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

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FXUS63 KEAX 190522
AFDEAX

AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
1122 PM CST Sun Feb 18 2018

.Discussion...
Issued at 246 PM CST SUN FEB 18 2018

We`ve got quite the dynamic system getting ready to impact the
local area for the latter portion of this holiday weekend. Breezy
conditions currently felt across the region will slacken a bit
after sunset, although the LL jet will crank up. Simultaneously,
we`ve got a direct moisture feed coming in from the Pacific Ocean,
running through the Gulf of California/Baja Peninsula. This
atmospheric river, with some pull starting to come in from the
GoMex by early Tuesday, will advect in plenty of moisture for an
approaching cold front to work with. Initially for tonight, this
deepening LL moisture pooling in will allow for LL cloud cover to
build in with sprinkles possible. By early tomorrow morning, more
widespread precipitation chances will be taking over out ahead of
the aforementioned front. Additionally, there looks to be an
uptick in instability, especially as the day progresses,
introducing the chance for thunder.

From Monday night into Tuesday is where model discrepancies begin
to highlight the big differences that temperatures will play into
what will end up actually occurring. At this point, it appears
that the latest NAM run(s) are a bit too bullish in bringing in
sub-freezing surface temperatures, and have leaned away from that
particular solution. Have essentially confined much of the
freezing rain potential (yes, this looks more like a freezing rain
setup instead of a wintry mix situation given the deep warm layer
aloft) to NW MO tomorrow night into early Tuesday. That said, the
NAM`s solution isn`t entirely out of the realm of possibilities.
Bottom line is that if the NAM holds true and the shallow layer
of cold air advects in quicker than currently forecast, could see
higher ice accumulations possible further south. What can be
agreed upon with the various models is that NW MO is in the
crosshairs to receive at least some accumulating ice. However,
given that there is still time in the decision making process in
that this won`t come to fruition until tomorrow night, and given
the uncertainty that remains with respect to how far south ice
accumulations could get, have held off on headlines for this
forecast package. Stay tuned though.

Because there isn`t much of a push to keep the front moving
through until an UL trough assists in its progression later this
week, portions of the area could be in for a prolonged period of
periodic precip chances. The GFS doesn`t have the front clearing
the eastern counties of this forecast area until early Wednesday,
and even then, central MO could see additional chances into the
latter half of the week as it sits on the periphery of a stagnant
surface high centered near the SD/NE/MN/IA borders. The overall
pattern starts to look more progressive by the end of the week
into next weekend, but given how far out it is at this point,
probably wise not to hang hats on anything substantial just yet.

&&

.Aviation...(For the 06Z TAFS through 06Z Monday Night)
Issued at 1117 PM CST SUN FEB 18 2018

Ceiling heights will continue to degrade overnight as ample low-
level moisture advects into the region. Expecting low-end MVFR
ceilings overall with periodic reductions to IFR. Low-level wind
shear is favorable overnight as winds near 2kft approach 45 to
50 kts. The speed change with height will be relatively uniform,
though periodic variations could produce abrupt changes within the
lower levels down to the surface. Precip will make its arrival
into the area by Monday morning, though should remain fairly
isolated to scattered until late Monday night.

&&

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

$$

Discussion...lg
Aviation...Welsh



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