Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 262048

Area Forecast Discussion
National Weather Service Saint Louis MO
348 PM CDT THU MAY 26 2016

.SHORT TERM...  (Through Late Tonight)
Issued at 310 PM CDT Thu May 26 2016

Convection from morning MCS has finally shifted southeast of our
forecast area this afternoon. Convection was currently developing
across northwest MO and this activity may eventually shift east
into northeast MO this evening. New development is also expected
across southwest MO along a weak warm front and also along an
outflow boundary left over from the morning convective complex.
These storms should move northeastward into central MO this
evening. Activity may congeal into an MCS later this evening and
overnight and impact much of the forecast area, eventually moving
into our IL counties late tonight. Some of the storms this evening
may be severe, especially across northeast and central MO where
the better instability and shear exists.


.LONG TERM...  (Friday through Next Thursday)
Issued at 310 PM CDT Thu May 26 2016

A better potential for widespread showers/storms is expected on
Friday and Friday night as the upper level trough now over the
southwest US approaches our area. Will go with likely to
catagorical pops. The high temperatures will be cooler on Friday
due to the cloud cover and widespread and potentially long lasting
precipitation. At least scattered showers/storms should occur on
Saturday and Saturday evening until the upper level trough shifts
northeast of our area. Quieter and drier weather is expected by
Sunday as a weak surface trough moves southeastward through the
forecast area with only slight chance pops over the southern and
eastern portion of the forecast area. Precipitation chances should
increase again by Tuesday as an upper level trough moves eastward
through the northern Plains sending a cold front southeastward
through our area. The ECMWF model is quicker than the GFS with the
progression of the upper level trough and associated cold front.
Potentially cooler and less humid conditions can be expected by
the end of the extended forecast period after the passage of the
cold front.



.AVIATION...  (For the 18z TAFs through 18z Friday Afternoon)
Issued at 1227 PM CDT Thu May 26 2016

Earlier complex of thunderstorms has moved off well to the south
of the terminals. Expectation is for VFR/dry weather through this
afternoon/early evening. Exception could be at KCOU where a
complex of showers/storms will try and near central Missouri by
late afternoon so have a VCTS group in for now. Better chance for
widespread activity affecting the remaining terminals will be late
tonight and on Friday. been alluded to the previous
couple of days...after the first 6 hours in particular is a highly
uncertain forecast.

Specifics for KSTL:

Expect dry/VFR conditions in wake of earlier showers/storms. By
late evening...threat for showers and thunderstorms will increase
across the area with the best chance late for storms early on
Friday morning. been alluded to above...after the
first 6 hours in particular is a highly uncertain forecast as
convective trends this evening/overnight are not clear at the





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