Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 112024
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
324 PM CDT Fri Jul 11 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 321 PM CDT Fri Jul 11 2014

Psuedo warm front currently stretching from northern Kansas across
northern Missouri into southern Illinois will lift northward tonight
and better defined across Nebraska, Iowa and north-central Illinois.
This boundary will also be the main focus for convection tonight
with lift provided by a veering west-southwesterly LLJ and a series
of weak mid-level impulses tracking east along the southern edge of
the westerlies. Model QPFs and convection allowing models all
generally agree that convection across eastern Iowa will take a more
southeastward turn overnight in response to veering flow aloft,
potentially impacting portions of northeast Missouri into west
central and south central Illinois. Warming aloft should generally
limit the westward extent into Missouri. Temperatures should be much
warmer tonight due to bouts of clouds, southerly winds and higher
dew points.

Glass

.LONG TERM:  (Saturday through Next Friday)
Issued at 321 PM CDT Fri Jul 11 2014

On Saturday, best chances of rain for our area will be over
northeast MO and west central IL as overnight complex dies out. Hot
and humid weather to return to the region with highs in the low
to mid 90s, and heat indicies approaching 100.

By Saturday night, main frontal boundary begins to slide south
into forecast area with chances of showers and thunderstorms on the
increase and expand south across rest of forecast area by Sunday.
Could see chances of severe weather through this period with main
threat being damaging winds. Best chances Saturday night will be
across far northern portions of MO and north half of IL as MCS
develops and tracks east along boundary. By Sunday, as front
continues to track south through region, will see steeper lapse
rates by afternoon with plenty of low level moisture, so could see
clusters or line segments develop. Lows through the weekend to
remain mild with low to mid 70s Saturday night and mid 60s to low
70s Sunday night. Highs on Sunday will be a bit cooler north due to
storms, clouds and cold front, in the mid 80s north to the mid 90s
far south.

Despite front moving south of forecast area by Sunday night,
activity to persist as strong upper level shortwave slides into the
Great Lakes region by Monday helping to trigger more showers and
thunderstorms along secondary cold front. Dry and cooler conditions
expected by Tuesday as strong surface ridge builds in. Highs to drop
into the 70s by Tuesday then begin to moderate a bit by the end of
the work week.

Byrd
&&

.AVIATION:  (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1206 PM CDT Fri Jul 11 2014

Main forecast concern at this time is the probability of any showers
or thunderstorms impacting any of the TAF sites. Any development
this afternoon expected to be quite sparse in coverage. Tonight
the main zone of shower and thunderstorm activity will be focused
in the vicinity of a boundary stretching from Nebraska across Iowa
into northwest Illinois. This is expected to remain north of the
terminals, although we will have to keep a close eye on KUIN
overnight. Otherwise VFR flight conditions are expected to be
prevalent through the forecast period.

Specifics for KSTL:

VFR flight conditions are expected to be prevalent through the
forecast period. At this time it appears the main threat of
showers and thunderstorms will remain well north of KSTL, and
elsewhere coverage will be quite isolated.

Glass
&&

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

$$
WFO LSX





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