Viewing archive of Sunday, 30 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 30 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 150 Issued at 2200Z on 30 MAY 1999IA. Analysis of Solar Active Regions and Activity from 29-2100Z to 30-2100Z
SOLAR ACTIVITY WAS LOW. THE PERIOD WAS HIGHLIGHTED BY
SEVERAL SUBFLARES IN REGION 8558 (N16E43) AND A PAIR OF C1 X-RAY
LONG DURATION EVENTS (LDE). REGION 8558 EXHIBITED STEADY GROWTH AND
NOW CONSISTS OF APPROXIMATELY 30 SPOTS MEASURING 300 MILLIONTHS OF
WHITE LIGHT AREA. FREQUENT BRIGHTNESS FLUCTUATIONS AND SURGES WERE
ALSO OBSERVED IN THIS REGION, BUT ONLY MINOR MAGNETIC COMPLEXITY WAS
NOTED. THE FIRST OF TWO C1 LDE X-RAY EVENTS OCCURRED AT 30/0328Z,
LIKELY ASSOCIATED WITH A CME OFF THE NE LIMB. THE SECOND C1 LDE
OCCURRED AT 30/1155Z AND ALSO APPEARS TO BE ASSOCIATED WITH A CME,
THIS TIME FROM THE W LIMB.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE. CONTINUED C-CLASS ACTIVITY IS LIKELY FROM REGION 8558
AND C-CLASS FLARES ARE ALSO POSSIBLE FROM 8560 (S24E35), 8552
(N19W18), AND 8559 (N20E03) WITH AN OUTSIDE CHANCE FOR AN M-CLASS.
IIA. Geophysical Activity Summary 29-2100Z to 30-2100Z
THE GEOMAGNETIC FIELD WAS QUIET
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET TO UNSETTLED. GEOMAGNETIC ACTIVITY IS NOT
EXPECTED FROM THE LONG DURATION C1 X-RAY EVENTS AND ASSOCIATED CME'S
DUE TO THE PRESUMED DIRECTION OF THE EJECTA.
III. Event Probabilities 31 MAY to 02 JUN
| Class M | 40% | 40% | 40% |
| Class X | 05% | 05% | 05% |
| Proton | 05% | 05% | 05% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 30 MAY 157 Predicted 31 MAY-02 JUN 160/160/160 90 Day Mean 30 MAY 131
V. Geomagnetic A Indices
OBSERVED AFR/AP 29 MAY 003/006 ESTIMATED AFR/AP 30 MAY 007/006 PREDICTED AFR/AP 31 MAY-02 JUN 010/010-008/010-008/008
VI. Geomagnetic Activity Probabilities 31 MAY to 02 JUN
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 20% | 20% | 20% |
| Minor storm | 01% | 01% | 01% |
| 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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