Viewing archive of Wednesday, 19 August 1998
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 1998 Aug 19 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 231 Issued at 2200Z on 19 AUG 1998IA. Analysis of Solar Active Regions and Activity from 18-2100Z to 19-2100Z SOLAR ACTIVITY HAS BEEN HIGH. AN X4.9 OCCURRED AT
18/2210 AND WAS ASSOCIATED WITH REGION 8307 (N32E72). AN M2.3 AT
19/1222 AND M3.0 AT 19/1404 WERE ALSO ASSOCIATED WITH THIS REGION.
THIS REGION IS EXPECTED TO CONTINUE TO PRODUCE X- AND M-CLASS
FLARES.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO MODERATE
TO HIGH THROUGHOUT THE PERIOD AS REGION 8307 MOVES TOWARDS THE
CENTER OF THE DISK.
IIA. Geophysical Activity Summary 18-2100Z to 19-2100Z
THE GEOMAGNETIC FIELD HAS BEEN QUIET.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO BE UNSETTLED TO ACTIVE WITH PERIODS OF MINOR STORM AT
HIGHER LATITUDES. CORONAL HOLES ARE MOVING INTO A GEOEFFECTIVE
LOCATIONS FOR THE REMAINDER OF THE PERIOD. AS REGION 8307 (N32E72)
ROTATES TO THE CENTER OF THE DISK, ERUPTIONS OF CMES ARE GOING TO BE
MORE GEOEFFECTIVE AS WELL. TYPE II (IMPORTANCE 3) AND IV
(IMPORTANCE 2) BURSTS WERE ASSOCIATED WITH THE X4.9 AND M3.0 X-RAY
FLARES. ESTIMATED SHOCK SPEED FROM X4.9 EVENT IS 1900 KM/S, AND
1000 KM/S +/- 200 KM/S FOR THE M3.0 FLARE.
III. Event Probabilities 20 AUG to 22 AUG
| Class M | 75% | 75% | 75% |
| Class X | 30% | 30% | 30% |
| Proton | 10% | 15% | 15% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 19 AUG 135 Predicted 20 AUG-22 AUG 138/140/144 90 Day Mean 19 AUG 114
V. Geomagnetic A Indices
OBSERVED AFR/AP 18 AUG 003/006 ESTIMATED AFR/AP 19 AUG 010/010 PREDICTED AFR/AP 20 AUG-22 AUG 015/015-025/020-015/010
VI. Geomagnetic Activity Probabilities 20 AUG to 22 AUG
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 10% | 20% | 20% |
| Minor storm | 05% | 10% | 10% |
| Major-severe storm | 01% | 05% | 05% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 15% | 25% | 25% |
| Minor storm | 05% | 10% | 15% |
| Major-severe storm | 01% | 05% | 05% |
All times in UTC
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