibited a brief beta-gamma magnetic configuration early in the
  49. week.  As the week progressed, Region 6487 began to decay.  It is now
  50. a relatively simple beta group of significantly reduced area and will
  51. pass beyond the east limb on 18 February.  There has been no other
  52. significant sunspot activity this week.
  53.  
  54.      Probably the most noteworthy solar event to occur this week was the
  55. disappearance of a very long filament in the southwest solar hemisphere
  56. between approximately 16:00 UT and 19:00 UT on 14 February.  The filament
  57. was about 50 degrees in length and produced some very minor radio emissions.
  58. The event was believed responsible for a coronal mass ejection, although
  59. this has not been reliably confirmed.
  60.  
  61.      M-class flare activity has increased as of late.  Two optically
  62. uncorrelated M-class events have been observed since 16 February.  The
  63. signatures of these events are characteristic of those events which occur
  64. around the eastern limb.  Indeed, this is the most likely area for flare
  65. activity to be observed, considering the fact that several previously
  66. very active regions are due to return around 18 February.  The latest
  67. event (an optically uncorrelated class M1.5 event with an observed Type II
  68. sweep) occurred at 06:22 UT on 17 February.
  69.  
  70.      Geomagnetic activity increased to active levels over most latitudes
  71. (with periodic minor storming at high latitudes) on 12 and 13 February.
  72. A well placed coronal hole is held responsible for the increased activity.
  73. Activity has since declined to generally quiet levels.
  74.  
  75.      Auroral activity increased in tandem with geomagnetic activity on
  76. 12 and 13 February.  High latitudes witnessed periods of moderate activity.
  77. Middle and low latitudes were generally unable to witness any activity.
  78.  
  79.      HF radio propagation conditions have been normal to above normal over
  80. the past week.  The only exceptions were on 12 and 13 February when increased
  81. magnetic and auroral activity degraded radio conditions slightly over most
  82. latitudes.  High latitudes were affected the strongest, although even at
  83. high latitudes, no significant degradations were observed.
  84.  
  85.      VHF propagation conditions continued to be normal this week.  Conditions
  86. remained stable.  No SID enhancements or other anomalies were observed due to
  87. the quiet levels of solar activity which occurred.
  88.  
  89.  
  90. SHORT TERM SOLAR TERRESTRIAL FORECAST
  91.  
  92.      Solar activity is on the rise again.  Indices have been climbing now
  93. for the past several days.  The background X-ray flux has increased from
  94. a class C1.2 level on 15 February to a class C2.3 level on 17 February.  The
  95. 10.7 cm radio solar flux has increased from 194 on 15 February to 214 on
  96. 17 February.  M-class flare activity has increased notably over the past
  97. 24 hours.  They have so far been optically uncorrelated, which suggests that
  98. the region(s) which are spawning the events are still out of view near the
  99. eastern limb.
  100.  
  101.      M-class flaring is likely to continue at an enhanced rate for the next
  102. two weeks as the active regions begin to traverse the visible solar disk.
  103. There is also an elevated risk for major flaring.  Major flares are likely
  104. to be observed with the passage of the active regions across the solar disk
  105. over the next two weeks.  However, the rate of major flaring (if indeed
  106. major flaring does redevelope) will not be known until the regions in
  107. question rotate into view.  At the present time, major flaring is not
  108. expected to be as frequent as was observed during the last appearance of
  109. these returning regions.  More will obviously be known within the next
  110. several days.
  111.  
  112.      The geomagnetic field is expected to remain generally quiet until near
  113. 22 February.  At that time, geomagnetic activity is expected to increase
  114. to mostly unsettled to active levels.  A well placed coronal hole should
  115. increase magnetic activity at that time.  A return to more quiet levels
  116. should be observed by 24 February (barring any significant solar activity).
  117.  
  118.      Auroral activity will remain dormant until 21/22 February.  It should
  119. become mostly moderate in intensity over the higher latitudes on 22/23 February
  120. and is expected to return to generally dormant levels by 24 February (again,
  121. barring any significant solar events).  Northerly middle latitudes should
  122. observe an increase in low level auroral activity near 22/23 February.  Lower
  123. latitudes will be unable to witness any activity.  However, please note that
  124. the risk for potential auroral storming will increase as the week progresses,
  125. dependent upon the intensity of activity of the returning active solar regions.
