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000
FXUS63 KDDC 010544
AFDDDC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DODGE CITY KS
1144 PM CST Sat Nov 30 2013

...Updated aviation discussion...

.SHORT TERM...(This evening through Sunday)
ISSUED AT 212 PM CST SAT NOV 30 2013

Dry northwesterly flow at mid and upper levels will persist through
Sunday. The surface pressure gradient is advertised to be weak, with
only small low level thermal advections. Good radiational cooling can be
expected tonight with mainly clear skies and light winds with
dewpoints in the 20s. Temperatures should bottom out in the mid to
high 20s. Sunday will be only slightly cooler with continued light
winds and highs in the mid to high 50s, along with only a few high
level clouds in association with a strong upper level jet streak.

.LONG TERM...(Sunday through Friday)
ISSUED AT 409 AM CST SAT NOV 30 2013

A dramatic change is in store for the latter half of the Long Term
period as the next arctic air outbreak unfolds across the Great
Plains.  In the meantime, temperatures will continue to be above
seasonal average both Monday and Tuesday as highs should easily
touch lower 60s with lows slightly above freezing in the lower to
mid 30s as a general rule. The GFS model is largely discounted as it
appears to be over-developing the lead shortwave trough across the
Dakotas Tuesday, which is in stark contrast from the Canadian GEM
and ECMWF models...which lift this initial wave north-northeastward
into southern Canada without much in the way of lower tropospheric
development.  Less lower-tropospheric development of the initial
wave would lead to much weaker cold frontogenesis on the backside,
which is why the GFS is showing such a strong initial surge south
through much of the Central Plains on Tuesday.  The best forecast at
this point is a compromise between the GEM and the ECMWF...which
both show the leading edge of the cold air at the surface across
western Nebraska by late in the day Tuesday (with perhaps a
penetration as far south as far northwestern Kansas).

The low level cold advection will, however, be in full swing by
Wednesday morning with the front most likely reaching an Elkhart to
Hays line by daybreak. Temperatures will most likely hold steady in
the lower to mid 30s initially, but slowly fall to around 30 or the
upper 20s through the day.  The exception to this may be far
south-central KS locations (Barber County) where it may warm up a
few degrees with insolation before the strongest cold air advection
hits.  There is one caveat to this, though, and that is the fact
that very strong southwest downslope momentum by midday into
afternoon (in the 900-700mb layer) could halt the southwest push of
the cold air into the Elkhart area.  Should this occur, then Elkhart
could actually be fairly warm Wednesday...and there would be a very
tight temperature gradient across southwest Kansas.  At this
time...a stronger push of the cold air is favored and will be going
with highs around 40 for Elkhart on Wednesday. There could be a big
bust potential at Elkhart Wednesday, though, depending on where the
surface low wants to develop within the strong southwest mid level
flow. Precipitation chances initially do not look all that good
until the 700mb front reaches southwest Kansas. It does not look
like the front at 700mb will reach southwest KS until sometime late
in the day Thursday.  It will take its time getting down here with
all the southwest momentum in the mid levels through late Thursday
(per ECMWF and GEM models).  The arctic air at the surface will be
well into the southwest Kansas region by then...and it is hard to
imagine temperatures getting above lower 20s anywhere in southwest
Kansas with 850mb temperatures in the -12 to -15C range and stratus
clouds around. This is shaping up to be one of the more impressive
arctic airmasses this forecaster has seen for early December in
quite some time.  Usually these types of arctic airmass are favored
late December through mid-January.  The longwave trough looks to
reload with another meridional jet streak diving down the west side
of the trough (along the west coast) in the Day 7-9 time frame (per
the latest ECMWF) which would only exacerbate the arctic cold
environment across the Western Plains going into the December 7-10
time frame.  The entire Day 8-14 period looks much below normal for
temperatures and perhaps slightly above average precipitation with
the 700mb baroclinic zone hanging around the central portion of the
country.

&&

.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
ISSUED AT 1144 PM CST SAT NOV 30 2013

VFR conditions will prevail through this taf period. A very weak
surface trough of low pressure will extend across western Kansas
through the period, resulting in light and variable winds.

&&

.PRELIMINARY POINT TEMPS/POPS...
DDC  26  58  31  65 /   0   0   0   0
GCK  25  59  29  64 /   0   0   0   0
EHA  26  59  33  64 /   0   0   0   0
LBL  26  59  30  64 /   0   0   0   0
HYS  26  55  30  63 /   0   0   0   0
P28  28  57  30  65 /   0   0   0   0

&&

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

$$


SHORT TERM...Finch
LONG TERM...Umscheid
AVIATION...Gerard