acus03 kwns 210730
Storm Prediction Center ac 210729
Day 3 convective outlook
National Weather Service Storm Prediction Center Norman OK
0229 am CDT Tuesday may 21 2013
Valid 231200z - 241200z
..there is a slight risk of severe thunderstorms Texas/OK Panhandle vicinity...
an eastern noam upper trough is forecast to continue eastward this
period...while upstream ridging spreads eastward into the central U.S.
Ahead of the next upper system. This system -- a large/very upper
low over the Pacific northwest...will make very little progress through the
At the surface...a cold front crossing Montana/WY/the Great Basin will --
like its parent upper system -- make only slow eastward progress.
Meanwhile...a second front will continue advancing across the northestern
U.S. Toward the Atlantic coast.
..TX/OK Panhandle vicinity...
Subsidence/capping is forecast across the southern High Plains region
under the evolving upper ridge. However...strong instability above
the cap and strongly veering flow with height otherwise indicate
some potential for severe weather.
Models -- to varying degrees -- do forecast at least isolated storm
initiation in vicinity of the Texas/OK Panhandle vicinity. Any storm which
could develop would likely organize rapidly and become
severe/supercellular. Thus -- will introduce conditional slight
risk across this region...with refinements likely to be needed in
later forecasts as convective potential becomes more clear.
..New England southward across the middle-Atlantic region...
Ample flow aloft but weak instability should characterize the
pre-frontal warm sector across the northeast and middle-Atlantic region
Thursday. Thus -- overall severe potential appears relatively low
at this time. Will introduce low severe weather probability across this
area for isolated hail/wind threat where a few stronger afternoon
storms can form...but will wait until later outlooks to issue a more
specific/possibly higher-probability forecast.