Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 281157
AFDLSX

Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
657 AM CDT SAT MAY 28 2016

.SHORT TERM...  (Through Late This Afternoon)
Issued at 353 AM CDT Sat May 28 2016

Today should not be as wet as yesterday. Most if not all of the SHRA
activity from overnight has either dssptd or moved out of the CWA as
of early this mrng. Although an isolated SHRA can`t be ruled out the
rest of this mrng...think most locations should remain dry.
SHRA/TSTM activity should slowly increase across the NWrn portion of
the CWA thru the aftn as a negatively tilted short wave approaches
the area. A broken line of convection should sink SE thru the
evening. SB CAPE of 1000-2000 J/kg with 0-6km bulk shear of 30 kts
may be enough to support a few stronger storms...consequently SPC
has a good portion of the FA area outlooked in a marginal risk.
Large hail and damaging winds are the primary threats with any
stronger storm. Skies are expected to remain mostly cloudy thru the
day which should limit high temps to the upper 70s to low 80s. Any
addtnl breaks in the clouds will allow temps to climb into the mid
80s.

2%

.LONG TERM...  (Tonight through Friday)
Issued at 353 AM CDT Sat May 28 2016

The storm system centered currently over KS is expected to track
northeastward and be well on its way to the upper-MS river valley by
this evening.  This will take much of the upper level support to our
north and leave a weak cold front at the surface as the primary
focus for any convection early this evening, with what does develop
tracking east.  Kept PoPs in chance category for areas around STL
Metro and mainly north and west, tapering to slight chance to the
south and east of STL Metro overnight.  With better upper support,
would have felt better about likely category.

The weak cold front drops to our south by Sunday morning, and with a
weak upper RIDGE and surface high building in, should see a rare dry
day or two for most areas to wrap up the holiday weekend.

The wet pattern then resumes for a few days next week as southwest
flow aloft with a stream of upper level disturbances pair with
southerly flow at the surface.  PoPs should peak on late Wednesday
with a more defined cold front dropping down and will not only
benefit of this feature but should also have good upper support.
Despite the front expected to be thru Thursday, the main upper TROF
is still upstream with this looking like a setup for post-frontal
showers.

Temperatures thru Wednesday will remain above average during this
period with max temps mainly in the 80s and mins in the 60s.

From Thursday onward, temperatures should drop to at or below
average levels behind the cold front with cool high pressure
building in, equating to daytime maxes in the 70s and mins in the
50s.

TES

&&

.AVIATION...  (For the 12z TAFs through 12z Sunday Morning)
Issued at 642 AM CDT Sat May 28 2016

Patchy MVFR CIGs dot the area this mrng with more IDLS IFR CIGS
across SE MO and SE IA. CIGs should improve to VFR by 15Z with IFR
conditions thru the remainder of the prd. Most of the prd should
be dry but there is a chance for scttrd SHRAs/TSTMs this aftn/evng
in assoc with an upper lvl disturbance. Some of the stronger
storms could be produce IFR/MVFR conditions but way too soon to
attempt to include that lvl of detail in the the fcst. Sthrly
flow is expected to continue thru the prd.

Specifics for KSTL:

Patchy MVFR CIGs floating around the metro area early this mrng should
dsspt over the next few hrs with VFR conditions expected thru the
remainder of the prd. Broken line of convection should move thru
the terminal this evng. Some of the stronger storms will be
capable of producing IFR/MVFR conditions but too soon to attempt
to include that lvl of detail in the fcst. Sthrly flow thru the
prd.

2%

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&

$$

WFO LSX



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