:Product: 20010511RSGA.txt :Issued: 2001 May 11 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 131 Issued at 2200Z on 11 May 2001 IA. Analysis of Solar Active Regions and Activity from 10/2100Z to 11/2100Z: Solar activity was low during the last 24 hours. Three C-class flares occurred including a C1 at 0717 UTC, a C1/Sf from newly assigned 9455 (S18E17) at 1006 UTC, and a C3 apparently from 9455 at 2022 UTC. New Region 9455 grew quickly on the disk to a D-type sunspot group and appears to have a weak delta configuration. Region 9454 (S18E17) continues to be the largest group on the disk at 430 millionths. The group was not observed to produce any flares, but did exhibit frequent plage fluctuations throughout the day. It appears to have a simple beta magnetic configuration. An 18 degree filament near S11E14 disappeared sometime between 0507 UTC and 1314 UTC. IB. Solar Activity Forecast: Solar activity is expected to be mostly low, but there is a fair chance for an isolated M-class event from either of Region 9454 or Region 9455. IIA. Geophysical Activity Summary 10/2100Z to 11/2100Z: The geomagnetic field has been quiet to unsettled during the past 24 hours. The greater than 2 MeV electron fluxes attained high levels today. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to unsettled for the next three days. III. Event Probabilities 12 May-14 May Class M 25/25/25 Class X 05/05/05 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 11 May 137 Predicted 12 May-14 May 140/145/150 90 Day Mean 11 May 167 V. Geomagnetic A Indices Observed Afr/Ap 10 May 023/028 Estimated Afr/Ap 11 May 008/008 Predicted Afr/Ap 12 May-14 May 007/008-007/009-007/009 VI. Geomagnetic Activity Probabilities 12 May-14 May A. Middle Latitudes Active 20/20/20 Minor storm 05/05/05 Major-severe storm 05/05/05 B. High Latitudes Active 20/20/20 Minor storm 10/10/10 Major-severe storm 05/05/05