Joint USAF/NOAA Report of Solar and Geophysical Activity 11 Feb 2008

Product: Report of Solar-Geophysical Activity
Issued: 2008 Feb 11 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 042 Issued at 2200Z on 11 Feb 2008

IA. Analysis of Solar Active Regions and Activity from 10/2100Z to 11/2100Z: Solar activity was at very low levels. The visible solar disk remained spotless.

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

IIA. Geophysical Activity Summary 10/2100Z to 11/2100Z: The geomagnetic field was at unsettled to active levels due to the continued influence of a recurrent coronal hole high speed stream. Solar wind speed at the ACE spacecraft reached a maximum of approximately 760 km/s at 11/0825Z. At the end of the summary period wind speed had declined to below 680 km/s. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels today.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at mostly unsettled levels throughout the forecast period (12-14 February). Isolated periods of active conditions at middle latitudes and minor storm levels at high latitudes are possible all three days, due to continued effects of the high speed stream.

III. Event Probabilities 12 Feb-14 Feb

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

IV. Penticton 10.7 cm Flux

• Observed 11 Feb 072
• Predicted 12 Feb-14 Feb 072/072/072
• 90 Day Mean 11 Feb 075

V. Geomagnetic A Indices

• Observed Afr/Ap 10 Feb 013/018
• Estimated Afr/Ap 11 Feb 015/020
• Predicted Afr/Ap 12 Feb-14 Feb 012/012-010/012-010/015

VI. Geomagnetic Activity Probabilities 12 Feb-14 Feb

A. Middle Latitudes

• Active 35/35/35
• Minor storm 10/10/10
• Major-severe storm 05/05/05

B. High Latitudes

• Active 40/40/40
• Minor storm 15/15/15
• Major-severe storm 05/05/05