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

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FXUS63 KEAX 260005

605 PM CST Wed Feb 25 2015

Issued at 334 PM CST WED FEB 25 2015

Surface low is just north of Maryville this afternoon with a strong
cold front trailing to the southwest. Surface low will track to near
Chillicothe around 6 PM...and to near Sedalia around 8 PM. Most
accumulating snow will stay just to the east of this track where 1"
to 3" will be the general rule. Can`t rule out a few amounts a bit
higher than this near and north of Kirksville, but with temperatures
having risen quite a bit warmer than was expected this afternoon,
snow that falls initially will have to battle some warmer ground
temperatures and may melt at first. With the track of the higher
amounts continuing to shift east, a few more counties over north
central MO were removed from the winter weather advisory. These
counties should see snow amounts of an inch or less.

Further south...still expect a band of light precipitation to trail
the front as it swings into eastern KS and western MO later this
evening. Rapid drop in temperatures behind the front should keep most
of this in the form of snow although some rain is still possible
initially. Snow should only last 2 or 3 hours at most for these areas and
will again have to battle warm ground temperatures, so any snowfall
amounts to the west of the surface low track should only be a few
tenths of an inch. This matches up with what was measured at NWS Omaha
where only 0.2" of snow was measured with this snow band.

Perhaps a bigger concern will be the rapid drop in temperatures
immediately following frontal passage. Some areas could fall from the
50s into the 20s in just a couple of hours, bringing flash-freeze
concerns to any areas that see rain or melting snow when precipitation
begins. This will be especially true across the advisory area where
more precipitation will fall, but could be a concern anywhere that
sees enough rain or melted snow to wet the ground. Will highlight
this concern with a special weather statement for any areas not in
the current advisory.

Behind this system the story turns to cold for Thursday and Friday.
1041 mb Arctic high building into the area will keep highs in the
teens for most areas both days. Nighttime temperatures will drop into
the single digits, and probably some sub-zero readings over any areas
with snow on the ground. May see wind chills dip into advisory
criteria (-15 F) over north central MO Thursday night.

Attention then turns to the increasing potential for a winter storm
over the weekend. GFS and ECMWF have been surprisingly consistent the
past few runs bringing quite a bit of accumulating snow across the
region Saturday afternoon into Sunday. Consensus of both models is to
bring warning-criteria snowfall, or 6"+, into much of the forecast
area with the highest values right along I-70. Despite this
consensus, major pattern shifts like this one almost always throw
high variability into medium range models, so that even higher-
than-normal model agreement such as this can quickly go away. With that
said, it`s still too early to start pinpointing precipitation amounts
or where the highest will fall, but confidence is increasing that
precipitation should stay mostly snow Saturday and Saturday night.

Forecast remains interesting into early next week with continued
upper-level troughing to our west. This should send one or two
additional rounds of precipitation into the region especially Monday
night and Tuesday. Precipitation type with this round is highly
uncertain with increasing signs that it could fall as a wintry mix or
even rain.


.AVIATION...(For the 00Z TAFS through 00Z Thursday Evening)
Issued at 600 PM CST WED FEB 25 2015

Cold front passing through the terminals as I type. Very strong and
gusty northwest winds through the night. Band of post frontal
rain and snow follows passage of front. Initially rain but quickly
changes to snow as temperatures fall dramatically, typically 15-20F
in around an hour of frontal passage. MVFR cigs also move in quickly
behind the front and will last through tomorrow morning. Cloud
bearing temperatures are cold enough to support flurries through the
night. Minor snow accumulations over western MO and eastern KS, less
than half an inch.

Expect VFR conditions by Thursday afternoon as MVFR cigs scatter out
but breezy conditions continue.





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