Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 18 Aug 2004

By SpaceRef Editor
August 18, 2004
Filed under , ,

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

Updated 2004 Aug 18 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 231 Issued at 2200Z on 18 Aug 2004

IA. Analysis of Solar Active Regions and Activity from 17/2100Z
to 18/2100Z: Solar activity has been high. Region 656 (S15,L=87)
produced significant flare activity, including an X1.8/Sf at 18/1740
UTC. Region 661 (N09E06) exhibited gradual growth in size over the
period, and produced several C-class flares. New Region 662
(N12E28) was numbered today.

IB. Solar Activity Forecast: Solar activity is expected to be low
to moderate. Region 661 may produce C- or M-class flares.

IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z:
The geomagnetic field has been quiet to unsettled.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be quiet to unsettled all three days. Isolated active
conditions are possible on days two and three (20-21 Aug) from minor
effects of a small coronal hole that will reach geoeffective

III. Event Probabilities 19 Aug-21 Aug

  • Class M 40/20/15
  • Class X 10/05/01
  • Proton 05/05/01
  • PCAF green

IV. Penticton 10.7 cm Flux

  • Observed 18 Aug 140
  • Predicted 19 Aug-21 Aug 115/115/110
  • 90 Day Mean 18 Aug 109

V. Geomagnetic A Indices

  • Observed Afr/Ap 17 Aug 009/011
  • Estimated Afr/Ap 18 Aug 009/012
  • Predicted Afr/Ap 19 Aug-21 Aug 008/010-008/015-005/010

VI. Geomagnetic Activity Probabilities 19 Aug-21 Aug

  • A. Middle Latitudes
  • Active 20/30/20
  • Minor storm 01/05/01
  • Major-severe storm 01/01/01

B. High Latitudes

  • Active 30/35/30
  • Minor storm 05/10/05
  • Major-severe storm 01/01/01

SpaceRef staff editor.