:Product: 0218RSGA.txt :Issued: 2011 Feb 18 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 049 Issued at 2200Z on 18 Feb 2011 IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: Solar activity was high during the past 24 hours. Region 1158 (S19W64) produced several C-class events with a C1 at 17/2135Z that was associated with a Type II Sweep and an M1 event at 18/1303Z. Region 1161 (N12W02) grew slightly in area and maintained a beta-gamma magnetic classification. New Region 1162 (N18W06) was numbered today and developed rapidly into a Dai-type sunspot group with a beta-gamma magnetic classification. The bulk of the activity originated from this new region, including two M1 events and an M6 event at 18/1011Z. IB. Solar Activity Forecast: Solar activity is expected to be moderate with a chance for isolated high level activity for the next three days (19-21 February). IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field was unsettled to active with an isolated minor storm period at high latitudes. This activity was due to the effects of the CMEs associated with two M-class events and an X-class event observed from 13-15 February. A sudden impulse of 33 nT was observed at 18/0136Z at the Boulder magnetometer in association with this event. The ACE spacecraft indicated solar wind velocities increased to approximately 700 km/s along with a sustained period of southward Bz between -10 and -15 nT from 18/0200-0300Z. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to unsettled with a chance for isolated active periods for day one (19 February) due to the residual effects of the recent CMEs. Days two and three (20-21 February) are expected to be mostly quiet. III. Event Probabilities 19 Feb-21 Feb Class M 75/75/75 Class X 15/15/15 Proton 10/10/10 PCAF Green IV. Penticton 10.7 cm Flux Observed 18 Feb 125 Predicted 19 Feb-21 Feb 120/120/110 90 Day Mean 18 Feb 086 V. Geomagnetic A Indices Observed Afr/Ap 17 Feb 005/002 Estimated Afr/Ap 18 Feb 018/022 Predicted Afr/Ap 19 Feb-21 Feb 010/012-005/005-005/005 VI. Geomagnetic Activity Probabilities 19 Feb-21 Feb A. Middle Latitudes Active 25/15/05 Minor storm 10/05/01 Major-severe storm 01/01/01 B. High Latitudes Active 25/20/05 Minor storm 10/05/01 Major-severe storm 01/01/01