Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 17 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 17 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 230 Issued at 2200Z on 17 Aug 2004

IA. Analysis of Solar Active Regions and Activity from 16/2100Z
to 17/2100Z: Solar activity has been moderate. Region 656 (S14W77)
produced several major flares over the period. The largest flare
was an M2.4 flare at 17/1937 UTC. Region 656 decayed slightly as it
approached the west limb. A large filament erupted in the southeast
quadrant of the solar disk at 0500 UTC, observed on SOHO/EIT
imagery. Shortly thereafter a CME was observed emerging from the
southeast limb at 0630 UTC on LASCO imagery. The CME was not
directed towards Earth. No new regions were numbered today.

IB. Solar Activity Forecast: Solar activity is expected to be
moderate to high. Region 656 may still produce major flare activity
before it crosses the west limb in the next day.

IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z:
Geomagnetic activity has been quiet to unsettled. The greater than 2
MeV electron flux at geosynchronous orbit reached high levels today.

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

III. Event Probabilities 18 Aug-20 Aug

  • Class M 75/50/25
  • Class X 20/10/01
  • Proton 10/05/01
  • PCAF green

IV. Penticton 10.7 cm Flux

  • Observed 17 Aug 135
  • Predicted 18 Aug-20 Aug 125/115/115
  • 90 Day Mean 17 Aug 109

V. Geomagnetic A Indices

  • Observed Afr/Ap 16 Aug 005/008
  • Estimated Afr/Ap 17 Aug 008/009
  • Predicted Afr/Ap 18 Aug-20 Aug 008/008-005/008-008/015

VI. Geomagnetic Activity Probabilities 18 Aug-20 Aug

A. Middle Latitudes

  • Active 20/20/30
  • Minor storm 05/01/01
  • Major-severe storm 01/01/01

B. High Latitudes

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

SpaceRef staff editor.