Joint USAF/NOAA Report of Solar and Geophysical Activity 28 Sep 2006

Product: Report of Solar-Geophysical Activity
Issued: 2006 Sep 28 2200 UTC
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 271 Issued at 2200Z on 28 Sep 2006

IA. Analysis of Solar Active Regions and Activity from 27/2100Z to 28/2100Z: Solar activity continues at very low levels. An eruptive prominence was observed at S31 on the west limb during the middle of the period. Three new regions were numbered today, Regions 912 (N06E65), 913 (S18E68), and 914 (S07E75).

IB. Solar Activity Forecast: Solar activity is expected to remain at very low levels.

IIA. Geophysical Activity Summary 27/2100Z to 28/2100Z: The geomagnetic field was at quiet levels. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels again today.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on 29 September. Active to minor storm conditions are expected to begin late in the period on 30 September due to a recurrent coronal hole. The elevated field conditions should persist into 01 October.

III. Event Probabilities 29 Sep-01 Oct

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

IV. Penticton 10.7 cm Flux

• Observed 28 Sep 073
• Predicted 29 Sep-01 Oct 075/075/080
• 90 Day Mean 28 Sep 077

V. Geomagnetic A Indices

• Observed Afr/Ap 27 Sep 002/004
• Estimated Afr/Ap 28 Sep 002/005
• Predicted Afr/Ap 29 Sep-01 Oct 006/008-015/015-015/020

VI. Geomagnetic Activity Probabilities 29 Sep-01 Oct A. Middle Latitudes

• Active 15/25/25
• Minor storm 05/15/15
• Major-severe storm 01/05/05

B. High Latitudes

• Active 20/30/40
• Minor storm 05/15/20
• Major-severe storm 01/05/10