Viewing archive of Sunday, 24 January 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 Jan 24 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.comJoint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 024 Issued at 2200Z on 24 JAN 1999
IA. Analysis of Solar Active Regions and Activity from 23-2100Z to 24-2100Z
SOLAR ACTIVITY WAS LOW. THE LARGEST EVENT OF THE PERIOD
WAS A C5/SF FLARE FROM REGION 8444 (N20W38) AT 24/0820Z. A MORE
INTERESTING EVENT WAS A GRADUAL RISE AND FALL C3 X-RAY EVENT FROM
24/1555-1920Z. A REPORT WAS RECEIVED OF CORONAL RAIN AND A WEAK LOOP
PROMINENCE SYSTEM VISIBLE NEAR SW28 TOWARD THE END OF THE X-RAY
EVENT. NO SIGNIFICANT FLARE WAS OBSERVED IN NEARBY REGION 8439
(S23W81) DURING THE EVENT BUT, IN MOVIE SEQUENCES, FIBRIL DISTORTIONS
WERE. IT IS LIKELY THAT A FILAMENT ERUPTED BEHIND THE WEST LIMB AND
SOME MATERIAL FLOWED DOWN ALONG FIELD LINES NEAR REGION 8439.
REGIONS 8439 AND 8440 (N19W78) SHOWED SLIGHT DECAY BUT THAT MAY BE
DUE IN PART TO FORESHORTENING.
IB. Solar Activity Forecast
SOLAR ACTIVITY SHOULD BE PREDOMINANTLY
LOW FOR THE NEXT THREE DAYS DUE TO SUBFLARES FROM REGIONS 8439,
8440, AND 8444. REGIONS 8439 AND 8440 REMAIN CAPABLE OF PRODUCING
ISOLATED M-CLASS EVENTS.
IIA. Geophysical Activity Summary 23-2100Z to 24-2100Z
DURING THE FIRST HALF OF THE PERIOD, THE GEOMAGNETIC FIELD WAS AT
UNSETTLED TO ACTIVE LEVELS. QUIET TO UNSETTLED CONDITIONS WERE
OBSERVED DURING THE LATTER HALF. THE GT 10 MEV PROTON FLUX REMAINED
ENHANCED BUT BELOW EVENT LEVEL FOR THE ENTIRE PERIOD. A FORBUSH
DECREASE BEGAN EARLY ON 23 JAN. THE NEUTRON FLUX DURING THE EVENT
WAS DEPRESSED BY APPROXIMATELY 6 PERCENT NEAR MIDDAY ON 24 JAN. AT
THE END OF THE PERIOD, THE FORBUSH DECREASE WAS SLOWLY RECOVERING TO
NORMAL VALUES.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD SHOULD BE
QUIET TO UNSETTLED FOR THE NEXT THREE DAYS. THE GT 10 MEV PROTON
FLUX SHOULD RETURN TO BACKGROUND LEVELS DURING THE PERIOD.
III. Event Probabilities 25 JAN to 27 JAN
Class M | 40% | 20% | 15% |
Class X | 10% | 05% | 05% |
Proton | 10% | 05% | 05% |
PCAF | GREEN
|
IV. Penticton 10.7 cm Flux
Observed 24 JAN 162
Predicted 25 JAN-27 JAN 153/142/137
90 Day Mean 24 JAN 143
V. Geomagnetic A Indices
OBSERVED AFR/AP 23 JAN 017/016
ESTIMATED AFR/AP 24 JAN 013/015
PREDICTED AFR/AP 25 JAN-27 JAN 008/010-008/010-010/008
VI. Geomagnetic Activity Probabilities 25 JAN to 27 JAN
A. Middle Latitudes |
Active | 15% | 10% | 15% |
Minor storm | 05% | 05% | 05% |
Major-severe storm | 01% | 01% | 01% |
B. High Latitudes |
Active | 20% | 15% | 15% |
Minor storm | 05% | 05% | 05% |
Major-severe storm | 01% | 01% | 01% |
All times in UTC
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