Viewing archive of Thursday, 11 February 1999

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 1999 Feb 11 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 042 Issued at 2200Z on 11 FEB 1999

IA. Analysis of Solar Active Regions and Activity from 10-2100Z to 11-2100Z

SOLAR ACTIVITY WAS LOW. THE LARGEST EVENT THIS PERIOD WAS A LONG DURATION C3.7 X-RAY EVENT AT 10/2346Z. SPACE BASED IMAGERY SUGGEST REGION 8457 (N16E36) AS THE LIKELY SOURCE OF THIS EVENT. REGION 8356 (N23E16) ALSO PRODUCED MINOR C-CLASS SUBFLARES AS IT CONTINUES TO DEVELOP AND NOW EXHIBITS A MODERATELY COMPLEX BETA-GAMMA CONFIGURATION. THE MOST IMPRESSIVE GROWTH OCCURRED IN REGION 8458 (S22E42) WHERE A WEAK DELTA CONFIGURATION DEVELOPED LATE IN THE PERIOD. OTHER DYNAMIC DEVELOPMENTS IN THIS REGION INDICATE INCREASED FLARE POTENTIAL AS THE REGION NOW MEASURES 700 MILLIONTHS OF WHITE LIGHT AREA. REMAINING REGIONS HAVE BEEN QUIET.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW TO MODERATE. EXPECT CONTINUED C-CLASS X-RAY ACTIVITY FROM REGIONS 8456 AND 8457 WITH A SLIGHT CHANCE FOR AN M-CLASS. REGION 8458 IS QUICKLY DEVELOPING AS A LIKELY SOURCE FOR M-CLASS ACTIVITY.
IIA. Geophysical Activity Summary 10-2100Z to 11-2100Z
THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED UNTIL A WEAK INTERPLANETARY SHOCK WAS OBSERVED AT 11/0900Z; UNSETTLED TO ACTIVE CONDITIONS HAVE PREVAILED SINCE.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO REMAIN UNSETTLED TO ACTIVE THROUGH THE FIRST HALF OF NEXT PERIOD, BECOMING QUIET TO UNSETTLED THEREAFTER.
III. Event Probabilities 12 FEB to 14 FEB
Class M35%35%35%
Class X10%10%10%
Proton05%05%10%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       11 FEB 164
  Predicted   12 FEB-14 FEB  170/175/175
  90 Day Mean        11 FEB 141
V. Geomagnetic A Indices
OBSERVED AFR/AP 10 FEB  003/006
ESTIMATED AFR/AP 11 FEB  017/010
PREDICTED AFR/AP 12 FEB-14 FEB  012/012-008/012-008/012
VI. Geomagnetic Activity Probabilities 12 FEB to 14 FEB
A. Middle Latitudes
Active70%15%15%
Minor storm20%05%05%
Major-severe storm01%01%01%
B. High Latitudes
Active80%20%20%
Minor storm40%05%05%
Major-severe storm10%01%01%

All times in UTC

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