Viewing archive of Monday, 25 January 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 Jan 25 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 025 Issued at 2200Z on 25 JAN 1999

IA. Analysis of Solar Active Regions and Activity from 24-2100Z to 25-2100Z

SOLAR ACTIVITY BECAME MODERATE. REGION 8444 (N20W51) PRODUCED AN IMPULSIVE M2/SN AT 25/0056Z WITH MODERATE RADIO BURSTS IN THE 245-606 MHZ RANGE. THIS EVENT WAS PRECEDED BY A LONG DURATION C3/SF AT 25/0012Z FROM REGION 8444. THIS EVENT PRODUCED A MODERATE INTENSITY TYPE II RADIO BURST. REGION 8444 ALSO PRODUCED A C8/SF AT 25/1407Z. THIS REGION EXHIBITED SLIGHT GROWTH DURING THE PERIOD. ITS FLARE PRODUCTION RATE BELIES ITS SMALL SIZE AND RELATIVE STABILITY IN WHITE LIGHT. IT IS LIKELY THERE ARE MIXED POLARITIES IN THIS REGION BUT THE LACK OF MAGNETOGRAPH DATA PREVENTED VERIFICATION. REGIONS 8439 (S23W93) AND 8440 (N19W87) MAY HAVE PRODUCED SEVERAL SMALL X-RAY ENHANCEMENTS.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE PREDOMINANTLY LOW. REGION 8444 IS OBVIOUSLY CAPABLE OF GENERATING OCCASIONAL SMALL M-CLASS EVENTS. HOWEVER, ANY SIMPLIFICATION IN THIS SMALL REGION COULD RESULT IN THE CESSATION OF FLARE PRODUCTION. REGIONS 8439 AND 8440 REMAIN CAPABLE OF PRODUCING OCCASIONAL M-CLASS FLARES. THIS IS A PERSISTENCE FORECAST DUE TO THE FORESHORTENING OF THESE REGIONS.
IIA. Geophysical Activity Summary 24-2100Z to 25-2100Z
THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED. SOLAR WIND VELOCITIES DECREASED DURING THE PERIOD. THE GT 10 MEV PROTON ENHANCEMENT CONTINUED SLIGHTLY ABOVE BACKGROUND. THE FORBUSH DECREASE THAT BEGAN ON 23 JAN CONTINUED TO SLOWLY RECOVER.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO BE QUIET TO UNSETTLED FOR THE NEXT THREE DAYS. BRIEF PERIODS OF ACTIVE CONDITIONS ARE POSSIBLE TOWARD THE END OF THE PERIOD IN RESPONSE TO A THIN TRANSEQUATORIAL CORONAL HOLE THAT PASSED CENTRAL MERIDIAN ON 24 JAN.
III. Event Probabilities 26 JAN to 28 JAN
Class M45%30%20%
Class X10%05%05%
Proton10%05%05%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       25 JAN 138
  Predicted   26 JAN-28 JAN  125/120/118
  90 Day Mean        25 JAN 144
V. Geomagnetic A Indices
OBSERVED AFR/AP 24 JAN  011/013
ESTIMATED AFR/AP 25 JAN  009/010
PREDICTED AFR/AP 26 JAN-28 JAN  008/010-010/010-010/008
VI. Geomagnetic Activity Probabilities 26 JAN to 28 JAN
A. Middle Latitudes
Active10%15%15%
Minor storm05%05%05%
Major-severe storm01%01%01%
B. High Latitudes
Active10%15%15%
Minor storm05%05%05%
Major-severe storm01%01%01%

All times in UTC

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