Viewing archive of Thursday, 28 October 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 Oct 28 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 301 Issued at 2200Z on 28 OCT 1999

IA. Analysis of Solar Active Regions and Activity from 27-2100Z to 28-2100Z

SOLAR ACTIVITY WAS LOW. THE DEPARTURE OF REGION 8737 NEAR SW13 AND THE SIMPLIFICATION OF REGION 8739 (S11W37) CAUSED FLARE COUNTS TO FALL OVER THE PAST 24 HOURS. VERY LITTLE ACTIVITY OCCURRED, THE MOST NOTABLE EVENT BEING A C1/SF FROM 8739 AT 0457Z. NEWLY ASSIGNED REGION 8747 (N10E59) HAS BRIGHT PLAGE AND DID PRODUCE A FEW SUBFLARES DURING THE INTERVAL.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW TO MODERATE. ALTHOUGH SEEMINGLY MORE BENIGN, REGION 8739 MAY STILL GENERATE AN ISOLATED M-CLASS EVENT.
IIA. Geophysical Activity Summary 27-2100Z to 28-2100Z
THE GEOMAGNETIC FIELD VARIED FROM QUIET TO MINOR STORM LEVELS DURING THE DAY. ABOUT 1200Z, SOLAR WIND PLASMA AND MAGNETIC FIELD EXPERIENCED A CHANGE AT THE ACE SPACECRAFT, RESULTING IN THE DISTURBED LEVELS SEEN DURING THE LATTER HALF OF THE PERIOD. THESE DATA SUGGEST A GLANCING BLOW BY A TRANSIENT AS THE CAUSE OF THE ELEVATED ACTIVITY. THE GREATER THAN 2 MEV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT REACHED HIGH LEVELS FROM 1330-1630Z, APPROXIMATELY.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO BE AT UNSETTLED TO ACTIVE LEVELS FOR THE NEXT FEW DAYS. EPISODIC MINOR STORM CONDITIONS ARE DISTINCTLY POSSIBLE DURING LOCAL NIGHTTIME HOURS. A HIGH SPEED STREAM IS EXPECTED TO PROLONG THE UNSETTLED CONDITIONS THROUGH OCTOBER 31.
III. Event Probabilities 29 OCT to 31 OCT
Class M30%30%30%
Class X01%01%01%
Proton01%01%01%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       28 OCT 184
  Predicted   29 OCT-31 OCT  175/165/160
  90 Day Mean        28 OCT 157
V. Geomagnetic A Indices
OBSERVED AFR/AP 27 OCT  010/017
ESTIMATED AFR/AP 28 OCT  015/015
PREDICTED AFR/AP 29 OCT-31 OCT  020/020-015/020-015/015
VI. Geomagnetic Activity Probabilities 29 OCT to 31 OCT
A. Middle Latitudes
Active40%30%30%
Minor storm25%20%20%
Major-severe storm05%01%01%
B. High Latitudes
Active50%40%40%
Minor storm30%25%25%
Major-severe storm05%05%05%

All times in UTC

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