Viewing archive of Wednesday, 19 September 2001

Solar activity report

Report of Solar-Geophysical Activity 2001 Sep 19 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 262 Issued at 2200Z on 19 Sep 2001

IA. Analysis of Solar Active Regions and Activity from 18-2100Z to 19-2100Z

Solar activity was low with numerous C-Class flares. Region 9628 (S18E64) produced the largest flare of the day, a C7.5 at 19/1845 UTC. This region is the return of old Region 9591, which produced a major flare during its last rotation. A long duration C6.7 event occurred at 19/1607 UTC. LASCO/EIT imagery indicated a partial halo CME originated from Region 9620 (N12E30) at 18/1531 UTC with a plane of sky speed estimated at 332 km/s. Region 9629 (N26E38) was numbered today.
IB. Solar Activity Forecast
Solar forecast is expected to be low to moderate. Region 9628 (S18E64), 9620 (N12E30) and 9616 (S13W24) all have the potential to produce M-Class flares. Region 9628 also has a slight possibility of producing a major flare.
IIA. Geophysical Activity Summary 18-2100Z to 19-2100Z
Geomagnetic activity was quiet to unsettled.
IIB. Geophysical Activity Forecast
Geomagnetic activity is expected to be quiet to unsettled on the first day, increasing to unsettled to active levels on the second and third day due to an expected CME passage.
III. Event Probabilities 20 Sep to 22 Sep
Class M80%80%80%
Class X10%10%10%
IV. Penticton 10.7 cm Flux
  Observed       19 Sep 199
  Predicted   20 Sep-22 Sep  200/200/195
  90 Day Mean        19 Sep 165
V. Geomagnetic A Indices
  Observed Afr/Ap 18 Sep  007/008
  Estimated     Afr/Ap 19 Sep  008/008
  Predicted    Afr/Ap 20 Sep-22 Sep  012/010-015/015-010/012
VI. Geomagnetic Activity Probabilities 20 Sep to 22 Sep
A. Middle Latitudes
Minor storm10%20%15%
Major-severe storm01%05%01%
B. High Latitudes
Minor storm15%30%20%
Major-severe storm01%10%04%

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