Report of Solar-Geophysical Activity

Issued: 2006 Apr 13 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 103 Issued at 2200Z on 13 Apr 2006 IA. Analysis of Solar Active Regions and Activity from 12/2100Z to 13/2100Z: Solar activity was very low. Only a few B-class flares occurred. All sunspot regions were relatively small and simple.

IB. Solar Activity Forecast: Solar activity is expected to be very low to low. A small C-class flare is possible.

IIA. Geophysical Activity Summary 12/2100Z to 13/2100Z:

The geomagnetic field ranged from quiet to active. Solar wind observations suggest the onset of a coronal hole high speed stream as the likely cause of the activity.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be mostly unsettled to active with the possibility of isolated storm conditions as the high-speed stream induced activity continues.

III. Event Probabilities 14 Apr-16 Apr

Class M 01/01/01

Class X 01/01/01

Proton 01/01/01

PCAF green

IV. Penticton 10.7 cm Flux

Observed 13 Apr 080

Predicted 14 Apr-16 Apr 080/080/080

90 Day Mean 13 Apr 080

V. Geomagnetic A Indices

Observed Afr/Ap 12 Apr 001/002

Estimated Afr/Ap 13 Apr 015/018

Predicted Afr/Ap 14 Apr-16 Apr 020/030-015/040-010/025 VI. Geomagnetic Activity Probabilities 14 Apr-16 Apr A. Middle Latitudes

Active 30/30/30

Minor storm 10/10/05

Major-severe storm 05/05/05

B. High Latitudes

Active 40/40/40

Minor storm 15/15/15

Major-severe storm 10/10/10