Viewing archive of Saturday, 18 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 18 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 352 Issued at 2200Z on 18 DEC 1999

IA. Analysis of Solar Active Regions and Activity from 17-2100Z to 18-2100Z

SOLAR ACTIVITY HAS BEEN MODERATE. ACTIVE REGIONS 8798 (S13E09) AND 8806 (N19E62) HAVE PRODUCED FREQUENT MINOR FLARES INCLUDING 2 WEAK CLASS M EVENTS IN THE LAST 24 HOURS. REGION 8806 AND NEWLY NUMBERED REGION 8807 (N11E68) ARE TWO ACTIVE REGIONS THAT HAVE ROTATED INTO VIEW ON THE NORTHEAST LIMB.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE MODERATE WITH UP TO CLASS M EVENTS LIKELY FROM REGIONS 8798,8806, AND 8807.
IIA. Geophysical Activity Summary 17-2100Z to 18-2100Z
GEOMAGNETIC ACTIVITY HAS DECLINED FROM UNSETTLED TO QUIET.
IIB. Geophysical Activity Forecast
GEOMAGNETIC ACTIVITY IS EXPECTED TO BE INCREASING SLIGHTLY LATER IN THE FORECAST PERIOD AS A SMALL CORONAL HOLE ROTATES INTO POSITION TO AFFECT EARTH.
III. Event Probabilities 19 DEC to 21 DEC
Class M45%45%45%
Class X15%15%15%
Proton05%05%05%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       18 DEC 206
  Predicted   19 DEC-21 DEC  205/200/195
  90 Day Mean        18 DEC 170
V. Geomagnetic A Indices
OBSERVED AFR/AP 17 DEC  008/005
ESTIMATED AFR/AP 18 DEC  003/005
PREDICTED AFR/AP 19 DEC-21 DEC  007/008-008/015-006/012
VI. Geomagnetic Activity Probabilities 19 DEC to 21 DEC
A. Middle Latitudes
Active05%09%07%
Minor storm02%02%05%
Major-severe storm01%01%01%
B. High Latitudes
Active06%12%10%
Minor storm03%03%06%
Major-severe storm01%01%01%

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