Joint USAF/NOAA Report of Solar and Geophysical Activity 12 May 2008

Product: Report of Solar-Geophysical Activity
Issued: 2008 May 12 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 133 Issued at 2200Z on 12 May 2008

IA. Analysis of Solar Active Regions and Activity from 11/2100Z to 12/2100Z: Solar activity was very low. There have been several low-level flares observed during the period. The most probable source is an active region located just behind the east limb.

IB. Solar Activity Forecast: Solar activity is expected to be very low. There is a slight chance for an isolated C-class event from the new active region making its way onto the solar disk from behind the east limb.

IIA. Geophysical Activity Summary 11/2100Z to 12/2100Z: The geomagnetic field has been at quiet levels. The greater than 2 MeV electron flux at geosynchronous orbit was at high levels.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled conditions on day one (13 May) of the period due to the influence of a recurrent coronal hole high speed stream. Predominately quiet levels are expected to return for days two and three (14-15 May).

III. Event Probabilities 13 May-15 May

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

IV. Penticton 10.7 cm Flux

• Observed 12 May 068
• Predicted 13 May-15 May 070/070/070
• 90 Day Mean 12 May 071

V. Geomagnetic A Indices

• Observed Afr/Ap 11 May 003/003
• Estimated Afr/Ap 12 May 003/003
• Predicted Afr/Ap 13 May-15 May 008/008-005/005-005/005

VI. Geomagnetic Activity Probabilities 13 May-15 May

A. Middle Latitudes

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

B. High Latitudes

• Active 15/10/10
• Minor storm 05/05/05
• Major-severe storm 01/11/01