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

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FXUS63 KEAX 232151

351 PM CST Mon Feb 23 2015

Issued at 349 PM CST MON FEB 23 2015

The surface ridge that brought the chilly air mass into the area is
on its way out, and southerly surface flow should commence in short
time. The southerly winds overnight will help keep temperatures
relatively elevated, meaning overnight lows will only be a couple
degrees cooler than the daytime highs today. With lows only being in
the upper teens and with good SW-ly surface flow for Tuesday expect
daytime temps to be able to climb to a more normal 35 to 45 degrees
across the area for Tuesday afternoon. This will then set the stage
for a weather making trough to move through the area, bringing a
chance for some accumulating snow.

Southerly surface flow at the surface will keep temperatures through
the day on Wednesday in the middle 30s to lower 40s. Typical to this
season`s pattern northwest mid level flow will run over the area,
which generally speaks to a quiet or at least low-impact pattern.
However for Wednesday night into Thursday morning there will be a
short wave trough embedded within the NW flow aloft. This trough
will quickly dive through the area, bringing enough ascent to
produce some light snow. While the bulk of the precipitation will
hold off until the overnight period on Wednesday night, especially
farther south. The better likelihood is that the colder air will
beat the precipitation to the area, which would cause the bulk of
the precipitation to fall as snow through the overnight period.
There does not appear to be a strong isentropic component to this
system, and the instability looks to be rather minimal, so the
majority of the ascent with this weak system will be in the form of
modest lower and mid level frontogenesis and mid level ascent
associated with the trough. All said, NAM progs about 5 to 10
ubars/sec of Omega at the height of the event. By the end of the
event there could be around .10 to .25 inch of liquid across the
area. Along and west of the I-35 corridor there is a good chance
that much of the day and the beginning of the evening hours would be
enough above freezing at the surface to allow for some rain or
rain/snow mix before the bulk of the precip falls. The result would
be slightly lower snow amounts along and west of I-35. Areas of
north central and central Missouri, where temps don`t get as warm
could see more snow. All told, around 2-3 inches is expected in NC
and C Missouri, with lower amounts farther west, toward the KC Metro
and western MO. These amounts could change a bit as we approach that
time period and the thermal profile becomes more focused.

After another arctic air mass moves in for the end of the work week
another strong winter system looms on the horizon for the area. At
this point the long range models have been rather consistent in
moving in more significant precipitation for the Saturday and Sunday
time period. The typical caveats apply to this system, especially
for the 5-7 days-out period. The track and timing is much in
question, as well as the thermal profile. For now, it appears that
with the cold air in place from the late week cold air mass that the
leading portion of the precip could be snow, but with warm air
moving in at the surface it could become a mixed bag of precip
through the day, then changing back to snow by Saturday night. While
the details of this event are unclear it will definitely bear
watching over the next several days.


.AVIATION...(For the 18Z TAFS through 18Z Tuesday Afternoon)
Issued at 1132 AM CST MON FEB 23 2015

Expect VFR conditions for the entire forecast period with gradually
veering and increasing winds through the day on Tuesday. There is a
hint that there could be some low level clouds on Tuesday, with
perhaps a period of MVFR CIGS, however a majority of models and
guidance do not support the low level clouds, so opted to leave them
out for now. Will reassess that forecast element on subsequent
aviation forecasts.




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