QUOTE
On August 4th, active sunspot 1261 unleashed a strong solar flare, the third in as many days. The blast, which registered M9.3 on the Richter Scale of Flares, hurled a bright coronal mass ejection (CME) almost directly toward Earth.
Moving at an estimated speed of 1950 km/s, this CME is expected to sweep up an earlier CME already en route. Analysts at the GSFC Space Weather Lab say the combined-CME should reach Earth on August 5th at 10:00 UT plus or minus 7 hours: "The impact on Earth is likely to be major. The estimated maximum geomagnetic activity index level Kp is 7 (Kp ranges from 0 - 9). The flanks of the CME may also impact STEREO A, Mars and Mercury/MESSENGER."
Moving at an estimated speed of 1950 km/s, this CME is expected to sweep up an earlier CME already en route. Analysts at the GSFC Space Weather Lab say the combined-CME should reach Earth on August 5th at 10:00 UT plus or minus 7 hours: "The impact on Earth is likely to be major. The estimated maximum geomagnetic activity index level Kp is 7 (Kp ranges from 0 - 9). The flanks of the CME may also impact STEREO A, Mars and Mercury/MESSENGER."
Mid Latitudes have a 35% Minor Storm expectation, and 50% Severe Storm expectation within 24 hours from 8/4 @2200 UTC. High latitudes have an additional 5%.