Area Forecast Discussion
Issued by NWS Cheyenne, WY

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000
FXUS65 KCYS 230850
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
250 AM MDT Sun Jul 23 2017

.SHORT TERM...(Today through Monday night)
Issued at 249 AM MDT Sun Jul 23 2017

A much drier airmass on the whole expected across the forecast
area today, although enough moisture still around to expect to see
isolated showers and thunderstorms this afternoon along weak
convergence zone in the mountains that will slowly move out to
near the I-25 corridor this afternoon. By early evening, a
shortwave that we are watching over southern Idaho early this
morning will be crossing northern Wyoming and will aid in the
generation of isolated thunderstorms across the northern zones.
MUCAPE values today will range from 500-1000 j/kg with bulk shear
values limited to between 15 and 20 kts, so overall severe storms
are not expected, although with drier subcloud layer we can
expect some storms to produce gusty winds to around 50 mph. A bit
warmer today in the midlevels by a few degrees, so expect less
coverages compared to yesterday.

Not much in the way of rain chances expected into Monday as deeper
monsoonal moisture remains to our south, but by late Monday we doo
see midlevel moisture increase a bit along and east of the Laramie
Range so have included some mention of isolated storms east into
the Nebraska Panhandle late Monday afternoon into the evening
hours.

.LONG TERM...(Tuesday through Saturday)
Issued at 249 AM MDT Sun Jul 23 2017

Tuesday...With adequate low and mid level moisture present, and a
weak shortwave trough aloft moving overhead near peak heating,
isolated to scattered afternoon and evening showers and
thunderstorms will occur, focused along a surface trough axis.

Wednesday...Despite weak ridging aloft, enough low and mid level
moisture present will help produce isolated to scattered afternoon
and evening showers and thunderstorms. Cooler with more cloud cover
and upslope east winds in the wake of a passing cold front.

Thursday...Drier and warmer with flow aloft becoming northwest and
with a decrease in low and mid level moisture.

Friday...Mostly dry day with heights aloft rising and a ridge aloft
building overhead.

Saturday...Continued mostly dry with strong ridging and warm
temperatures aloft.

&&

.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1135 PM MDT Sat Jul 22 2017

VFR.

&&

.FIRE WEATHER...
Issued at 249 AM MDT Sun Jul 23 2017

Minimal fire weather concerns through Monday. Minimum afternoon
humidity values will drop to 15-20 percent over portions of
southeast Wyoming today and Monday. The lowest humidity of 10-15
percent will be found across lower elevations of Carbon county,
but again we don`t expect wind speeds with afternoon mixing to
bring us into Red Flag Warning criteria for critical fire weather
conditions.

&&

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

$$

SHORT TERM...JG
LONG TERM...RUBIN
AVIATION...RUBIN
FIRE WEATHER...JG



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