Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO

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FXUS63 KEAX 190354

National Weather Service Kansas City/Pleasant Hill MO
1054 PM CDT Tue Apr 18 2017

Issued at 239 PM CDT TUE APR 18 2017

Deep mixing is causing the low stratus deck over west central
Missouri to quickly scatter out this afternoon, and most areas
should be mostly clear by late afternoon. In the meantime a cold
front over northern Nebraska will drop close to or just north of
the Missouri/Iowa border overnight before becoming stalled and
lifting back north on Wednesday. This feature will likely spark
off an area of showers and thunderstorms overnight, particularly
after midnight when it will begin interacting with a strengthening
LLJ over northeast KS. Most of this activity should stay just
north of the state line in closer proximity to the low level
boundary, but convergence ahead of the low level jet could assist
in getting convection as far south as St. Joseph and Kirksville
late tonight. Any strong storms or heavy rain are likely to stay
north of the forecast area where elevated instability and shear
will be stronger.

Gusty south winds on Wednesday will help boost temperatures into
the lower and possibly even middle 80s across the entire forecast
area on Wednesday. This will set the stage for some possibly
strong or severe storms Wednesday evening when a cold front will
drop in from the northwest. Models have slowed down the southward
progression of this feature, which is now not expected to enter
far northwest Missouri until late evening and not getting east of
I-35 until well after midnight, maybe even closer to sunrise. This
slower movement will keep the threat for strong and severe storms
confined mostly to areas northwest of the I-35 corridor Wednesday
evening. MLCAPE values around 1000 to 2000 J/kg and modest shear
values could support scattered hail storms and a few areas of
damaging winds, but veered low-level flow will keep the tornado
threat low. Instability will decrease fairly quickly after
midnight bringing a quick downward trend to any convection as it
gets east of I-35.

High pressure behind Wednesday`s front will bring cooler
conditions for Thursday and particularly by Friday. Meanwhile the
next storms system will eject out into the Plains on Friday and
bring widespread rain, some of which may be heavy, to parts of the
Plains and Mississippi River Valley Friday into Saturday. All
models have taken an noticeable southward shift with this system
over the past several runs, so at this time the highest threat for
widespread heavy rain appears to be south of Interstate 70, and
perhaps south of the entire forecast area across the Ozarks if
models keep shifting south. Areas sensitive to flooding will want
to keep an eye on this system as it could produce as much as 2 to
4 inches of rain wherever the heaviest precipitation tracks.


.Aviation...(For the 06Z TAFS through 06Z Wednesday Night)
Issued at 1054 PM CDT TUE APR 18 2017

VFR conditions will persist through the forecast period at all TAF
sites. Showers and thunderstorms that are developing in north
central KS will continue to focus near the low-level jet axis,
which will only slightly pivot to the northeast with time early
Wednesday morning, keeping nearly all precipitation away from the
terminals. Maintained the VCSH for KSTJ in case a few weakening
showers edge near the site, but do not expect any impact from
storms to the west. Otherwise, winds will increase after sunrise
and veer to the southwest, reaching sustained speeds of 20 kts
with gusts to 30 kts by early afternoon. Scattered to broken cumulus
will develop in the afternoon as well, but should be based above
3 kft.




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