:Product: 20030331RSGA.txt :Issued: 2003 Mar 31 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 090 Issued at 2200Z on 31 Mar 2003 IA. Analysis of Solar Active Regions and Activity from 30/2100Z to 31/2100Z: Solar activity was low. Occasional low C-class flares were observed from Regions 318 (S13W49) and 321 (N06W16). Region 323 (S08W29) maintained its moderate size and magnetic complexity, but was mostly stable this period. Region 319 (N13W57) underwent considerable decay over the past 24 - 36 hours. New Regions 327 (S07W12) and 328 (S03E14) were numbered today. No other significant developments were observed. IB. Solar Activity Forecast: Solar activity is expected to be low. There is a small chance for a low M-class flare from Region 323. IIA. Geophysical Activity Summary 30/2100Z to 31/2100Z: The geomagnetic field ranged from quiet to minor storm levels, with occasional major storm periods at high latitudes. The high speed stream that began early on 30 March continues. An extended period of southward Bz that began at around 1100Z, has continued through the end of the period and was responsible for the most disturbed periods. The greater than 2 MeV electrons at geosynchronous orbit reached high levels. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to minor storm levels. Disturbed periods due to high speed stream effects will continue for the next 2-3 days. III. Event Probabilities 01 Apr-03 Apr Class M 30/30/30 Class X 05/05/05 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 31 Mar 160 Predicted 01 Apr-03 Apr 160/155/150 90 Day Mean 31 Mar 134 V. Geomagnetic A Indices Observed Afr/Ap 30 Mar 019/026 Estimated Afr/Ap 31 Mar 020/030 Predicted Afr/Ap 01 Apr-03 Apr 015/020-015/020-015/015 VI. Geomagnetic Activity Probabilities 01 Apr-03 Apr A. Middle Latitudes Active 40/40/30 Minor storm 20/20/10 Major-severe storm 10/10/05 B. High Latitudes Active 50/50/40 Minor storm 30/30/20 Major-severe storm 15/15/10