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

Product: Report of Solar-Geophysical Activity
Issued: 2008 Jan 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 018 Issued at 2200Z on 18 Jan 2008

IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: Solar activity was very low. The visible disk remains spotless.

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

IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field was quiet to unsettled with isolated active periods at middle latitudes. Solar wind speed remains elevated at greater than 600 km/s due to the continued influence of a geoeffective coronal hole high speed stream. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels again today.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to unsettled with the continued possibility of isolated active periods for 19 January. The geomagnetic field should abate to quiet to unsettled for 20 January and then quiet for 21 January as the high speed stream rotates from its geoeffective position.

III. Event Probabilities 19 Jan-21 Jan

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

IV. Penticton 10.7 cm Flux

• Observed 18 Jan 071
• Predicted 19 Jan-21 Jan 070/070/070
• 90 Day Mean 18 Jan 074

V. Geomagnetic A Indices

• Observed Afr/Ap 17 Jan 007/010
• Estimated Afr/Ap 18 Jan 010/010
• Predicted Afr/Ap 19 Jan-21 Jan 008/008-005/005-005/005

VI. Geomagnetic Activity Probabilities 19 Jan-21 Jan

A. Middle Latitudes

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

B. High Latitudes

• Active 25/25/15
• Minor storm 15/15/10
• Major-severe storm 01/01/01