Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 280439

1139 PM CDT Sun Jul 27 2014

Issued at 851 PM CDT Sun Jul 27 2014
Issued at 558 PM CDT Sun Jul 27 2014

Just made some minor changes to the temperature and wind
forecasts. otherwise going forecast look good. We can really use
some rain around here.



.SHORT TERM:  (Through Late Tonight)
Issued at 335 PM CDT Sun Jul 27 2014

Primary cold front is through the area, and the secondary push of
cooler and much drier air is filtering through the area at this
time.  Dewpoint temperatures are already falling through the 60s
into the 50s and ambient temperatures are either steady or have
fallen a degree or so across parts of central and northeast Missouri
and west central Illinois.  The primary forecast challenge for
tonight will be temperatures and cloud cover behind the front.  The
shortwave over the Upper Midwest is continuing to dig to the
east-southeast and a broad swath of stratocumulus is following in
its wake.  Some of the strato-cu is undoubtedly diurnally driven and
will dissipate.  However, some of it looks thick enough to make it
into the area.  Not very confident on areal coverage tonight so have
only few-scattered clouds in the forecast.  MOS lows look reasonable
so followed them closely.


.LONG TERM:  (Monday through Next Sunday)
Issued at 335 PM CDT Sun Jul 27 2014

A deep longwave upper TROF will dominate eastern North America thru
the period, resulting in NW flow over our region.  An extended
period of below normal temps should be the result with maxes in the
upper 70s and low 80s each day with mins in the 50s and low 60s.
Quite a treat for the climatologically hottest time of the year.

The NW upper flow is expected to initially give us dry wx thru
Wednesday night, but what looks to be a bit stronger non-sheared
disturbances trickling down for Thursday thru Saturday with a bit
more moisture thru the column in place looks to be good enough for a
low PoP at this time for what should be diurnally driven SHRA/TSRA.



.AVIATION:  (For the 06z TAFs through 06z Monday Night)
Issued at 1128 PM CDT Sun Jul 27 2014

Northwest winds near or below 10KT tonight will increase and become
gusty once again by mid- morning on Monday, but not quite as gusty
as on Sunday afternoon. Through the day, winds will slowly veer
to a more northerly direction before becoming light
northerly/light and variable overnight Monday night. Expect
diurnal cumulus to return on Monday as well, and while most
locations should see scattered coverage, models indicate several
hours of broken ceilings Monday morning through early Monday
afternoon that could affect metro area TAF sites. However,
ceilings will be around 5000ft, thus, VFR flight conditions will
prevail through the period.

Specifics for KSTL:
Light northwest winds tonight will increase and gust to around
18KT by late morning on Monday. Expect diurnal cumulus to develop
by around 15Z, and with cooler air aloft and models indicating
steepening lapse rates, broken ceilings are expected for at least
several hours from late Monday morning through Monday afternoon.
However, cloudcover should scatter out by late afternoon and then
clear, with winds becoming light northerly overnight. VFR through
the period.





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