NOAA SEC Report of Solar-Geophysical Activity 23 Apr 2001
:Product: Report of Solar-Geophysical Activity :Issued: 2001 Apr 23 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 113 Issued at 2200Z on 23 Apr 2001 IA. Analysis of Solar Active Regions and Activity from 22/2100Z to 23/2100Z: Solar activity has been moderate. Region 9433 (N17E14) produced two M-class events during the period, an M1/1f flare at 23/0128 UTC and an M4/2n at 23/2030 UTC. Region 9431 (S11W29) produced an C2/Sf at 23/1223 UTC with an associated 6 degree long disappearing filament. Region 9433 continues to grow in spot count and area. This region has retained its F-type sunspot group with mixed polarities and a delta configuration. IB. Solar Activity Forecast: Solar activity is expected to be moderate. Region 9433 is likely to continue to produce M-class events with the chance for an isolated major flare during the next three days. IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z: The geomagnetic field has been at quiet to minor storm conditions for the last 24 hours. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to unsettled. There remains a chance for an energetic proton event if a major flare occurs in Region 9433. III. Event Probabilities 24 Apr-26 Apr Class M 75/75/75 Class X 10/10/10 Proton 05/05/05 PCAF green IV. Penticton 10.7 cm Flux Observed 23 Apr 196 Predicted 24 Apr-26 Apr 205/210/210 90 Day Mean 23 Apr 166 V. Geomagnetic A Indices Observed Afr/Ap 22 Apr 017/028 Estimated Afr/Ap 23 Apr 020/025 Predicted Afr/Ap 24 Apr-26 Apr 010/010-010/010-010/015 VI. Geomagnetic Activity Probabilities 24 Apr-26 Apr A. Middle Latitudes Active 10/10/10 Minor storm 05/05/05 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/20 Minor storm 10/10/10 Major-severe storm 05/05/05
