Viewing archive of Tuesday, 12 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 12 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 285 Issued at 2200Z on 12 OCT 1999IA. Analysis of Solar Active Regions and Activity from 11-2100Z to 12-2100Z
SOLAR ACTIVITY WAS LOW. REGION 8731 (N10E49) PRODUCED
MOST OF TODAY'S LOW LEVEL SUBFLARE ACTIVITY. THE REGION ROTATED MORE
FULLY INTO VIEW AS A MODERATE SIZED D-TYPE GROUP. REGION 8728
(N22E25) CONTINUES TO BE THE LARGEST REGION ON THE DISK BUT WAS
FAIRLY STABLE, EXHIBITING ONLY OCCASIONAL POINT BRIGHTENINGS. NEW
REGION 8732 (N20E41) WAS ASSIGNED TODAY.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW.
THERE IS, HOWEVER, A CHANCE FOR AN ISOLATED M-CLASS EVENT FROM
EITHER REGION 8728 OR 8731.
IIA. Geophysical Activity Summary 11-2100Z to 12-2100Z
THE GEOMAGNETIC FIELD RANGED FROM UNSETTLED TO MINOR STORM LEVELS,
WITH AN INTERVAL OF MAJOR STORM AT HIGH LATITUDES FROM 0900-1200Z.
AN INITIALLY ACTIVE LEVEL DISTURBANCE STRENGTHENED TO MOSTLY MINOR
STORM LEVELS FROM 0000-1200Z. CONDITIONS APPEARED TO BE SUBSIDING
DURING THE LAST NINE HOURS OF THE REPORTING INTERVAL (1200-2100Z),
WITH MID-LATITUDES ATTAINING UNSETTLED AND HIGH LATITUDES AT ACTIVE
TO MINOR STORM. THE GREATER THAN 2 MEV ELECTRON FLUXES ATTAINED HIGH
LEVELS DURING THE PAST 24 HOURS.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO BE ACTIVE AT MID-LATITUDES AND ACTIVE TO MINOR STORM AT
HIGH LATITUDES DURING THE NEXT THREE DAYS. THE INCREASE IS EXPECTED
AS A RESULT OF EARTH'S INTERACTION WITH A HIGH-SPEED SOLAR-WIND
STREAM FROM A FAVORABLY POSITIONED CORONAL HOLE.
III. Event Probabilities 13 OCT to 15 OCT
| Class M | 30% | 30% | 30% |
| Class X | 05% | 05% | 05% |
| Proton | 05% | 05% | 05% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 12 OCT 184 Predicted 13 OCT-15 OCT 185/190/190 90 Day Mean 12 OCT 155
V. Geomagnetic A Indices
OBSERVED AFR/AP 11 OCT 018/023 ESTIMATED AFR/AP 12 OCT 027/034 PREDICTED AFR/AP 13 OCT-15 OCT 020/030-020/030-020/025
VI. Geomagnetic Activity Probabilities 13 OCT to 15 OCT
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 45% | 45% | 45% |
| Minor storm | 15% | 15% | 15% |
| Major-severe storm | 10% | 10% | 10% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 40% | 40% | 40% |
| Minor storm | 20% | 20% | 20% |
| Major-severe storm | 10% | 10% | 10% |
All times in UTC
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