Report of Solar-Geophysical Activity

Issued: 2006 Apr 17 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 107 Issued at 2200Z on 17 Apr 2006 IA. Analysis of Solar Active Regions and Activity from 16/2100Z to 17/2100Z: Solar activity was very low.

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

IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z:

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

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

III. Event Probabilities 18 Apr-20 Apr

Class M 01/01/01

Class X 01/01/01

Proton 01/01/01

PCAF green

IV. Penticton 10.7 cm Flux

Observed 17 Apr 078

Predicted 18 Apr-20 Apr 080/080/080

90 Day Mean 17 Apr 078

V. Geomagnetic A Indices

Observed Afr/Ap 16 Apr 008/010

Estimated Afr/Ap 17 Apr 004/005

Predicted Afr/Ap 18 Apr-20 Apr 005/008-005/008-005/008 VI. Geomagnetic Activity Probabilities 18 Apr-20 Apr A. Middle Latitudes

Active 10/10/10

Minor storm 05/05/05

Major-severe storm 01/01/01

B. High Latitudes

Active 20/20/20

Minor storm 05/05/05

Major-severe storm 01/01/01