  126.  
  127.      HF propagation conditions are expected to remain at normal to above
  128. normal levels for the next two weeks.  The increased levels of energy being
  129. received from the sun should maintain high MUF's throughout this week.
  130. Openings on 6 meters could become common beginning this week, lasting possibly
  131. into the first week of March.  The frequency of SID's and SWF's will increase
  132. and persist for the next two weeks.  Daytime HF absorption will increase
  133. during periods of M-class flare activity, which could become quite a frequent
  134. phenomena.  Propagation conditions should experience some degradation on
  135. 22/23 February in response to the expected increase in geomagnetic activity on
  136. this date.  No significant HF problems are anticipated.
  137.  
  138.      VHF propagation conditions should remain normal throughout most of the
  139. coming week.  The potential for experiencing SID-enhanced propagation will
  140. exist throughout the next two weeks as flare activity is expected to increase
  141. in both frequency and magnitude.  SID enhancing effects are only noticable
  142. over the sunlit hemisphere.  High latitudes will not notice the effects as
  143. strongly as middle and low latitudes.
  144.  
  145.  
  146. SUMMARY OF ALL ACTIVE REGIONS VISIBLE ON THE SOLAR DISK AS OF 18 FEBRUARY
  147.  
  148. Region #   Location   LO   Area   Class   LL    Spots     Magnetic Type
  149. --------   --------  ---   ----   -----   --    -----     -------------
  150.   6487      N13W88   009   0480    DAO    08     005      BETA
  151.   6488      S12W52   333   0000    AXX    01     001      ALPHA
  152.   6492      S12W93   014   0180    CAO    06     002      BETA
  153.   6495      S05W43   324   0030    BXO    05     004      BETA
  154.   6496      N28W07   288   0000    AXX    01     002      ALPHA
  155.   6497      S11E16   265   0390    CSO    05     006      BETA
  156.   6498      N24W05   286   0180    CAO    05     011      BETA
  157.   6501      S08W68   349   0180    CAO    06     010      BETA
  158.   6502      S13W71   352   0330    DAO    08     005      BETA
  159.   6504      S16E51   230   1020    EKO    11     018      BETA
  160.   6505      S13E28   253   0090    CSO    05     008      BETA
  161.   6506      N29E48   233   0030    BXO    05     004      BETA
  162.   6507      S04E57   224   0000    AXX    01     002      ALPHA
  163.   6508      S12E80   201   0060    HRX    02     002      ALPHA
  164.   6509      S20E81   200   0480    CSO    10     009      BETA
  165.   6510      S17E23   258   0030    BXO    04     006      BETA
  166.  
  167. NOTES:  Area is in million square kilometers.  Angular extent (LL) and solar
  168. longitude (LO) are in degree's.  For more information regarding the terminology
  169. used above, request the Glossary of Solar Terrestrial Terms from:
  170. "std_oler@hg.uleth.ca".
  171.  
  172.  
  173. H-ALPHA PLAGES WITHOUT SPOTS.  LOCATIONS VALID AS OF 00:00 UT ON 18 FEBRUARY.
  174.  
  175. REGION           LOCATION            LO             COMMENTS (IF ANY)
  176. ------           --------            ---      -------------------------------
  177.  6489             S11W48             329                   NONE
  178.  6490             S07W79             360
  179.  6491             S06W36             317
  180.  6500             S07W28             309
  181.  6503             S20W62             343
  182.  
  183.  
  184. ACTIVE REGIONS DUE TO RETURN BETWEEN 18 FEBRUARY AND 20 FEBRUARY.
  185.  
  186. Region   Latitude  Longitude (Helio.)
  187. ------   --------  ---------
  188. 6472       N11        189
  189. 6469       S13        184
  190. 6482       N07        182
  191.  
  192. NOTES:  For definitions regarding the above, request the "Glossary of Solar
  193.         Terrestrial Terms" from "std_oler@hg.uleth.ca".
  194.  
  195.  
  196. GRAPHICAL ANALYSIS OF RECENT PLANETARY (GLOBAL) GEOMAGNETIC ACTIVITY
  197.  
