Viewing archive of Monday, 12 July 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 Jul 12 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 193 Issued at 2200Z on 12 JUL 1999

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

SOLAR ACTIVITY WAS LOW. THERE ARE 12 SPOTTED REGIONS ON THE DISK WITH ONLY SMALL C-CLASS FLARES BEING OBSERVED. THE MOST SPECTACULAR EVENT OF THE DAY WAS THE DISAPPEARANCE OF A LARGE FILAMENT NEAR S33E60 EARLY IN THE UT DAY. A CME OVER THE SOUTHEAST LIMB OF THE SUN OBSERVED BY THE SOHO SPACECRAFT AROUND 0700UT APPEARS TO BE ASSOCIATED WITH THIS EVENT. A TYPE II SWEEP WAS REPORTED AT 11/1840UT, HOWEVER, NO OPTICAL REPORTS HAVE BEEN ASSOCIATED WITH THIS EVENT. TWO NEW REGIONS WERE NUMBERED, REGION 8633 (N42E21) AND REGION 8634 (S18E69).
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW. THERE IS A GOOD CHANCE FOR C-CLASS FLARES.
IIA. Geophysical Activity Summary 11-2100Z to 12-2100Z
THE GEOMAGNETIC FIELD HAS RANGED FROM QUIET TO ACTIVE LEVELS. THE FIELD BECAME UNSETTLED TO ACTIVE FOLLOWING A SUDDEN IMPULSE AT 12/0218UT (20 NT AT BOULDER). THE FIELD IS CURRENTLY BACK AT QUIET LEVELS.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO BE QUIET TO UNSETTLED FOR MOST OF THE PERIOD. ANY TERRESTRIAL IMPACT FROM TODAY'S DISAPPEARING FILAMENT OR THE SOLAR SOURCE OF THE TYPE II IS NOT EXPECTED UNTIL 16 JUL.
III. Event Probabilities 13 JUL to 15 JUL
Class M30%30%30%
Class X01%01%01%
Proton01%01%01%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       12 JUL 154
  Predicted   13 JUL-15 JUL  149/147/145
  90 Day Mean        12 JUL 151
V. Geomagnetic A Indices
OBSERVED AFR/AP 11 JUL  002/006
ESTIMATED AFR/AP 12 JUL  013/010
PREDICTED AFR/AP 13 JUL-15 JUL  005/008-005/005-005/005
VI. Geomagnetic Activity Probabilities 13 JUL to 15 JUL
A. Middle Latitudes
Active15%10%10%
Minor storm01%01%01%
Major-severe storm01%01%01%
B. High Latitudes
Active20%15%15%
Minor storm01%01%01%
Major-severe storm01%01%01%

All times in UTC

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