Viewing archive of Wednesday, 20 October 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 Oct 20 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 293 Issued at 2200Z on 20 OCT 1999

IA. Analysis of Solar Active Regions and Activity from 19-2100Z to 20-2100Z

SOLAR ACTIVITY WAS MODERATE. REGION 8731 (N14W55) PRODUCED AN M1/1F FLARE AT 20/0622Z ACCOMPANIED BY A TYPE II SWEEP. THIS REGION CONTINUES TO SLOWLY DECAY AS IT APPROACHES THE WEST LIMB. REGION 8732 (N22W64) HAS STABILIZED SINCE PRODUCING A C8/SF LATE LAST PERIOD AND A C7/1F AT 19/2204Z. NEW REGIONS 8738 (N16E28) AND 8739 (S13E81) WERE NUMBERED TODAY:
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW TO MODERATE. REGIONS 8731 AND 8732 ARE IN DECAY BUT POSSESS POTENTIAL FOR AN ISOLATED M-CLASS EVENT.
IIA. Geophysical Activity Summary 19-2100Z to 20-2100Z
THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO REMAIN QUIET TO UNSETTLED FOR DAYS ONE AND TWO. ACTIVE CONDITIONS ARE EXPECTED WITH THE RETURN OF A GEOEFFECTIVE CORONAL HOLE BY DAY THREE.
III. Event Probabilities 21 OCT to 23 OCT
Class M45%40%30%
Class X10%10%05%
Proton10%10%05%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       20 OCT 159
  Predicted   21 OCT-23 OCT  165/160/150
  90 Day Mean        20 OCT 159
V. Geomagnetic A Indices
OBSERVED AFR/AP 19 OCT  005/007
ESTIMATED AFR/AP 20 OCT  006/008
PREDICTED AFR/AP 21 OCT-23 OCT  010/010-010/012-015/020
VI. Geomagnetic Activity Probabilities 21 OCT to 23 OCT
A. Middle Latitudes
Active20%20%40%
Minor storm10%10%20%
Major-severe storm01%01%10%
B. High Latitudes
Active25%25%50%
Minor storm15%15%30%
Major-severe storm05%05%15%

All times in UTC

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