Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 27 Apr 2004

By SpaceRef Editor
April 27, 2004
Filed under , ,

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

Updated 2004 Apr 27 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 118 Issued at 2200Z on 27 Apr 2004

IA. Analysis of Solar Active Regions and Activity from 26/2100Z
to 27/2100Z: Solar activity has been low. Region 599 (N14E02)
produced a C3.1 flare at 27/0723 UTC with an associated Type II
flare with a speed of 732 km/s. LASCO imagery was not available, but
EIT imagery indicated significant dimming in the area of Region 599,
suggesting the existence of a CME. No significant development was
observed on regions on the visible disk, and no new regions were

IB. Solar Activity Forecast: Solar activity is expected to be very
low to low. Region 599 has the potential to produce C- and isolated
M-class flares.

IIA. Geophysical Activity Summary 26/2100Z to 27/2100Z:
The geomagnetic field has been quiet to unsettled.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be quiet to unsettled, with isolated active or minor
storm conditions possible on day three (30 April) from a CME
associated with the C3 flare observed today.

III. Event Probabilities 28 Apr-30 Apr

  • Class M 10/10/10
  • Class X 01/01/01
  • Proton 01/01/01
  • PCAF green

IV. Penticton 10.7 cm Flux

  • Observed 27 Apr 095
  • Predicted 28 Apr-30 Apr 095/090/090
  • 90 Day Mean 27 Apr 107

V. Geomagnetic A Indices

  • Observed Afr/Ap 26 Apr 004/007
  • Estimated Afr/Ap 27 Apr 005/007
  • Predicted Afr/Ap 28 Apr-30 Apr 005/008-005/008-010/020

VI. Geomagnetic Activity Probabilities 28 Apr-30 Apr

A. Middle Latitudes

  • Active 15/15/20
  • Minor storm 10/10/15
  • Major-severe storm 05/05/10

B. High Latitudes

  • Active 20/20/25
  • Minor storm 15/15/20
  • Major-severe storm 10/05/10

SpaceRef staff editor.