Report of Solar-Geophysical Activity

Issued: 2006 Apr 27 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 117 Issued at 2200Z on 27 Apr 2006 IA. Analysis of Solar Active Regions and Activity from 26/2100Z to 27/2100Z: Solar activity was high. Region 875 (S11E20) produced an M7/1N flare at 27/1552 UTC. The flare was highly impulsive; no associated radio sweeps were observed and no proton events are expected.

IB. Solar Activity Forecast: Solar activity is expected to be low to moderate. Further M-class flares are possible from Region 875.

IIA. Geophysical Activity Summary 26/2100Z to 27/2100Z:

The geomagnetic field has been quiet to unsettled.

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

III. Event Probabilities 28 Apr-30 Apr

Class M 30/30/30

Class X 05/05/05

Proton 01/01/01

PCAF green

IV. Penticton 10.7 cm Flux

Observed 27 Apr 101

Predicted 28 Apr-30 Apr 100/100/100

90 Day Mean 27 Apr 080

V. Geomagnetic A Indices

Observed Afr/Ap 26 Apr 002/005

Estimated Afr/Ap 27 Apr 004/005

Predicted Afr/Ap 28 Apr-30 Apr 003/005-003/005-003/005 VI. Geomagnetic Activity Probabilities 28 Apr-30 Apr A. Middle Latitudes

Active 10/10/10

Minor storm 01/01/01

Major-severe storm 01/01/01

B. High Latitudes

Active 15/15/15

Minor storm 05/05/05

Major-severe storm 01/01/01