Viewing archive of Wednesday, 17 November 1999

Solar activity report

Report of Solar-Geophysical Activity 1999 Nov 17 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 321 Issued at 2200Z on 17 NOV 1999

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

SOLAR ACTIVITY WAS HIGH. TWO M-CLASS X-RAY FLARES WERE OBSERVED. THE LARGEST, AN M7/2B FLARE FROM REGION 8766 (N17E21), OCCURRED AT 0957Z. TYPE II AND IV RADIO SWEEPS, A 390 SFU TENFLARE, AND OTHER DISCRETE RADIO BURSTS ACCOMPANIED THIS EVENT. THE SECOND FLARE, AN M2/1N FROM REGION 8765 (S11E08), PEAKED AT 16/2124Z. THE REMAINDER OF THE PERIOD SAW NUMEROUS C-CLASS SUBFLARES SUPERIMPOSED ON AN ELEVATED BACKGROUND FLUX LEVEL OF NEARLY C2. REGION 8765 ATTAINED A WHITE-LIGHT AREA OF 1190 MILLIONTHS AND REMAINS A BETA-GAMMA-DELTA GROUP. NEW REGION 8771 (S14W33) WAS NUMBERED TODAY.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE MODERATE TO HIGH. BOTH REGIONS 8765 AND 8766 HAVE THE POTENTIAL TO GENERATE A MAJOR PROTON PRODUCING FLARE WITHIN THE NEXT FEW DAYS. ISOLATED M-CLASS ACTIVITY IS ALSO POSSIBLE FROM REGION 8768. IIA. GEOPHYSICAL ACTIVITY SUMMARY FROM 16/2100Z TO 17/2100Z: THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO BE QUIET TO UNSETTLED FOR THE FIRST DAY OF THE PERIOD. BY DAYS TWO AND THREE ACTIVE TO MINOR STORM CONDITIONS ARE POSSIBLE DUE TO CME EFFECTS. PARTIAL HALO CMES WERE OBSERVED ON SOHO/LASCO IMAGERY YESTERDAY AND TODAY'S FLARE ACTIVITY PRODUCED RADIO CME SIGNATURES.
III. Event Probabilities 18 NOV to 20 NOV
Class M 90%90%90%
Class X 30%30%30%
Proton15%15%15%
PCAFYELLOW
IV. Penticton 10.7 cm Flux
  Observed       17 NOV 221
  Predicted    18 NOV-20 NOV  215/200/195
  90 Day Mean        17 NOV 165
V. Geomagnetic A Indices
OBSERVED AFR/AP 16 NOV  011/016
ESTIMATED AFR/AP 17 NOV  011/016
PREDICTED AFR/AP 18 NOV-20 NOV  012/012-020/020-020/020
VI. Geomagnetic Activity Probabilities 18 NOV to 20 NOV
A. Middle Latitudes
Active35%45%45%
Minor storm 10%20%20%
Major-severe storm 05%10%10%
B. High Latitudes
Active40%50%50%
Minor storm 20%25%25%
Major-severe storm 10%10%10%

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