  198.                   Cumulative Geomagnetic Activity History
  199.         Peak Planetary Geomagnetic Activity during the past 96 hours
  200.      ____________________________________________________________________
  201.     |  EXTREMELY SEVERE |        |        |        |        | VERY HIGH! |
  202.     | VERY SEVERE STORM |        |        |        |        | HIGH       |
  203.     |      SEVERE STORM |        |        |        |        | MODERATE   |
  204.     |       MAJOR STORM |        |        |        |        | LOW - MOD. |
  205.     |       MINOR STORM |        |        |        |        | LOW        |
  206.     |       VERY ACTIVE |        |        |        |        | NONE       |
  207.     |            ACTIVE |     *  |        |*       |        | NONE       |
  208.     |         UNSETTLED | * *****|   *****|* * ** *|   * ** | NONE       |
  209.     |             QUIET |********|********|********|********| NONE       |
  210.     |        VERY QUIET |********|********|********|********| NONE       |
  211.     |-------------------|--------|--------|--------|--------|------------|
  212.     | Geomagnetic Field |  Thu.  |  Fri.  |  Sat.  |  Sun.  |  Anomaly   |
  213.     |    Conditions     |     Given in 3-hour intervals     | Intensity  |
  214.     |____________________________________________________________________|
  215.  
  216. NOTES:
  217.        The data above represents planetary geomagnetic activity.  Data from
  218. many magnetic observatories around the world are used in constructing the
  219. above chart.  The first graph line for each day represents geomagnetic
  220. activity which occurred between 00 UT and 03 UT.  The second graph line
  221. represents activity which occurred between 03 UT and 06 UT, etc.  For
  222. information regarding the interpretation and/or use of these charts, send
  223. a request for the document "Understanding Solar Terrestrial Reports" to:
  224. std_oler@hg.uleth.ca.
  225.  
  226.  
  227. PLANETARY 10-DAY GEOMAGNETIC ACTIVITY OUTLOOK (17 FEBRUARY - 26 FEBRUARY)
  228.  
  229.     ________________________________________________________________________
  230.    |  EXTREMELY SEVERE |   |   |   |   |   |   |   |   |   |   | VERY HIGH! |
  231.    | VERY SEVERE STORM |   |   |   |   |   |   |   |   |   |   | HIGH       |
  232.    |      SEVERE STORM |   |   |   |   |   |   |   |   |   |   | MODERATE   |
  233.    |       MAJOR STORM |   |   |   |   |   |   |   |   |   |   | LOW - MOD. |
  234.    |       MINOR STORM |   |   |   |   |   |   |   |   |   |   | LOW        |
  235.    |       VERY ACTIVE |   |   |   |   |   |   |   |   |   |   | NONE       |
  236.    |            ACTIVE |   |   |   |   |   | * | * |   |   |   | NONE       |
  237.    |         UNSETTLED |   | **|** | * | **|***|***|** | * | * | NONE       |
  238.    |             QUIET |***|***|***|***|***|***|***|***|***|***| NONE       |
  239.    |        VERY QUIET |***|***|***|***|***|***|***|***|***|***| NONE       |
  240.    |-------------------|---|---|---|---|---|---|---|---|---|---|------------|
  241.    | Geomagnetic Field |Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun|Mon|Tue|  Anomaly   |
  242.    |    Conditions     |       Given in 8-hour intervals       | Intensity  |
  243.    |________________________________________________________________________|
  244.  
  245.                             CONFIDENCE LEVEL: 65%
  246.  
  247. NOTES:
  248.        Predicted geomagnetic activity is based heavily on recurrent phenomena.
  249. Transient energetic solar events cannot be predicted reliably over periods in
  250. excess of several days.  Hence, there may be some deviations from the
  251. predictions due to the unpredictable transient solar component.
  252.  
  253.  
  254. GRAPHICAL ANALYSIS OF SOLAR ACTIVITY OVER THE PAST 60 DAYS
  255.  
  256.                    Cumulative Graphical Analysis of
  257.                            Solar Activity
  258.     ____________________________________________________________
  259. 377|                                                            | V.HIGH
  260. 363|                                         F                  | V.HIGH
  261. 348|                                        *FF                 | V.HIGH
  262. 334|                                        *FF                 | V.HIGH
  263. 320|                                       **FF                 | V.HIGH
  264. 306|                                       **FF*                | V.HIGH
  265. 291|                                      F**FF**               | HIGH
  266. 277|                                     *F**FF**               | HIGH
  267. 263|                                    F*F**FF***              | HIGH
  268. 249|                                    F*F**FF***              | MOD.
