Viewing archive of Sunday, 20 June 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 Jun 20 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 171 Issued at 2200Z on 20 JUN 1999

IA. Analysis of Solar Active Regions and Activity from 19-2100Z to 20-2100Z

SOLAR ACTIVITY BECAME MODERATE. REGION 8592 (N22E64) PRODUCED AN M2/SB AT 20/1535Z. A DISAPPEARING FILAMENT AND MINOR CENTIMETRIC RADIO BURSTS ACCOMPANIED THIS EVENT. THIS REGION ALSO PRODUCED A LONG DURATION C5/SF AT 20/2007Z WITH A LARGE BRIGHT SURGE TO 1.14R. REGION 8592 APPEARS TO BE COMPRISED OF SEVERAL REGIONS BUT FORESHORTENING PREVENTED ACCURATE MAGNETIC SEPARATION. THIS SHOULD BE POSSIBLE WITH ONE MORE DAY OF ROTATION ONTO THE DISK. ANOTHER REGION BEGAN TO ROTATE OVER THE NORTHEAST LIMB AT NE14. IT WAS NUMBERED AS NEW REGION 8594 (N14E85) AND CONSISTED OF A LARGE H CLASS SPOT. IT IS LIKELY TRAILER SPOTS WILL FOLLOW.
IB. Solar Activity Forecast
SOLAR ACTIVITY SHOULD BE AT LOW TO MODERATE LEVELS FOR THE NEXT THREE DAYS. THE REGIONS ROTATING OVER THE NORTHEAST LIMB POSSESS THE CAPABILITY OF PRODUCING OCCASIONAL M-CLASS EVENTS. THERE IS A SLIGHT CHANCE OF AN X-CLASS EVENT FROM THIS AREA.
IIA. Geophysical Activity Summary 19-2100Z to 20-2100Z
THE GEOMAGNETIC FIELD WAS QUIET TO SLIGHTLY UNSETTLED.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD SHOULD REMAIN QUIET TO SLIGHTLY UNSETTLED FOR THE NEXT THREE DAYS.
III. Event Probabilities 21 JUN to 23 JUN
Class M50%50%50%
Class X15%15%15%
Proton05%05%05%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       20 JUN 152
  Predicted   21 JUN-23 JUN  152/157/163
  90 Day Mean        20 JUN 137
V. Geomagnetic A Indices
OBSERVED AFR/AP 19 JUN  004/007
ESTIMATED AFR/AP 20 JUN  005/005
PREDICTED AFR/AP 21 JUN-23 JUN  005/005-005/005-007/007
VI. Geomagnetic Activity Probabilities 21 JUN to 23 JUN
A. Middle Latitudes
Active10%10%10%
Minor storm05%05%05%
Major-severe storm01%01%01%
B. High Latitudes
Active10%10%10%
Minor storm05%05%05%
Major-severe storm01%01%01%

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