Viewing archive of Tuesday, 21 July 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 Jul 21 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 202 Issued at 2200Z on 21 JUL 1998

IA. Analysis of Solar Active Regions and Activity from 20-2100Z to 21-2100Z

SOLAR ACTIVITY WAS VERY LOW. THREE NEW REGIONS WERE NUMBERED TODAY: REGION 8279, (EMERGED ON DISK AT N26E33), REGION 8280 (ROTATING INTO VIEW AT S22E76), AND 8281 (A SIMPLE A-TYPE GROUP AT N16E73). REGION 8280 APPEARS TO HAVE MATURE PENUMBRA ON LEADER AND TRAILER PORTIONS OF THE GROUP. REGION 8277 (S12W41) GREW STEADILY AND EXHIBITED BRIGHT H-ALPHA PLAGE, BUT COULD ONLY MUSTER ONE SUBFLARE OVER THE PAST 24 HOURS.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE PREDOMINANTLY LOW. THERE IS A CHANCE, HOWEVER, FOR AN ISOLATED M-CLASS FLARE OVER THE NEXT THREE DAYS. REGIONS 8277 AND 8280 ARE CONSIDERED TO BE THE MOST LIKELY SOURCE REGIONS FOR ENHANCED ACTIVITY.
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED AT MID-LATITUDES AND RANGED FROM QUIET TO MINOR STORM LEVELS AT HIGH LATITUDES. ALTHOUGH MOST OF THE LAST 24 HOURS WAS QUIET, AN INTERVAL OF ENHANCED ACTIVITY OCCURRED FROM 0300-1200Z. REAL-TIME SOLAR WIND DATA INDICATED THAT A SECTOR BOUNDARY CROSSING OCCURRED SHORTLY AFTER 03Z, AND WAS FOLLOWED BY FLUCTUATING INTERPLANETARY MAGNETIC FIELD CONDITIONS THAT INCLUDED SOME MODERATE NEGATIVE BZ.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO BE MOSTLY QUIET TO UNSETTLED FOR THE NEXT THREE DAYS.
III. Event Probabilities 22 JUL to 24 JUL
Class M20%20%20%
Class X05%05%05%
Proton05%05%05%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       21 JUL 110
  Predicted   22 JUL-24 JUL  112/112/115
  90 Day Mean        21 JUL 107
V. Geomagnetic A Indices
OBSERVED AFR/AP 20 JUL  003/006
ESTIMATED AFR/AP 21 JUL  010/009
PREDICTED AFR/AP 22 JUL-24 JUL  010/010-010/008-005/007
VI. Geomagnetic Activity Probabilities 22 JUL to 24 JUL
A. Middle Latitudes
Active25%25%20%
Minor storm10%10%10%
Major-severe storm05%05%05%
B. High Latitudes
Active25%25%20%
Minor storm10%10%10%
Major-severe storm05%05%05%
EFFECTIVE MONDAY, 27 JULY, GOES-9 WILL BE TAKEN OUT OF OPERATIONAL STATUS, AND GOES-10 WILL BECOME THE PRIMARY SATELLITE FOR SWO DATA AND PRODUCTS.

All times in UTC

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