000
FXUS63 KDDC 111120
AFDDDC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DODGE CITY KS
620 AM CDT Tue Mar 11 2014

...UPDATE TO AVIATION...

.SYNOPSIS...
ISSUED AT 343 AM CDT TUE MAR 11 2014

Water vapor loop as of 08Z showed an impressive shortwave trough
continuing to dig southeastward into Utah. RAP analysis had a 400mb
potential vorticity (PV) anomaly extending from the base of the
trough near Great Salt Lake northeastward into eastern
Washington...suggesting a little more digging before the wave
translates eastward. Warmest temperatures in the lower troposphere
(850mb) were found across the High Plains of western Kansas into
West Texas (+17C at both North Platte and Dodge City; +20C at
Amarillo). The 08Z surface analysis showed a deepening surface low
centered near the western Nebraska-Kansas state border. Surface
winds continued to respond with overnight winds in the 10 to 13 knot
range, helping keep temperatures from dropping much. It was still in
the lower to mid 40s across much of the southwest and west central
Kansas region. Surface cold frontogenesis was noted across
northeastern Wyoming into the northern Nebraska Panhandle.

&&

.SHORT TERM...(Today and tonight)
ISSUED AT 343 AM CDT TUE MAR 11 2014

Moderate to high impact wind event this afternoon/evening is the
main forecast challenge and how to handle this event with headlines
(advisory vs. warning). Now that the forecast wind event is within
higher resolution short-term models (RAP13, for instance) temporal
range, we are gaining a bit higher confidence in the wind forecast.
As the surface low moves southeast into central Kansas, it will
continue to deepen down to about 995mb while surface
anticyclogenesis will ramp up across the northern Rockies and
adjacent High Plains.  This will induce a very tight pressure
gradient across western Kansas by midday...and especially this
afternoon.

The combined effect of the pressure gradient and the
isallobaric wind due to pressure change, will likely lead to
sustained winds around 40 mph for areas along and west of Highway
283 corridor...especially in the 22-01Z time frame. Forecast
soundings off the NAM12 and RAP13 both show around 35 knots just off
the surface around 900mb at Dodge City at 21Z with mixing up to
800-825mb. The winds around 800-850mb will pick up quite a bit as
the north wind low level jet strengthens west of the low at this
level. For Dodge City, the 00Z forecast soundings support a high
wind event (40mph sustained and/or 58mph gusts) with 50 knots shown
by both the NAM12 and RAP13 at the top of the mixed layer (which by
that point will be due to vigorous cold advection). Based on this
information, we will upgrade to a High Wind Warning for US283
corridor (Ness City down to Englewood) west to the Colorado border.

Per collaboration with surrounding offices, we will also include
areas of blowing dust where the High Wind Warning will be in effect
and hit it pretty hard in the NPW product. As far as precipitation
goes, the only area expected to see any measurable precipitation
will be the I-70 corridor, and will carry around 50 POPs up there. A
few tenths of an inch of wet snow may accumulate during the 23-02Z
time frame in particular.

.LONG TERM...(Wednesday through Monday)
ISSUED AT 300 AM CDT TUE MAR 11 2014

Medium range models indicate an upper level shortwave breaking
away from a larger scale trough Wednesday as it digs southeast
across the Rockies, and developing into a closed off upper level
low across the Intermountain West. Meanwhile, a general westerly
flow aloft will prevail across the Western High Plains through the
end of the week. This will result in dry conditions persisting
across western Kansas through Thursday night with insufficient
low/mid level moisture present. The closed off upper level low in
the Desert Southwest is then expected to open up and push eastward
into the South Plains early Friday bringing marginal precip
chances to the Texas and Oklahoma panhandles based on the
projected track of the shortwave. Cannot rule out a slight chance
for light rain across extreme southern portions of southwest and
south central Kansas Friday as the upper level system skirts
across our southern fringe.

Much cooler temperatures are likely Wednesday as arctic air spills
southward into western Kansas in wake of a departing cold front. The
NAM/GFS/ECMWF show H85 temperatures dropping well below 0C across
central and western Kansas initially Tuesday night. A slight
rebound to around 0C across central Kansas to near 5C along the
Colorado border is expected Wednesday afternoon due to some
northwesterly downsloping developing. Expect highs up into the
upper 40s(F) to possibly the lower to mid 50s(F) under decreasing
cloud cover. A quick bounce back to warmer temperatures will occur
Thursday as the arctic high dips further south across Texas while
lee side troughing redevelops across eastern Colorado. This will
quickly return a southwesterly downslope flow to western Kansas
pushing H85 temperatures up into the lower to mid Teens(C) across
central and western Kansas. Highs will easily reach the 60s(F)
Thursday afternoon with near 70F not out of the question in some
locations. Another cold front is projected to push through western
Kansas early Friday once again dropping temperatures across the
area.

&&

.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
ISSUED AT 620 AM CDT TUE MAR 11 2014

VFR conditions will prevail at all TAF sites through early this
afternoon. Low level stratus is expected to develop behind a cold
front as it pushes across western Kansas this afternoon. MVFR
cigs will be possible late this afternoon into this evening at
all TAF sites as a result. Strong northerly winds will develop
behind the cold front this afternoon with sustained winds of 35 to
45kt and gusts up to 50kt. This may result in periods of blowing
dust reducing visibilities to MVFR in the vicinity of KGCK and
KDDC. Brief IFR vsbys cannot be ruled out. Light snow will be
possible in the vicinity of KHYS this evening which may result in
IFR vsbys in blowing snow. The winds will become more
northwesterly tonight while subsiding somewhat.

&&

.PRELIMINARY POINT TEMPS/POPS...
DDC  59  27  51  26 /  20  20   0   0
GCK  56  25  50  24 /  20  20   0   0
EHA  63  27  48  28 /  10  10   0   0
LBL  64  26  50  25 /  10  10   0   0
HYS  55  27  50  24 /  40  50   0   0
P28  62  30  52  28 /  10  10   0   0

&&

.DDC WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING from 1 PM CDT /Noon MDT/ this afternoon to 11
PM CDT /10 PM MDT/ this evening FOR KSZ043>045-061>064-074>078-
084>088.

WIND ADVISORY from 1 PM this afternoon to 11 PM CDT this evening
FOR KSZ030-031-046-065-066-079>081-089-090.

&&

$$

SYNOPSIS...Umscheid
SHORT TERM...Umscheid
LONG TERM...JJohnson
AVIATION...JJohnson