Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 20 Apr 2004

By SpaceRef Editor
April 20, 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 20 2200 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 111 Issued at 2200Z on 20 Apr 2004

IA. Analysis of Solar Active Regions and Activity from 19/2100Z
to 20/2100Z: Solar activity has been very low. Region 596 (S09E31)
remains the largest region on the visible solar disk at 340
millionths of white light coverage. A new region was numbered today
as Region 597 (S06W60).

IB. Solar Activity Forecast: Solar activity is expected to be very
low to low. Region 596 has the potential for continued C-class

IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z:
The geomagnetic field was at quiet to unsettled levels.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be predominately at quiet to unsettled levels. Isolated
periods of active conditions are possible on 23 April due to a
recurrent coronal hole high speed stream.

III. Event Probabilities 21 Apr-23 Apr

  • Class M 20/20/20
  • Class X 05/05/05
  • Proton 01/01/01
  • PCAF green

IV. Penticton 10.7 cm Flux

  • Observed 20 Apr 111
  • Predicted 21 Apr-23 Apr 115/120/120
  • 90 Day Mean 20 Apr 107

V. Geomagnetic A Indices

  • Observed Afr/Ap 19 Apr 004/006
  • Estimated Afr/Ap 20 Apr 005/006
  • Predicted Afr/Ap 21 Apr-23 Apr 005/010-010/010-010/015

VI. Geomagnetic Activity Probabilities 21 Apr-23 Apr

A. Middle Latitudes

  • Active 20/25/25
  • Minor storm 05/05/05
  • Major-severe storm 01/01/01

B. High Latitudes

  • Active 25/25/30
  • Minor storm 10/10/10
  • Major-severe storm 01/01/01

SpaceRef staff editor.