Viewing archive of Sunday, 23 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 23 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 143 Issued at 2200Z on 23 MAY 1999

IA. Analysis of Solar Active Regions and Activity from 22-2100Z to 23-2100Z

SOLAR ACTIVITY WAS LOW. THERE WERE EIGHT LOW-LEVEL C-CLASS EVENTS DURING THE PAST 24 HOURS. OF THE REGIONS ON THE DISK, 8545 (N36W37), 8550 (S14E30), AND 8551 (N33E37) WERE THE MOST ACTIVE. BOTH REGION 8545 AND 8551 HAVE COMPLICATED INVERSION LINES BUT RELATIVELY WEAK MAGNETIC STRENGTHS NEAR THE APPARENT SHEAR POINTS. REGION 8550 IS GROWING SLOWLY AND APPEARED TO BE FORMING A MODERATE STRENGTH DELTA CONFIGURATION. NEW REGION 8552 (N21E80) BEGAN TO ROTATE INTO VIEW TODAY WITH THE APPEARANCE OF A LEADER SPOT WITH MATURE PENUMBRA.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE MOSTLY LOW, BUT THERE IS A FAIR CHANCE FOR AN ISOLATED M-CLASS EVENT SOMETIME DURING THE NEXT THREE DAYS.
IIA. Geophysical Activity Summary 22-2100Z to 23-2100Z
THE GEOMAGNETIC FIELD RANGED FROM QUIET TO ACTIVE LEVELS. THE GREATER THAN 2 MEV ELECTRONS ATTAINED HIGH LEVELS DURING THE PAST 24 HOURS BUT APPEARED TO BE DECREASING TOWARDS NORMAL BACKGROUND LEVELS NEAR THE END OF THE REPORTING PERIOD.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO BE MOSTLY UNSETTLED FOR THE NEXT THREE DAYS. THERE IS AN ENHANCED POSSIBILITY FOR SOME ACTIVE PERIODS ON THE THIRD DAY DUE TO RECURRENCE EFFECTS.
III. Event Probabilities 24 MAY to 26 MAY
Class M30%30%30%
Class X01%01%01%
Proton01%01%01%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       23 MAY 141
  Predicted   24 MAY-26 MAY  143/145/145
  90 Day Mean        23 MAY 128
V. Geomagnetic A Indices
OBSERVED AFR/AP 22 MAY  003/005
ESTIMATED AFR/AP 23 MAY  010/008
PREDICTED AFR/AP 24 MAY-26 MAY  010/012-010/012-015/012
VI. Geomagnetic Activity Probabilities 24 MAY to 26 MAY
A. Middle Latitudes
Active15%15%25%
Minor storm05%05%10%
Major-severe storm01%01%05%
B. High Latitudes
Active15%15%30%
Minor storm10%10%15%
Major-severe storm05%05%10%

All times in UTC

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