NOAA SEC Report of Solar-Geophysical Activity 18 Aug 2001
:Product: Report of Solar-Geophysical Activity :Issued: 2001 Aug 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 230 Issued at 2200Z on 18 Aug 2001 IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: Solar activity was low. Several C-class flares occurred, principally from Region 9582 (N28E33). The other main area of note is Region 9585 (N15E50) which has grown considerably in sunspot area and has increased its magnetic complexity. IB. Solar Activity Forecast: Solar activity is expected to be low. Additional C-class flares are possible in Regions 9582 and 9585. A small chance of M-level activity also exists. IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field remained at storm levels until about 18/0000 UTC and was mostly unsettled to active after that. The greater than 10 MeV solar energetic proton event continues to slowly decay and has been fluctuating around the 10 pfu event threshold for most of the day. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be unsettled to active becoming quiet to unsettled by the second day of the forecast period. The greater than 10 MeV proton event is expected to end by 19 August. III. Event Probabilities 19 Aug-21 Aug Class M 10/10/10 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 18 Aug 156 Predicted 19 Aug-21 Aug 160/165/170 90 Day Mean 18 Aug 151 V. Geomagnetic A Indices Observed Afr/Ap 17 Aug 027/029 Estimated Afr/Ap 18 Aug 015/015 Predicted Afr/Ap 19 Aug-21 Aug 012/012-010/015-010/012 VI. Geomagnetic Activity Probabilities 19 Aug-21 Aug A. Middle Latitudes Active 15/15/15 Minor storm 05/01/01 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor storm 05/05/05 Major-severe storm 01/01/01
