Area Forecast Discussion
Issued by NWS Cheyenne, WY

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FXUS65 KCYS 300412

Area Forecast Discussion
National Weather Service Cheyenne WY
1012 PM MDT SUN MAY 29 2016

Issued at 930 PM MDT Sun May 29 2016

Recent radar trends indicated convection quickly dissipating or
exiting east of the CWA at mid-evening. Updated grids to remove
pops from Nebraska Panhandle and mountain zones.


.SHORT TERM...(This evening through Tuesday Night)
Issued at 210 PM MDT Sun May 29 2016

Scattered showers and some storms moving generally ENE across the
southeast half of the CWA this afternoon. Expect these to
continue into the evening hours before dissipating as instability
is lost with evening cooling. Quiet weather overnight under partly
cloudy skies.

An upper shortwave over the pacific NW will move generally east
along the US/Canadian border overnight and Monday and close off an
upper low over northeast Montana by evening. A surface low will
develop over western South Dakota with an attendant trough
extending south across the Nebraska Panhandle. This trough will
move east during the day and should help to focus some strong
convection along it. Currently appears this trough will be just
east of the CWA Monday afternoon with CAPES in excess of 1000 J/kg
progged to remain east of the Panhandle Monday so severe storm
threat in out area looks to be low with shear and instability
relatively modest. Still should see some showers and a few storms
Monday into Monday night as the upper low drifts slowly east and a
lobe of vorticity shifts across the northern high plains. A cool
front will move across the CWA Monday night bringing some cooling
for Tuesday. Still some convection possible Tuesday but it should
be confined to areas over se WY near the Colorado border. Dry and
cool Tuesday night with a surface high settling over Wy.

.LONG TERM...(Wednesday through Saturday Night)
Issued at 241 PM MDT Sun May 29 2016

The main story in the long term period is the trend towards
warmer and drier weather. An omega block pattern will develop
over the western CONUS Wed-Thurs and looks to persist through the
weekend. Broad-scale subsidence within the ridge will keep
convection to a minimum but could see isolated showers/storms in
the afternoon over the mountains. 700mb temps will steadily rise
through the latter part of the week with readings on average of 8
to 10C likely through Friday, and increasing further for
Saturday. Main concern as we approach the weekend continues to be
increase in snowmelt rates in the higher mountain elevations, and
resultant rises in river levels across the forecast area.


.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1008 PM MDT Sun May 29 2016

Wyoming TAFS...VFR prevails. Isolated thunderstorms in the
afternoon and early evening on Monday producing gusty winds.

Nebraska TAFS...VFR prevails...except for localized IFR at
Scottsbluff and Sidney from 09Z to 15Z in fog and low clouds.
Isolated thunderstorms Monday afternoon and early evening
producing gusty winds.


Issued at 241 PM MDT Sun May 29 2016

Concerns to remain minimal for at least the next few days as
conditions and fuels remain non-critical. A cool front will move
across the area Monday night keeping temperatures mild through
Tuesday. warmer and mainly dry weather should arrive on Weds and
persist for the rest of the week.


Issued at 241 PM MDT Sun May 29 2016

The North Platte and Laramie Rivers will continue to run high,
but remain steady or slowly recede over the next couple of days.
The exception will be areas that receive moderate rainfall today
and Monday which could produce short-term rises in river levels.
Warmer temperatures mid to late week will increase snowmelt once
again. Therefore, expect rises on area rivers, creeks and streams
by next weekend.


.CYS Watches/Warnings/Advisories...


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