Joint USAF/NOAA Report of Solar and Geophysical Activity 20 Feb 2006

Product: Report of Solar-Geophysical Activity
Issued: 2006 Feb 20 2200 UTC
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 051 Issued at 2200Z on 20 Feb 2006

IA. Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity was at very low levels. No significant activity was noted again today. The visible disk remains spotless.

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

IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic field ranged from quiet to major storm levels. An enhancement of the solar wind speed occurred near 20/1000Z (400 km/sec to 550/ km/sec) due to a geoeffective coronal hole. A brief period of major storm levels occurred at higher latitudes between 20/1500 and 1800Z.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on 21 and 22 February, due to a favorably positioned coronal hole. Quiet to unsettled levels are expected on 23 February as the coronal hole wanes.

III. Event Probabilities 21 Feb-23 Feb

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

IV. Penticton 10.7 cm Flux

• Observed 20 Feb 076
• Predicted 21 Feb-23 Feb 075/075/075
• 90 Day Mean 20 Feb 085

V. Geomagnetic A Indices

• Observed Afr/Ap 19 Feb 005/006
• Estimated Afr/Ap 20 Feb 015/020
• Predicted Afr/Ap 21 Feb-23 Feb 010/015-012/020-008/015

VI. Geomagnetic Activity Probabilities 21 Feb-23 Feb

A. Middle Latitudes

• Active 20/25/20
• Minor storm 05/10/05
• Major-severe storm 01/05/01

B. High Latitudes

• Active 30/35/30
• Minor storm 15/25/15
• Major-severe storm 05/15/05