Viewing archive of Friday, 28 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 28 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 148 Issued at 2200Z on 28 MAY 1999

IA. Analysis of Solar Active Regions and Activity from 27-2100Z to 28-2100Z

SOLAR ACTIVITY HAS BEEN LOW. REGIONS 8558 (N14E68) AND 8559 (N21E20) WERE NUMBERED TODAY. REGION 8559 IS NOW A LARGE ALPHA-TYPE SPOT GROUP WHICH TRAILS REGION 8552 (N21E11). REGIONS 8558 AND 8557 (S26E60) PRODUCED C2 XRAY FLARES AT 28/0553UT AND 28/1212UT, RESPECTIVELY. REGION 8552 CONTINUES TO GROW IN COMPLEXITY.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW TO MODERATE.
IIA. Geophysical Activity Summary 27-2100Z to 28-2100Z
THE GEOMAGNETIC FIELD HAS BEEN QUIET TO UNSETTLED.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO BE QUIET TO ACTIVE WITH ISOLATED PERIODS OF MINOR STORM AT HIGH LATITUDES FOR THE FIRST DAY OF THE PERIOD DUE TO RECURRENT CORONAL HOLE EFFECTS AND POSSIBLE CME INFLUENCE. THE SECOND AND THIRD DAYS ARE EXPECTED TO BE QUIET TO UNSETTLED WITH ISOLATED ACTIVE PERIODS AT HIGH LATITUDES.
III. Event Probabilities 29 MAY to 31 MAY
Class M50%50%50%
Class X10%10%10%
Proton05%05%05%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       28 MAY 152
  Predicted   29 MAY-31 MAY  158/163/170
  90 Day Mean        28 MAY   130
V. Geomagnetic A Indices
OBSERVED AFR/AP 27 MAY  007/010
ESTIMATED AFR/AP 28 MAY  010/012
PREDICTED AFR/AP 29 MAY-31 MAY  020/025-012/020-012/010
VI. Geomagnetic Activity Probabilities 29 MAY to 31 MAY
A. Middle Latitudes
Active50%35%20%
Minor storm20%10%05%
Major-severe storm05%01%01%
B. High Latitudes
Active60%40%30%
Minor storm30%15%10%
Major-severe storm10%05%01%

All times in UTC

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