NOAA SEC Report of Solar-Geophysical Activity 21 Jul 2001
:Product: Report of Solar-Geophysical Activity :Issued: 2001 Jul 21 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 202 Issued at 2200Z on 21 Jul 2001 IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: Solar activity has been low. Region 9543 (S23W06) produced today's largest flare, a C6/Sf at 0508 UTC. Region 9543 continues to be the largest group on the disk and is growing slowly. Region 9548 (N16E09) also showed growth but was stable. Region 9545 (N09W43) showed newly emerging magnetic flux in the middle of the old fields, and exhibited occasional plage fluctuations, but no flare-level activity. IB. Solar Activity Forecast: Solar activity is expected to be predominantly low. There is, however, a slight chance for an isolated M-class event. IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic field was quiet to unsettled. The greater than 2 MeV electron fluxes attained high levels during the past 24 hours. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to unsettled for the next three days. There is a possibility for a small increase in activity on the third day in response to a small but favorably positioned coronal hole. III. Event Probabilities 22 Jul-24 Jul Class M 25/25/25 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 21 Jul 139 Predicted 22 Jul-24 Jul 140/140/135 90 Day Mean 21 Jul 157 V. Geomagnetic A Indices Observed Afr/Ap 20 Jul 008/008 Estimated Afr/Ap 21 Jul 005/008 Predicted Afr/Ap 22 Jul-24 Jul 007/008-007/010-012/015 VI. Geomagnetic Activity Probabilities 22 Jul-24 Jul A. Middle Latitudes Active 20/20/35 Minor storm 10/10/20 Major-severe storm 05/05/05 B. High Latitudes Active 25/25/35 Minor storm 10/10/20 Major-severe storm 05/05/10
