Joint USAF/NOAA Report of Solar and Geophysical Activity 18 Feb 2008

Product: Report of Solar-Geophysical Activity
Issued: 2008 Feb 18 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 049 Issued at 2200Z on 18 Feb 2008

IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: 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 17/2100Z to 18/2100Z: The geomagnetic field was at mostly quiet to unsettled levels. An isolated active period was observed from 18/0900 – 1200Z due to sustained southward Bz (-5nT maximum) and elevated solar wind speed. Beginning at approximately 18/0600Z wind speed began a gradual rise from around 450 km/s to end the summary period at about 600 km/s. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels for the forecast period (19 – 21 February).

III. Event Probabilities 19 Feb-21 Feb

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

IV. Penticton 10.7 cm Flux

• Observed 18 Feb 071
• Predicted 19 Feb-21 Feb 070/070/070
• 90 Day Mean 18 Feb 075

V. Geomagnetic A Indices

• Observed Afr/Ap 17 Feb 003/005
• Estimated Afr/Ap 18 Feb 008/010
• Predicted Afr/Ap 19 Feb-21 Feb 008/008-005/005-008/008

VI. Geomagnetic Activity Probabilities 19 Feb-21 Feb

A. Middle Latitudes

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

B. High Latitudes

• Active 15/10/15
• Minor storm 10/05/10
• Major-severe storm 05/01/05