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

Product: Report of Solar-Geophysical Activity
Issued: 2008 Jan 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 013 Issued at 2200Z on 13 Jan 2008

IA. Analysis of Solar Active Regions and Activity from 12/2100Z to 13/2100Z: Solar activity was very low.

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

IIA. Geophysical Activity Summary 12/2100Z to 13/2100Z: The geomagnetic field was unsettled to active. The high speed stream that began yesterday was briefly interrupted during this period. The solar wind at ACE reached approximately 590 km/s at 2300Z yesterday before declining to 450 km/s from 0800Z until 1400Z. This slack period was accompanied by increased density and decreased temperature. At 1400Z, these trends all reversed and the wind speed leveled off at approximately 550 km/s by 1600Z.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be unsettled to active at mid latitudes with a chance for minor storm periods at high latitudes. Data from STEREO-Behind suggest a continued increase in solar wind speed through day 2 (15 Jan) reflecting the continued influence of the coronal hole high speed stream.

III. Event Probabilities 14 Jan-16 Jan

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

IV. Penticton 10.7 cm Flux

• Observed 13 Jan 075
• Predicted 14 Jan-16 Jan 075/070/070
• 90 Day Mean 13 Jan 073

V. Geomagnetic A Indices

• Observed Afr/Ap 12 Jan 004/009
• Estimated Afr/Ap 13 Jan 014/015
• Predicted Afr/Ap 14 Jan-16 Jan 012/015-012/015-012/012

VI. Geomagnetic Activity Probabilities 14 Jan-16 Jan

A. Middle Latitudes

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

B. High Latitudes

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