Joint USAF/NOAA Report of Solar and Geophysical Activity SDF Number 277 Issued at 2200Z on 04 Oct 2005 IA. Analysis of Solar Active Regions and Activity from 03/2100Z to 04/2100Z: Solar activity remained at very low levels. Old active Region 808 (S10, L=232) is rotating into view on the southeast limb and still appears relatively complex. Several B-class flares were observed including a long-duration B7 flare at 04/0622Z. This long-duration event was associated with a prominence eruption and CME on the southeast limb. A large loop structure was also observed near this location on EIT imagery. Newly numbered Region 813

(S06E30) emerged this period as a moderately complex and compact beta-gamma group.

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

Old Region 808, which is currently rotating onto the visible disk, may produce C-class activity. Newly numbered Region 813 also has C-class flare potential. There is a slight chance for an M-class flare.

IIA. Geophysical Activity Summary 03/2100Z to 04/2100Z:

The geomagnetic field was quiet. The greater than 2 MeV electron flux at geosynchronous orbit was at high levels again today.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet on 05 October. Isolated unsettled to active periods are possible on 06 and 07 October.

III. Event Probabilities 05 Oct-07 Oct

Class M 20/25/25

Class X 05/05/05

Proton 01/01/01

PCAF Green

IV. Penticton 10.7 cm Flux

Observed 04 Oct 083

Predicted 05 Oct-07 Oct 090/095/095

90 Day Mean 04 Oct 090

V. Geomagnetic A Indices

Observed Afr/Ap 03 Oct 005/007

Estimated Afr/Ap 04 Oct 005/004

Predicted Afr/Ap 05 Oct-07 Oct 005/005-008/008-005/010 VI. Geomagnetic Activity Probabilities 05 Oct-07 Oct A. Middle Latitudes

Active 15/20/20

Minor storm 05/05/05

Major-severe storm 01/01/01

B. High Latitudes

Active 20/25/25

Minor storm 05/10/10

Major-severe storm 01/01/01