Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 162024
AFDLSX

Area Forecast Discussion
National Weather Service Saint Louis MO
224 PM CST Tue Jan 16 2018

.SHORT TERM...  (Through Late Wednesday Afternoon)
Issued at 216 PM CST Tue Jan 16 2018

Upper level trough continues to move east out of the forecast area
this afternoon. In it`s wake we are left with scattered mid level
clouds and spotty snow showers in northeastern MO and west central
IL. Surface ridge will begin to build into the region this afternoon
and clouds will decrease and lift overnight.

The building of a surface ridge will begin to increase temps,
although not much warmer initially. Temps overnight will stay in the
single digits with CAA and some widespread snow cover in place but
no wind chill advisory will be needed as winds will remain light
overnight. Temps begin to moderate Wednesday as winds shift to the
southwest.

Walsh

.LONG TERM...  (Wednesday Night through Next Tuesday)
Issued at 216 PM CST Tue Jan 16 2018

The GFS and ECWMF continue to show mainly dry conditions through
Friday as moisture remains cut off from the Gulf of Mexico.  Both
models show that the surface high that is cutting off the moisture
flow will move southeast of the area by Wednesday evening.  This
will cause low level flow to turn out of the southwest which will
start the warm-up in earnest. 850mb temperatures will climb from
around -5C on Wednesday evening into the +5 to 10C range this
weekend.

It still looks like that chances for precipitation will increase
over the weekend as low level moisture transport in increase ahead
of deep trough that will approach the area from the west.  Will keep
a chance of showers going Saturday into Sunday. Still see enough
instability to keep slight chance of thunderstorms late Sunday
into Sunday evening over southeast Missouri into southwest
Illinois. Then the attendant cold front will move west to east
across the area on Sunday night into Monday morning. This is
still likely when there will be a transition from rain to snow.
Then the global models are showing that Monday and Tuesday will be
mainly dry in the wake of the weekend upper trough. Temperatures
early next week will be cooler behind the cold front, but still
above normal for mid-late January.


Britt

&&

.AVIATION...  (For the 18z TAFs through 18z Wednesday Afternoon)
Issued at 1137 AM CST Tue Jan 16 2018

VFR conditions for all terminals for the entire forecast period.
Some scattered mid level clouds will linger through the day today
but ceilings will continue to rise as upper level trough moves
off to the east. Conditions will remain dry with the exception of
some light snow showers and flurries this afternoon for UIN and
STL metro terminals. Winds will be from the northwest today around
10kts and will weaken late this afternoon to close to 5kts.

Walsh

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&

$$

WFO LSX



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