Major solar storm, alert for a CME, coronal mass ejection

Sunspot region 2158, the source of a solar flare today
From Spaceweather.com here

UPDATE 2: From space watch.com:

STORM WARNING (UPDATED): Among space weather forecasters, confidence is building that Earth's magnetic field will receive a double-blow from a pair of CMEs on Sept. 12th. The two storm clouds were propelled in our direction by explosions in the magnetic canopy of sunspot AR2158 on Sept. 9th and 10th, respectively. Strong geomagnetic storms are possible on Sept. 12th and 13th as a result of the consecutive impacts. Sky watchers, even those at mid-latitudes, should be alert for auroras in the nights ahead.

UPDATE 1: I have posted a number of relevant items over the past few years on solar storm activity: 

• General background about space weather, CME's and solar flare
• One of my most popular posts, a 2010 one titled "Solar activity (and Newt Gingrich)"
• An X5-class solar flare in March, 2012
• In January 2012, the biggest flare since 2005 and here.
• An aurora viewed as far south as the midwest
• And, another flare/CME on February 15, 2011___________________

While our daily earth-weather is filled with heat waves still hitting us as summer fades into autumn, something 'out there' is ready to hammer us! Sunspot region 2158 spat forth a "long duration X1.66 (R3-strong radio blackout) solar flare today. It peaked at 17:45 UTC on Sept. 11  (11:45 a.m. PST on Sept. 10).

This sunspot region has been active for a few months. On September 1 it was the source of a flare, but on the backside of the sun. However, this region is now directly facing the earth. Solar scientists are awaiting data, but they think that it's likely that a Coronal Mass Ejection (CME) of particles will follow.  Information is updated regularly at NOAA's Space Weather Prediction Center here.

Why should we care? A CME has the potential to disrupt electronics that we depend on, whether in space for communications or on earth in health care facilities, computer centers, or communications facilities. A CME can also pose biological risk to astronauts and to passengers and crew in high-altitudes--especially if they are flying cross-polar routes where the particles preferentially come into the earth along magnetic field lines.

According to Mike Wall, a senior writer at Space.com,  the sun "unleashed an X-class solar flare--the most powerful type" today, and it also fired off another intense flare yesterday. Fortunately, NASA in these times of diminishing funding, still has the Solar Dynamics Observatory spacecraft which recorded the event. The flare was an X1.6 storm, and space.com says that it "poses no danger to anyone on Earth or the astronauts living aboard the International Space Station." However, radio communications on earth, the side facing the sun could experience radio communications lasting 'more than an hour.' However, if the eruption is accompanied by a CME, in 2-3 days, there might be significant geomagnetic storms that can disrupt GPS signals, power grids, and  communications.

We are near the peak phase of the Sun's 11-year cycle (Solar Cycle 24), but this phase is the weakest in about 100 years....and that's a whole other discussion!