NOAA/USAF Report of Solar-Geophysical Activity 11 November 2000
:Product: Report of Solar-Geophysical Activity :Issued: 2000 Nov 11 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 316 Issued at 2200Z on 11 Nov 2000 IA. Analysis of Solar Active Regions and Activity from 10/2100Z to 11/2100Z: Solar activity was low. There were two C-class flares produced during the past 24 hours. The first was a C2/Sf at 0012Z from Region 9218 (N21W90+), and the second was a C2 which was not reported optically. An examination of SOHO/EIT images during the second event strongly suggest that it also originated from Region 9218. Region 9221 (S12W20) showed some magnetic flux development in the leader part of the group and Region 9227 (S12E12) displayed new spot growth just behind the leader spot. All regions currently on the disk are quiet and stable. IB. Solar Activity Forecast: Solar activity is expected to be predominantly low for the next three days, but there is a slight chance for an isolated M-class event. IIA. Geophysical Activity Summary 10/2100Z to 11/2100Z: The geomagnetic field has been quiet to unsettled during the past 24 hours. Solar wind measurements from ACE indicate the onset of a high-speed, low density flow that is consistent with a favorably positioned solar coronal hole. The interplanetary magnetic field, however, has been either northwards or has been fluctuating weakly between -3 nT and +5 nT, and the geomagnetic response so far has been weak. The proton event at greater than 100 MeV ended at 0240Z today (based on GOES-8 flux dropping below 1 pfu). The greater than 10 MeV protons decreased during the past 24 hours but continue to be above the event threshold of 10 pfu, with a current value at 2100Z of 23.6 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be unsettled to active during the next 24 hours due to possible enhanced activity from the high speed solar wind stream. A decline to mostly unsettled is expected for the second and third days. The greater than 10 MeV proton event is expected to end sometime during the next 24 hours. III. Event Probabilities 12 Nov-14 Nov Class M 15/15/15 Class X 01/01/01 Proton 99/30/05 PCAF yellow IV. Penticton 10.7 cm Flux Observed 11 Nov 150 Predicted 12 Nov-14 Nov 150/145/140 90 Day Mean 11 Nov 172 V. Geomagnetic A Indices Observed Afr/Ap 10 Nov 029/041 Estimated Afr/Ap 11 Nov 010/015 Predicted Afr/Ap 12 Nov-14 Nov 015/020-012/015-012/015 VI. Geomagnetic Activity Probabilities 12 Nov-14 Nov A. Middle Latitudes Active 35/30/25 Minor storm 25/15/10 Major-severe storm 10/05/05 B. High Latitudes Active 25/25/25 Minor storm 30/20/15 Major-severe storm 20/15/10
