Viewing archive of Wednesday, 26 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 26 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 146 Issued at 2200Z on 26 MAY 1999IA. Analysis of Solar Active Regions and Activity from 25-2100Z to 26-2100Z
SOLAR ACTIVITY WAS MODERATE. THERE WERE A LARGE NUMBER
OF WEAK C-CLASS X-RAY FLARES, TWO OF WHICH WERE LONG DURATION
EVENTS. THE FIRST LDE WAS AN OPTICALLY UNCORRELATED C1 AT 25/2137Z,
THE SECOND A C2/SF FROM REGION 8550 (S14W12) AT 26/0522Z. IN
ADDITION THERE WAS A TYPE II RADIO SWEEP (SPEED 650 KM/S) CORRELATED
TO A C2/SF FROM REGION 8554 (N26E26) AT 26/0230Z. FINALLY, THE
STRONGEST FLARE WAS AN M1/2N FLARE FROM REGION 8552 (N11E41) AT
26/1932Z. ONE REGION, 8555 (N16E75), WAS NUMBERED TODAY.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW
WITH A CHANCE OF AN ISOLATED M-CLASS FLARE.
IIA. Geophysical Activity Summary 25-2100Z to 26-2100Z
THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET TO UNSETTLED WITH A CHANCE FOR ACTIVE
CONDITIONS LATE TOMORROW. THE INFLUENCE OF A RECURRENT CORONAL HOLE
IS EXPECTED DURING THIS TIME.
III. Event Probabilities 27 MAY to 29 MAY
| Class M | 30% | 30% | 30% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 26 MAY 153 Predicted 27 MAY-29 MAY 150/155/160 90 Day Mean 26 MAY 129
V. Geomagnetic A Indices
OBSERVED AFR/AP 25 MAY 014/019 ESTIMATED AFR/AP 26 MAY 008/010 PREDICTED AFR/AP 27 MAY-29 MAY 010/010-010/012-010/012
VI. Geomagnetic Activity Probabilities 27 MAY to 29 MAY
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 25% | 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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