Viewing archive of Thursday, 31 December 1998

Solar activity report

Any mentioned solar flare in this report has a scaling factor applied by the Space Weather Prediction Center (SWPC). Because of the SWPC scaling factor, solar flares are reported as 42% smaller than for the science quality data. The scaling factor has been removed from our archived solar flare data to reflect the true physical units.
Report of Solar-Geophysical Activity 1998 Dec 31 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 365 Issued at 2200Z on 31 DEC 1998

IA. Analysis of Solar Active Regions and Activity from 30-2100Z to 31-2100Z

SOLAR ACTIVITY DECREASED TO LOW LEVELS. REGION 8421 (N27W27) CONTINUED TO PRODUCE FREQUENT C-CLASS FLARES. ALTHOUGH IT SHOWED NO SIGNIFICANT CHANGES, IT REMAINED A LARGE GROUP WITH A COMPACT SPOT DISTRIBUTION AND STRONG MAGNETIC GRADIENTS. REGION 8419 (N28W79) CONTINUED TO SLOWLY DECAY AS IT APPROACHED THE WEST LIMB. THE REMAINING REGIONS WERE SMALL AND STABLE. NEW REGION 8427 (N16W62) WAS NUMBERED.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW TO MODERATE. REGION 8421 MAY PRODUCE ISOLATED M-CLASS FLARES DURING THE PERIOD. THERE IS ALSO A CHANCE FOR A MAJOR FLARE FROM THIS REGION.
IIA. Geophysical Activity Summary 30-2100Z to 31-2100Z
THE GEOMAGNETIC FIELD WAS QUIET AT ALL LATITUDES.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO BE AT QUIET TO UNSETTLED LEVELS.
III. Event Probabilities 01 JAN to 03 JAN
Class M65%65%65%
Class X20%20%20%
Proton15%15%15%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       31 DEC 175
  Predicted   01 JAN-03 JAN  170/165/165
  90 Day Mean        31 DEC 136
V. Geomagnetic A Indices
OBSERVED AFR/AP 30 DEC  005/006
ESTIMATED AFR/AP 31 DEC  003/010
PREDICTED AFR/AP 01 JAN-03 JAN  007/010-005/010-005/010
VI. Geomagnetic Activity Probabilities 01 JAN to 03 JAN
A. Middle Latitudes
Active15%10%10%
Minor storm05%05%05%
Major-severe storm01%01%01%
B. High Latitudes
Active20%15%15%
Minor storm10%05%05%
Major-severe storm01%01%01%

All times in UTC

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