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 UTC
Prepared 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 1999

IA. 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 M30%30%30%
Class X01%01%01%
Proton01%01%01%
PCAFGREEN
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
Active35%35%35%
Minor storm10%10%10%
Major-severe storm05%05%05%
B. High Latitudes
Active40%40%40%
Minor storm15%15%15%
Major-severe storm05%05%05%

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