Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 112132

Area Forecast Discussion
National Weather Service Saint Louis MO
332 PM CST Wed Jan 11 2017

.SHORT TERM...  (Through Late Thursday Afternoon)
Issued at 326 PM CST Wed Jan 11 2017

Next system/frontal boundary extends from northeastern IL
southwestward through northeastern MO to southeastern KS. This
boundary will sink south exiting forecast area by mid morning on
Thursday. In the meantime, shortwave to slide along boundary helping
to generate scattered activity. Moisture is limited with this
system, so precipitation will be light in nature. Some concern about
brief freezing rain/drizzle after midnight tonight for portions of
northeast/central MO as well as west central IL. With pavement temps
in the mid 40s to low 50s, feel that these areas will be okay,
though will advise evening crew to keep eye out on conditions as
they develop.

Another issue later tonight will be slight chances of isolated
thunderstorms mainly to the south and east of the STL metro area
after midnight. Theta-e advection along the southwesterly low-level
jet will contribute to weak instability, thus MU CAPES between 100
and 300 J/kg possible. So added mention between 06z and 18z Thursday
for this area.

As for low temps, decent CAA behind boundary, so lows will depend on
where the cold front is. For now have lows ranging from the low 20s
far north to the upper 50s far south. Gusty winds ahead of boundary
to diminish shortly after sunset this evening.

Temperatures on Thursday will either be falling or steady most
locations as front exits area. For now highs will be from the low
30s to low 60s.


.LONG TERM...  (Thursday Night through Next Wednesday)
Issued at 326 PM CST Wed Jan 11 2017

The discussion will be delayed due to a software issue that
manifested itself today. However, there are no changes to the
going headline. A discussion will sent out as soon as possible.


.AVIATION...  (For the 12z TAFs through 12z Thursday Morning)
Issued at 548 AM CST Wed Jan 11 2017

Expect mainly VFR conditions through the morning and early
afternoon hours until a cold front moves from northwest to
southeast across the area. Then MVFR ceilings can be expected
behind this front. There will be some precipitation along this
front, with scattered showers ahead of the front. Gusty south
winds will occur again today which will cause crosswinds east-west
runways.  Winds will veer northwesterly behind the front.

SPECIFICS FOR KSTL: Mainly VFR conditions are expected through 06Z
tonight. Southerly surface winds will be gusty once again today.
Then a cold front will move through the terminal after 06Z with a
chance of rain and ceilings falling into the MVFR category.



Saint Louis     42  43  23  31 /  50  40  10  70
Quincy          26  31  15  27 /  30  20   0  20
Columbia        30  36  19  28 /  40  20   5  60
Jefferson City  34  38  21  30 /  40  20  10  60
Salem           53  54  25  32 /  70  60  10  70
Farmington      55  56  26  31 /  40  50  60  70


MO...Winter Storm Watch from late Thursday night through Saturday
     afternoon for Boone MO-Callaway MO-Cole MO-Crawford MO-
     Franklin MO-Gasconade MO-Iron MO-Jefferson MO-Madison MO-
     Moniteau MO-Montgomery MO-Osage MO-Reynolds MO-Saint
     Charles MO-Saint Francois MO-Saint Louis City MO-Saint
     Louis MO-Sainte Genevieve MO-Warren MO-Washington MO.

IL...Winter Storm Watch from late Thursday night through Saturday
     afternoon for Bond IL-Clinton IL-Madison IL-Marion IL-
     Monroe IL-Randolph IL-Saint Clair IL-Washington IL.



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