000
FXUS63 KDDC 012337
AFDDDC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DODGE CITY KS
537 PM CST Sun Dec 1 2013

...UPDATED AVIATION...

.SHORT TERM...(This evening through Monday)
ISSUED AT 156 PM CST SUN DEC 1 2013

The mid to upper level flow will shift from northwesterly to
west-northwesterly by Monday as upper level troughing digs into
the pacific northwest. This cross-mountain flow will cause surface
pressures to fall in the lee of the Rockies, along with some low
level downslope warming. Westerly winds at 5 to 10 kts and warmer air
just above the surface will tend to keep temperatures from falling
to the dewpoint tonight, with lows mainly in the lower 30s. For high
temperatures Monday, I opted to add 2-3 degrees to the NAM since
this model tends to underestimate surface temperatures in downslope
regimes. Skies should be mostly sunny with only a few high level clouds,
along with west to southwest winds at 5-10 kts.

.LONG TERM...(Monday night through Sunday)
ISSUED AT 353 PM CST SUN DEC 1 2013

The approaching arctic airmass presents the greatest challenge in
the forecast -- especially with respect to timing of the front
Tuesday and magnitude of cold airmass particularly Thursday through
Saturday. The models have trended just a bit faster with the front
Tuesday with the front most likely reaching an Elkhart to Dodge City
to Great Bend line by early to mid afternoon. The question becomes
how much of a warm-up can occur just ahead of the front.  It seems
likely that 60s will be common ahead of the front...if not well into
the mod to perhaps upper 60s.  Per collaboration with other offices,
have trended cooler in the forecast for Tuesday in the anticipation
of an even faster frontal passage than what the models are currently
showing.  The NAM12 is the fastest with the front, which should be
respected given this model`s higher resolution and better terrain
(and the non-hydrostatic influence the terrain has on density
currents on the High Plains). Fronts typically move through faster
than what global spectral models forecast in the 2-3 day time frame.
The forecast after Tuesday was really not altered that much as the
handling of the arctic air was already pretty good in the grids. We
did, however, go just a bit colder for Thursday and Friday as
confidence is growing that temperatures will not escape the teens
over much of southwest Kansas.

Snow chances continue to look decent, however development in the
700-500mb layer will not be strong enough to support substantial
accumulating snow anywhere across southwest Kansas...as it appears
now. There will be a tight thermal gradient at 700mb Wednesday Night
into Thursday...with the best chance for some deformation along the
700mb front and snow chances coming late Thursday and Thursday
Night. Given how cold the airmass will be...a tenth of an inch of
precipitation may yield a couple inches of snow during this time
frame. This shortwave trough will be shifting to the east Friday
with the arctic ridge firmly in place.  A little bit of sun Friday
may not make it feel as cold...but cold it will be...with -15C 850mb
temperatures supporting highs only in the 19 to 24F range across the
southwest Kansas region. The airmass will modify a bit going into
the Day 6-8 time frame...but another jet digging south out west
reinforcing the cold mid level trough may set the stage for a snow
event on the Central Plains somewhere during this time frame Dec
8-10.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
ISSUED AT 536 PM CST SUN DEC 1 2013

A weak surface pressure pattern across western Kansas is expected to
change very little over the next 24 hours. Local GFS MOS guidance
and mesoscale models indicate light westerly surface winds on
Monday. VFR conditions are expected given a very dry airmass in
place across the region.

&&

.PRELIMINARY POINT TEMPS/POPS...
DDC  32  65  35  52 /   0   0   0   0
GCK  30  65  33  51 /   0   0   0   0
EHA  34  66  36  52 /   0   0   0   0
LBL  31  66  35  54 /   0   0   0   0
HYS  31  65  34  48 /   0   0   0   0
P28  31  65  35  57 /   0   0   0   0

&&

.DDC WATCHES/WARNINGS/ADVISORIES...NONE.
&&

$$

SHORT TERM...Finch
LONG TERM...Umscheid
AVIATION...Russell