Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 172042

342 PM CDT Fri Oct 17 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 341 PM CDT Fri Oct 17 2014

Scattered to broken stratocumulus will begin to break up this evening
as some of this cloud cover is diurnally driven.  Partly cloudy
skies should stay through the night, particularly over the northern
and eastern counties where there will continue to be some low level
moisture in cyclonic flow.  Northwesterly winds will decrease early
this evening and went close to the agreeable MOS guidance for lows.


.LONG TERM:  (Saturday through Next Friday)
Issued at 341 PM CDT Fri Oct 17 2014

The subtle shortwave currently over Lake Winnipeg will dive south
and phase with the more prominent wave that`s gathering steam over
the northeast Plains and dive into the base of the longwave trof
over eastern North America on Saturday.  This will give the Canadian
airmass over Manitoba the final shove needed to send it streaming
into the Midwest.  Cool northerly flow will result on Saturday which
will keep temperatures mostly down in the upper 50s and low 60s.
Models are indicating another batch of stratocumulus will move
through with the shortwave on Saturday which should also help to
keep temperatures lower.

Strong high pressure will remain in place over the Ohio Valley
Sunday.  Sunday morning lows may be some of the coldest yet this
season as temperatures fall into the mid to low 40s across the
region.  Patchy frost in sheltered areas is a decent possibility.

The next shortwave in line dives through the Midwest Sunday night
into Monday.  The GFS is the wettest of the model suite, but the
ECMWF also develops some light precip ahead of the wave.  Have
increased PoPs to chance category before 12Z Sunday and kept slight
chance going during the day Sunday.  The cold front will go through
late in the day Monday, so it looks like there will be a decent warm
up during the day in southwest flow with highs reaching the upper
60s or low 70s.

Medium range guidance continues to develop a very blocky pattern
with Monday`s shortwave cutting off into a giant low over the East
Coast.  Upper level ridging over the Midwest should keep us dry with
an elongated surface ridge stretching from southeast Canada back
through the Mississippi Valley into the southeast Plains through the
end of the week.  Temperatures should say near or just a few degrees
below normal through the period.



.AVIATION:  (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1259 PM CDT Fri Oct 17 2014

Expect mainly dry and VFR conditions through the TAF period. Scattered
to broken cloud bases with ceilings between 3000-4000ft are moving
southeastward toward Columbia and the St. Louis metro TAF sites
and will be there between 18-20Z. Expect skies to scatter out
this evening before becoming broken again at KUIN and the St.
Louis metro TAF sites after 15Z Saturday morning. Northwest winds
gusts will diminish around sunset.

Specifics for KSTL: Low VFR ceilings will move into the terminal
between 18-19Z and then scatter out by this evening. Northwesterly
wind gusts will diminish around 00Z.



Saint Louis     49  62  41  63 /   0   0   0   5
Quincy          44  59  39  62 /   0   0   0   5
Columbia        43  62  41  66 /   0   0   0   5
Jefferson City  43  62  40  67 /   0   0   0   5
Salem           46  60  39  61 /   0   0   0   5
Farmington      46  62  38  63 /   0   0   0   5




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