Frost Advisory 4, NWS Cheyenne, WY

866 
WWUS75 KCYS 271249
NPWCYS

URGENT - WEATHER MESSAGE
National Weather Service Cheyenne WY
649 AM MDT Wed Sep 27 2017

...FROST ADVISORY FOR EAST CENTRAL WYOMING AND THE NORTHERN
NEBRASKA PANHANDLE WILL EXPIRE AT 7 AM MDT THIS MORNING...

NEZ002-003-095-096-WYZ101-102-271400-
/O.EXP.KCYS.FR.Y.0004.000000T0000Z-170927T1300Z/
Dawes-Box Butte-North Sioux-South Sioux-
Converse County Lower Elevations-Niobrara County-
Including the cities of Chadron, Chadron St Park, Alliance, 
Harrison, Agate, Bill, Douglas, Deer Creek, Glenrock, Lusk, 
and Redbird
649 AM MDT Wed Sep 27 2017

...FROST ADVISORY WILL EXPIRE AT 7 AM MDT THIS MORNING...

Temperatures bottomed out in the lower to mid 30s early this 
morning, and will begin rising after 7 AM.

$$

Area Forecast Discussion
National Weather Service Cheyenne WY
1122 AM MDT Tue Sep 26 2017

.SHORT TERM...(Today through Thursday)
Issued at 315 AM MDT Tue Sep 26 2017

Skies have cleared over much of the CWA early this morning with
just some low cloudiness hanging on around Cheyenne and the
northern Panhandle. Many areas in the 30s at this time so will
keep the Frost advy going through 7 AM.

Mild and mainly dry weather expected across the CWA through most
of Wednesday as a short upper ridge moves across the region.
Temperatures warmer today but still a little below seasonal
averages with mainly light winds. Should see clouds begin
increasing from the south tonight as a low pressure area develops
over the Desert Southwest later today and tonight and moisture
lifts northward towards the area. Some showers should reach
southern parts of the CWA by late Wednesday as this upper low
begins drifting northward with more widespread showers later
Wednesday night into Thursday. Cooler Thursday especially over
southeast Wyoming given the cloudy and showery conditions.

.LONG TERM...(Thursday night through Monday)
Issued at 315 AM MDT Tue Sep 26 2017

There are minor differences with the medium range and ensemble
models. UT upper low weakens as it lifts northward across western
WY and eastern MT Thursday night and Friday. The accompanying trough
will swing northeast through the region, bringing scattered showers
and possibly a few thunderstorms to most of the CWA. The southwest
flow aloft increases ahead of a stronger upper trough moving through
the Intermountain West Saturday. Southwest winds will become rather
breezy along and west of the Laramie Range Saturday afternoon.
Scattered showers and isolated thunderstorms will develop across
much of Carbon County by Saturday evening, with more isolated
coverage over east-central WY Saturday night. Downslope flow
across the southeast plains will preclude precipitation, and will
push temperatures into the upper 60s and 70s. A Pacific cold front
sweeps east across the CWA Sunday producing widely scattered
showers and cooler temperatures. Monday will be drier with seasonal
temperatures.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1121 AM MDT Tue Sep 26 2017

VFR should prevail through the TAF period with generally light
winds. With clear skies and light winds overnight can't rule out
some patchy fog but at this time did not include in the TAFs due
to uncertainty on formation and placement.

&&

.FIRE WEATHER...
Issued at 200 AM MDT Tue Sep 26 2017

Mild and mainly dry weather can be expected over the districts today
through most of Wednesday as a weak ridge of high pressure in the
upper atmosphere moves across the area. Winds will be on the light
side as well. Scattered showers are then expected to move into
southern parts of the area later Wednesday and Wednesday night with
widely scattered showers continuing Thursday as a low pressure
system moves towards the region.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&

SHORT TERM...RE
LONG TERM...MAJ
AVIATION...DEL
FIRE WEATHER...RE

Hazardous Weather Outlook
National Weather Service Cheyenne WY
331 AM MDT Tue Sep 26 2017

NEZ002-003-019>021-054-055-095-096-WYZ101-102-107-108-118-119-
270945-
Dawes-Box Butte-Scotts Bluff-Banner-Morrill-Kimball-Cheyenne-
North Sioux-South Sioux-Converse County Lower Elevations-
Niobrara County-East Platte County-Goshen County-
Central Laramie County-East Laramie County-
331 AM MDT Tue Sep 26 2017

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

.DAY ONE...TODAY AND TONIGHT

Frost and patchy fog are possible toward sunrise for portions of
the eastern plains.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

The probability for widespread hazardous weather is low.

.Spotter information statement...

Spotter activation will not be needed.

WYZ103>106-109>117-270945-
North Laramie Range-Ferris/Seminoe/Shirley Mountains-
Shirley Basin-Central Laramie Range and Southwest Platte 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-
331 AM MDT Tue Sep 26 2017

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

.DAY ONE...TODAY AND TONIGHT

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

The probability for widespread hazardous weather is low.

.Spotter information statement...

Spotter activation will not be needed.