Area Forecast Discussion
Issued by NWS Cheyenne, WY

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FXUS65 KCYS 240307 AAA

Area Forecast Discussion...UPDATED
National Weather Service Cheyenne WY
907 PM MDT Wed Aug 23 2017

Issued at 907 PM MDT Wed Aug 23 2017

Updated forecast package to continue isolated thunderstorms for
areas east of I-25 through late evening where greater instability
lies. Still may get a few gusts around 45 mph across the Nebraska
Panhandle until around 11 PM. Most of any stronger storms should
move east of the forecast area by midnight.


.SHORT TERM...(This evening through Friday night)
Issued at 223 PM MDT Wed Aug 23 2017

Some showers and storms currently noted mainly around the mtns of
southeast Wyoming but having some difficulty moving east off the
higher terrain. Should see some progress eastward through this
evening as a weak impulse moves by the area overnight with some
convection possibly maintaining itself later tonight over northern
parts of the CWA where a little stronger energy will clip that

Seasonably warm conditions will hold across the CWA Thursday and
Friday as upper ridging remains over the area. Weak impulses
riding atop the ridge will help set off some convection on
Thursday with a sfc trough over the high plains likely providing
some focus Thursday afternoon and evening. Modest upslope flow and
CAPES from about 1000-1500J/kg should exist over the Panhandle
but shear will be rather marginal, but s few stronger storms
possible there. Activity should wane/move out in the evening.
Mainly dry Friday as the upper ridge builds some over the area.

.LONG TERM...(Saturday through Wednesday)
Issued at 223 PM MDT Wed Aug 23 2017

No significant concerns during this portion of the forecast.
Models are in pretty good agreement in showing the upper level
ridge dominating the region. This ridge will tend to suppress any
convection that does try to develop over the mountains. There is a
slight chance that a shortwave may try to clip the northeast
Nebraska panhandle on Saturday afternoon. As this shortwave passes
to our east, it may tend to increase the pressure gradient a bit
across Wyoming as the upper level ridge builds in. This may
cause wind speeds to increase a bit especially west of the Laramie
Range and increase the risk for critical fire weather conditions
Saturday afternoon. Otherwise, dry and mild conditions can be
expected through early next week.


.AVIATION...(For the 00Z TAFS through 00Z Thursday night)
Issued at 907 PM MDT Wed Aug 23 2017

Still have a few thunderstorms in the vicinity of Chadron and
Alliance...with scattered lingering showers around Sidney. Most of
that activity will move off to the east over the next couple of
hours with VFR cigs and vsbys expected through the overnight
period. More scattered showers and thunderstorms tomorrow across
the area.


Issued at 223 PM MDT Wed Aug 23 2017

High pressure in the upper atmosphere will maintain warm and
mainly dry weather across the area for the rest of the week.
Widely scattered showers and storms are expected this evening
mainly over southeast Wyoming with just isolated activity possible
in the afternoon and evening Thursday and Friday. Overall fire
weather concerns will remain low as winds will be generally light.




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