The Solar Flares just keep on coming. This time Sunspot 1302 churned out an M7.4 Solar Flare at 04:50 UTC Sunday morning. Visit SolarHam.com for all of the latest information.
The large dark area is 1302
Prepared jointly by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center and the U.S. Air Force.
Updated 2011 Sep 25 2205 UTC
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 268 Issued at 2200Z on 25 Sep 2011
IA. Analysis of Solar Active Regions and Activity from 24/2100Z to 25/2100Z: Solar activity was high. Regions 1302 (N12E36) and 1303 (S28W79) each produced three M-class flares. The largest was an M7/2N at 25/0450Z. A partial halo CME was observed at 4/1936Z in LASCO C2 imagery which was likely associated with the M3 flare from Region 1302 that occurred at 24/1921Z. The event had an associated Type II (1369 km/s) and an approximate plane of sky speed of 800 km/s using LASCO C3 imagery. Two more CMEs were observed at 25/0236Z and 25/0312Z off the Southwest limb in LASCO C2 imagery, however they are not expected to be geoeffective.
IB. Solar Activity Forecast: Solar activity is expected to continue at high levels with a chance for isolated X-class flares from Region 1302.
IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z:
The geomagnetic field was mostly quiet. A sudden impulse (SI) was observed at the ACE spacecraft at approximately 25/1106Z. The IMF Bt increased from approximately 5 nT to 10 nT while the field density increased to around 7 p/cc. The greater than 10 MeV protons event that began at 23/2255Z reached a peak of 27.3 PFUs at 25/2030Z and continues to remain above the 10 PFU threshold.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to minor storm conditions with major storm periods possible at high latitudes on day 1 (26 September) due to activity from the CME associated with the M7 flare that occurred at 24/1320Z. Mostly unsettled conditions are expected on days 2-3 (27-28 September) due to continued activity from the CME as well as a possible glancing blow from a weak CME on day 3. The greater than 10 MeV proton flux is expected to continue to remain above threshold for the next three days.
III. Event Probabilities 26 Sep-28 Sep
Class M 80/80/80
Class X 40/40/40
GEOMAGNETIC STORM WARNING: A pair of closely-spaced CMEs propelled by explosions of sunspot AR1302 on Sept. 24th are heading not-quite directly toward Earth. A significant glancing blow to our planet's magnetic field is possible on Sept. 26th around 14:00 UT (+/- 7 hours). NOAA forecasters estimate a ~25% chance of geomagnetic storms when the clouds arrive. [CME forecast track]
STRONG SOLAR ACTIVITY: Having already unleashed two X-flares since Sept. 22nd, sunspot AR1302 appears ready for more. The active region has a complex "beta-gamma-delta" magnetic field that harbors energy for strong M- and X-class eruptions. Flares from AR1302 will become increasingly geoeffective as the sunspot turns toward Earth in the days ahead.