Viewing archive of Saturday, 19 December 1998

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 1998 Dec 19 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 353 Issued at 2200Z on 19 DEC 1998

IA. Analysis of Solar Active Regions and Activity from 18-2100Z to 19-2100Z

SOLAR ACTIVITY WAS LOW. REGION 8415 (N20E50) PRODUCED A C4/SF AT 19/1436Z AND REGION 8406 (S26W85) PRODUCED A C1/SF AT 19/0949Z. REGION 8415 EXHIBITED MIXED POLARITIES IN RECENT MAGNETOGRAMS. SMALL SPOTS RE-EMERGED IN REGION 8414 (N27E14) DURING THE PERIOD. MORE DATA BECAME AVAILABLE REGARDING THE M8/2N FLARE FROM REGION 8415 AT 18/1722Z. THIS FLARE WAS COINCIDENT WITH A LONG DURATION X-RAY EVENT (ESTIMATED AT M2) FROM A FILAMENT DISRUPTION AND PARALLEL RIBBON FLARE FROM AN AREA VERY NEAR REGION 8414. THE PARTIAL HALO CORONAL MASS EJECTION MENTIONED YESTERDAY APPEARS AT THIS TIME TO BE NEARLY A FULL HALO. IT IS NOT POSSIBLE TO ACCURATELY DETERMINE THE DENSITY EACH EVENT CONTRIBUTED TO THE HALO CME BUT THE MAJORITY OF MATERIAL SHOULD BE RELATED TO THE DISAPPEARING FILAMENT AND LDE.
IB. Solar Activity Forecast
SOLAR ACTIVITY SHOULD BE LOW TO MODERATE. REGIONS 8415 AND 8409 ARE CAPABLE OF PRODUCING OCCASIONAL M-CLASS EVENTS. THE FILAMENT IN REGION 8414 REFORMED AND MAY ERUPT AGAIN WITH ANOTHER LARGE LDE/CME PRIOR TO WEST LIMB TRANSIT.
IIA. Geophysical Activity Summary 18-2100Z to 19-2100Z
THE GEOMAGNETIC FIELD WAS QUIET. SOLAR WIND PARAMETERS WERE VARIABLE (TOTAL FIELD AND DENSITY INCREASES AND PERIODS OF BZ SOUTHWARD) AT THE END OF THE PERIOD BUT HAD LITTLE EFFECT ON THE FIELD.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD SHOULD BE QUIET TO UNSETTLED THROUGH MIDDAY ON 21 DEC. THEN, GENERALLY UNSETTLED TO ACTIVE CONDITIONS ARE FORECAST TO BEGIN BASED UPON THE HALO CME MENTIONED ABOVE. THIS DISTURBANCE SHOULD CONTINUE THROUGH 22 DEC. OCCASIONAL MINOR STORM CONDITIONS ARE POSSIBLE DURING THE DISTURBANCE AND HIGH LATITUDES COULD EXPERIENCE BRIEF PERIODS OF MAJOR STORMING.
III. Event Probabilities 20 DEC to 22 DEC
Class M50%50%40%
Class X10%10%05%
Proton05%05%05%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       19 DEC 138
  Predicted   20 DEC-22 DEC  135/130/128
  90 Day Mean        19 DEC 133
V. Geomagnetic A Indices
OBSERVED AFR/AP 18 DEC  001/003
ESTIMATED AFR/AP 19 DEC  003/009
PREDICTED AFR/AP 20 DEC-22 DEC  008/012-018/018-025/025
VI. Geomagnetic Activity Probabilities 20 DEC to 22 DEC
A. Middle Latitudes
Active15%30%30%
Minor storm10%20%20%
Major-severe storm01%20%20%
B. High Latitudes
Active20%25%25%
Minor storm10%25%25%
Major-severe storm01%30%30%

All times in UTC

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