Here is the AA space weather update for the morning of September 11th. An updated CME prediction model released by the NOAA Space Weather Prediction Center is calling for the plasma cloud generated by the X1.6 solar flare to impact our geomagnetic field by Friday. A moderate to major (G3) geomagnetic storm watch is now in effect. Solar wind speeds are predicted to reach near 800 km/s and could add fuel to another geomagnetic disturbance already in the forecast resulting from an earlier M4.5 flare and CME event.
Sky watchers at middle to high latitudes should be alert this weekend for visual aurora displays. Solar activity during the past 24 hours was strong. The largest and most noteworthy event was without a doubt the long duration X1.6 solar flare observed around region 2158 at 17:45 UTC. The flare was associated with Type II (3750 km/s) and Type IV radio emissions, a 10cm Radio Burst (TenFlare) lasting nearly an hour and measuring 1300 solar flux units, along with a full halo coronal mass ejection (CME). The majority of plasma appears to have a northward trajectory, however a still significant portion looks to be on line with our planet. Minor (G1) to major (G2-G3) geomagnetic storming will be possible within 24-48 hours thanks to this CME, in conjunction with an earlier CME associated with the M4.5 flare on Sept 9. Another isolated moderate to strong solar flare will remain a possibility today with regions 2157 and 2158 being the most likely source. All other visible sunspots are currently stable. A new sunspot in formation is now turning into view off the east limb, but is not yet considered a threat for strong solar flares. Energetic protons streaming past Earth remain above the minor (S1) radiation storm threshold this morning. These levels could persist until the expected passage of the CME events of Sept 9 and 10.
Stay tuned to our solar activity page for the latest information.