Viewing archive of Tuesday, 4 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 04 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 124 Issued at 2200Z on 04 MAY 1999IA. Analysis of Solar Active Regions and Activity from 03-2100Z to 04-2100Z
SOLAR ACTIVITY WAS MODERATE. THIS WAS DUE TO A SINGLE
M1 EVENT THAT OCCURRED AT 03/2311UT. THIS WAS AN OPTICALLY
UNCORRELATED EVENT. THE MOST ACTIVE REGION WAS 8527 (N26E12),
PRODUCING A C2/1F EVENT AT 04/1858. THIS WAS SOMEWHAT UNUSUAL
ACTIVITY FROM A SINGLE SPOT HSX CLASSIFICATION. THE REST OF THE
REGIONS SHOWED LITTLE CHANGE AND ONLY MINOR ACTIVITY DURING THE DAY.
A NEW REGION WAS NUMBERED: 8531 (N18E65), A 2 SPOT CSO BETA GROUP.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE. ISOLATED M-CLASS EVENTS CAN BE EXPECTED IN THE NEXT 72
HOURS.
IIA. Geophysical Activity Summary 03-2100Z to 04-2100Z
THE GEOMAGNETIC FIELD WAS MOSTLY QUIET WITH A SINGLE UNSETTLED PERIOD
OCCURRING AT 04/06-09UT. THE GREATER THAN 2 MEV ELECTRONS AT
GEOSYNCHRONOUS ORBIT WERE AT HIGH LEVELS ALL DAY.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO INCREASE FROM QUIET TO ACTIVE CONDITIONS OVER THE NEXT
TWO DAYS. THIS INCREASE SHOULD BE CAUSED BY THE CORONAL MASS
EJECTION THAT OCCURRED ON 03/0606UT AS SEEN BY SOHO-LASCO. THE EPAM
PLOT (ELECTRON AND PROTON PARTICLES) FROM THE ACE SATELLITE HAS
SHOWN A STRONG AND STEADY INCREASE SINCE APPROXIMATELY 03/2200UT.
THIS IS USUALLY AN INDICATOR OF AN IMMINENT SHOCK ARRIVAL AT EARTH.
III. Event Probabilities 05 MAY to 07 MAY
| Class M | 40% | 40% | 40% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 04 MAY 139 Predicted 05 MAY-07 MAY 125/125/125 90 Day Mean 04 MAY 129
V. Geomagnetic A Indices
OBSERVED AFR/AP 03 MAY 008/009 ESTIMATED AFR/AP 04 MAY 010/010 PREDICTED AFR/AP 05 MAY-07 MAY 020/020-020/020-015/015
VI. Geomagnetic Activity Probabilities 05 MAY to 07 MAY
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 40% | 40% | 30% |
| Minor storm | 25% | 25% | 20% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 60% | 60% | 40% |
| Minor storm | 20% | 20% | 15% |
| Major-severe storm | 01% | 01% | 01% |
All times in UTC
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