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000
FXUS63 KLSX 152104
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
404 PM CDT Tue Apr 15 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 357 PM CDT Tue Apr 15 2014

Another cool night is on tap tonight across the area, with
temperatures expected to range from around 30 degrees across
southeastern Missouri and southwest Illinois to the mid 30s over
central Missouri and in the St. Louis metropolitan area.  The main
concern overnight is once again frost/freeze headlines. As the ridge
axis shifts toward the Ohio Valley, winds will shift to the south in
its wake, and increased southerly flow and warmer temperatures will
preclude any widespread frost over zones further north and west.
However, over southeastern and eastern zones, where calm to light
south winds are anticipated as the ridge axis moves through that
area, along with our coolest temperatures of the night, have gone
ahead and replaced the inherited Frost Advisory with a Freeze
Warning, and expanded it by 3 counties in Illinois where subfreezing
temperatures are anticipated.

JP

.LONG TERM: (Wednesday through Next Tuesday)
Issued at 357 PM CDT Tue Apr 15 2014

(Wednesday through Friday)

Still expecting dry weather through early Thursday before a cold
front enters northeast Missouri and moves southeast across the CWA
on Thursday night.   Moisture convergence along the front is
somewhat limited along the front so have chance pops starting
Thursday afternoon over northeast Missouri.  Then have chance pops
across the entire area on Thursday night as large scale ascent
increases ahead of the mid-level trough.  This trough will move east
of the area by Friday, so have dropped POPs to slight chances during
the day.

After the cool start tomorrow morning, temperatures will be about 10
degrees warmer tomorrow than today.  Temperatures will also be
slightly warmer ahead of the cold front on Thursday ahead of the
cold front.

(Saturday through next Tuesday)

Will keep Saturday dry as both the GFS/ECMWF show an upper ridge
moving across the area.  Will keep chance of showers going Saturday
night into Sunday night as both models show a mid level trough and a
attendant surface front moving through the area.  Subsidence will
build in behind the trough and both models are showing that an upper
ridge will build into the area for the middle of next week with
temperatures starting to warm up above normal as early as next
Tuesday.


Britt

&&

.AVIATION:  (For the 18z TAFs through 18z Wednesday Afternoon)
Issued at 1237 PM CDT Tue Apr 15 2014

Dry, VFR conditions will prevail for the forecast period. West-
northwest winds today will become light/variable as the surface
ridge shifts east across the area, prior to backing to the south
and becoming strong and gusty Wednesday ahead of the next system
taking shape over the plains. The only concern tonight is the
possibility of LLWS at KUIN and KCOU as the low-level jet ramps up
during the late overnight and early morning. However, shear looks
marginal, thus have not mentioned in the TAF at this time.

Specifics for KSTL: Dry, VFR conditions expected to prevail
through the period. West-northwest winds will become light during
mid- to late afternoon as the ridge axis shifts across the area.
Overnight, the winds will begin to back to the south, increasing
in speed and becoming gusty Wednesday. Scattered diurnal cumulus
will clear tonight, with only high clouds expected on Wednesday.

JP

&&

.FIRE WEATHER:
Issued at 357 PM CDT Tue Apr 15 2014

Will be issuing a fire weather watch for Wednesday afternoon for a
small part of central and northeast Missouri. Model dewpoints are
too high based on recent trends and upstream dewpoints over the
central and southern Plains. Expected RH values tomorrow will be
in the lower 20s with southerly winds of 15 to 25 mph with higher
gusts.  These values along with 10 hour dry fuels falling below 9
percent warrant issuing a fire weather watch tomorrow.

Britt/JP

&&

.CLIMATE:

RECORD LOWS FOR 4/15:

STL - 27 IN 1928
COU - 25 IN 1928
UIN - 24 IN 1928
FAM - 24 IN 1928


&&

.LSX WATCHES/WARNINGS/ADVISORIES:
MO...FREEZE WARNING from 1 AM to 9 AM CDT Wednesday FOR Crawford MO-
     Iron MO-Jefferson MO-Madison MO-Reynolds MO-St. Francois MO-
     Ste. Genevieve MO-Washington MO.

     FIRE WEATHER WATCH from Wednesday morning through Wednesday
     evening FOR Audrain MO-Boone MO-Callaway MO-Cole MO-Knox MO-
     Moniteau MO-Monroe MO-Shelby MO.

IL...FREEZE WARNING from 1 AM to 9 AM CDT Wednesday FOR Bond IL-
     Clinton IL-Fayette IL-Marion IL-Monroe IL-Montgomery IL-
     Randolph IL-St. Clair IL-Washington IL.

&&

$$

WFO LSX