- Day Three
acus03 kwns 230635
Storm Prediction Center ac 230634
Day 3 convective outlook
National Weather Service Storm Prediction Center Norman OK
0134 am CDT Wednesday Apr 23 2014
Valid 251200z - 261200z
..no severe thunderstorm areas forecast...
isolated strong...or perhaps one or two severe thunderstorms...may
develop across parts of the southeastern U.S. And along a dryline
over northwestern Texas and western Oklahoma.
Subtle but potentially significant short-wave trough will shift east
of the Appalachians Friday afternoon. Timing of this feature does
not correlate well with diurnal heating but it may prove adequate in
generating a few thunderstorms across coastal Carolinas. If timing
of short wave is too early then strong boundary layer heating could
steepen low level lapse rates enough for a few Post-short wave thunderstorms
within veered but modestly unstable airmass. For now will introduce
5 percent severe probs to account for poor timing of short wave and
weakly convergent low levels.
..srn plains dryline...
Lee trough/dryline is expected to begin sharpening across the southern
High Plains Friday afteroon as troughing establishes itself over the
western U.S. Intense boundary layer heating is forecast across western
Texas/OK during the day where surface temperatures should soar through the
80s to perhaps near 90f and this should be adequate in removing
early-day inhibition. One major concern for organized deep
convection along the dryline is the expected short-wave ridging
forecast across this region during the afternoon. It/S not entirely
clear how much convection will ultimately evolve...with the primary
threat during the 22z-03z time frame. NAM is most aggressive in
allowing a few high-based thunderstorms to evolve within airmass
characterized by 1500 j/kg SBCAPE but strongly sheared...sfc-6km
values approaching 50kt. Low severe probs have been introduced for
isolated supercells that could produce large hail/wind.