Viewing archive of Friday, 10 September 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 Sep 10 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 253 Issued at 2200Z on 10 SEP 1999IA. Analysis of Solar Active Regions and Activity from 09-2100Z to 10-2100Z SOLAR ACTIVITY DECREASED TO VERY LOW LEVELS. REGION
8692 (S27E36) SHOWED A SMALL INCREASE IN SPOT NUMBER AND RETAINED A
MIXED-POLARITY (BETA-GAMMA) STRUCTURE. IT PRODUCED ISOLATED B-CLASS
SUBFLARES DURING THE PERIOD. MINOR PENUMBRAL DEVELOPMENT OCCURRED
WITHIN REGION 8690 (N13E20). THE REMAINING REGIONS WERE SMALL AND
STABLE, INCLUDING NEWLY NUMBERED REGION 8695 (N19E73).
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW.
REGIONS 8690 AND 8692 MAY PRODUCE ISOLATED C-CLASS FLARES.
IIA. Geophysical Activity Summary 09-2100Z to 10-2100Z
THE GEOMAGNETIC FIELD WAS AT QUIET TO UNSETTLED LEVELS DURING MOST OF
THE DAY WITH BRIEF ACTIVE TO MINOR STORM PERIODS DETECTED AT HIGH
LATITUDES.
IIB. Geophysical Activity Forecast
GEOMAGNETIC FIELD ACTIVITY IS
EXPECTED TO INCREASE TO UNSETTLED TO ACTIVE LEVELS DUE TO RECURRENT
CORONAL HOLE EFFECTS.
III. Event Probabilities 11 SEP to 13 SEP
| Class M | 30% | 30% | 30% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 10 SEP 122 Predicted 11 SEP-13 SEP 120/120/125 90 Day Mean 10 SEP 165
V. Geomagnetic A Indices
OBSERVED AFR/AP 09 SEP 007/008 ESTIMATED AFR/AP 10 SEP 012/017 PREDICTED AFR/AP 11 SEP-13 SEP 015/015-015/010-015/010
VI. Geomagnetic Activity Probabilities 11 SEP to 13 SEP
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 35% | 35% | 35% |
| Minor storm | 10% | 10% | 10% |
| Major-severe storm | 05% | 05% | 05% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 40% | 40% | 40% |
| Minor storm | 15% | 15% | 15% |
| Major-severe storm | 05% | 05% | 05% |
All times in UTC
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