Viewing archive of Thursday, 28 May 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 May 28 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 148 Issued at 2200Z on 28 MAY 1998IA. Analysis of Solar Active Regions and Activity from 27-2100Z to 28-2100Z SOLAR ACTIVITY WAS MODERATE. REGION 8226 (N18W81)
PRODUCED A M1/SF WITH AN ERUPTIVE PROMINENCE AND MINOR RADIO BURSTS
AT 28/1353Z. THIS REGION IS ALSO RESPONSIBLE FOR SEVERAL C-CLASS
SUBFLARES INCLUDING A C8 AT 26/1912Z WHICH ALSO PRODUCED AN ERUPTIVE
PROMINENCE. LIMB PROXIMITY HAS MADE MEASUREMENTS DIFFICULT BUT
MAGNETIC ANALYSIS SUGGEST A BETA-GAMMA CONFIGURATION. REGION 8224
HAS ROTATED AROUND THE WEST LIMB NEAR S24 BUT DID PRODUCE A C3/SF AT
26/0101Z. REGION 8227 (N26E53), A D-TYPE BETA GROUP, PRODUCED A
C2/SF WITH MINOR RADIO BURSTS AT 28/1126Z.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE. REGION 8226 IS CAPABLE OF FURTHER M-CLASS ACTIVITY AS
IT ROTATES THE WEST LIMB. ISOLATED C-CLASS FLARES ARE POSSIBLE FROM
REGION 8227.
IIA. Geophysical Activity Summary 27-2100Z to 28-2100Z
THE GEOMAGNETIC FIELD WAS QUIET TO ACTIVE.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO REMAIN QUIET TO UNSETTLED THROUGH 30/1600Z. WE EXPECT
PERIODS OF ACTIVE TO MINOR STORM CONDITIONS ON 30-31 MAY IN RESPONSE
TO THE LONG DURATION C7 X-RAY EVENT ON 27/1335Z. A CME OCCURRED WITH
THIS EVENT AND EJECTA APPEARS EARTHBOUND.
III. Event Probabilities 29 MAY to 31 MAY
| Class M | 20% | 10% | 10% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 28 MAY 098 Predicted 29 MAY-31 MAY 098/098/096 90 Day Mean 28 MAY 108
V. Geomagnetic A Indices
OBSERVED AFR/AP 27 MAY 008/007 ESTIMATED AFR/AP 28 MAY 006/008 PREDICTED AFR/AP 29 MAY-31 MAY 007/008-012/015-018/015
VI. Geomagnetic Activity Probabilities 29 MAY to 31 MAY
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 10% | 30% | 40% |
| Minor storm | 01% | 10% | 15% |
| Major-severe storm | 01% | 01% | 05% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 15% | 40% | 45% |
| Minor storm | 05% | 20% | 25% |
| Major-severe storm | 01% | 05% | 05% |
All times in UTC
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