High Wind Warning 4, NWS Cheyenne, WY

879 
WWUS75 KCYS 152119
NPWCYS

URGENT - WEATHER MESSAGE
National Weather Service Cheyenne WY
219 PM MST Tue Jan 15 2019

...HIGH WIND WARNING CANCELLED FOR BORDEAUX...


WYZ106-152230-
/O.CAN.KCYS.HW.W.0004.000000T0000Z-190115T2300Z/
Central Laramie Range and Southwest Platte County-
Including the city of Bordeaux
219 PM MST Tue Jan 15 2019

...HIGH WIND WARNING IS CANCELLED...

The National Weather Service in Cheyenne has cancelled the High
Wind Warning. Winds have come down over the last few hours and
will continue this evening and overnight.

.

$$

Area Forecast Discussion
National Weather Service Cheyenne WY
955 PM MST Mon Jan 14 2019

.UPDATE...
Issued at 949 PM MST Mon Jan 14 2019

...Please see latest 6Z aviation discussion...

&&

.SHORT TERM...(This evening through Tuesday afternoon)
Issued at 238 PM MST Mon Jan 14 2019

Today remains quiet overall with clear skies and high pressure
dominating the forecast. A classic blocking High was located
upstream keeping things very quiet. Temperatures have warmed up
nicely into the mid 40s at CYS this afternoon. The rest of the
area is also seeing a nice boost in temperatures with a few spots
in the Nebraska panhandle clawing their way into the low 50s. Out
west, the entrenched snowpack is keeping things much colder with
highs in the mid 20s and low 30s. Winds were up at Bordeaux, with
gusts as high as 50 mph noted today. This trend will continue
tonight and increase Tuesday morning as upper level flow
strengthens and an approaching shortwave tops the ridge aloft.

.HIGH WIND WATCH FOR BORDEAUX TUESDAY...

High Wind Watch was issued from 6 am to 4 pm Tuesday for the
Bordeaux area. Given the stronger winds seen today and the
increasing height gradients tomorrow, felt confident that winds
could reach criteria from the early morning through early
afternoon. 700 mb flow will increase to around 30 knots with 40
meter height gradients expected. This should drive low level gap
winds along the south laramie range, in particular, the Bordeaux
area. Vehicle Blow Over risk will be elevated from the morning
through the afternoon across I-25, with 35 to 45 mph winds and
the occasional gust to 60 mph possible. Temperatures Tuesday
should be warmer with clear skies and some help from the westerly
downslope flow and adiabatic warming. Expect highs near 50 for CYS
and the surrounding plains. The panhandle could push as high as
the mid 50s.

.LONG TERM...(Tuesday night through Monday)
Issued at 238 PM MST Mon Jan 14 2019

Tuesday evening and overnight, clouds should start to developing
in southwestern carbon county as the ridge of high pressure
begins to be influenced by a west coast trough. A leading
shortwave will flatten the ridge Tuesday night and Wednesday
morning bringing the potential for some mountain snow to the
Sierras and the Snowys. Models differ on the strength and moisture
content of the airmass with this system, but several inches
appear likely with the favorable orographics. Clouds will extend
further east onto the plains by day break Wednesday, as the nose
of a 30 to 40 kt mid level jet moves into southeastern Wyoming.
This will set the stage for some stronger winds on Wednesday and
Thursday. The best day looks to be Thursday with a better
combination of low level height gradients and mid level jet
support. However, 700 mb flow on Wednesday will be aided by the
passing of the aforementioned shortwave, which could contribute to
some turbulent mixing of stronger gusts in the afternoon hours.
Will punt on deciding what to do with the Wednesday wind potential
for now, but do expect that some product will be needed in that
general time frame.

Things start to get more interesting Thursday night and Friday
with the approach of a stronger trough. Snow potential will
increase over the western portions of the CWA Thursday night and
spread east early morning Friday continuing through Saturday.
Models differ on the intensity of the system through the weekend,
with the GFS more aggressive with QPF probably thanks to upstream
amplification of the Hudson Bay Vortex and stronger cold
advection. Given the nature of the system as a progressive
positively tilted open wave, it seems unlikely that much snow
accumulation will be seen across the plains of southeastern
Wyoming. The mountains on the other hand, should be in favorable
northwest flow orographics, which could mean significant snow
through the weekend. As it stands now, moderate pops were
introduced for the system with a focus on the northward facing slopes
of the higher terrain.

A much cooler air mass is expected to fill in behind the departing
trough Saturday evening and Sunday as northerly flow aloft takes
over. Expect temperatures below normal with isolated snow showers
in that time. This matches with the global models that have
locked onto this time period as a potential pattern shift toward a
cooler and more active weather pattern. The GEFS and climate
indicators are in good agreement with this pattern switch as the
Negative phase of the NAO is expected to develop. This should
drive colder air and a more active NW jet over the central plains
and the front range.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 949 PM MST Mon Jan 14 2019

VFR conditions will prevail for all sites through the period. Main
concerns are an increase in winds tomorrow morning and into the
afternoon. Skies will be mostly clear as high pressure continues
to remain over the central CONUS.

&&

.FIRE WEATHER...
Issued at 238 PM MST Mon Jan 14 2019

Fire weather concerns will be mostly low with snowpack in place.
High winds will be possible across portions of southeastern
Wyoming Tuesday and Wednesday. Warming temperatures will drive
relative humidity to down to the low 20s or high teens. Values
should remain above critical. Increasing chance for precipitation
thursday and Friday should limit any threat.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...High Wind Watch from 6 AM MST Tuesday through Tuesday afternoon
     for WYZ106.

NE...None.
&&

UPDATE...CW
SHORT TERM...AL
LONG TERM...AL
AVIATION...CW
FIRE WEATHER...AL

Hazardous Weather Outlook
National Weather Service Cheyenne WY
236 PM MST Mon Jan 14 2019

NEZ002-003-019>021-054-055-095-096-WYZ101>105-107>119-152145-
Dawes-Box Butte-Scotts Bluff-Banner-Morrill-Kimball-Cheyenne-
North Sioux-South Sioux-Converse County Lower Elevations-
Niobrara County-North Laramie Range-
Ferris/Seminoe/Shirley Mountains-Shirley Basin-East Platte County-
Goshen County-Central Carbon County-North Snowy Range Foothills-
Southwest Carbon County-Sierra Madre Range-
Upper North Platte River Basin-Snowy Range-Laramie Valley-
South Laramie Range-South Laramie Range Foothills-
Central Laramie County-East Laramie County-
236 PM MST Mon Jan 14 2019

This hazardous weather outlook is for portions of western
Nebraska...east central Wyoming...south central Wyoming and
southeast Wyoming.

.DAY ONE...THIS AFTERNOON AND TONIGHT

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

The potential for mountain snow will increase Wednesday and
Thursday. More widespread snow is expected Friday. temperatures
will become much colder over the weekend.

.Spotter information statement...

WYZ106-152145-
Central Laramie Range and Southwest Platte County-
236 PM MST Mon Jan 14 2019

This hazardous weather outlook is for portions of southeast
Wyoming.

.DAY ONE...THIS AFTERNOON AND TONIGHT

.HIGH WIND WATCH TUESDAY...

Strong crosswinds are expected along I-25 between Chugwater and
Wheatland Tuesday morning through the afternoon. light and high
profile vehicles will have an elevated blow over risk. Drivers
use caution and be alert for possible closures.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

High winds will again be likely through mid week across Bordeaux
and southeastern Wyoming. Widespread snow is expected Friday and
Saturday. Temperatures will become much colder over the weekend.

.Spotter information statement...