:Product: 20030605RSGA.txt :Issued: 2003 Jun 05 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 156 Issued at 2200Z on 05 Jun 2003 IA. Analysis of Solar Active Regions and Activity from 04/2100Z to 05/2100Z: Solar activity was low. There were two C-class flares today: a C2 at 1019 UT from Region 377 (N05E57), and a C1 at 1734 UT from Region 375 (N12E24). There was also a CME that erupted behind the southwest limb which first became visible in the SOHO/LASCO C2 coronagraph at 2006 UT. There was a Type II radio sweep associated with this CME. Region 375 dominates the disk in size and complexity, and shows mixed magnetic polarities as well as an east-west inversion line which could build up magnetic shear. However, there is no indication of emerging flux in the region at this time. New region number 378 (N16E69) was assigned to a small, C-type group today. IB. Solar Activity Forecast: Solar activity is expected to be mostly low, but there is a fair chance for an isolated M-class event sometime over the next three days. Region 375 is considered to be the most likely source for energetic flare activity. IIA. Geophysical Activity Summary 04/2100Z to 05/2100Z: The geomagnetic field was quiet to unsettled during the past 24 hours. Solar wind speed observations show a steady decline from values around 800 km/s at the start of the period to values around 500 km/s by the end of the period. A decline in temperature was also seen, suggesting that the Earth is moving into normal, ambient solar wind flow. The greater than 2 MeV electron fluxes reached high levels today. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be mostly unsettled, with a chance for some isolated active periods, during the next 24 to 36 hours. Another coronal hole will move into favorable position sometime in the next 36 to 48 hours, and conditions are expected to increase to active, most likely beginning late on the second day and lasting through the third day. III. Event Probabilities 06 Jun-08 Jun Class M 40/40/40 Class X 05/05/05 Proton 05/05/05 PCAF green IV. Penticton 10.7 cm Flux Observed 05 Jun 114 Predicted 06 Jun-08 Jun 115/118/120 90 Day Mean 05 Jun 123 V. Geomagnetic A Indices Observed Afr/Ap 04 Jun 013/021 Estimated Afr/Ap 05 Jun 010/013 Predicted Afr/Ap 06 Jun-08 Jun 015/015-015/020-020/030 VI. Geomagnetic Activity Probabilities 06 Jun-08 Jun A. Middle Latitudes Active 30/30/35 Minor storm 15/15/20 Major-severe storm 05/05/10 B. High Latitudes Active 35/35/25 Minor storm 30/30/35 Major-severe storm 10/10/20