:Product: 1005RSGA.txt :Issued: 2011 Oct 05 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 278 Issued at 2200Z on 05 Oct 2011 IA. Analysis of Solar Active Regions and Activity from 04/2100Z to 05/2100Z: Solar activity for the past 24 hours has been at low levels. New Region 1313 (S13E65) rotated onto the southeast limb early in the period and has been responsible for a majority of the activity. Region 1313, produced the largest event of the period, a C9/Sf flare at 05/1242Z. Multiple CMEs were observed during the past 24 hours, but none of them were considered to be geoeffective. IB. Solar Activity Forecast: Solar activity is expected to be at low to moderate levels for the next three days (06-08 October) as Region 1313 continues to evolve. IIA. Geophysical Activity Summary 04/2100Z to 05/2100Z: The geomagnetic field has been at quiet to minor storm levels during the past 24 hours. At 05/0742, a Sudden Impulse (SI) of 19 nT was observed by the Boulder magnetometer. Following this SI, solar wind speeds, as measured by the ACE spacecraft, increased from 370 km/s to around 480 km/s. The IMF also increased to around 12 nT, with some extended periods of southward Bz. These characteristics are congruent with the arrival of a CME. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels during the period. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to remain at unsettled to active levels with a chance for minor storm periods on day one (06 October). Predominantly quiet to unsettled levels are expected for days two and three (07-08 October) as the effects of the CMEs wane. III. Event Probabilities 06 Oct-08 Oct Class M 40/40/40 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 05 Oct 127 Predicted 06 Oct-08 Oct 125/125/130 90 Day Mean 05 Oct 113 V. Geomagnetic A Indices Observed Afr/Ap 04 Oct 004/006 Estimated Afr/Ap 05 Oct 015/018 Predicted Afr/Ap 06 Oct-08 Oct 015/015-008/008-008/008 VI. Geomagnetic Activity Probabilities 06 Oct-08 Oct A. Middle Latitudes Active 45/20/20 Minor storm 25/05/05 Major-severe storm 05/01/01 B. High Latitudes Active 45/25/25 Minor storm 30/10/10 Major-severe storm 05/01/01