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

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FXUS63 KEAX 281116

National Weather Service Kansas City/Pleasant Hill MO
616 AM CDT Wed Jul 28 2021

Issued at 406 AM CDT WED JUL 28 2021

Key Points:

-Heat looks to be a concern over the next 2-3 days.  Heat index
values today are expected to be ~105 F, and may approach ~110
degrees tomorrow across northern Missouri.  Will have to also watch
conditions on Friday, especially south of a line from the KC metro
to Sedalia where heat indices may warm to near 105 F.

-Cold front is expected to build into the region from the north, and
will be the focus for thunderstorms both Thursday and Friday
evenings.  A few storms may be strong producing gusty winds.

Detailed discussion...

Soupy environment the next few days with very warm and moist
environment.  Have seen some sporadic observations overnight report
reduced visibility, but expect those conditions to be largely
temporary prior to sunrise.  As the sun comes up, expect strong
heating to lead to a muggy day across the region. 850 hpa
temperatures hover near 23 C the next two days resulting in highs in
the mid and upper 90s. With dew points of 70-75, heat index values
around 105 look likely today.  Could see temperatures warm slightly
more across northern Missouri Thursday afternoon in advance of back
door cold front.  In addition, moisture pooling ahead of the front
may tip the heat index closer to 110 F.  Will need to keep a close
eye on this area for potential upgrade to Excessive heat warning.

With the arrival of the surface front in the late afternoon hours on
Thursday, expect nearly uncapped environment with nearly 4000 J/kg
of surface based CAPE.  Wind shear is fairly weak, with 0-6 km bulk
shear values remaining under 20 knots.  Expect thunderstorms to
develop along the front across northern Missouri mainly east of I-
35. Agree with day 2 marginal severe risk, with the potential for a
few stronger updrafts to lead to a marginal wind threat.
Precipitable water values are expected to surge above 2", and with
deep warm cloud layer depths of nearly 15000 feet, expect storms to
be efficient rain producers. Therefore, WPC has also outlined the
area in marginal risk for excessive rainfall.  Largely expect storms
to attempt to propagate south, but struggle to make significant
headway with largely capped environment.

Boundary is expected to stall across the area Thursday night into
Friday. South of the boundary, discussed the potential with
surrounding forecast offices of issuing another heat headline for
Friday, but precise location is unknown at this point. Most favored
area  will be south and west of a line from KC metro to Sedalia.
North of the front, a largely uncapped environment will likely lead
to additional showers and thunderstorms.  The potential exists for
training, which could lead to locally heavy rainfall.

The front is expected work south Friday night into Saturday, leading
to cooler conditions across the area, but could see the chance of
showers and thunderstorms linger much of the day on Saturday.

Sunday into early next week looks to be dry with northeast winds
drawing cooler drier air into the region.  This will lead to dry
conditions with below normal temperatures.


.Aviation...(For the 12Z TAFS through 12Z Thursday Morning)
Issued at 614 AM CDT WED JUL 28 2021

Patchy shallow ground fog should quickly burn off today. Light
winds this morning will become a bit more consistent out of the
southwest this afternoon. A few cumulus will be possible near
Sedalia today, otherwise clear skies should prevail through the
forecast period.


KS...Heat Advisory until 9 PM CDT Thursday for KSZ025-057-060-102>105.

MO...Heat Advisory from noon today to 9 PM CDT Thursday for

     Heat Advisory until 9 PM CDT Thursday for MOZ001-002-011-012-020-



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