Joint USAF/NOAA Report of Solar and Geophysical Activity 27 Sep 2008

Product: Report of Solar-Geophysical Activity
Issued: 2008 Sep 27 2200 UTC
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Weather Prediction Center and the U.S. Air Force.

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 271 Issued at 2200Z on 27 Sep 2008

IA. Analysis of Solar Active Regions and Activity from 26/2100Z to 27/2100Z: Solar activity was at very low levels. The visible solar disk was spotless.

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

IIA. Geophysical Activity Summary 26/2100Z to 27/2100Z: The geomagnetic field was at quiet levels.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at mostly quiet levels for the next three days (28 to 30 September). There is a chance for unsettled periods on days two and three due to a recurrent solar wind stream expected to begin influencing the geomagnetic field. On day three there is a slight chance for an isolated active period at high latitudes.

III. Event Probabilities 28 Sep-30 Sep

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

IV. Penticton 10.7 cm Flux

• Observed 27 Sep 067
• Predicted 28 Sep-30 Sep 066/066/066
• 90 Day Mean 27 Sep 066

V. Geomagnetic A Indices

• Observed Afr/Ap 26 Sep 002/004
• Estimated Afr/Ap 27 Sep 003/005
• Predicted Afr/Ap 28 Sep-30 Sep 005/005-008/008-008/010

VI. Geomagnetic Activity Probabilities 28 Sep-30 Sep

A. Middle Latitudes

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

B. High Latitudes

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