NOAA SEC Report of Solar-Geophysical Activity 26 Nov 2001
:Product: Report of Solar-Geophysical Activity :Issued: 2001 Nov 26 2200 UT # 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 330 Issued at 2200Z on 26 Nov 2001 IA. Analysis of Solar Active Regions and Activity from 25/2100Z to 26/2100Z: Solar activity was at low levels. Region 9715 (N06E44) was the lone source for optically correlated flare activity occurring from a numbered region during the period. Several C-class flares were noted from this region with the largest being a C4/Sf flare seen at 26/1354 UTC. Significant growth in magnetic complexity (beta-gamma) and penumbral areal coverage have made this region the most notable region currently on the visible disk. Region 9704 (S20W88) was quiet today as it transits the west limb. A C9 x-ray flare occurred on the east limb with an associated Type II radio sweep (251 km/s) at 25/2317 UTC. At S20, the source of this flare is believed to be old Region 9787 which produced M-class activity during it's last rotation. No new regions were numbered. IB. Solar Activity Forecast: Solar activity is expected to be at low to moderate levels. Region 9715 now appears capable of producing M-class activity. IIA. Geophysical Activity Summary 25/2100Z to 26/2100Z: The geomagnetic field was at quiet to unsettled levels. The greater than 10 MeV proton event that began at 22/2320 UTC, remained in progress (flux at 14 pfu) at the time of bulletin issue (peak flux was 18900 pfu at 24/0555 UTC). The polar cap absorption event ended at 26/0730 UTC. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels for day one of the forecast. Active periods are possible on days two and three due to a recurrent coronal hole. The greater than 10 MeV proton event is expected to end early on the 27th, as the proton integral flux continues to slowly decrease. III. Event Probabilities 27 Nov-29 Nov Class M 40/40/50 Class X 10/10/05 Proton 90/50/05 PCAF green IV. Penticton 10.7 cm Flux Observed 26 Nov 175 Predicted 27 Nov-29 Nov 175/180/185 90 Day Mean 26 Nov 217 V. Geomagnetic A Indices Observed Afr/Ap 25 Nov 006/008 Estimated Afr/Ap 26 Nov 004/006 Predicted Afr/Ap 27 Nov-29 Nov 010/010-012/012-010/010 VI. Geomagnetic Activity Probabilities 27 Nov-29 Nov A. Middle Latitudes Active 20/30/20 Minor storm 10/10/10 Major-severe storm 01/05/01 B. High Latitudes Active 30/40/30 Minor storm 15/15/15 Major-severe storm 05/10/05
