Area Forecast Discussion
Issued by NWS Dodge City, KS
FXUS63 KDDC 300600
Area Forecast Discussion
National Weather Service Dodge City KS
1200 AM CST Wed Nov 30 2016
...Updated Short Term...
.SHORT TERM...(Today and Tonight)
Issued at 1200 AM CST Wed Nov 30 2016
Wrapping up November with typical late November weather. Scattered
to broken mid-layer clouds will gradually thin out this morning,
as dry and subsident airmass takes control. Expecting a clear sky
areawide by late morning, continuing through tonight. NWly
pressure gradient is still quite tight, so for one more day
NW winds will pick up abruptly after sunrise. NW winds will
average 20-30 mph with a few higher gusts to near 35 mph, just a
bit less wind than yesterday. Much lighter winds expected today
across far SW Kansas (Morton and adjoining counties) where the
pressure gradient has already substantially weakened. Despite the
full sunshine by afternoon, temperatures will be restricted to
near normal in the face of the continued NW winds and cool
advection, in the upper 40s and lower 50s.
Tonight...Clear calm and cold. Modest surface high pressure near
1020 mb will build into eastern Colorado/western Kansas by sunrise
Thursday, allowing radiational cooling to operate at near optimal
levels. As such, undercut guidance for low temperatures Thursday
morning by several degrees, with widespread teens anticipated.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 338 PM CST Tue Nov 29 2016
The early to mid periods (through the weekend) of this Long Term
forecast have not changed much from the previous forecast thinking.
The ECMWF has come more in line with the GFS in closing off a mid
level cyclone deep into Mexico by the early weekend. The southwest
flow/warm conveyor belt sector of this system is still forecast to
make a push up into the Texas Panhandle, perhaps up to the southwest
Kansas border in the Friday Night through early Saturday period,
however whatever precipitation shield makes it clear up to our
latitude will dissolve as it enters a much more hostile environment
with confluent mid level flow and a rather anticyclonically curved
jet core centered to our south across Oklahoma. The SuperBlend
starting point still put in some small POPs in the south, but the
QPF/SnowAmt grids will remain very scant. No high impact, or even
moderate impact winter weather is anticipated with this weekend
system as just about the entire precipitation event will remain
across the Southern Plains.
We then look upstream for the second half of the weekend, and what
we will be watching for is the evolution of the first bitter cold,
arctic airmass currently over interior Alaska as it is forecast to
expand and migrate equatorward through western Canada. At D+6
(Sunday Night/Monday Morning), all three major global spectral
deterministic models show a large extent of -20C or colder arctic
air (at 850mb) expanding southward from the western Canadian boreal
forest into the Canadian Prairies of Alberta and Saskatchewan. All
the models also agree on an intense equatorward nosing upper jet
from just off British Columbia into the west coast of the CONUS.
This is a very favorable pattern signal for the aforementioned
arctic air to plunge down the High Plains of the central CONUS with
substantial density gradient enhancement. Details, of course, will
be ironed out in time, but there is too much signal to ignore
regarding the potential for a rather significant arctic air
intrusion into the northern and central Great Plains (including
western Kansas). What we really don`t know, and will not know with a
reasonable degree of confidence for a few days, is a high or even
moderate impact winter storm affecting western Kansas. Granted, the
12Z runs of the ECMWF and the GFS both show rather impressive
agreement for D+8 regarding vigorous cyclogenesis along the arctic
boundary, but the reader/end user must be reminded that Day 8 model
output has enormous error typically on the scale of states when it
comes to mid latitude cyclone tracks.
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1100 PM CST Tue Nov 29 2016
VFR through Wednesday. Scattered to broken mid clouds will
gradually thin out through Wed AM, with SKC expected after
15z Wed. NW winds near 12 kts overnight will once again increase
sharply after 15z, increasing to 22-32 kts at all airports.
NW winds will diminish rapidly around sunset Wednesday evening.
.PRELIMINARY POINT TEMPS/POPS...
DDC 25 50 18 49 / 0 0 0 0
GCK 23 49 17 47 / 0 0 0 0
EHA 22 48 20 46 / 0 0 0 0
LBL 24 51 18 48 / 0 0 0 0
HYS 26 46 19 47 / 0 0 0 0
P28 29 52 23 52 / 0 0 0 0