Viewing archive of Sunday, 17 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 17 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 017 Issued at 2200Z on 17 JAN 1999

IA. Analysis of Solar Active Regions and Activity from 16-2100Z to 17-2100Z

SOLAR ACTIVITY WAS LOW. THE TWO MOST ACTIVE REGIONS WERE 8439 (S24E24) AND 8440 (N19E16). REGION 8439 HAS SHOWN AN INCREASE IN ACTIVITY, PRODUCING 3 C-CLASS EVENTS. THE LARGEST BEING A C5/SF AT 17/1955UT. THIS EVENT ALSO PRODUCED A TYPE II SWEEP. THE REGIONS SPOT COUNT HAS INCREASED FROM 31 TO 40, WITH A SLIGHT REDUCTION IN AREA. CURRENTLY AN FAO SPOT GROUP WITH A BETA MAGNETIC CLASSIFICATION. REGION 8440 HAS SHOWN A REDUCTION IN ACTIVITY PRODUCING ONLY 5 C-CLASS FLARES, THE LARGEST A C4/SF AT 17/1156UT. THE REGIONS SPOT COUNT HAS INCREASED FROM 31 TO 42, WITH A SLIGHT REDUCTION IN AREA. CURRENTLY AN EAI SPOT GROUP WITH A BETA-GAMMA MAGNETIC CLASSIFICATION. ONE NEW REGION WAS NUMBERED TODAY; 8442 (N24W16). CURRENTLY AN 8 SPOT DSO BETA SPOT GROUP.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW TO MODERATE. REGIONS 8439 AND 8440 ARE STILL CAPABLE OF PRODUCING ISOLATED M-CLASS EVENTS.
IIA. Geophysical Activity Summary 16-2100Z to 17-2100Z
THE GEOMAGNETIC FIELD WAS QUIET. THE GREATER THAN 2 MEV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT WAS AT HIGH LEVELS FOR MOST OF THE DAY WITH THE EXCEPTION OF THE PERIOD BETWEEN 17/0000-0130UT. THE FLUX FELL BELOW THRESHOLD LEVELS DURING THAT PERIOD.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO BE QUIET TO UNSETTLED.
III. Event Probabilities 18 JAN to 20 JAN
Class M70%70%70%
Class X10%10%10%
Proton05%05%05%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       17 JAN 161
  Predicted   18 JAN-20 JAN  165/170/175
  90 Day Mean        17 JAN 138
V. Geomagnetic A Indices
OBSERVED AFR/AP 16 JAN  007/007
ESTIMATED AFR/AP 17 JAN  005/010
PREDICTED AFR/AP 18 JAN-20 JAN  005/008-005/008-005/008
VI. Geomagnetic Activity Probabilities 18 JAN to 20 JAN
A. Middle Latitudes
Active10%10%10%
Minor storm05%05%05%
Major-severe storm01%01%01%
B. High Latitudes
Active20%20%20%
Minor storm10%10%10%
Major-severe storm01%01%01%

All times in UTC

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