:Product: 0316RSGA.txt :Issued: 2011 Mar 16 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 075 Issued at 2200Z on 16 Mar 2011 IA. Analysis of Solar Active Regions and Activity from 15/2100Z to 16/2100Z: Solar activity was at low levels. During the period, Region 1169 (N17W75) produced a few low-level C-class events including a long-duration (LDE) C3/Sf flare at 16/2034Z. The flare was still in progress at the time of this writing. Associated with this LDE was a partial-halo CME, first observed in LASCO C2 imagery at 16/1912Z. A preliminary plane-of-sky estimate indicated a velocity near 500 km/s. The region maintained its beta-gamma magnetic classification as it approached the west limb. New Region 1173 (S28E39) emerged on the disk as a bi-polar C-type group. The Penticton 10.7 cm flux and the 90-day mean are estimated for today (16 March) due to flare enhanced readings. IB. Solar Activity Forecast: Solar activity is expected to be low with a chance for an M-class event from Region 1169 for the next two days (17 - 18 March). On day three (19 March), activity is expected to be very low with a chance for a C-class event. IIA. Geophysical Activity Summary 15/2100Z to 16/2100Z: The geomagnetic field was quiet. Observations from the ACE satellite indicated solar wind velocities averaged about 370 km/s while the Bz component of the interplanetary magnetic field was mostly north at +1 to +5 nT. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet for the next three days (17 - 19 March). III. Event Probabilities 17 Mar-19 Mar Class M 25/05/01 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 16 Mar 095 Predicted 17 Mar-19 Mar 090/085/080 90 Day Mean 16 Mar 094 V. Geomagnetic A Indices Observed Afr/Ap 15 Mar 000/000 Estimated Afr/Ap 16 Mar 001/002 Predicted Afr/Ap 17 Mar-19 Mar 005/005-005/005-005/005 VI. Geomagnetic Activity Probabilities 17 Mar-19 Mar A. Middle Latitudes Active 10/10/10 Minor storm 01/01/01 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor storm 01/01/01 Major-severe storm 01/01/01