Area Forecast Discussion
Issued by NWS St. Louis, MO

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KLSX 170820
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
320 AM CDT Fri Oct 17 2014

.SHORT TERM:  (Through Late This Afternoon)
Issued at 319 AM CDT Fri Oct 17 2014

A cold front extending from a surface low over WI southwest through
east central MO will continue moving southeastward through the rest
of our forecast area this morning as an upper level low over
northeast MN moves southeastward through the Great Lakes region
today.  Precipitation is not expected across our forecast area today
in association with this front, but cold air advection behind this
front will lead to cooler high temperatures for northeast and
central MO as well as west central IL today compared to yesterdays
maximum temperatures.  There was also a large area of low level
clouds across the northern Plains which will advect southeastward
into northeast MO later this morning and into west central IL and
parts of central MO this afternoon.  This cloudiness will limit
solar insolation this afternoon and hinder the diurnal rise in
temperatures along with the post frontal low level cold air
advection.

GKS

.LONG TERM:  (Friday through Next Thursday)
Issued at 333 PM CDT Thu Oct 16 2014

The shortwave currently over the Dakotas will move east into the
Upper Midwest and Great Lakes on Friday.  Large area of cloud cover
over eastern Montana and North Dakota is depicted well in the
models, and all models show a good slug of moisture between
900-850mb filtering down over the area Friday afternoon as the trof
sharpens over the Mid-Mississippi Valley.  Have increased clouds
over northern Missouri and west central Illinois Friday afternoon
into Friday evening and lowered temperatures a few degrees
accordingly.

High pressure will build across the Midwest Saturday and linger
Sunday which should provide a cool dry weekend for us.  Stuck pretty
close to guidance temperatures in the low to mid 60s for highs and
low to mid 40s for Saturday`s lows and even cooler in the upper 30s
to low 40s for lows Sunday.  Another shortwave will move across the
Midwest on Monday.  Medium range models hint at a few sprinkles or
light rain showers ahead of the surface trof, but have dropped PoPs
Monday to unmentionable levels until we get a better handle on the
timing and amount of available moisture.  Pattern becomes highly
amplified and blocky with a strong ridge over the area for Tuesday
and Wednesday.  ECMWF and GFS differ in the timing of when the ridge
will break down with the ECMWF being the slower of the two.  Am
inclined to believe the slower solution due to the blocky pattern
with a huge cutoff low over the East Coast clogging up the works.
Expect temperatures near or slightly below normal through the period.

Carney

&&

.AVIATION:  (For the 06z TAFs through 06z Friday Night)
Issued at 1109 PM CDT Thu Oct 16 2014

Dry and VFR conditions are expected through the TAF period.
Southerly winds are expected to turn westerly behind a cold front
that will move across the area between 06-08Z. Wind speeds and
gusts will increase after 15Z tomorrow with VFR deck of clouds
building south across the Midwest.

Specifics for KSTL:
Dry and VFR conditions are expected during the next 30 hours with
a cold FROPA around 07Z. Wind speeds and gusts will increase
after 15Z tomorrow with VFR cloud deck advancing overhead by 01Z.

CVKING

&&

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

$$

WFO LSX






USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.