Viewing archive of Wednesday, 20 October 2004

Solar activity report

Report of Solar-Geophysical Activity 2004 Oct 20 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 294 Issued at 2200Z on 20 Oct 2004

IA. Analysis of Solar Active Regions and Activity from 19-2100Z to 20-2100Z

Solar activity increased to moderate levels. Region 687 (N10E65) produced the largest flare of the period, an M2 x-ray flare that occurred at 20/1051Z. A CME was observed in LASCO imagery which does not appear to be Earth directed. This region remains too close to the eastern limb to fully discern magnetic complexity, although it does appear to contain a compact cluster of sunspots exhibiting both polarities. Region 682 (S13W33) produced multiple low level flares today, the largest was a C4/Sf which occurred at 20/0213Z. This region underwent moderate growth today. A beta-gamma magnetic structure is now evident and the sunspot area showed a modest increase during the period. Region 688 (S08W48) showed moderate growth over the period and was numbered today.
IB. Solar Activity Forecast
Solar activity is expected to be at low to moderate levels. Region 682 and 687 both have a fair potential for the production of isolated M-class flare activity.
IIA. Geophysical Activity Summary 19-2100Z to 20-2100Z
The geomagnetic field was at quiet to active levels. Active levels occurred in response to the sustained southward movement of the Bz component of the interplanetary magnetic field.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be at quiet to unsettled levels throughout the period.
III. Event Probabilities 21 Oct to 23 Oct
Class M50%50%50%
Class X01%01%01%
IV. Penticton 10.7 cm Flux
  Observed       20 Oct 111
  Predicted   21 Oct-23 Oct  115/120/125
  90 Day Mean        20 Oct 105
V. Geomagnetic A Indices
  Observed Afr/Ap 19 Oct  003/004
  Estimated     Afr/Ap 20 Oct  006/012
  Predicted    Afr/Ap 21 Oct-23 Oct  005/008-005/005-005/005
VI. Geomagnetic Activity Probabilities 21 Oct to 23 Oct
A. Middle Latitudes
Minor storm01%01%01%
Major-severe storm01%01%01%
B. High Latitudes
Minor storm05%05%05%
Major-severe storm01%01%01%

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