Area Forecast Discussion
Issued by NWS Cheyenne, WY

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FXUS65 KCYS 191528

Area Forecast Discussion
National Weather Service Cheyenne WY
928 AM MDT Wed Sep 19 2018

Issued at 924 AM MDT Wed Sep 19 2018

The dense fog advisory was dropped for Cheyenne and Kimball
counties in western Nebraska. this morning. Patchy areas of dense
fog and low ceilings will likely continue through he day on the
cool side of a stalled frontal boundary. Few impacts are expected
other than some MVFR aviation impacts at area TAF sites. Forecast
for showers and thunderstorms along the front later today is still
looking solid. Fire Weather is still a concern to the west as a
few sites are now seeing low RH and winds coming up.

UPDATE Issued at 604 AM MDT Wed Sep 19 2018

Dense fog advisory issued until 9 AM today for Kimball and
Cheyenne Counties in the Nebraska Panhandle.


.SHORT TERM...(Today through Friday)
Issued at 328 AM MDT Wed Sep 19 2018

Today...Areas of fog have already formed at Kimball and Sidney, and
with temperature and dewpoint spreads quite narrow across the
Nebraska Panhandle and far eastern Wyoming, expecting fog to develop
further in coverage through at least mid morning.

As the leading edge of the cold front backs westward to the Laramie
Range and I-25 this afternoon, and as a shortwave trough aloft moves
overhead, expect scattered showers and thunderstorms to develop in
the afternoon, especially focused along I-25 south of Douglas to the
Colorado state line. Quite cool over our eastern counties, including
the Nebraska Panhandle due to the widespread low clouds hanging on
all day, with warmer readings over our western counties in the warm

Tonight...With a moist airmass in place and a disturbance aloft, we
expect scattered to numerous showers and some thunderstorms, mainly
east of Interstate 25.

Thursday...Locations will be in the wake of the shortwave trough
aloft and behind a cold front with significant low and mid level
drying, thus dry in the afternoon. Near seasonal temperatures with
gusty west and northwest winds based on the low and mid level

Thursday night/Friday...Continued seasonable temperatures with 700
mb temperatures near 8 Celsius. The atmosphere looks too stable to
support shower or thunderstorm development.

.LONG TERM...(Friday Night through Tuesday)
Issued at 328 AM MDT Wed Sep 19 2018

Saturday/Sunday...Nearly perfect weekend weatherwise with west to
east, zonal, flow aloft and minimal low and mid level moisture.
Maximum temperatures in the 70s and lower 80s with 700 mb
temperatures around 11-12 Celsius.

Monday/Tuesday...Cooler temperatures in the wake of a cold frontal
passage. With limited low and mid level moisture, precipitation
chances will be slim.


.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 453 AM MDT Wed Sep 19 2018

Persistent easterly upslope wind over the Nebraska Panhandle will
keep low stratus and IFR/LIFR conditions much of the day today for
our Nebraska airports. Stratus may be sufficient enough to keep
thunderstorms from forming this afternoon. So held off on
including predominant showers/TStms on station and continued VCTS
wording in their TAFs.


Issued at 328 AM MDT Wed Sep 19 2018

Critical conditions expected this afternoon and early evening
across much of Carbon County due to gusty wind and low humidity.
Critical conditions will be more widespread Thursday afternoon and
early evening and affect southeast Wyoming zones south of a
Douglas to Lusk line, due to gusty wind and low humidity. Low
afternoon humidity will continue Friday through the weekend across
much of southeast Wyoming, and gusty winds at times will produce
near critical or critical conditions.


WY...Red Flag Warning from noon to 8 PM MDT Thursday for WYZ302>310.

     Red Flag Warning until 8 PM MDT this evening for WYZ303-304-306.



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