Area Forecast Discussion
Issued by NWS St. Louis, MO

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000
FXUS63 KLSX 220849
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
349 AM CDT Tue Jul 22 2014

.SHORT TERM:  (Through Late This Afternoon)
Issued at 348 AM CDT Tue Jul 22 2014

During the day today the upper ridge will remain in place with
surface temperatures expected to warm up into the low to mid 90s.
Low level moisture continues to increase as well, so will see heat
indicies between 100 and 105 for central and northeast MO as well as
west central IL.

Byrd

.LONG TERM:  (Tonight through Monday)
Issued at 348 AM CDT Tue Jul 22 2014

In the meantime, cold front associated with next weather system
to move into far northern portions of MO by 00z Wednesday. Short
term models begin to develop complex along frontal boundary around
this time and track it to the south and southeast through forecast
area tonight. Some differences on timing and coverage between the
models, so went with a blend and increased pops to likely late
this evening and into the overnight hours as it moves through.
Despite all of the instability and moisture, some concern about
mid level capping, but confident cap will weaken sufficiently to
allow storm development. With decent capes, moisture and
instability, SPC has placed northern portions of forecast area in
a slight risk for tonight with main threats being large hail and
damaging winds.

System to continue tracking south through southern portions of
forecast area Wednesday morning, before tapering off Wednesday
afternoon. As for highs on Wednesday, will range from the low 80s
far north to around 90 far south.

By Wednesday night, surface ridge begins to build in and bring in
drier and cooler weather for the last half of the work week. Highs
on Thursday will be in the upper 70s to mid 80s.

Surface ridge to move off to the east by Friday with a warm front
developing across region with elevated convection possible for
portions of forecast area Friday and Friday night. Then as main cold
front moves into region on Saturday, will see additional rounds of
storms through Sunday night before system exits region on Monday.
Temperatures to moderate through the weekend once again.

Byrd
&&

.AVIATION:  (For the 06z TAFs through 06z Tuesday Night)
Issued at 1144 PM CDT Mon Jul 21 2014

VFR with sly to swly winds aob 10kts is expected thru Tues
afternoon. SUS may see some FG a couple of hours before sunrise
Tues morning, however, confidence in this event is decreasing due
to greater dewpoint spread and ssely flow. There is some
indication that TSRA may form during the pre-dawn hours Tues
morning across the srn half of IA. If these TSRA do form, believe
they will remain N of UIN, but this remains uncertain. A cdfnt is
expected to approach the region Tues evening. This fnt may bring
isod to sct TSRA along and just ahead of the fnt with winds
becoming nly behind the fnt. Due to less and somewhat uncertain
coverage of TSRA, have only added VCTS for now.

Specifics for KSTL: VFR and dry thru the TAF period with sly to
swly winds ahead of an approaching cdfnt. This fnt is expected to
push thru the terminal late Tues night. This fnt may be
accompanied by TSRA. However, there is too much uncertainty
regarding coverage and occurrence and have kept out of TAF for now.

Tilly
&&

.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&

$$
WFO LSX





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