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

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FXUS63 KEAX 261126

National Weather Service Kansas City/Pleasant Hill MO
526 AM CST THU NOV 26 2015

.SHORT TERM...(Today through Sunday Afternoon)
Issued at 346 AM CST THU NOV 26 2015

Forecast remains on track for significant rainfall today, then
wintry precipitation beginning this evening and continuing through
at least Friday. Main concerns are ice accumulation across NW MO and
far NE KS, and possible flooding across central MO.

Very light showers have drifted across the region this morning as
the atmosphere gradually saturates, and will become more widespread
during the morning hours as surface low pressure deepens and bulges
out of the southern High Plains. Convergence along a strengthening
cold front and isentropic lift out ahead of the boundary will both
be on the increase today, helping rainfall expand and intensify this
afternoon and evening near and ahead of the cold front as it sweeps
through the region. The front has already inched into our far NWern
counties this morning, and should begin making some southeastward
progress by mid- to late-morning, passing through the length of the
forecast area by midnight.

Significant precipitation is still expected along the elevated cold
front today and tonight, and will be well supported by upper-level
forcing from a deep trough that will elongate and eventually eject
out across the northern Plains/Midwest. The strong warm nose sitting
above the elevated boundary will melt any hydrometeors well above
the surface; thus the only real factor in precipitation type remains
very low-level temperatures. Cold air will surge down behind the
front this evening through Friday, progressively lowering surface
temperatures without any diurnal rise Friday afternoon, and edging
the freezing line into the forecast area as early as 6 PM.

The biggest caveat to what should be a cut and dry "T<32 = ice" are
slight model differences in the strength of the surface cold air;
but more so the influence of the currently very warm ground and how
well ice will accumulate on wet surfaces, especially where
temperatures will hover right around or just below that 32 degree
mark. The best bet for ice accumulation will be in far northwest MO
where temperatures are already in the lower 40s behind the front and
will spend more time in chillier conditions, possibly allowing ice
to accumulate more efficiently. Elsewhere, the majority of ice may
only accumulate on elevated surfaces like bridges, trees, and power
lines; and even then, may take a few hours below freezing to start
accumulating. As a result, will issue just a one county WSW for ice
in Atchison county MO, and a freezing rain advisory in areas that
are most likely to see some ice accumulate before the system moves

The boundary will stall near our southern border late Friday into
Saturday, generating additional chances of light precipitation for
the weekend. The stout warm nose remains in place where precip is
possible, so liquid precipitation is still anticipated if any occurs
during this period. Model spread is a little higher on temperatures,
the possibility of precipitation, and the position of the front, so
while below freezing conditions are currently coincident with at
least a low-end chances of precipitation, am currently not thinking
that ice accumulation will be a major issue for the weekend.

.LONG TERM...(Sunday Night through Wednesday)
Issued at 346 AM CST THU NOV 26 2015

Another round of precipitation will spread across the region Sunday
night into Monday when the primary trough axis finally swings
through. GFS and ECMWF are coming into better agreement that a
resulting surface low will track across central or eastern Missouri
early Monday. For now it appears this track will keep most of the
sub-freezing temperatures confined to far northwest Missouri and
points north, so that most of the forecast area would see mostly rain
with this system. Meanwhile thermal profiles across far northwest MO
appear supportive of a mix of wintry precipitation with some minor
snow/ice accumulation possible. Will need to watch how models trend
with this system since a westward/warmer track would keep things
almost all rain everywhere, while an eastward/cooler track would
bring wintry precipitation further into the forecast area Sunday
night into Monday morning.

Behind Monday`s system, a large area of low-level ridging building
into the central U.S. will keep things dry for much of the rest of
the week while temperatures stay close to average for the beginning
of December.


.AVIATION...(For the 12Z TAFS through 12Z Friday Morning)
Issued at 526 AM CST THU NOV 26 2015

MVFR ceilings will lower just a shade this morning ahead of the cold
front that will sweep through all TAF sites between 16-19z today,
then IFR ceilings and gusty north to northwest winds are expected in
its wake. Light rain showers will expand in coverage and intensity
this morning, becoming widespread along and just behind the cold
front. A period of freezing rain is possible at KSTJ and especially
points north of there after 06z, then patchy freezing drizzle is
possible on the back side of the system at all TAF sites around 12z
Friday morning.


.EAX Watches/Warnings/Advisories...
KS...Freezing Rain Advisory from 9 PM this evening to 6 PM CST Friday
     for KSZ025-102.

     Flood Watch from this evening through Friday evening for KSZ057-

MO...Winter Storm Warning from 6 PM this evening to 9 AM CST Friday
     for MOZ001.

     Freezing Rain Advisory from 9 PM this evening to 6 PM CST Friday
     for MOZ002>005-011-012.

     Flood Watch from this evening through Friday evening for



LONG TERM...Hawblitzel
AVIATION...Laflin is the U.S. government's official web portal to all federal, state and local government web resources and services.