  269. 234|                                   *F*F**FF***F             | MOD.
  270. 220|                      *          ***F*F**FF***F*            | MOD.
  271. 206|                    *****   F    ***F*F**FF***F* F        **| MOD.
  272. 192|* *    F****       ******* *F*******F*F**FF***F**FF      ***| MOD.
  273. 177|***FFF*F*******  ***********F*******F*F**FF***F**FF* *******| LOW
  274. 163|***FFF*F********************F*******F*F**FF***F**FF*********| LOW
  275.     ------------------------------------------------------------
  276.                Cumulative 60 day Solar Activity Record
  277.                    Start Date:  December 19, 1990
  278.  
  279. NOTES:
  280.        Left-hand column digits represent the 10.7 cm solar radio flux obtained
  281. from Ottawa.  The right-hand column describes the relative solar activity for
  282. that period based on the average number of major and minor flares that can be
  283. expected for related solar flux values.  Plot lines labeled with the letter "F"
  284. represent days where at least one major flare occurred (ie. class M5 or greater
  285. flare).
  286.  
  287.  
  288. GRAPHICAL 20-DAY SOLAR ACTIVITY PREDICTION
  289.  
  290.                            Solar Activity
  291.  _________________________________________________________________
  292. | 285 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
  293. | 278 |  |  |  |  |  |  |  |**|**|**|  |  |  |  |  |  |  |  |  |  |
  294. | 271 |  |  |  |  |  |**|**|  |  |  |**|**|**|  |  |  |  |  |  |  |
  295. | 264 |  |  |  |  |**|  |  |  |  |  |  |  |  |**|  |  |  |  |  |  |
  296. | 257 |  |  |  |**|  |  |  |  |  |  |  |  |  |  |**|  |  |  |  |  |
  297. | 250 |  |  |**|  |  |  |  |  |  |  |  |  |  |  |  |**|  |  |  |  |
  298. | 243 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
  299. | 236 |  |**|  |  |  |  |  |  |  |  |  |  |  |  |  |  |**|  |  |  |
  300. | 229 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
  301. | 222 |**|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |**|  |  |
  302. | 215 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |**|  |
  303. | 208 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |**|
  304. | 201 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
  305. |-----|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|
  306. |Solar|18|19|20|21|22|23|24|25|26|27|28|01|02|03|04|05|06|07|08|09|
  307. |Flux |           February             |          March           |
  308.  -----------------------------------------------------------------
  309.  
  310.                       CONFIDENCE LEVEL: 50%
  311.  
  312.  
  313. HF RADIO SIGNAL PROPAGATION PREDICTIONS (17 FEBRUARY - 26 FEBRUARY)
  314.  
  315.                               High Latitude Paths
  316.             ________________________________________________________
  317.            | EXTREMELY GOOD |   |   |   |   |   |   |   |   |   |   |
  318.            |      VERY GOOD |   |   |   |   |   |   |   |   |   |   |
  319. CONFIDENCE |           GOOD |   |   |   |   |   |   |   |   |   |   |
  320.   LEVEL    |           FAIR |***|***|***|* *|*  |   |   |  *|* *|* *|
  321.  -------   |           POOR |   |   |   | * | **|***|***|** | * | * |
  322.    60%     |      VERY POOR |   |   |   |   |   |   |   |   |   |   |
  323.            | EXTREMELY POOR |   |   |   |   |   |   |   |   |   |   |
  324.            |----------------|---|---|---|---|---|---|---|---|---|---|
  325.            |  PROPAGATION   |Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun|Mon|Tue|
  326.            |    QUALITY     |     Given in 8-Hour UT Intervals      |
  327.             --------------------------------------------------------
  328.  
  329.                              Middle Latitude Paths
  330.             ________________________________________________________
  331.            | EXTREMELY GOOD |   |   |   |   |   |   |   |   |   |   |
  332.            |      VERY GOOD |***|***|***|***|* *|   |   |  *|* *|* *|
  333. CONFIDENCE |           GOOD |   |   |   |   | * |***|* *|** | * | * |
  334.   LEVEL    |           FAIR |   |   |   |   |   |   | * |   |   |   |
  335.  -------   |           POOR |   |   |   |   |   |   |   |   |   |   |
  336.    65%     |      VERY POOR |   |   |   |   |   |   |   |   |   |   |
  337.            | EXTREMELY POOR |   |   |   |   |   |   |   |   |   |   |
  338.            |----------------|---|---|---|---|---|---|---|---|---|---|
  339.            |  PROPAGATION   |Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun|Mon|Tue|
  340.            |    QUALITY     |     Given in 8-Hour UT Intervals      |
  341.             --------------------------------------------------------
  342.  
