Viewing archive of Friday, 18 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 18 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 169 Issued at 2200Z on 18 JUN 1999IA. Analysis of Solar Active Regions and Activity from 17-2100Z to 18-2100Z SOLAR ACTIVITY RETURNED TO LOW LEVELS. THE LARGEST
EVENT OF THE PERIOD WAS A C7/1N FROM REGION 8585 (N38E05). SEVERAL
OTHER SMALL TO MIDDLE LEVEL C-CLASS EVENTS WERE OBSERVED. SOHO DATA
INDICATED THAT MOST OF THESE EVENTS WERE FROM BEYOND THE NORTHWEST
LIMB. HOWEVER, A MODERATE DURATION C5 X-RAY EVENT WAS OBSERVED AT
18/1657Z THAT CORRELATED WITH A FLARE BRIGHT MOUND NEAR NE25. LAST
ROTATION, THIS AREA WAS COMPRISED OF SEVERAL ACTIVE REGIONS THAT
PRODUCED FREQUENT C-CLASS AND OCCASIONAL M-CLASS EVENTS. OTHER DISK
REGIONS EXHIBITED ONLY MINOR EVOLUTION.
IB. Solar Activity Forecast
SOLAR ACTIVITY SHOULD BE GENERALLY LOW
FOR THE NEXT THREE DAYS. M-CLASS EVENTS ARE POSSIBLE FROM THE AREA
ROTATING OVER THE NORTHEAST LIMB. A BETTER DETERMINATION OF THE
FLARE POTENTIAL OF THIS AREA MUST AWAIT ITS APPEARANCE TO THE
VISIBLE DISK.
IIA. Geophysical Activity Summary 17-2100Z to 18-2100Z
THE GEOMAGNETIC FIELD WAS QUIET.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET TO SLIGHTLY UNSETTLED FOR THE NEXT THREE DAYS.
III. Event Probabilities 19 JUN to 21 JUN
| Class M | 25% | 25% | 25% |
| Class X | 05% | 05% | 05% |
| Proton | 01% | 01% | 01% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 18 JUN 147 Predicted 19 JUN-21 JUN 150/153/156 90 Day Mean 18 JUN 136
V. Geomagnetic A Indices
OBSERVED AFR/AP 17 JUN 006/007 ESTIMATED AFR/AP 18 JUN 005/008 PREDICTED AFR/AP 19 JUN-21 JUN 007/007-007/007-007/007
VI. Geomagnetic Activity Probabilities 19 JUN to 21 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% | 15% |
| Minor storm | 05% | 05% | 05% |
| Major-severe storm | 01% | 01% | 01% |
All times in UTC
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