:Product: 20040621RSGA.txt :Issued: 2004 Jun 21 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 173 Issued at 2200Z on 21 Jun 2004 IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: Solar activity was at low levels today. Region 635 (S12W14) produced the largest flare of the period, a C2/Sf flare at 21/1716Z. There was a slight decay seen in the sunspot area today. The delta magnetic structure in the trailing portion of Region 635 remains intact. Region 634 (N12W31) also underwent slight decay in sunspot coverage today although the region retains a beta-gamma-delta magnetic structure. Region 637 (N08E63) was numbered today. IB. Solar Activity Forecast: Solar activity is expected to be at low to moderate levels. Regions 635 remains capable of producing M-class flare activity. IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic field was at quiet to unsettled levels. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels throughout the period. III. Event Probabilities 22 Jun-24 Jun Class M 50/50/50 Class X 10/10/10 Proton 05/05/05 PCAF green IV. Penticton 10.7 cm Flux Observed 21 Jun 116 Predicted 22 Jun-24 Jun 115/110/110 90 Day Mean 21 Jun 102 V. Geomagnetic A Indices Observed Afr/Ap 20 Jun 003/003 Estimated Afr/Ap 21 Jun 004/006 Predicted Afr/Ap 22 Jun-24 Jun 004/008-004/008-004/008 VI. Geomagnetic Activity Probabilities 22 Jun-24 Jun A. Middle Latitudes Active 15/15/15 Minor storm 01/01/01 Major-severe storm 01/01/01 B. High Latitudes Active 20/20/20 Minor storm 05/05/05 Major-severe storm 01/01/01