  343.                                 Low Latitude Paths
  344.             ________________________________________________________
  345.            | EXTREMELY GOOD |   |   |   |   |   |   |   |   |   |   |
  346.            |      VERY GOOD |***|***|***|***|***|*  |   |* *|* *|* *|
  347. CONFIDENCE |           GOOD |   |   |   |   |   | **|***| * | * | * |
  348.   LEVEL    |           FAIR |   |   |   |   |   |   |   |   |   |   |
  349.  -------   |           POOR |   |   |   |   |   |   |   |   |   |   |
  350.    65%     |      VERY POOR |   |   |   |   |   |   |   |   |   |   |
  351.            | EXTREMELY POOR |   |   |   |   |   |   |   |   |   |   |
  352.            |----------------|---|---|---|---|---|---|---|---|---|---|
  353.            |  PROPAGATION   |Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun|Mon|Tue|
  354.            |    QUALITY     |     Given in 8-Hour UT Intervals      |
  355.             --------------------------------------------------------
  356.  
  357. NOTES:
  358.        High latitudes >= 55       degree's north latitude
  359.      Middle latitudes >= 40 < 55  degree's north latitude
  360.         Low latitudes  < 40       degree's north latitude
  361.  
  362.  
  363.  
  364. POTENTIAL VHF DX PROPAGATION PREDICTIONS (17 FEBRUARY - 26 FEBRUARY)
  365.    INCLUDES SID AND AURORAL BACKSCATTER ENHANCEMENT PREDICTIONS
  366.  
  367.                    HIGH LATITUDES
  368.  __________________________________________________      ___________________
  369. |  SIGNAL  | Given in 8 hour local time intervals  |    |  SID ENHANCEMENT  |
  370. | QUALITY  |Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun|Mon|Tue|    |S|M|T|W|T|F|S|S|M|T|
  371. |__________|___|___|___|___|___|___|___|___|___|___|    |-|-|-|-|-|-|-|-|-|-|
  372. | VERY GOOD|   |   |   |   |   |   |   |   |   |   |  0%|*|*|*|*|*|*|*|*|*|*|
  373. |ABOVE NORM|   |   |   |   |   |   |   |   |   |   | 20%|*|*|*|*|*|*|*|*|*|*|
  374. |    NORMAL|***|***|***|***|***|***|***|***|***|***| 40%| | |*|*|*|*|*|*|*|*|
  375. |BELOW NORM|   |   |   |   |   |   |   |   |   |   | 60%| | | | | | | | | | |
  376. | VERY POOR|   |   |   |   |   |   |   |   |   |   | 80%| | | | | | | | | | |
  377. |  BLACKOUT|   |   |   |   |   |   |   |   |   |   |100%| | | | | | | | | | |
  378. |==========|===|===|===|===|===|===|===|===|===|===|    |-------------------|
  379. |     100% |   |   |   |   |   |   |   |   |   |   |100%| | | | | | | | | | |
  380. |      80% |   |   |   |   |   |   |   |   |   |   | 80%| | | | | | | | | | |
  381. |      60% |   |   |   |   |   |   |   |   |   |   | 60%| | | | | | | | | | |
  382. |      40% |   |   | * | * | * | * | * | * | * | * | 40%| | | | | | | | | | |
  383. |      20% | * | * | * |** |** |** |** |** |** |** | 20%| | | | | |*|*|*|*|*|
  384. |       0% |***|***|***|***|***|***|***|***|***|***|  0%|*|*|*|*|*|*|*|*|*|*|
  385. |----------+---|---|---|---|---|---|---|---|---|---|    |-|-|-|-|-|-|-|-|-|-|
  386. |CHANCE OF |Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun|Mon|Tue|    |S|M|T|W|T|F|S|S|M|T|
  387. |  VHF DX  | Given in 8 hour local time intervals  |    |AURORAL BACKSCATTER|
  388. |__________|_______________________________________|    |___________________|
  389.  
  390.  
