Viewing archive of Wednesday, 13 October 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 Oct 13 2200 UTCPrepared 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 1999IA. 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 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 M | 30% | 30% | 30% |
| Class X | 05% | 05% | 05% |
| Proton | 05% | 05% | 05% |
| PCAF | GREEN | ||
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 | |||
|---|---|---|---|
| Active | 45% | 45% | 10% |
| Minor storm | 15% | 15% | 05% |
| Major-severe storm | 10% | 10% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 40% | 40% | 10% |
| Minor storm | 20% | 20% | 05% |
| Major-severe storm | 10% | 10% | 01% |
All times in UTC
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