Joint USAF/NOAA Report of Solar and Geophysical Activity 02 Dec 2005

Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.

Updated 2005 Dec 02 2204 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 336 Issued at 2200Z on 02 Dec 2005

IA. Analysis of Solar Active Regions and Activity from 01/2100Z to 02/2100Z: Solar activity increased to high levels today. Region 826 (S02E09) continues to show strong growth in 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. Sunspot area more than doubled since yesterday and measures 490 millionths in white light analysis. Region 826 produced two major flares during the period, the largest was an M7/1n flare that occurred at 02/1012Z, and had an associated Tenflare (490 sfu), and a Type II radio sweep with an estimated shock velocity of 824 km/sec. There was a very faint partial halo CME following this flare, which was first seen on LASCO imagery at 02/1054Z. The second major flare today was an M6 x-ray event occurring at 02/0252Z which had an associated Tenflare (460 sfu). Regions 829 (N11E02) and 830 (N14E78) were numbered today.

IB. Solar Activity Forecast: Solar activity is expected to be at moderate to high levels. Region 826 is expected to continue to produce major flares.

IIA. Geophysical Activity Summary 01/2100Z to 02/2100Z: The geomagnetic field ranged from quiet to active levels. An isolated minor storm period was observed at the Boulder magnetometer between 01/2100 and 2400Z. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels today.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to range from quiet to active levels throughout the period. The high speed coronal hole stream is expected to move out of geoeffective position on 03 December. A weak transient passage from the partial halo CME that occurred today, may lead to isolated minor storm conditions late on 04 or early on 05 December.

III. Event Probabilities 03 Dec-05 Dec

• Class M 60/60/60
• Class X 25/25/25
• Proton 10/10/10
• PCAF green

IV. Penticton 10.7 cm Flux

• Observed 02 Dec 106
• Predicted 03 Dec-05 Dec 110/110/110
• 90 Day Mean 02 Dec 085

V. Geomagnetic A Indices

• Observed Afr/Ap 01 Dec 012/013
• Estimated Afr/Ap 02 Dec 012/015
• Predicted Afr/Ap 03 Dec-05 Dec 010/015-010/012-012/015

VI. Geomagnetic Activity Probabilities 03 Dec-05 Dec

A. Middle Latitudes

• Active 20/20/25
• Minor storm 05/05/10
• Major-severe storm 01/01/05

B. High Latitudes

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