  391.                   MIDDLE LATITUDES
  392.  __________________________________________________      ___________________
  393. |  SIGNAL  | Given in 8 hour local time intervals  |    |  SID ENHANCEMENT  |
  394. | QUALITY  |Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun|Mon|Tue|    |S|M|T|W|T|F|S|S|M|T|
  395. |__________|___|___|___|___|___|___|___|___|___|___|    |-|-|-|-|-|-|-|-|-|-|
  396. | VERY GOOD|   |   |   |   |   |   |   |   |   |   |  0%|*|*|*|*|*|*|*|*|*|*|
  397. |ABOVE NORM|   |   |   | * | * | * | * | * | * | * | 20%|*|*|*|*|*|*|*|*|*|*|
  398. |    NORMAL|***|***|***|* *|* *|* *|* *|* *|* *|* *| 40%| | |*|*|*|*|*|*|*|*|
  399. |BELOW NORM|   |   |   |   |   |   |   |   |   |   | 60%| | | | | |*|*|*|*|*|
  400. | VERY POOR|   |   |   |   |   |   |   |   |   |   | 80%| | | | | | | | | | |
  401. |  BLACKOUT|   |   |   |   |   |   |   |   |   |   |100%| | | | | | | | | | |
  402. |==========|===|===|===|===|===|===|===|===|===|===|    |-------------------|
  403. |     100% |   |   |   |   |   |   |   |   |   |   |100%| | | | | | | | | | |
  404. |      80% |   |   |   |   |   |   |   |   |   |   | 80%| | | | | | | | | | |
  405. |      60% |   |   |   |   | * | * | * | * | * | * | 60%| | | | | | | | | | |
  406. |      40% |   |   | * | * | * | * | * | * | * | * | 40%| | | | | | | | | | |
  407. |      20% | * | * | **| **|***|***|***|***|***|***| 20%| | | | | |*|*|*|*|*|
  408. |       0% |***|***|***|***|***|***|***|***|***|***|  0%|*|*|*|*|*|*|*|*|*|*|
  409. |----------+---|---|---|---|---|---|---|---|---|---|    |-|-|-|-|-|-|-|-|-|-|
  410. |CHANCE OF |Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun|Mon|Tue|    |S|M|T|W|T|F|S|S|M|T|
  411. |  VHF DX  | Given in 8 hour local time intervals  |    |AURORAL BACKSCATTER|
  412. |__________|_______________________________________|    |___________________|
  413.  
  414.                     LOW LATITUDES
  415.  __________________________________________________      ___________________
  416. |  SIGNAL  | Given in 8 hour local time intervals  |    |  SID ENHANCEMENT  |
  417. | QUALITY  |Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun|Mon|Tue|    |S|M|T|W|T|F|S|S|M|T|
  418. |__________|___|___|___|___|___|___|___|___|___|___|    |-|-|-|-|-|-|-|-|-|-|
  419. | VERY GOOD|   |   |   |   |   |   |   |   |   |   |  0%|*|*|*|*|*|*|*|*|*|*|
  420. |ABOVE NORM|   |   |   | * | * | * | * | * | * | * | 20%|*|*|*|*|*|*|*|*|*|*|
  421. |    NORMAL|***|***|***|* *|* *|* *|* *|* *|* *|* *| 40%| |*|*|*|*|*|*|*|*|*|
  422. |BELOW NORM|   |   |   |   |   |   |   |   |   |   | 60%| | | | | |*|*|*|*|*|
  423. | VERY POOR|   |   |   |   |   |   |   |   |   |   | 80%| | | | | | | | | | |
  424. |  BLACKOUT|   |   |   |   |   |   |   |   |   |   |100%| | | | | | | | | | |
  425. |==========|===|===|===|===|===|===|===|===|===|===|    |-------------------|
  426. |     100% |   |   |   |   |   |   |   |   |   |   |100%| | | | | | | | | | |
  427. |      80% |   |   |   |   |   |   |   |   |   |   | 80%| | | | | | | | | | |
  428. |      60% |   |   |   | * | * | * | * | * | * | * | 60%| | | | | | | | | | |
  429. |      40% |   | * | * | * | * | * | * | * | * | * | 40%| | | | | | | | | | |
  430. |      20% | * | * | **| **| **| **| **| **| **| **| 20%| | | | | | | | | | |
  431. |       0% |***|***|***|***|***|***|***|***|***|***|  0%|*|*|*|*|*|*|*|*|*|*|
  432. |----------+---|---|---|---|---|---|---|---|---|---|    |-|-|-|-|-|-|-|-|-|-|
  433. |CHANCE OF |Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun|Mon|Tue|    |S|M|T|W|T|F|S|S|M|T|
  434. |  VHF DX  | Given in 8 hour local time intervals  |    |AURORAL BACKSCATTER|
  435. |__________|_______________________________________|    |___________________|
  436.  
