Viewing archive of Thursday, 8 April 1999

Solar activity report

Report of Solar-Geophysical Activity 1999 Apr 08 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 098 Issued at 2200Z on 08 APR 1999

IA. Analysis of Solar Active Regions and Activity from 07-2100Z to 08-2100Z

SOLAR ACTIVITY WAS MODERATE. REGION 8508 (N22E13) PRODUCED AN IMPULSIVE M1/SF AT 08/1613Z. THIS EVENT WAS PRECEDED BY MANY PLAGE FLUCTUATIONS AND SEVERAL SMALL TO MID C-CLASS FLARES FROM THIS REGION. DURING THE LAST 24 HOURS, REGION 8508 MAINTAINED ITS MIXED POLARITIES AND GREW AT A MODERATE PACE. A SMALL REGION EMERGED NEAR S27E53 AND WAS NUMBERED AS REGION 8512.
IB. Solar Activity Forecast
SOLAR ACTIVITY SHOULD BE LOW TO MODERATE FOR THE NEXT THREE DAYS. REGION 8508 MAY BE ENTERING A PHASE OF RE-GROWTH AND THE FREQUENCY OF M-CLASS EVENTS MAY INCREASE. X-CLASS FLARES ARE NOT EXPECTED AT THIS TIME BUT CONTINUED GROWTH IN REGION 8508 WOULD CHANGE THAT FORECAST. IIA. GEOPHYSICAL ACTIVITY SUMMARY FROM 07/2100Z TO 08/2100Z: THE GEOMAGNETIC FIELD BEGAN THE PERIOD AT QUIET LEVELS. ACTIVE CONDITIONS WERE OBSERVED DURING THE 08/1500-1800Z PERIOD. UNSETTLED CONDITIONS OCCURRED AT THE END OF THE PERIOD. NO SHOCK WAS OBSERVED IN THE NEARLY CONTINUOUS SOLAR WIND RECORD AND VELOCITY WAS RELATIVELY LOW BETWEEN 350-400 KM/S. ENERGETIC ELECTRON FLUXES AT GEOSYNCHRONOUS ORBIT REACHED HIGH LEVELS DURING THE PERIOD.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD SHOULD BE PREDOMINANTLY QUIET TO UNSETTLED FOR THE NEXT THREE DAYS. ISOLATED ACTIVE INTERVALS ARE POSSIBLE ON 09 APR.
III. Event Probabilities 09 APR to 11 APR
Class M 50%50%50%
Class X 10%10%10%
Proton10%10%10%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       08 APR 139
  Predicted    09 APR-11 APR  140/139/135
  90 Day Mean        08 APR 134
V. Geomagnetic A Indices
OBSERVED AFR/AP 07 APR  010/009
ESTIMATED AFR/AP 08 APR  010/012
PREDICTED AFR/AP 09 APR-11 APR  010/010-010/010-008/008
VI. Geomagnetic Activity Probabilities 09 APR to 11 APR
A. Middle Latitudes
Active25%15%15%
Minor storm 15%05%05%
Major-severe storm 05%01%05%
B. High Latitudes
Active25%15%15%
Minor storm 15%05%05%
Major-severe storm 05%01%05%

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