Viewing archive of Monday, 27 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 27 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 270 Issued at 2200Z on 27 SEP 1999

IA. Analysis of Solar Active Regions and Activity from 26-2100Z to 27-2100Z

SOLAR ACTIVITY WAS LOW DUE TO A SINGLE C-CLASS EVENT. THIS WAS A C2/SF FROM REGION 8704 (S12W60) AT 27/0912UT. ACTIVITY FOR THE REST OF THE PERIOD WAS VERY LOW.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO CONTINUE TO BE VERY LOW TO LOW.
IIA. Geophysical Activity Summary 26-2100Z to 27-2100Z
THE GEOMAGNETIC FIELD WAS UNSETTLED TO MINOR STORM LEVELS. THESE CONDITIONS WERE THE RESULT OF A HIGH SPEED CORONAL HOLE STREAM.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO BE UNSETTLED TO ACTIVE WITH POSSIBLE MINOR STORM CONDITIONS, ESPECIALLY AT HIGH LATITUDES, FOR THE FIRST DAY OF THE FORECAST PERIOD. THESE CONDITIONS WOULD BE THE RESULT OF THE HIGH SPEED CORONAL HOLE STREAM MENTIONED ABOVE. CONDITIONS SHOULD DECREASE TO UNSETTLED TO ACTIVE ON THE SECOND DAY AND QUIET TO UNSETTLED ON THE THIRD DAY OF THE PERIOD.
III. Event Probabilities 28 SEP to 30 SEP
Class M01%01%01%
Class X01%01%01%
Proton01%01%01%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       27 SEP 124
  Predicted   28 SEP-30 SEP  120/115/115
  90 Day Mean        27 SEP 159
V. Geomagnetic A Indices
OBSERVED AFR/AP 26 SEP  013/015
ESTIMATED AFR/AP 27 SEP  035/040
PREDICTED AFR/AP 28 SEP-30 SEP  025/040-015/018-010/010
VI. Geomagnetic Activity Probabilities 28 SEP to 30 SEP
A. Middle Latitudes
Active25%20%15%
Minor storm15%10%05%
Major-severe storm01%01%01%
B. High Latitudes
Active35%25%15%
Minor storm20%15%10%
Major-severe storm01%01%01%

All times in UTC

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