:Product: 0819RSGA.txt :Issued: 2012 Aug 19 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 232 Issued at 2200Z on 19 Aug 2012 IA. Analysis of Solar Active Regions and Activity from 18/2100Z to 19/2100Z: Solar activity was moderate. Region 1548 (N19E62) produced two M-class flares, an M1/Sf at 18/2254Z and an M1/Sn flare at 18/2322Z. Activity then decreased to low levels for the remainder of the period. Region 1548 decreased in area and ended the period as a Cso type group with beta magnetic characteristics. New Region 1549 (S16W30) was numbered today and also a simple Cso-beta type group. IB. Solar Activity Forecast: Solar activity is expected to be low with a chance for an M-class event for the next three days (20-22 August). IIA. Geophysical Activity Summary 18/2100Z to 19/2100Z: The geomagnetic field ranged from quiet to unsettled levels. A coronal hole high speed stream became geoeffective during the past 24 hours. At approximately 18/08Z, solar wind speed at the ACE spacecraft began increasing from about 400 km/s to 580 km/s. Shortly after, the Bz component of the interplanetary magnetic field (IMF) became negative, eventually reaching -12nT. Bz returned to positive values around 14Z. Earth is currently in the positive sector of the IMF. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at mostly unsettled levels with a chance for active conditions on day 1 (20 August), decreasing to a slight chance on days 2-3 (21-22 August). The disturbed conditions are expected in response to the continued presence of the coronal hole high speed stream. III. Event Probabilities 20 Aug-22 Aug Class M 20/20/20 Class X 01/01/01 Proton 01/01/01 PCAF Green IV. Penticton 10.7 cm Flux Observed 19 Aug 096 Predicted 20 Aug-22 Aug 100/100/105 90 Day Mean 19 Aug 125 V. Geomagnetic A Indices Observed Afr/Ap 18 Aug 011/013 Estimated Afr/Ap 19 Aug 010/013 Predicted Afr/Ap 20 Aug-22 Aug 012/012-007/008-007/008 VI. Geomagnetic Activity Probabilities 20 Aug-22 Aug A. Middle Latitudes Active 20/10/10 Minor storm 05/05/05 Major-severe storm 01/01/01 B. High Latitudes Active 20/15/15 Minor storm 30/20/20 Major-severe storm 25/15/20