:Product: 20041229RSGA.txt :Issued: 2004 Dec 29 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 364 Issued at 2200Z on 29 Dec 2004 IA. Analysis of Solar Active Regions and Activity from 28/2100Z to 29/2100Z: Solar activity increased to moderate levels today. Region 715 (N04E61) produced the largest flare of the period, an M2 x-ray flare that occurred at 29/1627Z. An associated Tenflare (510 sfu) and a spectral Type II radio sweep with an estimated shock velocity of 411 km/s. This flare also produced a CME that does appear to be Earth directed. Several lesser C-class flares were also reported from this region during the period. The large asymmetrical sunspot contains both polarities and appears to be magnetically complex. Region 713 (S09W91) produced an M1 x-ray flare that occurred at 29/1920Z. Multiple lesser C-class flares originated from this region and the sunspot cluster was in a growth phase as the spot group transited the solar west limb. No new regions were numbered today. IB. Solar Activity Forecast: Solar activity is expected to be at low to moderate levels. Region 715 is capable of producing isolated M-class flare activity. IIA. Geophysical Activity Summary 28/2100Z to 29/2100Z: The geomagnetic field was at quiet to active levels. The elevated conditions were most likely the result of the geoeffective transequatorial high speed coronal hole stream that had a mean radial speed today of approximately 430km/s. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels today. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at predominantly quiet to unsettled levels throughout the period. Isolated active conditions early on the first day (30 Dec) of the period are possible as the coronal hole rotates out of geoeffective position. III. Event Probabilities 30 Dec-01 Jan Class M 60/50/50 Class X 10/10/10 Proton 05/05/05 PCAF green IV. Penticton 10.7 cm Flux Observed 29 Dec 099 Predicted 30 Dec-01 Jan 100/100/105 90 Day Mean 29 Dec 105 V. Geomagnetic A Indices Observed Afr/Ap 28 Dec 012/016 Estimated Afr/Ap 29 Dec 018/022 Predicted Afr/Ap 30 Dec-01 Jan 008/008-008/008-008/008 VI. Geomagnetic Activity Probabilities 30 Dec-01 Jan A. Middle Latitudes Active 20/20/20 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