Report of Solar-Geophysical Activity

Issued: 2006 Apr 25 2200 UTC

Prepared jointly by the U.S. Dept. of Commerce, NOAA, # Space Environment Center and the U.S. Air Force.

Joint USAF/NOAA Report of Solar and Geophysical Activity SDF Number 115 Issued at 2200Z on 25 Apr 2006 IA. Analysis of Solar Active Regions and Activity from 24/2100Z to 25/2100Z: Solar activity was low. Region 875 (S10E46), a beta gamma delta magnetic group, produced a long duration C1 flare at

25/0726 UTC. An associated CME was observed in LASCO imagery off the east limb with a speed of approximately 520 Km/s. This CME is not expected to be geoeffective.

IB. Solar Activity Forecast: Solar activity is expected to be very low to low. An isolated M-class flare is possible from Region 875.

IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z:

The geomagnetic field was mostly quiet.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be mostly quiet.

III. Event Probabilities 26 Apr-28 Apr

Class M 15/15/15

Class X 05/05/05

Proton 01/01/01

PCAF green

IV. Penticton 10.7 cm Flux

Observed 25 Apr 095

Predicted 26 Apr-28 Apr 095/095/095

90 Day Mean 25 Apr 079

V. Geomagnetic A Indices

Observed Afr/Ap 24 Apr 004/007

Estimated Afr/Ap 25 Apr 005/005

Predicted Afr/Ap 26 Apr-28 Apr 005/005-005/005-003/005 VI. Geomagnetic Activity Probabilities 26 Apr-28 Apr A. Middle Latitudes

Active 15/15/10

Minor storm 05/05/05

Major-severe storm 01/01/01

B. High Latitudes

Active 15/15/15

Minor storm 05/05/05

Major-severe storm 01/01/01