NOAA SEC Report of Solar-Geophysical Activity 25 Jul 2001
:Product: Report of Solar-Geophysical Activity :Issued: 2001 Jul 25 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 206 Issued at 2200Z on 25 Jul 2001 IA. Analysis of Solar Active Regions and Activity from 24/2100Z to 25/2100Z: Activity remained low. Gradual decay occurred in Region 9543 (S23W58), which produced an isolated C-class subflare. Minor spot growth occurred in Region 9553 (N13E08) early in the period. The remaining active regions were small, stable, and simply structured, including newly numbered Region 9556 (S07W42). IB. Solar Activity Forecast: Solar activity is expected to remain low. However, there will be a slight chance for an isolated M-class flare from Region 9543. IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z: Geomagnetic field activity ranged from unsettled to active levels with brief minor to major storm levels detected at high latitudes. This activity was likely due to coronal hole effects. IIB. Geophysical Activity Forecast: Geomagnetic field activity is expected to be at quiet to active levels during the first day as coronal hole effects continue. Activity is expected to decrease to quiet to unsettled levels during the rest of the period as coronal hole effects subside. III. Event Probabilities 26 Jul-28 Jul Class M 25/25/25 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 25 Jul 133 Predicted 26 Jul-28 Jul 135/130/130 90 Day Mean 25 Jul 155 V. Geomagnetic A Indices Observed Afr/Ap 24 Jul 011/015 Estimated Afr/Ap 25 Jul 018/021 Predicted Afr/Ap 26 Jul-28 Jul 015/015-012/012-010/012 VI. Geomagnetic Activity Probabilities 26 Jul-28 Jul A. Middle Latitudes Active 30/25/20 Minor storm 15/10/10 Major-severe storm 05/01/01 B. High Latitudes Active 35/30/25 Minor storm 20/15/10 Major-severe storm 05/05/05
