Area forecast discussion
National Weather Service Kansas City/Pleasant Hill MO
314 PM CDT Mon may 20 2013
Short term...(this evening through Tuesday night)
issued at 311 PM CDT Monday may 20 2013
Thunderstorm chances remain the Focal Point in the short term
portions of the forecast. Late this afternoon, convection was
beginning to Blossom over southeastern Kansas and west central
Missouri in response to a speed Max rotating around the base of the
expansive upper trough. MLCAPE values approaching 2000-3000 j/kg
have spread northeast across the Kansas/MO border. Initial convection
this afternoon appears to be rooted at or above 800 mb as a fairly
substantial eml persists around 850mb (as noted from 19z aircraft
sounding from mci). Rap/NAM soundings seem to be too aggressive in
eroding this eml this afternoon, perhaps due to the poor
initialization of mid-level moisture advection northward.
Nevertheless, these elevated supercells will continue for the
upcoming few hours with the potential for very large hail. This
activity also is riding just north of a remnant outflow boundary
just south of the cwa, which if it can be forced northward, would
lead to a higher potential damaging winds isolated tornadoes should
storms begin to become rooted in the boundary layer. Storm
trajectories continue to push activity northeast and with flow aloft
rather unidirectional, training and flash flooding may become an
issue over the southern zones this evening.
Tonight, short term models have partially backed off on the
development of a broken line of convection over NE Kansas and northwest
Missouri towards 00z as a secondary front begins to sweep into the
County Warning Area. However, soundings continue to look favorable for severe
convection and given projected height falls, feel that this
convection may become more of a reality.
Tuesday: secondary shortwave now beginning to rotate through Nevada
will lift northeast through southern Missouri on Tuesday. This
shortwave may produce renewed convection over the eastern County Warning Area int
the afternoon, with severe chances primarily focused over eastern
and southeastern Missouri.
Long term...(wednesday through monday)
issued at 311 PM CDT Monday may 20 2013
Upper level trough will gradually lift northeastward into the
southern Great Lakes region by the end of the workweek. Thunderstorm
chances will decrease as this system moves out of the region...with
some lingering convection into Wednesday morning across northern
Missouri. Cooler weather will follow the out going system with high
temperatures remaining in the 70s and lows generally in the 50s.
Shortwave ridging will begin to build into the Central Plains by the
weekend bringing warmer temperatures with it. A series of shortwave
troughs moving along the ridge will result in the chance for
scattered showers and thunderstorms to develop towards the end of
the week along a frontal boundary that is forecast to set up across
the Kansas and Missouri.
&&
Aviation...(for the 18z tafs through 18z Tuesday afternoon)
issued at 1216 PM CDT Monday may 20 2013
A rather messy afternoon forecast continues for convective chances
near the major terminals. Several outflow boundaries linger over the
cwa, with the one with the highest potential developing convection
stretching from Fort Scott eastward to Columbia. Further north, a
secondary elevated boundary continues to lift through northern
Missouri and Kansas, and as we continually destabilize this
afternoon, it too may become a focus for scattered convection.
Will also need to watch the true cold front entering northwest Missouri
later today. For now, unable to pinpoint an exact time or location
for convective development in relationship to the terminals, and will
continue to advertise thunderstorms in the vicinity through the evening.
Quiet conditions do return after midnight, with VFR prevailing.
&&
Eax watches/warnings/advisories...
Kansas...none.
MO...none.
&&
$$
Short term...dux
long term...pmm
aviation...dux
