Viewing archive of Saturday, 13 March 1999

Solar activity report

Report of Solar-Geophysical Activity 1999 Mar 13 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 072 Issued at 2200Z on 13 MAR 1999

IA. Analysis of Solar Active Regions and Activity from 12-2100Z to 13-2100Z

SOLAR ACTIVITY INCREASED TO MODERATE LEVELS. REGION 8487 (N17E39) REMAINED A RELATIVELY SMALL D-TYPE GROUP AND SHOWED MINOR PENUMBRAL GROWTH AS WELL AS SOME MAGNETIC SHEAR IN THE VICINITY OF THE DOMINANT LEADER SPOT. IT PRODUCED AN IMPULSIVE M1/1N AT 13/2034Z AND NUMEROUS SUBFLARES EARLIER IN THE DAY, A FEW OF WHICH REACHED C-CLASS. NONE OF THESE FLARES WERE IMPRESSIVE IN RADIO EMISSION. REGION 8485 (N23E00) REMAINED A MODERATE-SIZED E-TYPE GROUP WITH SOME MIXED POLARITIES. IT WAS GENERALLY STABLE AND PRODUCED ISOLATED SUBFARES. THE REMAINING REGIONS WERE QUIET AND STABLE.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE AT MOSTLY LOW LEVELS. HOWEVER, ANOTHER ISOLATED M-CLASS FLARE COULD OCCUR FROM REGION 8487 SOMETIME DURING THE PERIOD. REGION 8485 ALSO PROVIDES A SLIGHT CHANCE FOR AN ISOLATED M-CLASS FLARE. IIA. GEOPHYSICAL ACTIVITY SUMMARY FROM 12/2100Z TO 13/2100Z: GEOMAGNETIC FIELD ACTIVITY INCREASED TO UNSETTLED TO ACTIVE LEVELS DURING 13/1200 - 1400Z. OTHERWISE, THE FIELD WAS AT QUIET TO UNSETTLED LEVELS.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO BE AT UNSETTLED TO ACTIVE LEVELS THROUGH THE PERIOD. BRIEF MINOR STORM PERIODS ARE ALSO POSSIBLE. THIS ACTIVITY IS EXPECTED IN RESPONSE TO CME EFFECTS. AN ISOLATED, POSITIVE POLARITY CORONAL HOLE MAY ALSO DISTURB THE FIELD SOMETIME DURING THE PERIOD.
III. Event Probabilities 14 MAR to 16 MAR
Class M 30%30%30%
Class X 05%05%05%
Proton05%05%05%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       13 MAR 144
  Predicted    14 MAR-16 MAR  145/145/140
  90 Day Mean        13 MAR 142
V. Geomagnetic A Indices
OBSERVED AFR/AP 12 MAR  009/010
ESTIMATED AFR/AP 13 MAR  007/009
PREDICTED AFR/AP 14 MAR-16 MAR  020/015-015/012-015/010
VI. Geomagnetic Activity Probabilities 14 MAR to 16 MAR
A. Middle Latitudes
Active45%40%40%
Minor storm 20%10%10%
Major-severe storm 05%01%01%
B. High Latitudes
Active55%45%45%
Minor storm 25%15%15%
Major-severe storm 10%05%05%

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