Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 272035
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
335 PM CDT Sun Jul 27 2014

.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.

Carney

.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.

TES

&&

.AVIATION:  (For the 18z TAFs through 18z Monday Afternoon)
Issued at 1245 PM CDT Sun Jul 27 2014

Expect VFR flight conditions and gusty northwest wind to continue
to prevail this afternoon. A large area of stratocumulus clouds is
headed south through Iowa toward the area; however ceilings are
AOA 3500 FT all the way up into Minnesota and Wisconsin. Also,
guidance is indicating that the leading edge of this cloud deck
will likely continue to dissipate this afternoon into the evening.
There may be some redevelopment tonight, tho am not confident it
will become a solid ceiling again. If it does, it should be
between 2000-3000FT. Clouds should dissipate by mid-morning Monday
and VFR conditions should prevail after that.

Specifics for KSTL:

Expect VFR flight conditions and gusty northwest wind to continue
to prevail this afternoon. Some uncertainty as to how far south
the large area of VFR stratocumulus over the Upper Midwest will
get, but current indications are that it will dissipate before
reaching Lambert. There may be some redevelopment tonight, tho am
not confident it will become a solid ceiling again. If it does, it
should be between 2000-3000FT. Clouds should dissipate by mid-
morning Monday and VFR conditions should prevail after that.

Carney

&&

.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&

$$

WFO LSX




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