  437. NOTES:
  438.       These VHF DX prediction charts are defined for the 50 MHz to 150 MHz
  439. bands.  They are based primarily on phenomena which can affect VHF DX
  440. propagation globally.  They should be used only as a guide to potential
  441. DX conditions on VHF bands.  Latitudinal boundaries are the same as those for
  442. the HF predictions charts.  For more information, request the document
  443. "Understanding Solar Terrestrial Reports" from: "std_oler@hg.uleth.ca".
  444.  
  445.  
  446. AURORAL ACTIVITY PREDICTIONS (17 FEBRUARY - 26 FEBRUARY)
  447.  
  448.                             High Latitude Locations
  449.             ________________________________________________________
  450.            | EXTREMELY HIGH |   |   |   |   |   |   |   |   |   |   |
  451. CONFIDENCE |      VERY HIGH |   |   |   |   |   |   |   |   |   |   |
  452.   LEVEL    |           HIGH |   |   |   |   |   |   |   |   |   |   |
  453.  -------   |       MODERATE |   |   |   |   | * |***|***| * |   |   |
  454.    70%     |            LOW | * | * | * |***|***|***|***|***|***|***|
  455.            |    NOT VISIBLE |***|***|***|***|***|***|***|***|***|***|
  456.            |----------------|---|---|---|---|---|---|---|---|---|---|
  457.            |    AURORAL     |Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun|Mon|Tue|
  458.            |   INTENSITY    |  Eve.Twilight/Midnight/Morn.Twilight  |
  459.             --------------------------------------------------------
  460.  
  461.                           Middle Latitude Locations
  462.             ________________________________________________________
  463.            | EXTREMELY HIGH |   |   |   |   |   |   |   |   |   |   |
  464. CONFIDENCE |      VERY HIGH |   |   |   |   |   |   |   |   |   |   |
  465.   LEVEL    |           HIGH |   |   |   |   |   |   |   |   |   |   |
  466.  -------   |       MODERATE |   |   |   |   |   |   |   |   |   |   |
  467.    65%     |            LOW |   |   |   |   | * |***|***| * |   |   |
  468.            |    NOT VISIBLE |***|***|***|***|***|***|***|***|***|***|
  469.            |----------------|---|---|---|---|---|---|---|---|---|---|
  470.            |    AURORAL     |Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun|Mon|Tue|
  471.            |   INTENSITY    |  Eve.Twilight/Midnight/Morn.Twilight  |
  472.             --------------------------------------------------------
  473.  
  474.                              Low Latitude Locations
  475.             ________________________________________________________
  476.            | EXTREMELY HIGH |   |   |   |   |   |   |   |   |   |   |
  477. CONFIDENCE |      VERY HIGH |   |   |   |   |   |   |   |   |   |   |
  478.   LEVEL    |           HIGH |   |   |   |   |   |   |   |   |   |   |
  479.  -------   |       MODERATE |   |   |   |   |   |   |   |   |   |   |
  480.    80%     |            LOW |   |   |   |   |   |   |   |   |   |   |
  481.            |    NOT VISIBLE |***|***|***|***|***|***|***|***|***|***|
  482.            |----------------|---|---|---|---|---|---|---|---|---|---|
  483.            |    AURORAL     |Sun|Mon|Tue|Wed|Thu|Fri|Sat|Sun|Mon|Tue|
  484.            |   INTENSITY    |  Eve.Twilight/Midnight/Morn.Twilight  |
  485.             --------------------------------------------------------
  486.  
  487. NOTE:
  488.      For more information regarding these charts, send a request for the
  489. document, "Understanding Solar Terrestrial Reports" to: std_oler@hg.uleth.ca.
  490.  
  491.  
  492. **  End of Report  **
  493.  
  494. ------------------------------
  495.  
  496. End of SPACE Digest V13 #174
  497. *******************
  498.