:Product: 1125RSGA.txt :Issued: 2012 Nov 25 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 Solar Geophysical Activity Report and Forecast SDF Number 330 Issued at 2200Z on 25 Nov 2012 IA. Analysis of Solar Active Regions and Activity from 24/2100Z to 25/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C1 event observed at 25/2014Z from the west limb. Region 1618 (N08W55) was responsible for a B9 flare at 24/0617Z. Region 1618 was classified as an Ekc type group covering 270 millions of the visible solar disk. Further magnetic simplification was observed in Region 1618s leader spot, however it contained a delta in its larger trailing spot earlier in the period. Region 1620 (S13W14) appeared to develop gamma characteristics over the past 24 hours. New flux emergence was noted in the southeast quadrant near S17E38 and S24E30. These regions were small, simple beta type groups and will be monitored for continued development before being numbered. IB. Solar Activity Forecast: Solar activity is expected to be at low levels on days one, two, and three (26 Nov, 27 Nov, 28 Nov) with a chance for an M-class event. IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. There were no obvious signs the 21 November CME passage in the time series data from the ACE spacecraft in the past 24 hours. Solar wind speed began rising slowly from 350 km/s around 25/0400 UTC and peaked at 487 km/s 11 hours later. The Phi angle was near 225 degrees until 25/1000 UTC when it became variable. It came to rest at 315 degrees (negative sector) about 90 minutes later. Coincident with the variable period, Bz became negative. In the hours prior, it had been between 0 and +10nT. The temperature also began rising about the same time as the wind speed, but peaked around 25/1100 UTC. The EPAM instrument reported low energy particle flux rose from around 25/0600 to 0900 UTC, but abruptly leveled off afterwards and only minor fluctuations have followed. Total IMF reached 12.3 nT at 25/0303Z. The maximum southward component of Bz reached -8.1 nT at 25/1259Z. IIB. Geophysical Activity Forecast: The geomagnetic field should begin at mostly quiet levels with some isolated unsettled periods. WSA-ENLIL model runs place the 23 Nov CME at earth at the earliest by 15 UTC on the 26th and at the latest by about 00 UTC on the 27th. With the CME arrival, conditions are expected to be unsettled to active with a slight chance for isolated minor storm levels, particularly at high latitudes. III. Event probabilities 26 Nov-28 Nov Class M 30/30/30 Class X 05/05/05 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 25 Nov 121 Predicted 26 Nov-28 Nov 120/115/110 90 Day Mean 25 Nov 123 V. Geomagnetic A Indices Observed Afr/Ap 24 Nov 011/015 Estimated Afr/Ap 25 Nov 005/006 Predicted Afr/Ap 26 Nov-28 Nov 009/010-013/015-008/008 VI. Geomagnetic Activity Probabilities 26 Nov-28 Nov A. Middle Latitudes Active 20/25/10 Minor Storm 10/10/05 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 25/25/15 Major-severe storm 30/35/15