Viewing archive of Monday, 31 May 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 May 31 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 151 Issued at 2200Z on 31 MAY 1999

IA. Analysis of Solar Active Regions and Activity from 30-2100Z to 31-2100Z

SOLAR ACTIVITY WAS LOW. THE LARGEST EVENT OF THE PERIOD WAS AN OPTICALLY UNCORRELATED C8 X-RAY BURST THAT OCCURRED AT 30/2345Z. RECENT MAGNETIC MAP ANALYSIS MADE IT CLEAR THAT REGION 8557 (S30E21) AND REGION 8560 (S24E22) SHOULD BE COMBINED AS A SINGLE BIPOLE GROUP. THEY HAVE BEEN COMBINED AS REGION 8557. THIS REGION DID PRODUCE A C4/SF AT 31/0810Z. REGION 8552 (N18W32) PRODUCED AN IMPULSIVE C2/SF WITH A TYPE II SWEEP AND A MINOR MULTI-FREQUENCY RADIO BURST AT 31/0940Z. NEW REGION 8562 (S15E22) EMERGED RAPIDLY IN THE LAST 24 HOURS AND HAS ALREADY PRODUCED LOW C-CLASS FLARING. NEW REGION 8563 (S25E63) WAS ALSO NUMBERED TODAY.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW TO MODERATE. BOTH REGION 8557 AND 8562 WILL LIKELY PRODUCE C-CLASS FLARING AND THEIR PROXIMITY TO EACH OTHER COULD RESULT IN AN M-CLASS EVENT. REGION 8552 AND 8558 (N16E30) ALSO HAVE POTENTIAL FOR C-CLASS FLARES.
IIA. Geophysical Activity Summary 30-2100Z to 31-2100Z
THE GEOMAGNETIC FIELD WAS QUIET.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO BE QUIET TO UNSETTLED.
III. Event Probabilities 01 JUN to 03 JUN
Class M50%50%50%
Class X10%10%10%
Proton05%05%05%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       31 MAY 165
  Predicted   01 JUN-03 JUN  165/165/165
  90 Day Mean        31 MAY 131
V. Geomagnetic A Indices
OBSERVED AFR/AP 30 MAY  003/005
ESTIMATED AFR/AP 31 MAY  005/010
PREDICTED AFR/AP 01 JUN-03 JUN  008/010-008/010-008/008
VI. Geomagnetic Activity Probabilities 01 JUN to 03 JUN
A. Middle Latitudes
Active20%20%20%
Minor storm05%05%05%
Major-severe storm01%01%01%
B. High Latitudes
Active25%25%25%
Minor storm05%05%05%
Major-severe storm01%01%01%

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