Joint USAF/NOAA Report of Solar and Geophysical Activity SDF Number 324 Issued at 2200Z on 20 Nov 2005 IA. Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity was low. Region 822 (S08W25) produced two C-class flares. A C2.5 flare occurred at 20/0736Z, and a C1.5 flare occurred at 20/1520Z. This region continues to slowly decay.

New Region 824 (S13E68) rotated onto the visible disk today.

IB. Solar Activity Forecast: Solar activity is expected to be low to moderate. Region 822 is capable of producing an M-class flare.

IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z:

The geomagnetic field was predominantly quiet, with periods of active conditions occurring between 19/1500Z and 19/2100Z.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels, with isolated active periods possible on 21 November due to a solar sector boundary crossing.

III. Event Probabilities 21 Nov-23 Nov

Class M 40/40/40

Class X 05/05/05

Proton 05/05/05

PCAF green

IV. Penticton 10.7 cm Flux

Observed 20 Nov 096

Predicted 21 Nov-23 Nov 095/095/095

90 Day Mean 20 Nov 085

V. Geomagnetic A Indices

Observed Afr/Ap 19 Nov 006/010

Estimated Afr/Ap 20 Nov 007/008

Predicted Afr/Ap 21 Nov-23 Nov 012/015-008/008-005/005 VI. Geomagnetic Activity Probabilities 21 Nov-23 Nov A. Middle Latitudes

Active 25/20/10

Minor storm 15/10/05

Major-severe storm 10/05/01

B. High Latitudes

Active 35/25/25

Minor storm 20/10/05

Major-severe storm 10/05/01