The weather could soon get ugly across Texas, Louisiana and further north into the Midwest, according to the latest outlook from the nation's Storm Prediction Center in Norman, Okla., thanks to a move by the jet stream.
A split in the jet stream — common this time of the year during La Niña — has produced the atmospheric conditions ripe for severe weather in the Ohio River Valley.
The above image, captured by the GOES-13 satellite, shows wind speeds at about 3.5 miles (3.7 kilometers) high in the mid-atmosphere on Nov. 14. The fast atmospheric winds characteristic of the jet stream can be seen splitting in the Pacific Northwest, with one branch bringing cool air into the United States from Canada, while another branch sweeps low into the Pacific and Gulf of Mexico, bringing with it warm, moist air.
The union of these two air masses creates the instability associated with severe weather. The National Oceanic and Atmospheric Administration (NOAA) is monitoring the situation as high winds, hail and even tornadoes may result from this weather system. The wind speeds shown in the above image are high in the atmosphere and are much greater than those to be expected on the ground for most areas.
The Storm Prediction Center said there is a slight risk of severe thunderstorms late this afternoon and tonight across parts of East Texas and into the Lower Mississippi Valley. The system could produce damaging winds and isolated supercell storms may spawn tornadoes. The system is then expected to move north.
Another image was taken at 2 pm EST, also by the GOES-13 satellite, and shows the atmospheric instability can also be seen in the disarray of cloud structures — especially the wispy high cirrus clouds. The banding patterns seen in these clouds are also associated with areas of turbulence. In addition, the high over-shooting cloud tops that are characteristic of severe convective weather can be seen forming over central Indiana. [Images: Reading the Clouds]
The so-called second tornado season is currently underway. The main tornado season runs from spring to early summer, but tornadoes can form under a variety of conditions and strike during fall and winter.
Tornadoes have killed 548 people so far in 2011, according to the Storm Prediction Center, making this one of the most active and deadly tornado years in U.S. history. A massive outbreak in April killed nearly 250 people in Alabama alone. One month later, another massive twister killed more than 150 in Joplin, Mo.
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