Viewing archive of Friday, 22 October 1999

Solar activity report

Report of Solar-Geophysical Activity 1999 Oct 22 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

: : : : : : : CORRECTED COPY : : : : : : : SDF Number 295 Issued at 2200Z on 22 OCT 1999

IA. Analysis of Solar Active Regions and Activity from 21-2100Z to 22-2100Z

SOLAR ACTIVITY WAS LOW. THE LARGEST EVENT OF THE PERIOD WAS A C4/SF IN REGION 8732 (N20W89) AT 22/0915Z. TWO TYPE II'S OCCURRED AT 22/0853Z AND 22/1300Z, LIKELY DUE TO THE CME ACTIVITY IN THE CLUSTER OF REGIONS TRANSITING THE NORTHWEST LIMB. REGIONS 8737 (S15W26) AND 8739 (S13E43) BOTH EXHIBITED GROWTH THIS PERIOD WITH REGION 8739 PRODUCING A 1F/SF AT 22/1929Z. NEW REGIONS 8740 (N27W83) AND 8741 (S25E64) WERE NUMBERED TODAY.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW TO MODERATE. AN ISOLATED M-CLASS EVENT IS STILL POSSIBLE FROM REGIONS 8731 (N12W79) AND REGION 8732, AS THEY ROTATE AROUND THE WEST LIMB. C-CLASS ACTIVITY IS LIKELY FROM REGIONS 8737 AND 8739. IIA. GEOPHYSICAL ACTIVITY SUMMARY FROM 21/2100Z TO 22/2100Z: THE GEOMAGNETIC FIELD WAS AT ACTIVE TO SEVERE STORM LEVELS. THIS STORM WAS ASSOCIATED WITH THE SUDDEN IMPULSE (SI) OBSERVED AT 21/0226Z. A SUSTAINED PERIOD OF RELATIVE CALM FOLLOWED THE SI, BUT CONDITIONS CHANGED CONSIDERABLY AROUND 21/2240Z. A DRAMATIC CHANGE IN THE IMF BZ TO A STRONG SOUTHWARD ORIENTATION PRODUCED SEVERE CONDITIONS AT MID AND HIGH LATITUDES. THE DISTURBANCE BEGAN TO WANE SOON AFTER 22/1200Z. ACTIVE CONDITIONS HAVE PERSISTED SINCE.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO BE AT ACTIVE TO MINOR STORM LEVELS WITH ISOLATED MAJOR STORM PERIODS LIKELY AT HIGH LATITUDES. A FAVORABLY POSITIONED GEOEFFECTIVE CORONAL HOLE SHOULD RESULT IN UNSETTLED TO ACTIVE CONDITIONS THROUGH ALL THREE DAYS.
III. Event Probabilities 23 OCT to 25 OCT
Class M 40%35%30%
Class X 10%05%05%
Proton10%05%05%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       22 OCT 160
  Predicted    23 OCT-25 OCT  155/145/140
  90 Day Mean        22 OCT 158
V. Geomagnetic A Indices
OBSERVED AFR/AP 21 OCT  014/015
ESTIMATED AFR/AP 22 OCT  055/090
PREDICTED AFR/AP 23 OCT-25 OCT  025/040-020/030-020/020
VI. Geomagnetic Activity Probabilities 23 OCT to 25 OCT
A. Middle Latitudes
Active30%30%30%
Minor storm 40%40%30%
Major-severe storm 10%10%05%
B. High Latitudes
Active30%40%40%
Minor storm 50%40%40%
Major-severe storm 20%20%10%

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