Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 261829

Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
129 PM CDT TUE JUL 26 2016

.SHORT TERM...  (Through Late This Afternoon)
Issued at 309 AM CDT Tue Jul 26 2016

A few storms were across southwest IL, northeast of STL early this
morning. This activity appeared to be associated with a surface
dewpoint gradient and along the 850 mb front. A surface ridge
centered over eastern Nebraska and Iowa was bringing slightly
cooler air and lower humidities to northeast MO and west central
IL along with a clear sky. The chance of showers and storms will
continue today, mainly across southeast MO and southwest IL,
south of STL near a weakening cold front and where low-mid level
moisture and instability will be maximized.


.LONG TERM...  (Tonight through Monday)
Issued at 309 AM CDT Tue Jul 26 2016

The threat for convection should be mainly confined to southeast
MO and southwest IL tonight into Wednesday, then across most of
the forecast area by Wednesday night and Thursday as the weak
front lifts back northward as a warm front and the surface ridge
shifts east of the area allowing low level moisture and
instability to spread northward. Shortwave energy will also be
carving out an upper level trough over the central US by Thursday
leading to more cloud cover and possibly slightly cooler high
temperatures. This upper level trough should bring another cold
front slowly southeastward through our area by Thursday night.
This may eventually shunt much of the convection south of our
forecast area by Friday night with surface ridging moving slowly
eastward through the Great Lakes region, or at least to parts of
southeast MO and southwest IL. Temperatures Friday and Saturday
may be slightly below normal, but then return to near normal
values by Sunday as southerly surface/low level flow returns.



.AVIATION...  (For the 18z TAFs through 18z Wednesday Afternoon)
Issued at 122 PM CDT Tue Jul 26 2016

Mainly dry and VFR conditions are expected during the period at
the terminals. Lower ceilings from this morning have already moved
out. Showers and thunderstorms associated with a front are
expected to stay south of the terminals near a quasi-stationary
front. Some MVFR fog formation is possible tonight with light
winds tonight.

SPECIFICS FOR KSTL: Mainly dry and VFR conditions is expected over
the next 30 hours. Only exception will be some MVFR fog late





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