Joint USAF/NOAA Report of Solar and Geophysical Activity 13 Feb 2008

Product: Report of Solar-Geophysical Activity
Issued: 2008 Feb 13 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 044 Issued at 2200Z on 13 Feb 2008

IA. Analysis of Solar Active Regions and Activity from 12/2100Z to 13/2100Z: 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 12/2100Z to 13/2100Z: The geomagnetic field was at quiet to active levels, due to continued effects from a coronal hole high speed stream. Solar wind speed at the ACE spacecraft reached a maximum of approximately 690 km/s at 13/1110Z. By the end of the summary period wind speed had declined to around 620 km/s. The greater than 2 MeV electron flux reached high levels again today.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at mostly unsettled levels, with possible isolated active conditions on all three days (14 – 16 February), due to continued influence from the coronal hole.

III. Event Probabilities 14 Feb-16 Feb

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

IV. Penticton 10.7 cm Flux

• Observed 13 Feb 071
• Predicted 14 Feb-16 Feb 072/072/072
• 90 Day Mean 13 Feb 075

V. Geomagnetic A Indices

• Observed Afr/Ap 12 Feb 006/011
• Estimated Afr/Ap 13 Feb 010/015
• Predicted Afr/Ap 14 Feb-16 Feb 010/012-010/010-008/010

VI. Geomagnetic Activity Probabilities 14 Feb-16 Feb

A. Middle Latitudes

• Active 35/35/30
• Minor storm 10/10/05
• Major-severe storm 05/05/01

B. High Latitudes

• Active 40/35/35
• Minor storm 15/10/10
• Major-severe storm 05/05/05