Report of Solar-Geophysical Activity

Issued: 2005 Dec 04 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 338 Issued at 2200Z on 04 Dec 2005 IA. Analysis of Solar Active Regions and Activity from 03/2100Z to 04/2100Z: Solar activity was low. Region 826 (S04W21) produced the only C-flare of the period; a C2.1 at 04/0945 UTC. New Region

831 (S06W07) was numbered today.

IB. Solar Activity Forecast: Solar activity is expected to be very low to low with a chance for an isolated M-flare from Region 826.

IIA. Geophysical Activity Summary 03/2100Z to 04/2100Z:

The geomagnetic field was quiet to unsettled. Solar wind speed at ACE decreased from approximately 680 km/s to 560 km/s. The greater than

2 MeV electron flux at geosynchronous orbit reached high levels again today.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to active with minor storm periods possible on

05 December due to transient flow from the 02 December CME. On 06 December quiet to unsettled conditions are expected. On 07 December, quiet to active conditions are expected.

III. Event Probabilities 05 Dec-07 Dec

Class M 35/30/25

Class X 10/05/05

Proton 10/05/05

PCAF green

IV. Penticton 10.7 cm Flux

Observed 04 Dec 095

Predicted 05 Dec-07 Dec 095/095/095

90 Day Mean 04 Dec 086

V. Geomagnetic A Indices

Observed Afr/Ap 03 Dec 009/011

Estimated Afr/Ap 04 Dec 006/007

Predicted Afr/Ap 05 Dec-07 Dec 012/015-010/012-010/015 VI. Geomagnetic Activity Probabilities 05 Dec-07 Dec A. Middle Latitudes

Active 30/25/25

Minor storm 15/10/10

Major-severe storm 05/01/01

B. High Latitudes

Active 35/30/35

Minor storm 15/15/15

Major-severe storm 05/05/05