Area Forecast Discussion
Issued by NWS Cheyenne, WY

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574
FXUS65 KCYS 291009
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
409 AM MDT WED JUN 29 2016

.SHORT TERM...(Today through Friday)
Issued at 350 AM MDT Wed Jun 29 2016

Looks like one more day having to deal with some severe convection
as the overall pattern similar to yesterday. Currently a band of
showers and a couple embedded weak storms moving southeast along a
Torrington to Sidney line. These should end over the next few
hours.

Upper high centered around the 4-corners area with NW flow across
the CWA. next impulse in the flow looks to pass across the area
late this afternoon into this evening. CAPES should rise into the
1000-2500 J/kg range east of the mtns this afternoon with easterly
low level upslope flow setting the stage for another round of
strong/severe convection this afternoon and evening. Large hail
and strong winds the main threat again with activity moving
generally southeastward. Should see a decrease in convection
during the evening but some may hang around through tonight helped
by another weak impulse moving down the front side of the upper
high. Meanwhile a cool surface high will drop south out of
central Canada tonight pushing a front against the mtns Thursday.
Cooler temps will move over the plains Thursday and continue
through Friday which will act to reduce instability so severe
storm threat will be much lower. Scattered showers and tstms
remaining in the forecast Thursday and Friday with a monsoonal-
like moisture feed continuing across the region.

.LONG TERM...(Friday night through next Tuesday night)
Issued at 410 AM MDT Wed Jun 29 2016

Showers and thunderstorms will likely continue through Saturday
across the forecast area as subtropical moisture remains in place
and an upper level shortwave slowly moves eastward across the
central and southern Rockys. Nocturnal convection is certainly
possible late friday night as several models show the shortwave
aloft and associated cooler air moving over the area.
However...there are substantial timing difference in model
guidance...but this is expected this time of the year due to the
relatively slow movement of these waves. Later in the
weekend...all models show signs of resolving these timing
differences and show the upper level shortwave east of the
forecast area and gradually accelerating eastward into the central
Great Plains states. This will result in somewhat drier zonal flow
as PW/s lower from 1.0 to 1.5 inches on Friday to between 0.5 to
0.75 inches on Sunday and Monday. With some instability present
and nearly zonal flow...can not completely rule out daily isolated
thunderstorms early next week...but coverage should be
considerably less compared to recent days...especially east of the
Laramie Range. Temperatures will be near or slightly below normal
at the start of the weekend...generally in the mid 70s to mid
80s...but then are expected to gradually modify into early next
week. Highs Tuesday and Wednesday will become very warm or hot
across the area...as temperatures rise between the upper 80s
across the high valleys to the mid/upper 90s over western
Nebraska.

&&

.AVIATION...(For the 12Z TAFS through Wednesday night)
Issued at 315 AM MDT Wed Jun 29 2016

Low cigs have developed in the last hour at KCYS early this
morning with MVFR conditions expected to continue through sunrise.
There is a chance that low CIGS and some patchy fog will develop
over the Nebraska panhandle...but surface winds will have to
diminish as winds are currently between 8 to 15 MPH from KSNY to
KCDR at this hour. Otherwise...another round of strong
thunderstorms are expected this afternoon and this
evening...especially along and east of the Laramie Range.

&&

.FIRE WEATHER...
Issued at 350 AM MDT Wed Jun 29 2016

Fire weather concerns look to be on the low side for the rest of
the week with widely scattered afternoon and evening showers and
storms...especially today through Thursday. Wetting rains expected
in many areas east of the mountains.

&&

.CYS Watches/Warnings/Advisories...
WY...None.
NE...None.
&&

$$

SHORT TERM...RE
LONG TERM...TJT
AVIATION...TJT
FIRE WEATHER...RE



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