:Product: 0320RSGA.txt :Issued: 2011 Mar 20 2200 UTC # Prepared jointly by the U.S. Dept. of Commerce, NOAA, # Space Weather Prediction Center and the U.S. Air Force. # Joint USAF/NOAA Report of Solar and Geophysical Activity SDF Number 079 Issued at 2200Z on 20 Mar 2011 IA. Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity was at very low levels. Region 1175 (N14W36) continued to grow in areal coverage and produced the largest event of the period, a B7 X-ray event at 20/0733Z. Surging and low-level B-class X-ray emissions from the vicinity of the SE limb signal the return of old Region 1165 (S20, L=198). IB. Solar Activity Forecast: Solar activity is expected to be at predominately very low levels with a chance for C-class events for the next three days (21 - 23 March). A slight chance for isolated M-class activity exists all three days due to the return of old Regions 1165 late on 21 March and 1164 (N24, L=179) late on 22 March. IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic field was quiet. Solar wind velocities at the ACE satellite remained low, averaging about 350 km/s. The Bz component of the interplanetary magnetic field was southward the entire period, not varying much beyond 0 to -5 nT. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at predominately quiet levels for days one and two (21 - 22 March). By midday on day three (23 March), a small coronal hole high speed stream is expected to rotate into a geoeffective position. III. Event Probabilities 21 Mar-23 Mar Class M 10/20/20 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 20 Mar 092 Predicted 21 Mar-23 Mar 095/100/105 90 Day Mean 20 Mar 094 V. Geomagnetic A Indices Observed Afr/Ap 19 Mar 002/004 Estimated Afr/Ap 20 Mar 003/005 Predicted Afr/Ap 21 Mar-23 Mar 005/005-005/005-008/008 VI. Geomagnetic Activity Probabilities 21 Mar-23 Mar A. Middle Latitudes Active 10/10/15 Minor storm 01/01/05 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/20 Minor storm 01/01/10 Major-severe storm 01/01/01