:Product: 20040914RSGA.txt :Issued: 2004 Sep 14 2300 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 258 Issued at 2200Z on 14 Sep 2004 IA. Analysis of Solar Active Regions and Activity from 13/2100Z to 14/2100Z: Solar activity has been moderate. Region 672 (N05E10) produced several C-class flares and a long-duration M1.5/1f at 0930 UTC. A Type II radio sweep (1018 km/s) and a Type IV sweep was observed in association with the M flare. An associated CME most likely occurred, but could not be confirmed due to a LASCO data gap. Surging and plage fluctuations were observed in Region 672, which is now in a beta-delta magnetic configuration. No new regions were numbered today. IB. Solar Activity Forecast: Solar activity is expected to be low to moderate. Region 672 is expected to produce C- class flares, and may produce isolated M-class flares. IIA. Geophysical Activity Summary 13/2100Z to 14/2100Z: The geomagnetic field has been unsettled to active. Lingering effects of the CME which arrived on 13 September led to persistent active conditions early in the period. The greater than 10 MeV protons have been steadily delining since reaching a maximum of 273 pfu at 14/0005 UTC, and are currently at 17 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to unsettled on 15 September as the effects of the current disturbance subside. A CME originating from the M1.5 flare observed today may interact with Earth's geomagnetic field beginning midday on 16 September, and lasting through 17 September. Predominantly active conditions, with isolated minor or major storming, is likely on 16-17 September as a result of this CME arrival. The greater than 10 MeV Proton levels may increase as well in association with a CME shock arrival. III. Event Probabilities 15 Sep-17 Sep Class M 25/25/25 Class X 05/05/05 Proton 99/10/10 PCAF Yellow IV. Penticton 10.7 cm Flux Observed 14 Sep 115 Predicted 15 Sep-17 Sep 115/115/110 90 Day Mean 14 Sep 112 V. Geomagnetic A Indices Observed Afr/Ap 13 Sep 005/008 Estimated Afr/Ap 14 Sep 020/030 Predicted Afr/Ap 15 Sep-17 Sep 015/015-020/025-020/025 VI. Geomagnetic Activity Probabilities 15 Sep-17 Sep A. Middle Latitudes Active 30/40/40 Minor storm 20/25/25 Major-severe storm 01/01/01 B. High Latitudes Active 35/35/35 Minor storm 25/30/30 Major-severe storm 01/05/05