:Product: 20030809RSGA.txt :Issued: 2003 Aug 09 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 221 Issued at 2200Z on 09 Aug 2003 IA. Analysis of Solar Active Regions and Activity from 08/2100Z to 09/2100Z: Solar activity was very low. Region 424 (S18W28) maintains moderate size and complexity, but activity this period was limited to occasional intensity fluctuations in the plage field. New Region 431 (S12E68) was numbered today. This new region is likely the return of old Region 410 which produced multiple C-class flares during its last transit across the visible disk. A considerable degree of surging was observed, but limb proximity is still making it too difficult to assess this region's true complexity. Nothing remarkable in the remaining active regions. IB. Solar Activity Forecast: Solar activity is expected to be at low levels. Regions 424 and 431 both have potential for C-class activity. There is a slight chance for an M-class flare. IIA. Geophysical Activity Summary 08/2100Z to 09/2100Z: The geomagnetic field was unsettled to active. The high speed solar wind stream is subsiding as the large equatorial coronal hole rotates out of a geoeffective position. Wind speed began the period near 750 km/s, but has gradually declined to near 650 km/s. The greater than 2 MeV electron flux at geosynchronous orbit was at high levels. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to range from quiet to major storm levels. Predominantly quiet to unsettled levels with occasional active periods are expected on days one and two as the current high speed solar wind stream continues to weaken. Another recurrent equatorial coronal hole will move into a geoeffective position by day three and produce occasional minor to major storm periods. III. Event Probabilities 10 Aug-12 Aug Class M 30/30/30 Class X 05/05/05 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 09 Aug 130 Predicted 10 Aug-12 Aug 135/135/135 90 Day Mean 09 Aug 125 V. Geomagnetic A Indices Observed Afr/Ap 08 Aug 022/032 Estimated Afr/Ap 09 Aug 015/016 Predicted Afr/Ap 10 Aug-12 Aug 015/015-015/020-025/035 VI. Geomagnetic Activity Probabilities 10 Aug-12 Aug A. Middle Latitudes Active 30/30/40 Minor storm 10/10/20 Major-severe storm 01/01/10 B. High Latitudes Active 40/45/50 Minor storm 20/25/35 Major-severe storm 05/05/15