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Area forecast discussion 
National Weather Service Kansas City/Pleasant Hill MO
524 PM CST Wed Dec 24 2014

Discussion...
issued at 338 PM CST Wednesday Dec 24 2014

The light wintry mix of rain and snow has moved out of the area as
of 21z, and will likely remain east of the forecast area. Lingering
stratus will hold on for the next several hours, but the back edge
of the stratus is not far off to the west, across eastern Kansas.
Generally expect the stratus to hang in until the overnight hours,
and perhaps clear out by midnight tonight. Forecast soundings
indicate some moisture around the 500 mb layer, so while the low
level stratus will likely be a thing of the past there could be some
mid-high level clouds move through the area.

For Christmas day, still expecting a dramatic warm up with
temperatures rising to 10-15 degrees above normal. This push of warm
air will be a byproduct of a rather deep surface low, which will
form on the Lee-side of The Rockies overnight tonight and persist
through the day on Wednesday. A very strong low level jet will also
be present over the forecast area on Thursday. This jet will be
characterized by 850 mb winds nearing 60 mph. BUFKIT soundings for
the mid afternoon on Thursday indicate a few levels in the lowest
couple hundred mb reaching 60 to 65 mph. The strong surface pressure
gradient will bring winds in excess of 20 mph through the day. The
question becomes how strong the wind gusts will become, as the lower
levels mix out. With such strong winds located so close to the
surface concern does increase that advisory-criteria winds will be
experienced during the afternoon hours. BUFKIT soundings for the
area indicate rather shallow mixing though, even during the
afternoon hours. So with the lower levels not being mixed well
enough to get the true 50-60 mph winds to the surface, opted to not
go with an advisory...for now. Friday could bring another rather
comfortable day to the forecast area, with above normal
temperatures, as the surface low makes slow eastward progress. As
the low center approaches the surface pressure gradient slackens up,
and winds will respond by lessening through the overnight hours
Thursday night into Friday. A cold front will be sitting on the
doorstep of northwest Missouri through the day on Friday, so areas along
and north of Highway 36 and west of I-35 could see blustery conditions
as the front sags southward. Areas to the south and east of the
previously defined domain should see temperatures in the 40s and
50s. As a broad positively tilted mid level trough approaches the
area there could be enough lift to squeeze a little bit of moisture
out of the atmosphere to bring some very light rain and snow to
portions of the forecast area. The areas ahead of the cold front
would see mostly light rain, with Post frontal zones seeing some
very light snow. Given the very shallow nature of the moisture and
the very modest lift the prospects for precipitation are somewhat
minimal.

Friday will signal the Last Chance for seasonably comfortable
temperatures for quite a while. By Saturday the cold front sags far
enough south to encompass the entire forecast area. Looking
temperatures in the 30s for the weekend. Saturday morning could
bring some lingering snow showers to the area, but as stated above
any accumulations would be minimal. By the early to middle part of
next week, ec/GFS are both in agreement in a dramatic surge of
Canadian air into the Central Plains and lower Missouri River
valley. As of now, this air mass is projected to have 850 mb temps
of around -10c to -20c over the forecast area. Should this occur, we
could be seeing highs in the teens for the middle to latter part of
next week, with lows in the single digits. As far as precipitation
GOES for the extended period, with the deep trough dropping into the
area - accompanying the cold air mass - there could be enough lift
to get some snow to form through the week next week, but moisture
quality is likely to be lacking, so any significant accumulations
look to be unlikely at this point.

&&

Aviation...(for the 00z tafs through 00z Thursday evening)
issued at 513 PM CST Wednesday Dec 24 2014

The edge of the overhead stratus deck is currently positioned over
eastern Kansas and will make its way over kmci around 0500z. Once
this MVFR deck moves out of the area, VFR ceilings will filter in and
prevail through the forecast period. Aside from that, southerly winds
will increase during the early morning hours of Christmas day. There
looks to be about a 5 hour window of possible wind shear beginning at
10z with 10kt surface winds and 40kt winds at 1kft. This will be a
speed shear effect with little directional shear expected. This
feature will mix out around 15z, though increased winds are expected
throughout the remainder of the period with gusts as high as 30kts.

&&

Eax watches/warnings/advisories...
Kansas...none.
MO...none.
&&

$$

Discussion...Leighton
aviation...Welsh

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