Area Forecast Discussion
Issued by NWS Dodge City, KS

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FXUS63 KDDC 222300

600 PM CDT Tue Apr 22 2014

...Update to aviation...

.SHORT TERM...(This evening through Wednesday)

Short range models indicate upper level ridging moving eastward
across the Central Plains tonight giving way to a strengthening
southwest flow aloft across the Western High Plains. This will
coincide with a strong upper level trough digging southeast out
of the Pacific Northwest into the Great Basin Region. As the next
upper level system approaches this evening, a series of H5 vort
maxes will begin to eject northeast out of the Colorado Rockies
into the high plains of Colorado, western Nebraska, and western
Kansas. Although low level moisture is expected to remain marginal
at best, a southeasterly upslope flow combined with increased
convergence near the surface trough in eastern Colorado will lead
to thunderstorm development across eastern Colorado this evening.
A few isolated storms may drift into extreme western Kansas late
this evening then lift northeast overnight. Although severe
weather is not expected, small hail and gusty winds up to
55 mph will be possible.

For Wednesday, the approaching upper level trough will turn
eastward, moving out of the Rockies into and across the Western High
Plains bringing an increased chance for thunderstorms to central and
portions of western Kansas late in the afternoon. As the upper level
shortwave axis moves out of the Rockies, a developing dryline across
extreme eastern Colorado will sharpen as it shifts east into western
Kansas during the day. Ahead of the dryline, increasing moisture
and instability along with steepening low/mid level lapse rates
will set the stage for thunderstorm development along and ahead of
the dryline as it advances further east. Additionally, dynamics
aloft will become more favorable as a southwest-northeast oriented
upper level jet moves into western Kansas. Although a few storms
may become severe with CAPE values climbing in excess of 1000 J/KG,
NAM/GFS model soundings hint at a lower threat for tornadoes with
higher LCL`s generally above 7,000ft and a lack of favorable
directional shear.

Temperatures will be above normal tonight as a strengthening low
level flow across western Kansas enhances warm air advection into
the area. As surface dewpoints begin to slowly rise into the the
40s(F) overnight, look for lows only down into the 50s(F) across
central and southwest Kansas. For Wednesday, a prevailing southerly
flow will continue to draw warmer air northward with H85
temperatures upward of 20C across central Kansas to near 25C
in extreme southwest Kansas. As mostly sunny to partly cloudy skies
persist, widespread 80s(F) are expected Wednesday afternoon with
near 90F possible behind the dryline across extreme southwest

.LONG TERM...(Wednesday night through Tuesday)

Convection will increase along and south of a cold front early
Wednesday night as an upper level disturbance moves across the
Central High Plains. The cold front is forecast to move south
across western and central Kansas between 00z Thursday and 09z
Thursday and based on the location of where the low level thta-e
ridge axis will be early Wednesday night will stay close to the
previous forecast with increasing precipitation chances, mainly
east of highway 83. NAM and GFS preciptable water values Wednesday
night are expected to be around 1 inch so periods of moderate to
heavy rain will be possible with some of these storms overnight
across north central and south central Kansas.

Gusty northwest winds can be expected behind this cold front as
it crosses southwest Kansas during the overnight hours. The GFS
and NAM both indicated a tight surface pressure gradient along
with 30 to 40knots in the 925mb to 850mb level across much of
western Kansas. Wind speeds in the 25 to 35 mph range will be
likely for a couple of hours across portions of western Kansas
before these winds fall back into the 15 to 25 mph range. Based on
the cold air advection and decreasing clouds from northwest to
southeast late tonight will favor the cooler MAV guidance for
overnight lows.

An area of high pressure at the surface will cross western Kansas
on Thursday as the upper level trough moves from eastern Kansas
into the Mid Mississippi Valley. At this time will follow the
850mb temperature trends for highs Thursday afternoon which
continues to support temperatures warming mainly in the low to mid
70s. The warming trend will continue on Friday as an surface
trough of low pressure deepens across eastern Colorado and a mean
westerly downslope flow improves. Highs Friday afternoon are
expected to range from the mid 70s to lower 80s.

Precipitation chances will improve over the weekend period as the
next upper level storm system moves east across the southwest
United States. As this next storm system moves out into the plains
early next week an upper low is forecast to develop. The GFS,
ECMWF and ensembles differ on this upper low development Sunday
and Monday but despite these differences both the GFS and ECMWF do
agree that a surface cold front will cross western Kansas late
Sunday. As a result will stay close to the previous forecast for
highs over the weekend period but will lean towards cooling
temperatures from Sunday through Tuesday given the cooling trend
advertised in the 925mb and 850mb levels by both the GFS and ECMWF
behind a cold frontal passage.


.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)

In the immediate critical TAF pd, watching some showers and tstorms
across the CO/KS border. This could impact KGCK but confidence is pretty
low on the activity sustaining itself to create a reduction in flight
category. Otherwise, VFR conditions expected through much of TAF pd.
Sct tstorms tomorrow but will leave out for now due to uncertainty in
placement and timing. Southerly winds 18-25 kt will become S/SSW 25-30
kt by morning.



Relative humidity below 15 percent is likely across extreme
southwest Kansas Wednesday afternoon as a dryline moves eastward
across the area during the day. The question will be whether winds
will be strong enough to promote critical fire weather conditions.
The NAM/GFS show H85 winds of around 25 to 30kt just ahead of the
surface trough axis during much of the afternoon hours. As the
dryline advances through extreme southwest Kansas, lower/mid level
lapse rates will steepen allowing the stronger winds to mix down
to the surface. As a result, critical fire weather conditions are
expected to develop Wednesday afternoon. A Red Flag Warning has
been issued this afternoon for the counties affected.


DDC  53  83  46  74 /  10  50  70   0
GCK  55  85  44  73 /  20  40  50   0
EHA  58  87  45  73 /  20  20  20   0
LBL  57  86  45  76 /  10  30  40   0
HYS  53  83  46  72 /  20  60  90  10
P28  53  83  53  77 /  10  40  70   0


RED FLAG WARNING from 1 PM to 8 PM CDT Wednesday FOR KSZ074-075-



LONG TERM...Burgert
FIRE WEATHER...JJohnson is the U.S. government's official web portal to all federal, state and local government web resources and services.