Joint USAF/NOAA Report of Solar and Geophysical Activity 16 Dec 2007

Product: Report of Solar-Geophysical Activity
Issued: 2007 Dec 16 2200 UTC
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Weather Prediction Center and the U.S. Air Force.

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 350 Issued at 2200Z on 16 Dec 2007

IA. Analysis of Solar Active Regions and Activity from 15/2100Z to 16/2100Z: Solar activity was low to very low. Region 978 (S10W65) decreased in both size and number of spots.

IB. Solar Activity Forecast: Solar activity is expected to be very low. A slight chance for a C-class flare remains.

IIA. Geophysical Activity Summary 15/2100Z to 16/2100Z: The geomagnetic field was quiet.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to become unsettled to active by the afternoon of December 17th as a recurrent coronal hole high speed stream becomes geoeffective. Isolated minor storm periods at mid latitudes, and isolated major storms at high latitudes are possible. Conditions are expected to remain at unsettled levels with isolated active periods through 18 December, diminishing to unsettled levels by 19 December.

III. Event Probabilities 17 Dec-19 Dec

• Class M 05/01/01
• Class X 01/01/01
• Proton 01/01/01
• PCAF Green

IV. Penticton 10.7 cm Flux

• Observed 16 Dec 082
• Predicted 17 Dec-19 Dec 085/080/075
• 90 Day Mean 16 Dec 071

V. Geomagnetic A Indices

• Observed Afr/Ap 15 Dec 002/001
• Estimated Afr/Ap 16 Dec 005/010
• Predicted Afr/Ap 17 Dec-19 Dec 020/025-010/015-008/015

VI. Geomagnetic Activity Probabilities 17 Dec-19 Dec

A. Middle Latitudes

• Active 35/20/15
• Minor storm 20/15/10
• Major-severe storm 10/05/01

B. High Latitudes

• Active 35/30/20
• Minor storm 25/25/15
• Major-severe storm 10/10/05