:Product: 20010513RSGA.txt :Issued: 2001 May 13 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 133 Issued at 2200Z on 13 May 2001 IA. Analysis of Solar Active Regions and Activity from 12/2100Z to 13/2100Z: Solar activity increased to moderate levels. Region 9455 (S18W11) produced two M-class flares early in the period. The first was an M3/1b at 12/2335 UTC with an associated 230 SFU Tenflare and Type IV radio sweep. The second was an M3/Sn at 13/0304 UTC associated with a 220 SFU Tenflare and Type II and IV radio sweeps. Coronal mass ejections followed both flares, but the bulk of the mass appeared to be directed southward. Region 9455 remained a moderate-sized sunspot group with a mix of polarities evident within its interior spots. Region 9454 (N12E32) remained the largest spot on the disk at around 400 millionths, but was relatively inactive. It showed a weak mixing of polarities in the vicinity of its trailer spots. Minor spot development was noted within Region 9451 (S22W39), which produced an isolated subflare late in the period. New Region 9457 (S19E03) was numbered. IB. Solar Activity Forecast: Solar activity is expected to be at low to moderate levels with a fair chance for isolated M-class flares from Region 9455. There is also a slight chance for an isolated M-class flare from Region 9454. IIA. Geophysical Activity Summary 12/2100Z to 13/2100Z: Geomagnetic field activity ranged from unsettled to minor storm levels. Active to minor storm levels occurred until 13/0600 UTC, followed by mostly unsettled conditions. The greater than 2 MeV electron flux reached high levels during the period. IIB. Geophysical Activity Forecast: Geomagnetic field activity is expected to be at unsettled to active levels during the period. The greater than 2 MeV electron flux may reach high levels during the period. III. Event Probabilities 14 May-16 May Class M 40/40/40 Class X 05/05/05 Proton 05/05/05 PCAF green IV. Penticton 10.7 cm Flux Observed 13 May 139 Predicted 14 May-16 May 145/150/160 90 Day Mean 13 May 167 V. Geomagnetic A Indices Observed Afr/Ap 12 May 020/034 Estimated Afr/Ap 13 May 020/020 Predicted Afr/Ap 14 May-16 May 015/015-015/012-015/020 VI. Geomagnetic Activity Probabilities 14 May-16 May A. Middle Latitudes Active 30/30/30 Minor storm 10/10/10 Major-severe storm 05/05/05 B. High Latitudes Active 40/40/40 Minor storm 15/15/15 Major-severe storm 10/10/10