Saturday, September 17, 2011

Severe Storms Possible Central Plains Later This Afternoon & Evening...

The above image shows the latest severe weather outlook for this afternoon and evening from the SPC in Norman, OK. Severe thunderstorms are forecast within the yellow shaded area on the image, from southwest and southcentral Kansas into much of the Western half of Oklahoma and extreme northwest Texas.

Large hail and damaging winds will be the primary severe weather threats with storms this afternoon and evening, though isolated tornadoes also cannot be ruled out (particularly with any storm that is able to remain relatively isolated and become well organized).

Low level moisture and instability are flowing rapidly Northward through the Southern and into the central High Plains this afternoon.  The latest surface weather map below shows dew points in the 60s as far North as extreme Southwest Kansas at this time (green number on the lower left hand side of each station model):

At the same time, several weak to moderate disturbances in the middle and upper levels of the atmosphere will move Eastward across the region this afternoon and evening, which will result in thunderstorm development within the increasingly unstable airmass noted above.

The most likely area for initiation of thunderstorms later this afternoon will be in southwest or southcentral Kansas, Southward into northwestern Oklahoma. Activity may also develop Southward over time, across western Oklahoma and extreme northwest Texas.

The images below show the experimental "High Resolution Rapid Refresh" or HRRR model forecasts valid 3pm and 4pm CDT this afternoon, respectively (click to enlarge and defuzzify):

As you can see, the model suggests isolated to scattered development across southwest Kansas or northwest Oklahoma by 3pm, with the activity blossoming even further by 4pm.  Once developed, thunderstorms will move toward the East or East/Northeast.  (And take a look further South in Texas - boy I sure hope that forecast verifies - it would be quite welcome, indeed!  See my earlier post for more details on widespread rain potential in Texas during the coming days.)

The activity that forms in Kansas and Oklahoma later this afternoon is likely to congeal into one or more complexes or clusters of thunderstorms that will move East to East/Southeast across the remainder of those states later this evening and tonight, possibly reaching adjacent portions of Missouri and Arkansas by Sunday morning.

If you enjoy reading 'The Original Weather Blog', please be sure to "like" our facebook page!

No comments: