Joint USAF/NOAA Report of Solar and Geophysical Activity 25 Apr 2008

Product: Report of Solar-Geophysical Activity
Issued: 2008 Apr 25 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 116 Issued at 2200Z on 25 Apr 2008

IA. Analysis of Solar Active Regions and Activity from 24/2100Z to 25/2100Z: Solar activity was very low. The disk was spotless. A nine degree filament, located at S10W18, disappeared between 24/1633Z and 25/0524Z.

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

IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z: The geomagnetic field was at quiet to unsettled levels. The greater than 2 MeV electron flux at geosynchronous orbit was at high levels again today.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at predominately quiet levels for the next three days (26 – 28 April).

III. Event Probabilities 26 Apr-28 Apr

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

IV. Penticton 10.7 cm Flux

• Observed 25 Apr 070
• Predicted 26 Apr-28 Apr 070/070/070
• 90 Day Mean 25 Apr 072

V. Geomagnetic A Indices

• Observed Afr/Ap 24 Apr 013/018
• Estimated Afr/Ap 25 Apr 008/012
• Predicted Afr/Ap 26 Apr-28 Apr 005/008-005/005-005/005

VI. Geomagnetic Activity Probabilities 26 Apr-28 Apr

A. Middle Latitudes

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

B. High Latitudes

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