Joint USAF/NOAA Report of Solar and Geophysical Activity 21 Feb 2009

Product: Report of Solar-Geophysical Activity
Issued: 2009 Feb 21 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 052 Issued at 2200Z on 21 Feb 2009

IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: Solar activity was very low. No flares were observed during the past 24 hours. The visible solar disk remains spotless.

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

IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic field was at quiet levels with one period of unsettled conditions at mid-latitude. Solar wind speeds have increased steadily through the period from around 340 km/s to 430 km/s.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels with isolated active conditions on 22 February due to a recurrent coronal hole. Predominately quiet conditions are expected on 23-24 February as the coronal hole high speed stream subsides.

III. Event Probabilities 22 Feb-24 Feb

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

IV. Penticton 10.7 cm Flux

• Observed 21 Feb 071
• Predicted 22 Feb-24 Feb 070/070/070
• 90 Day Mean 21 Feb 070

V. Geomagnetic A Indices

• Observed Afr/Ap 20 Feb 003/003
• Estimated Afr/Ap 21 Feb 003/007
• Predicted Afr/Ap 22 Feb-24 Feb 008/009-005/005-005/005

VI. Geomagnetic Activity Probabilities 22 Feb-24 Feb

A. Middle Latitudes

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

B. High Latitudes

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