Area Forecast Discussion
Issued by NWS Cheyenne, WY

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FXUS65 KCYS 220914

Area Forecast Discussion
National Weather Service Cheyenne WY
314 AM MDT Sat Oct 22 2016

.SHORT TERM...(Today through Monday)
Issued at 215 AM MDT Sat Oct 22 2016

Broadscale high pressure will maintain hold of the southern CONUS
through early next week, keeping the upper jet well to our north.
As a result, our counties will be on the anticyclonic side of the
northern stream jet through this time, maintaining mostly dry,
breezy and mild conditions. A vigorous shortwave moving through
the flow pattern over the northern Rockies this afternoon will
induce leeside cyclogenesis over eastern MT/northeast WY. An
attendant sfc trough looks to extend down the Front Range by this
afternoon as well. The sfc pressure gradient across southeast
Wyoming will strengthen in response, but only enough to produce
breezy westerly winds across the CWA. Likely to see gusts up to
45 mph in the wind prone areas along and west of the Laramie
Range, with 25 to 35 mph elsewhere. With generally dry conditions
enhanced by the downslope winds, humidity values across the plains
will drop into low teens. Thus, still expect critical fire weather
conditions to develop by late this morning for these areas, and
think the Red Flag Warning is in good shape for the afternoon

Beyond today, Sunday will remain overall mild and dry. It will
be cooler on Sunday compared to today though in the wake of a
cool front dropping south across the plains late tonight. In
addition, expect increased moisture across the plains for Sunday
in the wake of this front. Thus, do not expect fire weather
concerns on Sunday. Flow aloft will back to the southwest Sunday
night and Monday in advance of an upper low moving toward the
west coast. A number of weak shortwaves moving overhead in this
new flow pattern along with increased Pacific moisture will bring
increasing chances for precip on Monday. The best chance will
remain over the high country where even a couple of t-storms are
possible within orographic forcing. Temperatures during the day
may keep precip type all rain, but certainly cannot rule out a few
snow showers over the highest peaks in the Snowy Range Monday
morning. Winds along and west of the Laramie Range look to be
breezy once again on Monday.

.LONG TERM...(Monday night through Friday)
Issued at 315 AM MDT Sat Oct 22 2016

Medium/long range models in pretty good agreement through next
week...and generally show dry conditions continuing through the
last week of October with mild temperatures. The only minor
forecast concern will be a weak Pacific upper level trough and
associated cold front moving across the central Rockys late Monday
and early Tuesday. There appears to be enough dynamic forcing for
period of rainfall across the high valleys and high plains with
this system...mainly on Tuesday as some llvl instability will be
present during the day. Precipitation type should be rain for all
lower elevations areas as 700mb temperatures should remain above
0c. Light snow accumulations above 9000 feet are possible in the
mountains Monday night through Tuesday. Slightly cooler
temperatures are expected on Tuesday as the upper level trough
moves through the area...but daytime temperatures should still be
a few degrees above normal. Models then show a warming trend by
the middle and end of the week as a strong ridge axis develops and
amplifies west of the continental divide. Expect highs to climb
back into the 70`s across most of the forecast area...with areas
like Saratoga...Laramie...and Rawlins slightly cooler and
remaining in the mid to upper 60`s during the day. Models indicate
the next Pacific system moving towards Wyoming on Friday...but
with poor model agreement and timing differences...confidence is
rather low at this time.


.AVIATION...(For the 12Z TAFS through Saturday night)
Issued at 300 AM MDT Sat Oct 22 2016

VFR conditions will prevail through the TAF period. Gusty west
winds will return to much of the area late Saturday morning,
especially across the Wyoming terminals, with gusts between 30 to
40 knots possible.


Issued at 215 AM MDT Sat Oct 22 2016

Very warm, dry and breezy westerly winds today will produce
critical fire weather conditions this afternoon along and east of
the Laramie Range. The Red Flag warning looks to be in good shape,
with humidities expected to drop into the low teens across this
area while winds gust 25 to 35 mph. A cool front dropping south
across the plains late tonight will bring cooler conditions along
with higher humidites for Sunday, so fire concerns will ease.
Similar conditions will occur on Monday.


WY...Red Flag Warning from 10 AM this morning to 6 PM MDT this
     evening for WYZ301-302-309-310.

NE...Red Flag Warning from 10 AM this morning to 6 PM MDT this
     evening for NEZ311>313.



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