Status Report

Joint USAF/NOAA Report of Solar and Geophysical Activity 29 Apr 2005

By SpaceRef Editor
April 29, 2005
Filed under , ,

Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.
Updated 2005 Apr 29 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 119 Issued at 2200Z on 29 Apr 2005

IA. Analysis of Solar Active Regions and Activity from 28/2100Z
to 29/2100Z: Solar activity remained at low levels. Region 756
(S06E17) produced the largest flare of the period, a C1/Sf event
that occurred at 29/2041Z. White light analysis indicates there was
a decrease in sunspot area during the period. This region remains
magnetically complex with a delta structure to the south and another
apparent in the trailing central portion of the large spot. Region
757 (S05W10) underwent a slight increase in sunspot area. The CME
on the eastern limb seen in LASCO imagery appears to be from a back
sided source. No new regions were numbered today.

IB. Solar Activity Forecast: Solar activity is expected to be at
low levels. Region 756 continues to have the potential to produce
an isolated M-class flare.

IIA. Geophysical Activity Summary 28/2100Z to 29/2100Z:
The geomagnetic field was at predominantly quiet to unsettled levels
today. An isolated active period occurred between 29/1800 and 2100Z
due to a solar sector boundary crossing and a sustained southward

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at predominantly quiet to unsettled levels for 29
April with isolated active periods possible in the nighttime
sectors. Active to minor storming conditions are expected on 01 May
due to the anticipated onset of a recurrent high speed coronal hole
stream. Peak solar wind speeds are expected on 02 May which may
lead to isolated periods of major storming.

III. Event Probabilities 30 Apr-02 May

  • Class M 30/30/30
  • Class X 01/01/01
  • Proton 01/01/01
  • PCAF green

IV. Penticton 10.7 cm Flux

  • Observed 29 Apr 105
  • Predicted 30 Apr-02 May 105/105/110
  • 90 Day Mean 29 Apr 091

V. Geomagnetic A Indices

  • Observed Afr/Ap 28 Apr 001/004
  • Estimated Afr/Ap 29 Apr 006/008
  • Predicted Afr/Ap 30 Apr-02 May 010/012-020/020-025/040

VI. Geomagnetic Activity Probabilities 30 Apr-02 May

A. Middle Latitudes

  • Active 20/35/45
  • Minor storm 10/15/25
  • Major-severe storm 05/10/15

B. High Latitudes

  • Active 25/40/40
  • Minor storm 10/20/40
  • Major-severe storm 05/10/20

SpaceRef staff editor.