WIND SHEAR

One key ingredient that is needed to produce severe weather is wind shear. Generally speaking wind shear is just a change in the speed or the direction of the wind with height. The two maps depicted above are those of the wind field at roughly 5000 feet (850mb) and 35,000’ (250mb). Focusing on the Panhandle region of Texas and Oklahoma, note how the direction of the wind field at 850mb is southerly and at 250mb it’s westerly. This is a prime example of directional wind shear.

Directional wind shear aids in severe thunderstorm development by inducing a spin to the storm and by allowing the rain / hail core to fall away and downwind from the storm. This in return allows the moisture or fuel source to remain intact in the updraft, leading to long-lived storms.

Several supercell thunderstorms, with reports of large hail, damaging winds and tornadoes developed across regions of the Panhandle as well as Southwestern Kansas yesterday afternoon, undoubtedly aided by wind shear.

Posted by Ted Zarras at 12:15 PM