Viewing archive of Sunday, 12 December 1999

Solar activity report

Report of Solar-Geophysical Activity 1999 Dec 12 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 346 Issued at 2200Z on 12 DEC 1999

IA. Analysis of Solar Active Regions and Activity from 11-2100Z to 12-2100Z

SOLAR ACTIVITY WAS LOW. ONLY ONE MINOR C-CLASS EVENT WAS OBSERVED DURING THE PERIOD. MOST OF THE REGIONS ARE CURRENTLY STABLE OR SHOWING SIGNS OF DECAY. NO NEW REGIONS WERE NUMBERED TODAY.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW. IIA. GEOPHYSICAL ACTIVITY SUMMARY FROM 11/2100Z TO 12/2100Z: THE GEOMAGNETIC FIELD WAS QUIET TO ACTIVE. SOLAR WIND DATA INDICATED A SIGNIFICANT INCREASE IN VELOCITY AND TEMPERATURE STARTING AROUND 12/1630Z. ACTIVE CONDITIONS WERE IMMEDIATELY OBSERVED AFTERWARDS. THE GREATER THAN 2 MEV ELECTRONS AT GEOSYNCHRONOUS ORBIT WERE AT HIGH LEVELS DURING THE PERIOD.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO BE PREDOMINANTELY QUIET TO ACTIVE ON THE FIRST DAY AS THE CURRENT DISTURBANCE SUBSIDES. QUIET TO UNSETTLED CONDITIONS ARE EXPECTED DURING THE REMAINDER OF THE PERIOD.
III. Event Probabilities 13 DEC to 15 DEC
Class M 10%10%10%
Class X 01%01%01%
Proton01%01%01%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       12 DEC 159
  Predicted    13 DEC-15 DEC  160/170/175
  90 Day Mean        12 DEC 168
V. Geomagnetic A Indices
OBSERVED AFR/AP 11 DEC  006/007
ESTIMATED AFR/AP 12 DEC  012/010
PREDICTED AFR/AP 13 DEC-15 DEC  010/012-010/010-010/010
VI. Geomagnetic Activity Probabilities 13 DEC to 15 DEC
A. Middle Latitudes
Active30%15%15%
Minor storm 15%05%05%
Major-severe storm 01%01%01%
B. High Latitudes
Active35%20%20%
Minor storm 20%05%05%
Major-severe storm 05%01%01%

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