A powerful solar flare was unleashed from a massive sunspot Thursday, blocking high-frequency radio communication in the Northern Hemisphere and producing the potential for auroras to rage across the northern United States.
The flare was rated as an X-class sun storm by the National Oceanic and Atmospheric Administration, which is the most powerful type of flare the sun can have.
A giant sunspot facing Earth, named Active Region 1520 by NASA officials, discharged the flare around 12:50 p.m. EDT. Joining the solar flare that burst on July 6 from another giant sunspot region - AR1515 - it's the second major solar storm to impact Earth in less than a week.
"The sunspot hasn't produced a lot of activity since it's been around, so the potential was there for it," said AccuWeather Astronomy Blogger Hunter Outten.
Outten said the NOAA predicted a 15 percent chance for an X-class flare to occur today, with an 80 percent chance for an M-flare to occur, which is one level lower on the solar storm strength scale.
By 5:30 p.m. EDT, communications around the northern pole regions were still nearly impossible, Outten said.
According to the NOAA's Space Weather Prediction Center, geometric storm activity could occur from the coronal mass ejection on Saturday, July 14, around 9 a.m. EDT, and the effects will be minor to moderate. CME particles are made up of solar plasma that damage Earth's electrical grid.
The last major geometric storm occurred this year on March 6, producing an R3-level radio blackout from the CME's particles. These storms also have the potential to create surges in power lines and jumble GPS information.
"This is something that is called long-duration, which we haven't had since early March," Outten said. "We can expect a pretty high geomagnetic storm."
However, the storms will also have a beautiful effect on the atmosphere.
According to AccuWeather Meteorologist Mark Paquette, "it may be the most impressive [aurora] showing in years."
Paquette said to expect the northern lights to extend across the northern U.S. over the next few nights. The farther north you live, the better chance you have to see them, he said, so those in Washington, northern Plains, northern Great Lakes, upstate New York and northern New England should keep an eye out.
"At least 50 percent of the United States could have auroras in their backyards," Outten said.
A swath of snow and wintry mix with slippery travel will develop from St. Louis to Albany, N.Y., prior to the weekend.
Plunging temperatures will threaten California agriculture with a frost and freeze this week.
A swath of ice and a wintry mix later this week threatens to slow travel and cut power from parts of Texas to Kentucky.
A storm system interacting with cold air in the West will lead to low snow levels in Oregon and California.
As cold air blasts into the West and spreads into the Central states, warmth will build in the East, including the Harrisburg, Pa., area much of this week.
As cold air blasts into the West and spreads into the Central states, warmth will build in the East, bringing above-average temperatures to the Boston area this week.
Vicksburg, MS (1953)
Killer tornado in Vicksburg - 38 dead, 270 injured, $25 million.
New Jersey (1927)
Heavy sleet storm left 1-4" in parts of the state.
Duluth, MN (1950)
Storm starting today set two records, max. 24 hour snowfall 25.4"; max. single storm total 35.2" (5th-8th).