Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 230844

344 AM CDT Sat May 23 2015

.SHORT TERM:  (Through Late This Afternoon)
Issued at 331 AM CDT Sat May 23 2015

Will continue to keep today mainly dry for parts of central and
southeast Missouri where the NAM shows some low level moisture
convergence developing in theses areas, especially later this
morning and this afternoon. The NCEP NMM WRF shows a few showers
developing over the area this afternoon. However, do not expect
widespread showers and thunderstorm development as the NAM also
shows an upper level ridge will build over the Midwest with the
NAM/ECMWF showing either neutral or subsidence over the area.
Temperatures will be slightly warmer today with 850mb temperatures
around +10C.


.LONG TERM:  (Tonight through Friday)
Issued at 331 AM CDT Sat May 23 2015

(Saturday Night through Monday Night)

NAM and ECMWF have shown better continuity than the GFS which also
shows gridscale feedback issues, so will use a blend of these two
models for the forecast solution.  Overall trends are pretty much
the same as going forecast. Upper ridge begins to move east tonight
which allows additional low level moisture convergence to move
into the area. Still expect a series of weak shortwave troughs to
move through the area in the southwest flow aloft with pockets of
low level moisture convergence. Will keep likely and categorical
PoPs going through this period. Will also go with a relatively small
diurnal swing given the clouds and rain. A blend of MOS guidance
looks reasonable given 850mb temperatures around +15C.

(Tuesday through Friday)

Will keep scattered thunderstorms in the forecast as upper flow
stays southwesterly with surface front staying nearby in a unstable
airmass.  ECMWF shows surface front moving just north of the area
which should allow temperatures to climb above normal by Thursday
and Friday.



.AVIATION:  (For the 06z TAFs through 06z Saturday Night)
Issued at 1054 PM CDT Fri May 22 2015

Mainly just VFR, mid-high level cloudiness through the period.
Could not rule out a brief sprinkle from mid level clouds, but it
appears that the more significant showers will remain west of the
taf sites. Light surface winds late tonight will become sely on
Saturday as the surface ridge over our region shifts well east of
the area.

Specifics for KSTL: VFR, mid-high level clouds through the
period. There may be a brief sprinkle, but the more significant
showers should remain west of STL. Light surface wind late tonight
will strengthen to around 10 kts from a sely direction by
Saturday afternoon.





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