Joint USAF/NOAA Report of Solar and Geophysical Activity 26 Oct 2008

Product: Report of Solar-Geophysical Activity
Issued: 2008 Oct 26 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 300 Issued at 2200Z on 26 Oct 2008

IA. Analysis of Solar Active Regions and Activity from 25/2100Z to 26/2100Z: Solar activity was very low. The visible solar disk remains spotless.

IB. Solar Activity Forecast: Solar activity is expected to be very low.

IIA. Geophysical Activity Summary 25/2100Z to 26/2100Z: The geomagnetic field was at quiet levels. Solar wind observations from the ACE spacecraft show a steady increase in velocity from around 290 km/s to 390 km/s between 26/0400Z to 26/0800Z.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be mostly quiet for 27 October. Quiet to unsettled levels with isolated active conditions are expected for 28 October. Predominately unsettled levels with isolated active periods, and possible isolated minor storm conditions at high latitudes, are forecast for 29 October. The increase in activity is due to a recurrent coronal hole high speed stream rotating into a geoeffective position.

III. Event Probabilities 27 Oct-29 Oct

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

IV. Penticton 10.7 cm Flux

• Observed 26 Oct 067
• Predicted 27 Oct-29 Oct 067/067/067
• 90 Day Mean 26 Oct 067

V. Geomagnetic A Indices

• Observed Afr/Ap 25 Oct 001/001
• Estimated Afr/Ap 26 Oct 002/005
• Predicted Afr/Ap 27 Oct-29 Oct 005/005-007/008-010/012

VI. Geomagnetic Activity Probabilities 27 Oct-29 Oct

A. Middle Latitudes

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

B. High Latitudes

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