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

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 118 Issued at 2200Z on 28 APR 1999

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

SOLAR ACTIVITY WAS LOW DUE TO A C3 X-RAY FLARE AT 28/2032UT. NO OPTICAL FLARE REPORTS CORRELATED TO THIS C-FLARE WERE RECEIVED. REGION 8524 (N22W02) CONTINUED TO GROW BUT APPEARS TO BE MATURING AS A MODERATE-SIZED E-TYPE GROUP. OTHER DISK REGIONS HAVE CHANGED LITTLE.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW. C-CLASS ACTIVITY IS POSSIBLE IN REGIONS 8523 (N32W09) AND 8524 (N22W02).
IIA. Geophysical Activity Summary 27-2100Z to 28-2100Z
THE GEOMAGNETIC FIELD WAS QUIET TO ACTIVE. MOST ACTIVITY OCCURRED DURING THE 06-12UT PERIODS.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO BE QUIET TO UNSETTLED. ISOLATED ACTIVE PERIODS ARE POSSIBLE. ACTIVITY LEVELS MAY INCREASE BY THE END OF THE FORECAST PERIOD DUE TO CORONAL HOLE EFFECTS.
III. Event Probabilities 29 APR to 01 MAY
Class M05%05%05%
Class X01%01%01%
Proton01%01%01%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       28 APR 110
  Predicted   29 APR-01 MAY  110/110/115
  90 Day Mean        28 APR 128
V. Geomagnetic A Indices
OBSERVED AFR/AP 27 APR  009/014
ESTIMATED AFR/AP 28 APR  012/018
PREDICTED AFR/AP 29 APR-01 MAY  010/025-015/025-015/030
VI. Geomagnetic Activity Probabilities 29 APR to 01 MAY
A. Middle Latitudes
Active15%15%15%
Minor storm10%10%10%
Major-severe storm05%05%05%
B. High Latitudes
Active15%15%15%
Minor storm10%10%10%
Major-severe storm05%05%05%

All times in UTC

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