Viewing archive of Monday, 31 May 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 May 31 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 151 Issued at 2200Z on 31 MAY 1999IA. Analysis of Solar Active Regions and Activity from 30-2100Z to 31-2100Z SOLAR ACTIVITY WAS LOW. THE LARGEST EVENT OF THE PERIOD
WAS AN OPTICALLY UNCORRELATED C8 X-RAY BURST THAT OCCURRED AT
30/2345Z. RECENT MAGNETIC MAP ANALYSIS MADE IT CLEAR THAT REGION
8557 (S30E21) AND REGION 8560 (S24E22) SHOULD BE COMBINED AS A
SINGLE BIPOLE GROUP. THEY HAVE BEEN COMBINED AS REGION 8557. THIS
REGION DID PRODUCE A C4/SF AT 31/0810Z. REGION 8552 (N18W32)
PRODUCED AN IMPULSIVE C2/SF WITH A TYPE II SWEEP AND A MINOR
MULTI-FREQUENCY RADIO BURST AT 31/0940Z. NEW REGION 8562 (S15E22)
EMERGED RAPIDLY IN THE LAST 24 HOURS AND HAS ALREADY PRODUCED LOW
C-CLASS FLARING. NEW REGION 8563 (S25E63) WAS ALSO NUMBERED TODAY.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE. BOTH REGION 8557 AND 8562 WILL LIKELY PRODUCE C-CLASS
FLARING AND THEIR PROXIMITY TO EACH OTHER COULD RESULT IN AN M-CLASS
EVENT. REGION 8552 AND 8558 (N16E30) ALSO HAVE POTENTIAL FOR C-CLASS
FLARES.
IIA. Geophysical Activity Summary 30-2100Z to 31-2100Z
THE GEOMAGNETIC FIELD WAS QUIET.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET TO UNSETTLED.
III. Event Probabilities 01 JUN to 03 JUN
| Class M | 50% | 50% | 50% |
| Class X | 10% | 10% | 10% |
| Proton | 05% | 05% | 05% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 31 MAY 165 Predicted 01 JUN-03 JUN 165/165/165 90 Day Mean 31 MAY 131
V. Geomagnetic A Indices
OBSERVED AFR/AP 30 MAY 003/005 ESTIMATED AFR/AP 31 MAY 005/010 PREDICTED AFR/AP 01 JUN-03 JUN 008/010-008/010-008/008
VI. Geomagnetic Activity Probabilities 01 JUN to 03 JUN
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 20% | 20% | 20% |
| Minor storm | 05% | 05% | 05% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 25% | 25% | 25% |
| Minor storm | 05% | 05% | 05% |
| Major-severe storm | 01% | 01% | 01% |
All times in UTC
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