NOAA SEC Report of Solar-Geophysical Activity 18 May 2001
:Product: Report of Solar-Geophysical Activity :Issued: 2001 May 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 138 Issued at 2200Z on 18 May 2001 IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: Solar activity was low. Region 9461 (N19E39) was the most active region during the period, producing a C4/Sf event at 17/2142 UTC. The largest event was an optically uncorrelated C6 flare at 18/0640 UTC. Regions 9454 (N14W33) and 9455 (S17W80) began to show signs of decay and decreased activity today. One new region was numbered overnight, 9462 (N16E65). IB. Solar Activity Forecast: Solar activity is expected to be mostly low. Region 9461 could possibly produce isolated M-class events. IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field ranged from quiet to unsettled levels. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels during the period. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be a quiet to unsettled levels. The greater than 2 MeV electron flux may reach moderate to high levels during the period. III. Event Probabilities 19 May-21 May Class M 30/30/30 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 18 May 138 Predicted 19 May-21 May 140/135/130 90 Day Mean 18 May 167 V. Geomagnetic A Indices Observed Afr/Ap 17 May 007/009 Estimated Afr/Ap 18 May 010/011 Predicted Afr/Ap 19 May-21 May 010/010-008/015-008/012 VI. Geomagnetic Activity Probabilities 19 May-21 May A. Middle Latitudes Active 01/01/01 Minor storm 01/01/01 Major-severe storm 01/01/01 B. High Latitudes Active 25/25/25 Minor storm 10/10/10 Major-severe storm 00/00/00
