:Product: 20031030RSGA.txt :Issued: 2003 Oct 30 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 303 Issued at 2200Z on 30 Oct 2003 IA. Analysis of Solar Active Regions and Activity from 29/2100Z to 30/2100Z: Solar activity was at high levels. Region 486 (S18W23) produced an X10/2b flare that peaked at the end of the last period (29/2049Z). Once again, intense radio emissions accompanied this flare, including a 360,000 sfu burst at 245 MHz, a 2500 sfu Tenflare, and strong Type II/IV radio sweeps. An extremely fast (over 1900 km/s) earth-directed full halo CME was observed on LASCO imagery. A new injection of high energy protons accompanied this flare. Region 486 maintains its tremendous size and magnetic complexity. Strong delta configurations exist in this spot group containing over 2500 millionths of white light areal coverage. Region 488 (N08W28) continues to develop in size and complexity and now nears 1800 millionths of areal overage. Despite its impressive size, this region's activity levels have so far been limited to high C-class and low M-class flares. New Regions 494 (S23E08) and 495 (S22E20) were numbered today. Region 495 is a very fast growing D-type spot group. IB. Solar Activity Forecast: Solar activity is expected to continue at high levels. Region 486 has been one of the most active regions of solar cycle 23 and maintains strong potential for further major proton flares. Large Region 488 also contains potential for a major flare. IIA. Geophysical Activity Summary 29/2100Z to 30/2100Z: The geomagnetic field was at predominantly minor to severe storm levels. The intense geomagnetic storm that began at 29/0611Z continued through the first half of this period. Severe (K8-9) levels were observed from 29/2100 - 30/0300Z. A short-lived "lull" (K5-6) in activity preceded the onset of another severe geomagnetic storm. The very fast CME from the X10 flare that peaked at 29/2049Z impacted the magnetic field at around 30/1600Z - a remarkably fast 19-hour transit from Sun to Earth. GOES-10,11, and 12 geosynchronous satellites have experienced magnetopause crossings and in fact have been outside the magnetopause for much of the time since the onset of this severe storm. Sustained southward IMF Bz in the -15 to -30 Nt range is assuring a severe response. A Forbush decrease at around 20% remains in progress. A new surge of high energy protons followed the X-10 flare, enhancing the existing greater than 10 MeV and greater than 100 MeV proton events from the X17 flare on the 28th. This enhancement reached 110 pfu (29/2310Z) in the greater than 100 MeV level, and 3300 pfu (30/1935Z) in the greater than 10 MeV level. A polar cap absorption continues and the proton event remains in progress. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to continue at major to severe storm levels through the first half of day one. The current severe geomagnetic storm is expected to gradually subside by the end of day one. Unsettled to occasional minor storm periods are possible on day two. Mostly unsettled levels are expected by day three. The greater than 100 MeV proton event is expected to end by day one. The greater than 10 MeV proton event will likely persist through day two. III. Event Probabilities 31 Oct-02 Nov Class M 90/90/90 Class X 50/50/50 Proton 99/99/75 PCAF in progress IV. Penticton 10.7 cm Flux Observed 30 Oct 271 Predicted 31 Oct-02 Nov 265/260/255 90 Day Mean 30 Oct 128 V. Geomagnetic A Indices Observed Afr/Ap 29 Oct 199/189 Estimated Afr/Ap 30 Oct 115/130 Predicted Afr/Ap 31 Oct-02 Nov 080/100-020/030-010/015 VI. Geomagnetic Activity Probabilities 31 Oct-02 Nov A. Middle Latitudes Active 10/40/20 Minor storm 20/15/05 Major-severe storm 70/10/01 B. High Latitudes Active 10/50/25 Minor storm 10/30/10 Major-severe storm 80/10/05