Viewing archive of Wednesday, 13 October 1999

Solar activity report

Report of Solar-Geophysical Activity 1999 Oct 13 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 286 Issued at 2200Z on 13 OCT 1999

IA. Analysis of Solar Active Regions and Activity from 12-2100Z to 13-2100Z

SOLAR ACTIVITY WAS LOW. REGIONS 8731 (N11E38) AND 8732 (N20E30) PRODUCED MOST OF TODAY'S OCCASIONAL C-CLASS SUBFLARES. BOTH GROUPS ARE SHOWING GROWTH AND INCREASING MAGNETIC STRENGTH. REGION 8728 (N22E12) CONTINUES TO BE LARGE BUT SEEMED TO BE SIMPLIFYING MAGNETICALLY AND WAS MOSTLY STABLE DURING THE DAY. A 27 DEGREE FILAMENT NEAR N45E15 ERUPTED BETWEEN 0000Z AND 0914Z ON THE 13TH. X-RAY AND CORONAGRAPH OBSERVATIONS CONFIRM THAT THE DISAPPEARANCE WAS ASSOCIATED WITH A CORONAL MASS EJECTION.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW. THERE IS A CHANCE, HOWEVER, FOR AN ISOLATED M-CLASS EVENT FROM REGION 8728, 8731 OR 8732. IIA. GEOPHYSICAL ACTIVITY SUMMARY FROM 12/2100Z TO 13/2100Z: THE GEOMAGNETIC FIELD RANGED FROM UNSETTLED TO MINOR STORM LEVELS DURING THE PAST 24 HOURS. LOCAL NIGHTTIME HOURS EXPERIENCED ACTIVE TO MINOR STORM LEVELS AND THE DAYTIME HOURS WERE UNSETTLED TO ACTIVE. THE ENHANCED ACTIVITY IS BEING CAUSED BY THE PRESENCE HIGH-SPEED CORONAL WIND STREAM AS INDICATED BY SOLAR WIND OBSERVATIONS. THE GREATER THAN 2 MEV ELECTRON FLUXES ATTAINED HIGH LEVELS TODAY.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO BE AT MOSTLY ACTIVE LEVELS DURING THE NEXT TWO DAYS, WITH OCCASIONAL MINOR STORM PERIODS AT HIGH LATITUDE, DUE TO CONTINUED EFFECTS FROM THE HIGH-SPEED STREAM. A DECREASE TO UNSETTLED TO SLIGHTLY ACTIVE IS EXPECTED BY THE THIRD DAY.
III. Event Probabilities 14 OCT to 16 OCT
Class M30%30%30%
Class X05%05%05%
Proton05%05%05%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       13 OCT 191
  Predicted   14 OCT-16 OCT  195/200/200
  90 Day Mean        13 OCT 156
V. Geomagnetic A Indices
OBSERVED AFR/AP 12 OCT  021/034
ESTIMATED AFR/AP 13 OCT  020/028
PREDICTED AFR/AP 14 OCT-16 OCT  025/030-025/025-010/020
VI. Geomagnetic Activity Probabilities 14 OCT to 16 OCT
A. Middle Latitudes
Active45%45%10%
Minor storm15%15%05%
Major-severe storm10%10%01%
B. High Latitudes
Active40%40%10%
Minor storm20%20%05%
Major-severe storm10%10%01%

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