Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 21 Oct 2004

By SpaceRef Editor
October 21, 2004
Filed under , ,

Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.

Updated 2004 Oct 21 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 295 Issued at 2200Z on 21 Oct 2004

IA. Analysis of Solar Active Regions and Activity from 20/2100Z
to 21/2100Z: Solar activity was at low levels today. Region 687
(N10E52) produced multiple C-class flares during the period, the
largest was a C9.9 x-ray flare that occurred at 21/1948Z. At
21/0040Z this region produced a C7/Sf flare with an associated CME
that was observed in LASCO. The CME does not appear to be
Earth-directed. Close scrutiny of available data indicates that the
penumbral area of Region 687 is a single polarity structure yielding
a CSO beta-gamma sunspot classification. Region 682 (S13W46)
produced two C-class flares during the period, a C1/Sf that occurred
at 21/1442Z and a C4/Sf event occurring at 21/1522Z. Although the
overall sunspot count went down the sunspot distribution of
intermediate spots matured during the period which accounts for the
compact classification. Region 689 (N12E74) seen on the solar east
limb was numbered today.

IB. Solar Activity Forecast: Solar activity is expected to be at
low to moderate levels. Region 682 and 687 are both capable of
producing M-class flare activity.

IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z:
The geomagnetic field was at quiet to unsettled levels.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at quiet to unsettled levels throughout the period.

III. Event Probabilities 22 Oct-24 Oct

  • Class M 50/50/50
  • Class X 01/01/01
  • Proton 01/01/01
  • PCAF Green

IV. Penticton 10.7 cm Flux

  • Observed 21 Oct 112
  • Predicted 22 Oct-24 Oct 115/120/115
  • 90 Day Mean 21 Oct 104

V. Geomagnetic A Indices

  • Observed Afr/Ap 20 Oct 009/012
  • Estimated Afr/Ap 21 Oct 007/008
  • Predicted Afr/Ap 22 Oct-24 Oct 005/005-005/005-005/005

VI. Geomagnetic Activity Probabilities 22 Oct-24 Oct

A. Middle Latitudes

  • Active 15/15/15
  • Minor storm 01/01/01
  • Major-severe storm 01/01/01

B. High Latitudes

  • Active 15/15/15
  • Minor storm 05/05/05
  • Major-severe storm 01/01/01

SpaceRef staff editor.