Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO

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FXUS63 KEAX 210003

National Weather Service Kansas City/Pleasant Hill MO
603 PM CST FRI NOV 20 2015

Issued at 351 PM CST FRI NOV 20 2015

Forecast remains on track for this evening/overnight. Water vapor
imagery shows two waves, one currently moving through the area
providing sufficient ascent to generate scattered showers and the
second wave over central Nebraska that will lead to continued
precipitation across the region. Current precipitation over the
forecast area has been generally all rain, with the exception of
isolated instances of sleet. This has been due to evaporative
cooling as rainfall has passed through a dry layer, and radar also
suggests some weak convective elements at play. The majority of
precipitation will remain in the form of rain through mid-evening as
continued warm air advection maintains a deep warm nose of +4 to
+5C, melting any seeding of ice crystals from top-down.

There is expected to be a fairly tight gradient between accumulating
snow and primarily rainfall with this system, and that line
currently looks to occur near the Iowa/Missouri border. Areas south
of the state line will have to wait for colder air to advect in
behind the system, allowing vertical temperature profiles to cool
sufficiently to support snow. The most northern row of counties in
Missouri should begin to see a changeover from rain to snow between
03-06Z. Overall rates should be light to moderate, and with air
temperatures remaining at or slightly above freezing during the
majority of snowfall and physical ground surfaces well above
freezing, some degree of melting will occur. It`s possible the
greatest accumulations will be reserved to elevated or grassy-type
surfaces, with lesser amounts on roadways. Furthermore, very strong
wind speeds will exist through the lower tropopause, fracturing snow
crystals and reducing some accumulation. Light precipitation will
exit the CWA from west to east Saturday morning, and while most
areas may see a narrow window of a rain/snow mix before
precipitation ends, the most likely areas to receive any
accumulation during the duration of this event will remain north of
Highway 36. Will continue the winter weather advisory in the 5 most
northeastern counties in the forecast area, as these areas may see
up to 2 inches of a wet snowfall. As the cold front moves through,
northwest winds will become gusty, with speeds of 20-30kts at times.
While this will lower visibility with any falling light snow, do not
expect any notable blowing snow at ground level due to the wet
nature of the snowfall. All precipitation is expected to come to an
end by mid-morning Saturday, with mostly clear skies to follow.

Other notable elements in the forecast period feature chilly low
temperatures Sunday morning across the area. Lows will fall into the
middle teens over potential snow covered areas of far northeast
Missouri to the lower 20s elsewhere. Otherwise, a warming trend is
expected beginning Monday into mid-week as broad southwesterly flow
persists ahead of an amplifying upper trough over the Intermountain
West. An increase in moisture is also anticipated, and with a few
weak waves ahead of this feature and an approaching frontal zone,
some precipitation chances are warranted ahead of the system. Rain
is expected during this period within the warm sector. There remains
some uncertainty along the backside of the system to how much
moisture and subsequent precipitation would exist and likewise the
arrival of the colder air. Parts of northwest Missouri may see some
potential for a rain/snow mix before precipitation ends, but with
the high level of uncertainty, scenario remains low-probability at
this time.


.AVIATION...(For the 00Z TAFS through 00Z Saturday Evening)
Issued at 535 PM CST FRI NOV 20 2015

Keeping a close eye on upstream observations as cold air sinks closer
to the terminal areas. For this TAF issuance, have included -RASN
mention at STJ and MCI but not at IXD and MKC as the better chance
for a wintry mix looks to remain north of the I-70 corridor/Missouri
River. NW winds will pick up during the overnight hours as the low
pressure system responsible for the inclement weather moves through,
slackening a bit tomorrow afternoon. Another concern for aviation
interests tonight will be the lowering ceilings, looking to drop down
into the IFR category. The terminals should remain above the LIFR
category but cannot be entirely ruled out. Will update with the next
TAF issuance if necessary.


.EAX Watches/Warnings/Advisories...
MO...Winter Weather Advisory from 9 PM this evening to 6 AM CST
     Saturday for MOZ006>008-016-017.



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