Report of Solar-Geophysical Activity

Issued: 2006 Dec 11 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 345 Issued at 2200Z on 11 Dec 2006

IA. Analysis of Solar Active Regions and Activity from 10/2100Z to 11/2100Z: Solar activity was low. Region 930 (S05W07) produced three C-flares; the largest of which was a C5.7 at 11/0818 UTC.

Region 930, a beta gamma delta magnetic group, has increased slightly in area and developed several new spots in the northwest section of the region.

IB. Solar Activity Forecast: Solar activity is expected to continue at low levels with a chance for M-flares from Region 930.

IIA. Geophysical Activity Summary 10/2100Z to 11/2100Z:

The geomagnetic field was quiet to active. Solar wind speed at ACE has increased slightly to approximately 680 km/s. The greater than 10 MeV proton event that began on 06/1555 UTC continues and is currently around 17 pfu'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 continue to be quiet to unsettled for 12 - 14 December.

Isolated active periods are possible on 12 December. The greater than 10 MeV proton event is expected to cross below 10 pfu's within the next 24 hours.

III. Event Probabilities 12 Dec-14 Dec

Class M 25/25/25

Class X 10/10/10

Proton 60/20/10

PCAF yellow

IV. Penticton 10.7 cm Flux

Observed 11 Dec 092

Predicted 12 Dec-14 Dec 090/090/090

90 Day Mean 11 Dec 081

V. Geomagnetic A Indices

Observed Afr/Ap 10 Dec 008/014

Estimated Afr/Ap 11 Dec 008/015

Predicted Afr/Ap 12 Dec-14 Dec 008/010-005/005-005/005 VI. Geomagnetic Activity Probabilities 12 Dec-14 Dec A. Middle Latitudes

Active 25/15/15

Minor storm 10/05/05

Major-severe storm 01/01/01

B. High Latitudes

Active 30/25/15

Minor storm 15/10/05

Major-severe storm 05/01/01

ALERT: Electron 2MeV Integral Flux exceeded 1000pfu Threshold Reached: 2006 Dec 12 0830 UTC

Station: GOES12

Observed Yesterday: Yes

Yesterday Maximum 2MeV Flux: 3970 pfu