Joint USAF/NOAA Report of Solar and Geophysical Activity 24 Jul 2005

Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.
Updated 2005 Jul 24 2204 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 205 Issued at 2200Z on 24 Jul 2005

IA. Analysis of Solar Active Regions and Activity from 23/2100Z
to 24/2100Z: Solar activity has been very low. Region 791 (N13E36)
remains the only numbered spot group on the solar disk. This region
has shown a slight growth in area and maintains a simple beta
magnetic configuration. Several CME’s were observed by LASCO
imagery over the past 24 hours. Analysis show these were backside
events and not Earth directed. One appears to be a halo CME first
observed by C2 imagery at 24/1354 UTC with an associated Type II
radio sweep.

IB. Solar Activity Forecast: Solar activity is expected to be very
low to low. There is a chance for an isolated C-class flare from
Region 791.

IIA. Geophysical Activity Summary 23/2100Z to 24/2100Z:
The geomagnetic field has been quiet to unsettled. The greater than
2 MeV electron flux at geosynchronous orbit was at high levels.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at quiet to unsettled levels.

III. Event Probabilities 25 Jul-27 Jul

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

IV. Penticton 10.7 cm Flux

• Observed 24 Jul 080
• Predicted 25 Jul-27 Jul 085/085/090
• 90 Day Mean 24 Jul 097

V. Geomagnetic A Indices

• Observed Afr/Ap 23 Jul 002/005
• Estimated Afr/Ap 24 Jul 005/005
• Predicted Afr/Ap 25 Jul-27 Jul 005/008-005/005-005/008

VI. Geomagnetic Activity Probabilities 25 Jul-27 Jul

A. Middle Latitudes

• Active 15/15/15
• Minor storm 05/05/05
• Major-severe storm 01/01/01

B. High Latitudes

• Active 20/15/20
• Minor storm 10/05/05
• Major-severe storm 01/01/01