Report of Solar-Geophysical Activity

Issued: 2005 Dec 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 351 Issued at 2200Z on 17 Dec 2005 IA. Analysis of Solar Active Regions and Activity from 16/2100Z to 17/2100Z: Solar activity was at low levels again today. Region

836 (S10W91) produced a C1 x-ray flare at 16/2103Z, as this region began to rotate off the west limb. An associated CME was seen in LASCO imagery that appears to have a westward component, not expecting any geoeffective conditions. Region 834 (S07W32) has shown growth during the period and has developed into a beta-gamma magnetic sunspot classification. Region 837 (S10E22) is a newly numbered four spot, Dso beta group.

IB. Solar Activity Forecast: Solar activity is expected to be at very low to low levels. Region 834 has the potential to produced C-class flares.

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

The geomagnetic field was at quiet top unsettled levels today.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels throughout the period.

III. Event Probabilities 18 Dec-20 Dec

Class M 10/15/15

Class X 01/01/01

Proton 01/01/01

PCAF green

IV. Penticton 10.7 cm Flux

Observed 17 Dec 085

Predicted 18 Dec-20 Dec 085/085/085

90 Day Mean 17 Dec 083

V. Geomagnetic A Indices

Observed Afr/Ap 16 Dec 003/005

Estimated Afr/Ap 17 Dec 005/005

Predicted Afr/Ap 18 Dec-20 Dec 004/008-004/005-004/008 VI. Geomagnetic Activity Probabilities 18 Dec-20 Dec A. Middle Latitudes

Active 15/15/15

Minor storm 01/01/01

Major-severe storm 01/01/01

B. High Latitudes

Active 20/15/20

Minor storm 05/05/05

Major-severe storm 01/01/01