Report of Solar-Geophysical Activity

Issued: 2005 Dec 01 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 335 Issued at 2200Z on 01 Dec 2005 IA. Analysis of Solar Active Regions and Activity from 30/2100Z to 01/2100Z: Solar activity decreased to low levels today. Region

826 (S02E22) continued to show explosive growth in both magnetic complexity and sunspot area. Magnetic analysis shows a strong east-west neutral line through the delta spot in the geometric center of the sunspot cluster. Region 826 produced multiple B and C-class flares during the period, the largest was a C6 x-ray flare occurring at 01/0837Z. Region 824 (S14W75) underwent little change since yesterday but did produce a C2 x-ray flare at 01/0238Z, which had an associated Type II radio sweep with an estimated shock velocity of 487 km/sec. Region 828 (S04E42) is a rapidly emerging DSO beta group that was numbered today.

IB. Solar Activity Forecast: Solar activity is expected to be at low to moderate levels. Region 826 has the potential to produce M-class flare activity.

IIA. Geophysical Activity Summary 30/2100Z to 01/2100Z:

The geomagnetic field was at quiet to active levels. The elevated conditions are due to a recurrent high speed coronal hole stream.

The solar wind speed has ranged between 650 and 750 km/sec throughout most of the period.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at predominantly quiet to unsettled levels with isolated active conditions on 02 December due to a favorability positioned coronal hole. Conditions should decrease to quiet to unsettled levels on 03 and 04 December.

III. Event Probabilities 02 Dec-04 Dec

Class M 50/50/50

Class X 15/15/15

Proton 05/05/05

PCAF green

IV. Penticton 10.7 cm Flux

Observed 01 Dec 098

Predicted 02 Dec-04 Dec 100/105/105

90 Day Mean 01 Dec 085

V. Geomagnetic A Indices

Observed Afr/Ap 30 Nov 009/010

Estimated Afr/Ap 01 Dec 010/012

Predicted Afr/Ap 02 Dec-04 Dec 012/015-010/012-005/008 VI. Geomagnetic Activity Probabilities 02 Dec-04 Dec A. Middle Latitudes

Active 25/20/15

Minor storm 10/05/01

Major-severe storm 05/01/01

B. High Latitudes

Active 30/25/20

Minor storm 15/10/05

Major-severe storm 10/05/01