Report of Solar-Geophysical Activity

Report of Solar-Geophysical Activity

Issued: 2006 Dec 18 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 352 Issued at 2200Z on 18 Dec 2006

IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: Solar activity was at very low levels. The visible disk is void of sunspots. No new regions were numbered today.

IB. Solar Activity Forecast: Solar activity is expected to be at very low levels.

IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z:

The geomagnetic field was at quiet to unsettled levels. The greater than 2 MeV electrons at geosynchronous orbit reached high levels again today.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on 19 December. A recurrent high speed coronal hole stream is expected to become geoeffective on 20 December with active to minor storm conditions likely to result and persist through the remainder of the forecast period. Brief isolated major storm periods may occur on 21 December.

III. Event Probabilities 19 Dec-21 Dec

Class M 05/01/01

Class X 01/01/01

Proton 05/01/01

PCAF green

IV. Penticton 10.7 cm Flux

Observed 18 Dec 075

Predicted 19 Dec-21 Dec 075/075/075

90 Day Mean 18 Dec 081

V. Geomagnetic A Indices

Observed Afr/Ap 17 Dec 003/004

Estimated Afr/Ap 18 Dec 004/005

Predicted Afr/Ap 19 Dec-21 Dec 004/005-010/020-015/030 VI. Geomagnetic Activity Probabilities 19 Dec-21 Dec A. Middle Latitudes

Active 15/20/30

Minor storm 05/10/15

Major-severe storm 01/05/05

B. High Latitudes

Active 20/40/45

Minor storm 05/15/25

Major-severe storm 01/10/20

ALERT: Electron 2MeV Integral Flux exceeded 1000pfu Threshold Reached: 2006 Dec 19 0515 UTC

Station: GOES12

Observed Yesterday: Yes

Yesterday Maximum 2MeV Flux: 38300 pfu

For current space weather conditions please refer to:

http://www.sec.noaa.gov/SWN/

http://www.sec.noaa.gov/alerts/

NOAA Space Weather Scale descriptions can be found at www.sec.noaa.gov/NOAAscales