Area Forecast Discussion
Issued by NWS Dodge City, KS
FXUS63 KDDC 030553
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DODGE CITY KS
1153 PM CST Mon Dec 2 2013
...Updated aviation discussion...
ISSUED AT 911 AM CST MON DEC 2 2013
The 02.12Z 250 hPa raob map showed 100-120 kt west-northwesterly flow
extending from KSLE to KDNR. Another 105-125 kt west-northwesterly jet
extended from KSHV to KJAX. At 500 hPa, a deep 528 dm cyclone was just
east of Vancouver Island. Very cold -35C to -37C temps were associated
with said pressure perturbation. Downstream, there were a few minor
waves moving across the northern Rockies in the NW flow at the mid levels.
At 850 hPa, all the really cold air with values below 0C were confined
across the Pacific Northwest and across the Canadian prairies. At the
sfc, a frontal system was located across the northern plains. A weak
lee trof was located across Kansas. The source region for the upcoming
cold was all the way up north in the Yukon with the temp at -40C (and
F) and MSLP at 1055 hPa.
.SHORT TERM...(This evening through Tuesday)
ISSUED AT 253 PM CST MON DEC 2 2013
...No precipitation expected through the short term period...
Quiescent weather is expected through the overnight hours. West-northwesterly
flow aloft mentioned in the synopsis will continue through tonight,
although increase in magnitude to around 100 kt by 03.12Z. At the sfc,
a lee trof will continue across western Kansas, resulting in light and
variable winds. Minimums into tomorrow morning are expected to be in
the lower 30sF.
Main problem for tomorrow was the speed of the front. This is a strong
Arctic front, so was a little reluctant in going with warmer temperatures.
Still, 12Z solutions (NAM, WRF, EC, GEM) all show a slower fropa. A
warm layer is forecast between 875-850 hPa, and with a little downslope
mixing ahead of the front, it will not take much for temperatures to
increase. After coordination with neighbors, went ahead with warmer
maximums - 60sF.
.LONG TERM...(Tuesday night through Monday)
ISSUED AT 230 PM CST MON DEC 2 2013
A strong cold front will push south into Oklahoma Tuesday night. A
tight surface pressure gradient north of this front will be located
across western Kansas during the overnight hours. Given this surface
pressure gradient, strong cold air advection, and 900-850mb mean
wind speeds in the 30 to 40kt range wind speeds early Tuesday night
the developing north winds may approach wind advisory criteria for a
few hours. These strong winds will then begin to gradually subside
after midnight, however sustained wind speeds of 15 to 25 mph will
be possible across western Kansas through Wednesday night.
In addition to the gusty winds, much colder air will be invading
western Kansas Tuesday night and Wednesday. Mean 900-850mb 24hour
temperature change varies from 10C to around 15C from 00z Wednesday
to 00z Thursday. Temperatures will continue to drop several more
degrees from 00z Thursday to 00z Friday with a straight 00z Friday
850mb mix down temperature from the GFS across western Kansas
suggesting highs will range from 17F to around 22F degrees. At the
same time this cold air advection will occurring across western
Kansas, isentropic lift and moisture advection will be improving
just above this cold layer from Wednesday through early Thursday.
Given the expected cloud cover along with cold near surface
temperatures on Thursday have decided to undercut guidance and favor
the cooler ECMWF. Will therefore favor highs on Thursday only around
15 degrees in western Kansas. South central Kansas will be slightly
warmer with highs around 20. Lows Thursday night are expected to
fall back into the 5 to near 15 degree range with the colder
overnight lows being located across west central Kansas.
Bitter cold wind chills will be the main hazard from Wednesday night
through Thursday night given the gusty winds and unseasonably cold
temperatures. Wind chill values each night are expected to fall back
into the -5F to around -10F degree range. On Thursday afternoon wind
chill values are expected to be mainly in the single digits.
Snow can also be expected across western Kansas from Wednesday night
through Thursday night. At this time it appears that light snow will
develop across portions of western Kansas early Wednesday night as
moisture and isentropic lift improves. An area more favorable for
measurable snowfall late Wednesday night and Thursday will be
across west central and portions of north central Kansas given the
location of the right entrance region of an upper level jet streak
and a 700mb deformation zone. At this time exact snow amounts are
unclear given the uncertainly of exactly where features will be
located Wednesday night and Thursday, however at this time it
appears that a couple of inches of snowfall will be possible between
Wednesday night and late Thursday.
The snow will taper off Thursday night as an upper level trough
crosses the plains late week. As this system exits the Central
Plains, another upper level low will be dropping south out of Canada
and into northwest United States. This next system is currently
forecast to move into the Rockies over the weekend period and this
will being another chance for snow to western Kansas either Saturday
night or Sunday.
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
ISSUED AT 1153 PM CST MON DEC 2 2013
VFR conditions will prevail at the taf sites across central and
southwest Kansas through much of this period. Look for winds to
increase by late morning at Dodge City and Garden City with gusts
to around 20 knots from the west. Winds will diminish by late
afternoon but then a strong cold front will push through the area
from around 23z-02z. Winds will increase from the north with gusts
to around 30 knots behind the front. MVFR to possibly IFR ceilings
will also develop within a few hours after frontal passage.
.PRELIMINARY POINT TEMPS/POPS...
DDC 34 65 22 31 / 0 0 0 0
GCK 33 64 21 29 / 0 0 0 10
EHA 36 64 20 29 / 0 0 0 10
LBL 32 68 22 31 / 0 0 0 0
HYS 32 62 22 31 / 0 0 0 0
P28 34 64 25 37 / 0 0 0 0