:Product: 20010414RSGA.txt :Issued: 2001 Apr 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 104 Issued at 2200Z on 14 Apr 2001 IA. Analysis of Solar Active Regions and Activity from 13/2100Z to 14/2100Z: Solar activity was moderate. Region 9415 (S22W72) produced an M1/SF event during 14/1715-1828 UTC. Peak x-ray flux occurred at 14/1811 UTC, after an extended and variable rise in flux levels. Also observed were an associated Type-II sweep, 150 sfu tenflare, eruptive prominence and bright surging on the limb. Imagery from SOHO/LASCO indicated a subsequent CME, however not appearing earth-directed. Region 9418 (N26W59) also produced a subfaint flare during the event, and now exhibits some increase in areal coverage and magnetic complexity. Two new regions were numbered today: 9428 (N14W39) and 9429 (N09E62). IB. Solar Activity Forecast: Solar activity is expected to be low to moderate. Regions 9415 and 9418 remain potential sources of isolated major flares. IIA. Geophysical Activity Summary 13/2100Z to 14/2100Z: The geomagnetic field was at unsettled to active levels, primarily due to lingering effects of the geomagnetic storm that commenced on 13 April. Greater-than-2 MeV electron flux at geosynchronous orbit reached high levels at 1415 UTC, and remained above threshold through the end of the period. IIB. Geophysical Activity Forecast: Geomagnetic field activity is expected to increase, with major storm levels possible during the next 24 hours, due to an expected shock arrival from CME activity observed on 12 April. Storm activity is expected to wane during the following two days, with quiet to unsettled levels expected by the end of the period. III. Event Probabilities 15 Apr-17 Apr Class M 70/60/50 Class X 20/10/10 Proton 20/10/10 PCAF green IV. Penticton 10.7 cm Flux Observed 14 Apr 139 Predicted 15 Apr-17 Apr 140/145/150 90 Day Mean 14 Apr 166 V. Geomagnetic A Indices Observed Afr/Ap 13 Apr 031/036 Estimated Afr/Ap 14 Apr 020/020 Predicted Afr/Ap 15 Apr-17 Apr 030/040-020/030-010/020 VI. Geomagnetic Activity Probabilities 15 Apr-17 Apr A. Middle Latitudes Active 35/25/20 Minor storm 15/10/05 Major-severe storm 10/05/01 B. High Latitudes Active 35/35/30 Minor storm 25/20/10 Major-severe storm 20/10/05