Viewing archive of Monday, 23 August 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 Aug 23 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 235 Issued at 2200Z on 23 AUG 1999IA. Analysis of Solar Active Regions and Activity from 22-2100Z to 23-2100Z SOLAR ACTIVITY WAS LOW. AS REGIONS 8673 (S19E32) AND
8674(S25E35) ROTATE ONTO THE DISC IT BECOMES APPARENT THAT THE TWO
REGIONS MAY MERGE INTO ONE SINGLE COMPLEX REGION. IMAGES FROM THE
EIT/SOHO SPACE CRAFT SHOW INDICATIONS OF AN ACTIVE REGION JUST OVER
THE NORTHEAST LIMB THAT WILL SOON BE ROTATING ONTO THE DISC. AN
11-DEGREE DISAPPEARING SOLAR FILAMENT (N60E33) WAS NOTED AT
23/1404UT.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE. REGIONS 8673 AND 8674 ARE BOTH CAPABLE OF PRODUCING
ISOLATED M-CLASS EVENTS AT ANY TIME.
IIA. Geophysical Activity Summary 22-2100Z to 23-2100Z
THE GEOMAGNETIC FIELD WAS UNSETTLED TO MINOR STORM CONDITIONS WITH
ONE PERIOD OF MAJOR STORMING OCCURRING AT HIGH LATITUDES FROM
03-0600UT. THE CAUSE OF THIS GEOMAGNETIC ACTIVITY IS INDETERMINATE
AT THIS TIME BUT MAY HAVE BEEN THE EFFECTS FROM THE M9.8/1N FLARE IN
CONJUNCTION WITH A TYPE II SWEEP THAT OCCURRED ON 20/2310UT.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET TO UNSETTLED.
III. Event Probabilities 24 AUG to 26 AUG
| Class M | 60% | 60% | 60% |
| Class X | 10% | 10% | 10% |
| Proton | 01% | 01% | 01% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 23 AUG 188 Predicted 24 AUG-26 AUG 190/195/200 90 Day Mean 23 AUG 164
V. Geomagnetic A Indices
OBSERVED AFR/AP 22 AUG 007/011 ESTIMATED AFR/AP 23 AUG 020/035 PREDICTED AFR/AP 24 AUG-26 AUG 015/015-010/012-015/017
VI. Geomagnetic Activity Probabilities 24 AUG to 26 AUG
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 10% | 05% | 10% |
| Minor storm | 05% | 05% | 05% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 20% | 15% | 20% |
| Minor storm | 10% | 05% | 10% |
| Major-severe storm | 01% | 01% | 01% |
All times in UTC
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