Viewing archive of Friday, 31 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 31 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 365 Issued at 2200Z on 31 DEC 1999

IA. Analysis of Solar Active Regions and Activity from 30-2100Z to 31-2100Z

SOLAR ACTIVITY WAS LOW. THE LARGEST EVENT THIS PERIOD WAS A C2/SF FROM NEWLY NUMBERED REGION 8815 (N10E61). THIS REGION EMERGED AS A SMALL, COMPACT C-CLASS SPOT GROUP. REMAINING REGIONS WERE QUIET.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO REMAIN AT LOW LEVELS. ISOLATED LOW LEVEL C-CLASS FLARES ARE LIKELY.
IIA. Geophysical Activity Summary 30-2100Z to 31-2100Z
THE GEOMAGNETIC FIELD WAS UNSETTLED TO ACTIVE. EFFECTS FROM A CORONAL HOLE, HIGH SPEED SOLAR WIND STREAM THAT BEGAN YESTERDAY, CONTINUED TODAY.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD WILL CONTINUE AT UNSETTLED TO ACTIVE LEVELS. A LARGE, GEOEFFECTIVELY POSITIONED CORONAL HOLE WILL PROLONG THE CURRENT DISTURBANCE THROUGH DAY THREE.
III. Event Probabilities 01 JAN to 03 JAN
Class M10%10%10%
Class X05%05%05%
Proton05%05%05%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       31 DEC 130
  Predicted   01 JAN-03 JAN  130/130/130
  90 Day Mean        31 DEC 176
V. Geomagnetic A Indices
OBSERVED AFR/AP 30 DEC  007/008
ESTIMATED AFR/AP 31 DEC  020/021
PREDICTED AFR/AP 01 JAN-03 JAN  020/025-020/025-015/018
VI. Geomagnetic Activity Probabilities 01 JAN to 03 JAN
A. Middle Latitudes
Active65%65%50%
Minor storm25%25%15%
Major-severe storm10%10%05%
B. High Latitudes
Active60%60%50%
Minor storm30%30%20%
Major-severe storm10%10%05%

All times in UTC

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