Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 182248

548 PM CDT Mon May 18 2015

.SHORT TERM: (Tonight through Thursday)
Issued at 250 PM CDT Mon May 18 2015

May still be some isolated showers and thunderstorms over far southern
parts of the CWA early this evening as the surface cold front will
be exiting the area in a moderately unstable environment. From
mid-evening through tomorrow, subsidence will set in behind the
front bringing dry weather. Have followed the NAM and ECMWF with
the next system has the GFS seems to be suffering from too much
convective feedback. Decent ascent accompanied by strong low level
moisture convergence still warrants likely PoPs on Wednesday.
Chance will linger into Wednesday night before subsidence sets in
behind the trough calling for a return to dry weather on Thursday.

A dry northerly fetch of air will also be responsible for bringing
in cooler and drier air into the region the next few days.
Temperatures will be 10-15 degrees below normal because of this,
particularly on Wednesday because of the clouds and the rain.  Went
below MOS guidance and went closer to model 2 meter temperatures in
some cases.


.LONG TERM: (Thursday Night through Next Monday)
Issued at 250 PM CDT Mon May 18 2015

Not too much change from yesterday`s thinking in that Friday will
likely be dry as shortwave ridging moves across the area.  Then the
next chance of rain will move into the area for the weekend as both
the GFS/ECMWF are showing a notable upper low moving from the
southwest CONUS into the Great Lakes.  There may be some differences
with regards to timing and precipitation amounts over the weekend
into early next week.  Both models and the GEFS ensemble members are
showing a decent spread in solutions.  But there is enough agreement
to go with at least a chance of showers and thunderstorms on
Saturday with likely PoPs over parts of the area Saturday night into
Monday.  Still expect temperatures to warm up ahead of the trough
this weekend as 850mb temperatures climb to around +15C.



.AVIATION:  (For the 00z TAFs through 00z Tuesday Evening)
Issued at 546 PM CDT Mon May 18 2015

VFR and dry with nwly to nly winds aob 10kts thru the period.





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