:Product: 20001016RSGA.txt :Issued: 2000 Oct 16 2200 UTC # 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 290 Issued at 2200Z on 16 Oct 2000 IA. Analysis of Solar Active Regions and Activity from 15/2100Z to 16/2100Z: Solar activity has been moderate. The largest event of the day was an LDE M2 flare at 16/0728UT (1.75 hr), with associated Type-II and Type-IV radio sweeps. SOHO/LASCO and EIT imagery suggest a CME source behind the west limb - most likely Region 9182, at about N04W105. An associated full halo (with faint east limb extension) was also reported by SOHO/LASCO. Prior to this event, a weaker LDE C7 flare was observed at 16/0549UT. Optical correlation was not available, but EIT imagery suggests the likely source as Region 9193 (N06W74). This region also produced a C1/Sf at 16/2020UT. Other activity was limited to region 9199 (N12E54), producing a C1/Sf at 16/1711UT. Region 9194 (S11E09) exhibited growth in spot count and magnetic complexity (now a Dai group in Beta-Gamma mag configuration), but produced no flares. Region 9200 (S16E58) was numbered today. IB. Solar Activity Forecast: Solar activity is expected to be predominantly low, with an isolated chance of moderate-level activity for the next three days. IIA. Geophysical Activity Summary 15/2100Z to 16/2100Z: The geomagnetic field was quiet to active. Coronal hole high speed stream effects were evident, but produced only one active period during 16/00-03UT. A 10 MeV solar proton event associated with the M2 LDE commenced at 16/1125UT, and remains in progress. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be mainly quiet to unsettled through day one, with some possibility of isolated active conditions due to waning coronal hole effects. The greater than 10 MeV SPE currently in progress is expected to end during day one. A greater chance of active levels during day two may result from flanking passage of a CME-associated shock from the LDE M2 flare discussed above. Quiet to unsettled conditions are expected for day three. III. Event Probabilities 17 Oct-19 Oct Class M 30/30/30 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 16 Oct 161 Predicted 17 Oct-19 Oct 160/165/175 90 Day Mean 16 Oct 175 V. Geomagnetic A Indices Observed Afr/Ap 15 Oct 009/008 Estimated Afr/Ap 16 Oct 011/010 Predicted Afr/Ap 17 Oct-19 Oct 010/010-012/015-008/010 VI. Geomagnetic Activity Probabilities 17 Oct-19 Oct A. Middle Latitudes Active 25/30/20 Minor storm 10/10/05 Major-severe storm 01/01/01 B. High Latitudes Active 30/35/30 Minor storm 10/15/05 Major-severe storm 01/01/01