Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 240820

320 AM CDT Sun May 24 2015

.SHORT TERM:  (Through Late This Afternoon)
Issued at 318 AM CDT Sun May 24 2015

Will see an gradual increase in rain chances today...particularly
over the western and northern parts of the CWA as the upper ridge
moves off to the east which will allow for southwesterly upper flow
to establish itself over the area.  Large area of rain over central
and western Missouri is being generated in an area of strong low
level moisture convergence under the broad area of upper level
ascent.  This low level moisture convergence will shift eastward
today and is being picked up well by the 00Z NMM WRF.


.LONG TERM:  (Tonight through Saturday)
Issued at 318 AM CDT Sun May 24 2015

(Tonight through Tuesday)

The NAM has been the most consistent of the models as of late.   A
notable shortwave will move across the area tonight which will bring
stronger ascent along with strong low moisture convergence ahead of
it.  Will continue with likely or categorical PoPs over the entire
area.  Then Memorial Day still looks mostly dry as subsidence sets
in behind aforementioned shortwave trough.  Will keep high chance
and likely PoPs on Monday night as the next shortwave trough moves
across the area.  Will also keep likely PoPs on Tuesday as yet
another shortwave moves across the area.

Will stick closer to the NAM MOS guidance for temperatures based on
model preference.

(Wednesday through next Saturday)

Will continue to go with chances of showers and thunderstorms for
most of the extended part of the forecast as a series of shortwaves
moves across the area.  A quasi-stationary front will over the area
which is typical for late May and temperatures will be determined be
what side the front is on.



.AVIATION:  (For the 06z TAFs through 06z Sunday Night)
Issued at 1102 PM CDT Sat May 23 2015

Mid-high level clouds will continue across the area late tonight
with at least light showers moving through COU late tonight and
possibly into UIN towards morning. Could not rule out sprinkles in
the St Louis metro area late tonight, but the better chance of
showers/storms should hold off until Sunday afternoon and night as
a sly low level jet moves through the area. Prevailing cloud
ceilings will also lower on Sunday, likely into the MVFR catagory
in UIN and COU and down to MVFR or at least low end VFR in the St
Louis metro area by afternoon. Sely surface wind will continue
late tonight, becoming relatively strong and gusty from a s-sely
direction on Sunday.

Specifics for KSTL: Prevailing VFR mid level cloudiness late
tonight, then the ceiling will lower into the MVFR or low end VFR
catagory by Sunday afternoon. May be some sprinkles late tonight
from mid level clouds, but the better threat of showers/storms
should occur Sunday afternoon and night. Sely surface wind
late tonight will strengthen and become gusty by late Sunday
morning or afternoon from a s-sely direction.





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