:Product: 20010514RSGA.txt :Issued: 2001 May 14 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 134 Issued at 2200Z on 14 May 2001 IA. Analysis of Solar Active Regions and Activity from 13/2100Z to 14/2100Z: Activity decreased to low levels. Region 9455 (S17W24) remained the most active of the visible regions. It produced isolated C-class subflares, the largest of which was a C5/Sf at 14/0324 UTC. No significant changes occurred within this region, but mixed polarities persisted within its intermediate spots. Some polarity mixing was also observed in the vicinity of the leading spots of Region 9454 (N12E18), which was relatively inactive during the period. The remaining spot groups were unremarkable, including newly numbered Regions 9458 (S11W45), 9459 (N26W09), and 9460 (S24E60). IB. Solar Activity Forecast: Solar activity is expected to be at low to moderate levels with a fair chance for an isolated M-class flare from Region 9455. There will also be a slight chance for an isolated M-class flare from Region 9454. IIA. Geophysical Activity Summary 13/2100Z to 14/2100Z: Geomagnetic field activity was at unsettled to active levels until approximately 14/0900 UTC, then decreased to quiet to unsettled levels for the rest of the period. The greater than 2 MeV electron flux at geosynchronous orbit increased to high levels during the latter half of the period. IIB. Geophysical Activity Forecast: Geomagnetic field activity is expected to be at quiet to unsettled levels during most of the period with a chance for active levels at high latitudes. The greater than 2 MeV electron flux is expected to reach high levels during the first half of the period. III. Event Probabilities 15 May-17 May Class M 30/30/30 Class X 05/05/05 Proton 05/05/05 PCAF green IV. Penticton 10.7 cm Flux Observed 14 May 138 Predicted 15 May-17 May 145/150/155 90 Day Mean 14 May 167 V. Geomagnetic A Indices Observed Afr/Ap 13 May 017/023 Estimated Afr/Ap 14 May 013/015 Predicted Afr/Ap 15 May-17 May 012/015-012/020-007/015 VI. Geomagnetic Activity Probabilities 15 May-17 May A. Middle Latitudes Active 25/20/15 Minor storm 05/05/05 Major-severe storm 01/01/01 B. High Latitudes Active 30/30/20 Minor storm 10/10/05 Major-severe storm 05/01/01