:Product: 20010401RSGA.txt :Issued: 2001 Apr 01 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 091 Issued at 2200Z on 01 Apr 2001 IA. Analysis of Solar Active Regions and Activity from 31/2100Z to 01/2100Z: Solar activity has been moderate. A Class M5 event began at 01/1055 UT. It has been associated with energetic post-flare type loops at the east limb near SE20. Coronal mass ejections have been numerous over the southeast limb, with the most dynamic occurring in temporal association with the Class M5 flare. The CME appeared to clear the LASCO field of view in half the time typical CME's require and appeared to extend from far south of the equator to very far north. Active Region 9393 (N15 W57) has changed little. It produced an impulsive Class M4 X-ray event beginning at 01/1943 UT. IB. Solar Activity Forecast: Solar activity is expected to remain moderate to high. Region 9393 (N15 W57) remains a probable source of Class M and Class X Flares. Other regions with high flare potential among the dozen or so spotted active regions now visible include Region 9408 (S10 W18), 9397 (S10 W35), and 9401 (N20 W40). IIA. Geophysical Activity Summary 31/2100Z to 01/2100Z: The geomagnetic field declined to quiet levels by 01/0900 UT. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be unsettled to active with a small chance of a minor storm. An energetic event in Region 9393 is likely to produce a prompt solar proton event. III. Event Probabilities 02 Apr-04 Apr Class M 80/80/80 Class X 35/35/35 Proton 30/30/30 PCAF green IV. Penticton 10.7 cm Flux Observed 01 Apr 258 Predicted 02 Apr-04 Apr 235/225/205 90 Day Mean 01 Apr 164 V. Geomagnetic A Indices Observed Afr/Ap 31 Mar 115/155 Estimated Afr/Ap 01 Apr 027/040 Predicted Afr/Ap 02 Apr-04 Apr 020/035-012/020-008/015 VI. Geomagnetic Activity Probabilities 02 Apr-04 Apr A. Middle Latitudes Active 28/28/28 Minor storm 18/18/18 Major-severe storm 17/12/08 B. High Latitudes Active 28/28/28 Minor storm 18/18/18 Major-severe storm 12/10/08