:Product: 20040526RSGA.txt :Issued: 2004 May 26 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 147 Issued at 2200Z on 26 May 2004 IA. Analysis of Solar Active Regions and Activity from 25/2100Z to 26/2100Z: Solar activity decreased to very low levels today. Region 618 (S10W13) was limited to the production of several B-class flares today. This region underwent decay during the period however it still maintains a complex beta-gamma-delta magnetic structure. Region 619 (S09E76) enhanced the x-ray flux late in the period as surges and plague fluctuations were evident in H-alpha from near region center. No new regions were numbered today. IB. Solar Activity Forecast: Solar activity is expected to be at low levels. Region 618 has the potential to produce an isolated M-class event. IIA. Geophysical Activity Summary 25/2100Z to 26/2100Z: 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. NOTE: The ACE spacecraft orbit will bring ACE nearly in line with the Sun from about May 30 to June 2, 2004. During that time solar radio noise is expected to interfere with spacecraft telemetry resulting in the loss of solar wind plasma, magnetic field, and particle data. III. Event Probabilities 27 May-29 May Class M 50/50/50 Class X 10/10/10 Proton 05/05/05 PCAF green IV. Penticton 10.7 cm Flux Observed 26 May 103 Predicted 27 May-29 May 100/105/105 90 Day Mean 26 May 105 V. Geomagnetic A Indices Observed Afr/Ap 25 May 005/008 Estimated Afr/Ap 26 May 003/008 Predicted Afr/Ap 27 May-29 May 006/008-006/010-004/010 VI. Geomagnetic Activity Probabilities 27 May-29 May A. Middle Latitudes Active 15/15/10 Minor storm 05/05/05 Major-severe storm 01/01/01 B. High Latitudes Active 15/20/20 Minor storm 05/10/10 Major-severe storm 05/05/05