Viewing archive of Friday, 12 February 1999

Solar activity report

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

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 043 Issued at 2200Z on 12 FEB 1999 ********CORRECTED COPY*********************************************

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

SOLAR ACTIVITY BECAME MODERATE. AN M1/1N FLARE ERUPTED IN REGION 8457 (N15E23) AT 12/0325Z. ASSOCIATED TYPE II/IV SWEEPS ALSO OCCURRED WITH MODERATE CENTIMETRIC BURSTS. A C5/SF ALSO OCCURRED IN THIS REGION AT 12/1527Z WHILE SLOW GROWTH WAS NOTED IN WHITE LIGHT BOTH IN AREA COVERAGE AND SPOT COUNT. FREQUENT LOW C-CLASS FLARES ALSO OCCURRED IN REGIONS 8456 (N23E04) AND 8458 (S23E29). THE DELTA CONFIGURATION IN REGION 8458 HAS FADED BUT THE REGION REMAINS COMPLEX WITH GOOD FLARE POTENTIAL. REGION 8456 APPEARED TO SIMPLIFY WITH SLIGHT DECAY OBSERVED IN WHITE LIGHT. FOUR NEW REGIONS WERE NUMBERED TODAY: REGIONS 8461 (S32E27), 8462 (N20E34), 8463 (S16E61), AND 8464 (N19E64). THE ADDITION OF THESE FOUR NEW REGIONS ON THE VISIBLE DISK RESULT IN A TOTAL OF EIGHT SPOTTED REGIONS EAST OF CENTRAL MERIDIAN. THE OFFICIAL 10.7CM FLUX FOR 12 FEB WAS 188 FLUX UNITS, MAKING IT THE HIGHEST OBSERVED 10.7CM FLUX SO FAR THIS CYCLE.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO CONTINUE AT MODERATE LEVELS. REGIONS 8457 AND 8458 HAVE GOOD POTENTIAL FOR M-CLASS FLARES. REGION 8456, THOUGH DECAYING SOMEWHAT, HAS POTENTIAL FOR AN ISOLATED M-CLASS EVENT. IIA. GEOPHYSICAL ACTIVITY SUMMARY FROM 11/2100Z TO 12/2100Z: THE GEOMAGNETIC FIELD WAS MOSTLY UNSETTLED TO ACTIVE WITH AN ISOLATED MINOR STORMING PERIOD DURING 12/06-09Z. THE INITIAL DISTURBANCE WAS ASSOCIATED WITH A CORONAL MASS EJECTION BUT A HIGH SPEED STREAM ASSOCIATED A FAVORABLY POSITIONED CORONAL HOLE IS LIKELY CAUSING THE DISTURBED CONDITIONS THIS PERIOD.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO CONTINUE AT UNSETTLED TO ACTIVE CONDITIONS WITH A CHANCE OF AN ISOLATED MINOR STORMING PERIOD AT HIGH LATITUDES. EXPECT MOSTLY QUIET TO UNSETTLED CONDITIONS LATE IN THE PERIOD AS THE CURRENT DISTURBANCE SUBSIDES.
III. Event Probabilities 13 FEB to 15 FEB
Class M 50%50%50%
Class X 20%20%20%
Proton10%15%15%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       12 FEB 188
  Predicted    13 FEB-15 FEB  190/190/190
  90 Day Mean        12 FEB 141
V. Geomagnetic A Indices
OBSERVED AFR/AP 11 FEB  016/016
ESTIMATED AFR/AP 12 FEB  025/020
PREDICTED AFR/AP 13 FEB-15 FEB  012/015-008/012-008/012
VI. Geomagnetic Activity Probabilities 13 FEB to 15 FEB
A. Middle Latitudes
Active60%15%15%
Minor storm 20%05%05%
Major-severe storm 01%01%01%
B. High Latitudes
Active70%20%20%
Minor storm 25%10%10%
Major-severe storm 01%01%01%

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