Viewing archive of Monday, 18 October 1999

Solar activity report

Report of Solar-Geophysical Activity 1999 Oct 18 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 291 Issued at 2200Z on 18 OCT 1999

IA. Analysis of Solar Active Regions and Activity from 17-2100Z to 18-2100Z

SOLAR ACTIVITY CONTINUED AT LOW LEVELS. REGION 8731 (N13W33) SHOWED A SMALL INCREASE IN SPOT COUNT AND REMAINED A LARGE, MAGNETICALLY COMPLEX REGION. IT PRODUCED ISOLATED C-CLASS SUBFLARES DURING THE PERIOD. NO SIGNIFICANT CHANGES WERE OBSERVED IN THE REMAINING REGIONS AND NO NEW REGIONS WERE ASSIGNED.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE AT LOW TO MODERATE LEVELS. REGION 8731, THOUGH RELATIVELY INACTIVE DURING THE PAST FEW DAYS, STILL APPEARS CAPABLE OF M-CLASS FLARE PRODUCTION. THERE IS A SLIGHT CHANCE FOR A MAJOR FLARE FROM THIS REGION AS WELL. IIA. GEOPHYSICAL ACTIVITY SUMMARY FROM 17/2100Z TO 18/2100Z: GEOMAGNETIC FIELD ACTIVITY WAS AT QUIET TO UNSETTLED LEVELS. THE GREATER THAN 2 MEV ELECTRON FLUX REMAINED AT MODERATE TO HIGH LEVELS.
IIB. Geophysical Activity Forecast
GEOMAGNETIC FIELD ACTIVITY IS EXPECTED TO REMAIN AT QUIET TO UNSETTLED LEVELS DURING THE FIRST TWO DAYS OF THE PERIOD. ACTIVITY IS EXPECTED TO INCREASE TO UNSETTLED TO ACTIVE LEVELS ON THE FINAL DAY DUE TO CORONAL HOLE EFFECTS. THE GREATER THAN 2 MEV ELECTRON FLUX IS EXPECTED TO REMAIN AT MODERATE TO HIGH LEVELS.
III. Event Probabilities 19 OCT to 21 OCT
Class M50%50%50%
Class X10%10%10%
Proton10%10%10%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       18 OCT 173
  Predicted   19 OCT-21 OCT  170/170/165
  90 Day Mean        18 OCT 158
V. Geomagnetic A Indices
OBSERVED AFR/AP 17 OCT  016/026
ESTIMATED AFR/AP 18 OCT  008/012
PREDICTED AFR/AP 19 OCT-21 OCT  008/010-010/008-015/015
VI. Geomagnetic Activity Probabilities 19 OCT to 21 OCT
A. Middle Latitudes
Active10%20%30%
Minor storm05%10%15%
Major-severe storm01%01%05%
B. High Latitudes
Active15%25%40%
Minor storm05%15%20%
Major-severe storm01%01%10%

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