Viewing archive of Monday, 27 December 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 Dec 27 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 361 Issued at 2200Z on 27 DEC 1999

IA. Analysis of Solar Active Regions and Activity from 26-2100Z to 27-2100Z

SOLAR ACTIVITY WAS MODERATE. REGION 8806 (N20W53) PRODUCED TWO SMALL M FLARES, AN M1/SF AT 27/0146UT AND AN M2/SN AT 27/1154UT. THIS MAGNETICALLY COMPLEX REGION IS SLOWLY DECLINING AS IT APPROACHES WEST LIMB. ONLY MINOR ACTIVITY WAS OBSERVED FROM THE REMAINING THREE SPOTTED REGIONS. THE PROMINENCE ON THE EAST LIMB NEAR N40 IS IN THE PROCESS OF ERUPTING. SOLAR X-RAY AND RADIO BACKGROUND FLUX ARE DROPPING.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW TO MODERATE. THERE IS A CHANCE FOR MAJOR FLARES UNTIL AFTER REGION 8806 ROTATES OFF THE DISK ON 31 DEC.
IIA. Geophysical Activity Summary 26-2100Z to 27-2100Z
THE GEOMAGNETIC FIELD HAS BEEN QUIET TO UNSETTLED. A SHOCK WAS OBSERVED AT THE ACE SPACECRAFT AT 26/2126UT RESULTING IN A MINOR INCREASE IN ACTIVITY AT THE EARTH AFTER 26/2230UT.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO BE MOSTLY QUIET.
III. Event Probabilities 28 DEC to 30 DEC
Class M50%50%50%
Class X10%10%10%
Proton10%10%10%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       27 DEC 162
  Predicted   28 DEC-30 DEC  160/155/150
  90 Day Mean        27 DEC 176
V. Geomagnetic A Indices
OBSERVED AFR/AP 26 DEC  002/002
ESTIMATED AFR/AP 27 DEC  005/006
PREDICTED AFR/AP 28 DEC-30 DEC  005/005-005/005-008/010
VI. Geomagnetic Activity Probabilities 28 DEC to 30 DEC
A. Middle Latitudes
Active10%10%15%
Minor storm05%05%05%
Major-severe storm01%01%01%
B. High Latitudes
Active15%15%20%
Minor storm10%10%10%
Major-severe storm01%01%01%

All times in UTC

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