NOAA SEC Report of Solar-Geophysical Activity 18 Oct 2001
:Product: Report of Solar-Geophysical Activity :Issued: 2001 Oct 18 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 291 Issued at 2200Z on 18 Oct 2001 IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: Solar activity was at low levels. The first half of the day produced multiple low level C-class flares that were not optically correlated. At 18/1350 UTC, Region 9658 (S14W48) produced a C6/1n flare and an associated radio enhancements. White light analysis of this region shows a slight decay in areal coverage of spots, though it remains a beta-gamma magnetic class group. Region 9661 (N16W23) followed with a C4/Sf flare at 18/1609 UTC and continues to show the potential to produce much more significant activity. This region has shown a small decay in areal coverage of spot group from yesterday, although it still continues to be a large, magnetically complex region. New Region 9672 (S21E69) produced the largest flare of the day, a C8/Sf flare that occurred at 18/1905 UTC. This region may very well be old Region 9632 which currently appears to have not fully rotated onto disk. Two new Regions were numbered today, 9672 and 9673 (N03E73). IB. Solar Activity Forecast: Solar activity is expected to be at low to moderate levels. There are several regions on the disk that are capable of producing M-class or isolated major flares, the most noteworthy being Region 9661. IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field was at quiet to unsettled levels. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to remain at quiet to unsettled levels through forecast period, barring the occurrence of an earth-directed CME. High latitudes may experience isolated periods of active conditions during days one and two. III. Event Probabilities 19 Oct-21 Oct Class M 60/60/60 Class X 10/10/10 Proton 05/05/05 PCAF yellow IV. Penticton 10.7 cm Flux Observed 18 Oct 229 Predicted 19 Oct-21 Oct 235/240/245 90 Day Mean 18 Oct 188 V. Geomagnetic A Indices Observed Afr/Ap 17 Oct 002/004 Estimated Afr/Ap 18 Oct 005/006 Predicted Afr/Ap 19 Oct-21 Oct 005/010-005/010-008/008 VI. Geomagnetic Activity Probabilities 19 Oct-21 Oct A. Middle Latitudes Active 15/15/20 Minor storm 05/05/05 Major-severe storm 01/01/01 B. High Latitudes Active 20/20/20 Minor storm 05/05/05 Major-severe storm 01/01/01
