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

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000
FXUS63 KEAX 270916
AFDEAX

AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
316 AM CST Sun Nov 27 2016

.Discussion...
Issued at 316 AM CST SUN NOV 27 2016

Main focus for this forecast issuance will be precipitation chances
today and tonight along and ahead of a surface low lifting out of the
High Plains. The low is currently centered just east of Denver, and
will be kicked eastward by a progressive shortwave trough, dragging
a cold front across the High Plains and generating a broad area of
WAA/isentropic lift in its warm sector this afternoon. A slug of low-
level moisture will also advect northward, progressively saturating
the column and setting the stage for a few rounds of light rain.

A few light showers or patchy drizzle will be possible as early as
12z-15z, when model soundings show very quick saturation of the 700
mb - near surface layer, then the coverage and intensity of rain
will increase after noon as isentropic lift increases and a subtle
fragment of shortwave energy passes over the forecast area. While
precipitation will initially spread from southwest to northeast in
line with the arrival of moisture, precipitation chances will trend
higher across our northern CWA where dynamics associated with the
shortwave trough and upper-level jet streak will be stronger. As a
result of this northward translation of upper dynamics and the
progressive nature of the isentropic lift, precipitation totals will
be limited to generally less than a quarter inch, and the period of
steadier rain will be short-lived during the afternoon in all but
northern MO. A few rumbles of thunder are perhaps possible this
afternoon when slightly cooler air filters in aloft and steepens
midlevel lapse rates just a shade, but even the isolated T mention
in the grids was a bit of a stretch.

A few very light showers or drizzle may persist this evening into the
overnight hours, but very little additional precipitation is
expected beyond the late afternoon. Light rain chances do linger
across our far eastern CWA on Monday where precipitation could
redevelop just ahead of the surface cold front, but it is more likely
that this will occur east of the CWA, especially with widespread
stratus preventing any instability from developing ahead of the
front.

In addition to the rain, winds will be quite breezy today and will
actually increase after sunset when the approaching, deepening low
sharpens the surface pressure gradient. Do not expect to reach wind
advisory criteria in our area, but sustained winds of 20 to 25 mph
and occasional gusts to 35 mph are not out of the question even
during the overnight period. These winds and boundary layer mixing
will help temperatures rise on Monday despite the cloud cover, so
expect temperatures to climb to near 60 degrees once more before the
more prolonged period of chillier conditions begins.

During the midweek period, a secondary wave will dig down the back
side of the longwave trough sitting over the western U.S., which will
act to broaden and slow the eastward progress of the upper trough.
This will delay the arrival of cold air behind Monday`s cold front,
but will also prolong the period of chilliest air once it does arrive
on Wednesday. Highs will fall to slightly below normal readings in
the low to mid 40s beginning Wednesday as cooler air filters down
unabated from Canada, and will remain there through at least the end
of the forecast period. Dry conditions will also prevail with any
shortwave energy either digging into the base of the trough well
south of our forecast area, or gliding along the Canadian border in
the wake of today`s - Monday`s system as it exits to the northeast.


&&

.Aviation...(For the 06Z TAFS through 06Z Sunday Night)
Issued at 1112 PM CST SAT NOV 26 2016

Main concern for the overnight period is low-level wind shear, though
lingering strong surface winds may minimize the full potential of
speed shear from the surface to 2kft, where SW winds will approach
40kts. MVFR ceilings will approach the area from the SW Sunday
morning ahead of the next storm system. Initially, moisture will be
confined to the lower levels and may result in light drizzle through
the morning hours, along with low-end MVFR ceilings, possibly
reducing to IFR at times. Ceiling heights will continue to degrade
early in the afternoon as moisture continues to deepen across the
area. Additionally, surface winds begin to gust to 30 kts and
persist through the afternoon. Widespread precipitation looks to be
slightly delayed than previously forecast, though should impact the
terminals by the mid afternoon hours. This activity should taper off
toward the end of the period, though ceiling heights will remain MVFR
or below Sunday night.


&&

.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&

$$

Discussion...Laflin
Aviation...Welsh



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