000
FXUS63 KDDC 240456
AFDDDC

Area Forecast Discussion
National Weather Service Dodge City KS
1156 PM CDT FRI SEP 23 2016

...Updated for Aviation...

.SHORT TERM...(This evening through Saturday)
Issued at 342 PM CDT Fri Sep 23 2016

A large upper low was spinning into southwest Wyoming and western
Colorado late this afternoon. This has really enhanced the leeside
trough across eastern Colorado with MSLP down to 995mb south of
Denver. The tight pressure gradient led to widespread 25 to 30 mph
sustained winds with at times 35 mph sustained winds near the
Colorado border.

The question going into this evening will be the coverage and
severity of any thunderstorm activity along the lee trough. There
was uniform southerly wind all the way west to Trinidad, CO, so low
level convergence was rather weak. Visible satellite did confirm a
north to south axis of cumulus developing across far eastern
Colorado, and this appeared to be along a nebulous dryline. Surface-
based CAPE was only objectively analyzed around 300 to 500 J/kg
along and just east of this dryline, due to the lack of appreciable
moisture and warm mid level temperatures ahead of the Pacific cold
front. Speaking of which, the Pacific Cold front (or more
appropriately, the leading edge of the strong mid level cold
advection) was still way out over the San Juan Mountains of
southwest Colorado. It is difficult to imagine much of a severe
weather threat given the aforementioned thermodynamic environment.
Once the mid level cold pool does overspread low level instability,
it will be after sunset. Some elevated showers and isolated
thunderstorms will probably advance northeast during the late night
hours, and for that reason we will carry some 20 to 30 POPs across
the forecast area through the night. Precipitation amounts look
fairly low, however.

The upper low will split on Saturday, as indicated by the three
major global models. A portion of the energy will dive down into
eastern Arizona while a bulk of the jet energy will pivot northeast
up into the Dakotas. This will leave much of western Kansas in a
region of poor forcing for deep vertical ascent. The old Pacific
cold front will lose some steam as it advances into central and
south central Kansas, but by afternoon, there should be enough
convergence and moisture ahead of it to promote thunderstorm
activity, including some isolated severe. Highest POPs, 50-60
percent, will be found across mainly Barber County as a result. The
airmass behind the initial frontal passage will not be much cooler
than what we have already seen, so highs in the lower to mid 80s
will be expected.

.LONG TERM...(Saturday night through Friday)
Issued at 342 PM CDT Fri Sep 23 2016

A secondary cold front will push south late Saturday Night into
early Sunday as anticyclogenesis really ramps up behind the trough
across the Northern Rockies. Quite a bit cooler air will advect
south through the High Plains, with 850mb temperatures down to +9 to
+11C by midday across western Kansas. This should result in highs
Sunday in the lower 70s. The cool temperatures will carry into
Monday as well as the upper level pattern becomes blocky in
nature. Monday and Tuesday morning could be rather cool with
perhaps some upper 30s creeping into the Arkansas River valley of
Hamilton County and other areas of far west central Kansas. The
absence of cross- mountain flow aloft will be favorable for a weak
pressure gradient with no lee trough in place. Look for much less
breezy conditions Monday and Tuesday. Eventually, the lee trough
will re- establish itself with a return to stronger southerly
winds by Wednesday. No precipitation is forecast, although a weak
disturbance suggested to move across next Thursday could promote
some scattered thunderstorms by then.

&&

.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 1152 PM CDT Fri Sep 23 2016

An upper level trough will move across western Kansas with most of
the thunderstorm activity west of the TAF sites with a cold pool
aloft. Southeast winds of 15-25kt will become light and variable
as an associated cold front moves slowly eastward, then may stall
out and become light south to southeasterly. VFR conditions are
mostly expected with some increasing mid and high cloudiness.

&&

.PRELIMINARY POINT TEMPS/POPS...
DDC  68  84  55  74 /  20  20  30  10
GCK  61  83  53  73 /  30  10  10  10
EHA  56  83  51  71 /  40  10  20  20
LBL  63  85  56  73 /  20  10  30  20
HYS  67  82  54  72 /  30  30  30  10
P28  70  84  63  73 /  30  60  70  30

&&

.DDC Watches/Warnings/Advisories...
NONE.
&&

$$

SHORT TERM...Umscheid
LONG TERM...Umscheid
AVIATION...Kruse