Area Forecast Discussion
Issued by NWS St. Louis, MO

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000
FXUS63 KLSX 200244
AFDLSX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ST LOUIS MO
944 PM CDT Sat Apr 19 2014

.UPDATE:
Issued at 941 PM CDT Sat Apr 19 2014

No significant changes were made to the grids for this update
though did decrease the cloud cover overnight from partly cloudy,
mainly after midnight, to mostly clear all night.

Miller

&&

.SHORT TERM:  (Through Late Tonight)
Issued at 330 PM CDT Sat Apr 19 2014

The expansive low level ridge extending from eastern Ontario into
the lower MS Valley will keep Gulf moisture return confined to the
Plains tonight, and allow for continued dry and tranquil weather for
our region. Bouts of high clouds will be the main story with
slightly above average temperatures.

Glass

.LONG TERM:  (Sunday through Next Saturday)
Issued at 330 PM CDT Sat Apr 19 2014

Sunday will be similar to today, except a couple of degrees warmer
due to southerly winds, and more high level cloudiness as weak
southwest flow shortwaves move through the area.  It appears that
the chance of showers will hold off until late Sunday night for
central MO, and Monday for the rest of our forecast area.  The mid
level trough now over the southwest US will move eastward through
our area on Monday, while a strong shortwave moving through the
northern portion of the Great Lakes region sends a cold front
southeastward through our forecast area Monday afternoon and
evening.  Low-mid level moisture and instability will also be
increasing ahead of the mid level trough and surface cold front.
This will lead to showers and a few thunderstorms Monday and Monday
evening across our area.  Most of the showers should shift southeast
of our forecast area by late Monday night as the mid level trough
shifts east of the region, and the cold front shifts southeast of
our area with colder and drier air filtering southeastward into the
region behind the cold front late Monday night into Tuesday.  This
cooler weather will be short lived as an upper level ridge moves
eastward over MO on Wednesday and southerly low level winds return
and strengthen.  The GFS model now keeps the convection on Wednesday
and Wednesday evening, associated with strong low-mid level warm air
advection ahead of shortwaves moving through the upper level ridge,
north of our forecast area.  The ECMWF model has the southern edge
of this convection skimming the extreme northern portion of our
forecast area during this time period.  Both the GFS and ECMWF are
fairly consistent now in bringing convection through our forecast
area late Wednesday night through Thursday evening as the upper
level ridge moves east of the region, while an upper level
trough/low moves slowly eastward through the northern Plains and an
associated surface low drags a trailing cold front southeastward
through our area Thursday and Thursday evening.  The ECMWF model is
a little quicker with the passage of this front through our forecast
area compared to the GFS.  The GFS model brings colder air
southward into our area Friday and Friday night with the upper level
low and associated surface low moving slowly southeastward through
the Great Lakes region.  The ECMWF model has a weaker and more
progressive solution and keeps the colder air north of our forecast
area.  For now will forecast cooler temperatures for Friday night
and Saturday.

GKS

&&

.AVIATION:  (For the 00z TAFs through 00z Sunday Evening)
Issued at 503 PM CDT Sat Apr 19 2014

VFR conditions expected with light southeast wind becoming south
on Easter Sunday.

Specifics for KSTL:

VFR conditions expected with light southeast wind becoming south
on Easter Sunday.

CVKING

&&

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

$$

WFO LSX






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