Viewing archive of Sunday, 20 June 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 Jun 20 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 171 Issued at 2200Z on 20 JUN 1999IA. Analysis of Solar Active Regions and Activity from 19-2100Z to 20-2100Z SOLAR ACTIVITY BECAME MODERATE. REGION 8592 (N22E64)
PRODUCED AN M2/SB AT 20/1535Z. A DISAPPEARING FILAMENT AND MINOR
CENTIMETRIC RADIO BURSTS ACCOMPANIED THIS EVENT. THIS REGION ALSO
PRODUCED A LONG DURATION C5/SF AT 20/2007Z WITH A LARGE BRIGHT SURGE
TO 1.14R. REGION 8592 APPEARS TO BE COMPRISED OF SEVERAL REGIONS BUT
FORESHORTENING PREVENTED ACCURATE MAGNETIC SEPARATION. THIS SHOULD
BE POSSIBLE WITH ONE MORE DAY OF ROTATION ONTO THE DISK. ANOTHER
REGION BEGAN TO ROTATE OVER THE NORTHEAST LIMB AT NE14. IT WAS
NUMBERED AS NEW REGION 8594 (N14E85) AND CONSISTED OF A LARGE H
CLASS SPOT. IT IS LIKELY TRAILER SPOTS WILL FOLLOW.
IB. Solar Activity Forecast
SOLAR ACTIVITY SHOULD BE AT LOW TO
MODERATE LEVELS FOR THE NEXT THREE DAYS. THE REGIONS ROTATING OVER
THE NORTHEAST LIMB POSSESS THE CAPABILITY OF PRODUCING OCCASIONAL
M-CLASS EVENTS. THERE IS A SLIGHT CHANCE OF AN X-CLASS EVENT FROM
THIS AREA.
IIA. Geophysical Activity Summary 19-2100Z to 20-2100Z
THE GEOMAGNETIC FIELD WAS QUIET TO SLIGHTLY UNSETTLED.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD SHOULD
REMAIN QUIET TO SLIGHTLY UNSETTLED FOR THE NEXT THREE DAYS.
III. Event Probabilities 21 JUN to 23 JUN
| Class M | 50% | 50% | 50% |
| Class X | 15% | 15% | 15% |
| Proton | 05% | 05% | 05% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 20 JUN 152 Predicted 21 JUN-23 JUN 152/157/163 90 Day Mean 20 JUN 137
V. Geomagnetic A Indices
OBSERVED AFR/AP 19 JUN 004/007 ESTIMATED AFR/AP 20 JUN 005/005 PREDICTED AFR/AP 21 JUN-23 JUN 005/005-005/005-007/007
VI. Geomagnetic Activity Probabilities 21 JUN to 23 JUN
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 10% | 10% | 10% |
| Minor storm | 05% | 05% | 05% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 10% | 10% | 10% |
| Minor storm | 05% | 05% | 05% |
| Major-severe storm | 01% | 01% | 01% |
All times in UTC
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