NOAA/USAF Report of Solar-Geophysical Activity 24 November 2000
:Product: Report of Solar-Geophysical Activity :Issued: 2000 Nov 24 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 329 Issued at 2200Z on 24 Nov 2000 IA. Analysis of Solar Active Regions and Activity from 23/2100Z to 24/2100Z: Solar activity is now at high levels. Magnetograms revealed developing complexity late last period in Region 9236 (N22W07) and a series of significant events followed. The first was an M1/1n at 23/2328Z with associated Type II sweep (1025km/s) and CME. At 24/0502Z, an X2/3b flare erupted with strong centimetric radio bursts including a Tenflare of 2200sfu. This event was also accompanied by a Type II sweep (1000km/s), a proton event, and a halo CME. The third significant event from this region was an X2/2b that occurred at 24/1513Z. This flare was also accompanied by large centimetric radio bursts, a Type II sweep (1200km/s), proton event, and a halo CME. This region, at over 500 millionths of sunspot areal coverage, is magnetically complex and still developing. Region 9231 (S24W74) was mostly stable this period, producing only an isolated low C-class flare. New region 9242 (N22E68) was numbered today. IB. Solar Activity Forecast: Solar activity is expected to be at moderate to high levels. Region 9236 continues to develop and is very capable of continued M-class and X-class events. Region 8231's complexity will likely result in occasional C-class events with an isolated chance of a small M-class flare. IIA. Geophysical Activity Summary 23/2100Z to 24/2100Z: The geomagnetic field was quiet to unsettled with isolated active conditions observed late in the period. Solar wind data indicates we've transitioned to a high speed stream over the past eighteen hours with current solar wind speed ranging 500 to 550km/s. A greater than 10 MeV proton event began at 24/1520Z and is currently in progress. A maximum of 84 pfu was reached at 24/1905Z. A greater than 100 MeV proton event began at 23/1720Z, with a maximum of 1.1pfu observed at 24/1810Z. The initial proton enhancement began following the X2/3b flare at 0502Z. A second impulse of protons was evident following the X2/2b at 1513Z. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be unsettled to active through day one due to high speed coronal hole flow. The first of a series of CME 's are expected to impact the field early on day two. As many as four individual CME's occurring over the past forty hours appeared earthbound. Minor to major storming is likely on days two and three. Another proton event is possible should Region 9236 produce an additional major flare. III. Event Probabilities 25 Nov-27 Nov Class M 70/70/70 Class X 40/40/40 Proton 99/80/50 PCAF green IV. Penticton 10.7 cm Flux Observed 24 Nov 197 Predicted 25 Nov-27 Nov 200/200/195 90 Day Mean 24 Nov 174 V. Geomagnetic A Indices Observed Afr/Ap 23 Nov 004/007 Estimated Afr/Ap 24 Nov 008/008 Predicted Afr/Ap 25 Nov-27 Nov 015/020-060/070-050/060 VI. Geomagnetic Activity Probabilities 25 Nov-27 Nov A. Middle Latitudes Active 40/20/20 Minor storm 25/40/40 Major-severe storm 10/40/40 B. High Latitudes Active 50/20/20 Minor storm 30/30/30 Major-severe storm 15/50/50
