Joint USAF/NOAA Report of Solar and Geophysical Activity 10 Feb 2008

Product: Report of Solar-Geophysical Activity
Issued: 2008 Feb 10 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 041 Issued at 2200Z on 10 Feb 2008

IA. Analysis of Solar Active Regions and Activity from 09/2100Z to 10/2100Z: Solar activity was very low. The visible disk was spotless.

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

IIA. Geophysical Activity Summary 09/2100Z to 10/2100Z: The geomagnetic field ranged from quiet to minor storm levels. The increase in activity is attributable to the arrival of a high speed stream. Solar wind speed increased from approximately 450 km/s to approximately 650 km/s. 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 active levels with isolated minor storm periods at high latitudes on day 1 (11 February) due to a recurrent coronal hole high-speed stream. Activity is expected to be at quiet to unsettled levels on days 2 and 3 (12-13 February) as the effects of the coronal hole high-speed stream wane.

III. Event Probabilities 11 Feb-13 Feb

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

IV. Penticton 10.7 cm Flux

• Observed 10 Feb 073
• Predicted 11 Feb-13 Feb 070/070/070
• 90 Day Mean 10 Feb 075

V. Geomagnetic A Indices

• Observed Afr/Ap 09 Feb 002/002
• Estimated Afr/Ap 10 Feb 015/020
• Predicted Afr/Ap 11 Feb-13 Feb 015/015-010/010-010/015

VI. Geomagnetic Activity Probabilities 11 Feb-13 Feb

A. Middle Latitudes

• Active 40/25/25
• Minor storm 10/05/05
• Major-severe storm 01/01/01

B. High Latitudes

• Active 45/30/40
• Minor storm 15/10/15
• Major-severe storm 01/01/01