Joint USAF/NOAA Report of Solar and Geophysical Activity 18 Dec 2005

Product: Report of Solar-Geophysical Activity
Issued: 2005 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 2005

IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: Solar activity was very low. Today’s activity consisted of a few B-class events, mostly from Region 834 (S06W45). Region 834 is the largest group on the disk with about 110 millionths sunspot area, but has decayed in magnetic complexity and is now a simple Beta group. No new regions were numbered today.

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

IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field was quiet during the past 24 hours.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to unsettled during the next three days (19 – 21 December).

III. Event Probabilities 19 Dec-21 Dec

• Class M 10/10/10
• Class X 01/01/01
• Proton 01/01/01
• PCAF green

IV. Penticton 10.7 cm Flux

• Observed 18 Dec 086
• Predicted 19 Dec-21 Dec 085/085/085
• 90 Day Mean 18 Dec 083

V. Geomagnetic A Indices

• Observed Afr/Ap 17 Dec 002/005
• Estimated Afr/Ap 18 Dec 002/005
• Predicted Afr/Ap 19 Dec-21 Dec 005/005-005/008-005/008

VI. Geomagnetic Activity Probabilities 19 Dec-21 Dec

A. Middle Latitudes

• Active 15/15/15
• Minor storm 05/05/05
• Major-severe storm 01/01/01

B. High Latitudes

• Active 20/25/25
• Minor storm 05/05/05
• Major-severe storm 01/01/01