Sunday, September 30, 2012

Incoming CME from Sept 28th, Storms Expected

The above X-ray image of the sun was taken September 30th at 03:08:00 UTC by the Solar X-ray Imager (SXI) aboard the GOES-15 satellite. Image Credit: NOAA

For the end of September 28th and most of September 29th, the solar activity was low. Numerous weak C-class events were observed, mostly from Active Regions 1575 and 1577 (AR 1575, AR 1577). New region AR 1583 emerged on the disk as a simple bipolar group. No significant changes were observed elsewhere. No Earth-directed coronal mass ejections (CMEs) were observed during the period. The forecast through October 2nd: The solar activity is expected to be low with a slight chance for M-class activity.

Above Earth, the geomagnetic field was quiet. The Advance Composition Explorer(ACE) satellite measurements indicated a steady decline in wind speed from about 325 km/s to near 275 km/s while the Bz component of the interplanetary magnetic field did not vary much beyond +/- 3 nT. On the 29th at about 01:00 UTC, a solar sector boundary crossing from a negative (toward) to a positive (away) orientation was observed. The forecast through October 2nd: The geomagnetic field activity is expected to be at predominately quiet levels through about midday on the 30th. By late on the 30th, active levels with a chance for minor to major storm periods are expected due to the arrival of the Earth-directed CME observed early on the 28th. On the 1st, continued minor to major storm conditions are expected early in the day, decreasing to mostly quiet to unsettled levels with a chance for isolated active periods as effects from the CME wane. Predominately quiet to unsettled conditions are expected on the 2nd. Stay tuned...

To monitor solar flare activity minute by minute, visit the "Today's Space Weather" page of NOAA's Space Weather Prediction Center (

To learn more about the sun and to stay current on solar activity, visit the mission home pages of the Solar Dynamics Observatory (SDO) (, the Solar and Heliospheric Observatory (SOHO) (, the Advanced Composition Explorer (ACE) (, and the Solar Terrestrial Relations Observatory (STEREO) (


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