Report of Solar-Geophysical Activity

Issued: 2006 Apr 12 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 102 Issued at 2200Z on 12 Apr 2006 IA. Analysis of Solar Active Regions and Activity from 11/2100Z to 12/2100Z: Solar activity was very low. Region 873 (S04E35) has developed in complexity and is now a Dai class spot group. All other regions have remained quiescent.

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

IIA. Geophysical Activity Summary 11/2100Z to 12/2100Z:

The geomagnetic field was quiet. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels today.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to unsettled on 13 April. Unsettled to active conditions with possible periods of minor storming are expected on

14 April, increasing to mostly active with possible minor to major storming on 15 April due to a recurrent coronal hole high speed stream.

III. Event Probabilities 13 Apr-15 Apr

Class M 05/05/05

Class X 01/01/01

Proton 01/01/01

PCAF green

IV. Penticton 10.7 cm Flux

Observed 12 Apr 081

Predicted 13 Apr-15 Apr 080/080/080

90 Day Mean 12 Apr 080

V. Geomagnetic A Indices

Observed Afr/Ap 11 Apr 003/005

Estimated Afr/Ap 12 Apr 002/005

Predicted Afr/Ap 13 Apr-15 Apr 005/010-015/025-020/040 VI. Geomagnetic Activity Probabilities 13 Apr-15 Apr A. Middle Latitudes

Active 15/35/40

Minor storm 01/15/20

Major-severe storm 01/05/05

B. High Latitudes

Active 20/35/20

Minor storm 05/30/40

Major-severe storm 01/15/20