Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 28 Apr 2004

By SpaceRef Editor
April 28, 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 28 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 119 Issued at 2200Z on 28 Apr 2004

IA. Analysis of Solar Active Regions and Activity from 27/2100Z
to 28/2100Z: Solar activity has been very low. Region 596 (S08W79)
was stable in size and Region 599 (N15W11) exhibited gradual decay.
No new regions were numbered today.

IB. Solar Activity Forecast: Solar activity is expected to be very
low to low. Isolated C-class flares are possible from Regions 596
and 599.

IIA. Geophysical Activity Summary 27/2100Z to 28/2100Z:
The geomagnetic field has been quiet to active. A rise in solar wind
speed from 400 to 550 km/s was observed late in the period which may
have given rise to isolated active geomagnetic conditions.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at quiet to unsettled levels, with isolated active to
minor storm conditions possible on day two (30 April). Activity
should return to quiet to unsettled levels on 1 May.

III. Event Probabilities 29 Apr-01 May

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

IV. Penticton 10.7 cm Flux

  • Observed 28 Apr 090
  • Predicted 29 Apr-01 May 090/090/090
  • 90 Day Mean 28 Apr 106

V. Geomagnetic A Indices

  • Observed Afr/Ap 27 Apr 005/005
  • Estimated Afr/Ap 28 Apr 005/007
  • Predicted Afr/Ap 29 Apr-01 May 005/008-010/020-005/010

VI. Geomagnetic Activity Probabilities 29 Apr-01 May

A. Middle Latitudes

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

B. High Latitudes

  • Active 30/30/30
  • Minor storm 15/20/20
  • Major-severe storm 05/10/05

SpaceRef staff editor.