Area Forecast Discussion
Issued by NWS Cheyenne, WY

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FXUS65 KCYS 152008

Area Forecast Discussion
National Weather Service Cheyenne WY
208 PM MDT Sun Oct 15 2017

.SHORT TERM...(This evening through Monday)
Issued at 140 PM MDT Sun Oct 15 2017

Ridging will build over the intermountain west through Monday with
the main northern stream jet shifting north into Canada. As
heights rise, a strong warming trend is expected to continue with
high temperatures reaching the mid to upper 60s west of the
Laramie Range and low to mid 70s east of the range Monday
afternoon. Moderately strong WNW flow aloft present over the area
on Monday and thus expect breezy conditions to develop west of the
surface trough roughly from I-25 west. GFS indicates low level
CAG-CPR gradients of 45-50 meters Monday morning so could see some
wind gusts of 40 to 50 mph near Arlington during this time.

.LONG TERM...(Monday night through Sunday)
Issued at 140 PM MDT Sun Oct 15 2017

Modest ridging will continue to shift eastward through the period
and emerge out over the plains by Thursday as troughing develops
along the US west coast. Warm, very dry, and breezy conditions can
be expected through mid week with the potential for fire weather
concerns each day. Models continue to struggle a bit with the
evolution of the west coast trough over the weekend with the GFS
now attempting to close off a low over the desert SW while the
EC/Canadian show a much more progressive and less amplified
feature. Still looks like a rather quick cold frontal passage
Saturday morning with little in the way of measurable precip with
the exception of some mountain snow. Ensembles indicate strong
ridging developing over the west early next week which would
indicate the return of warm and dry conditions.


.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1219 PM MDT Sun Oct 15 2017

VFR conditions will prevail through the period, with just some
high clouds increasing after 09z. West/northwest winds will
prevail today before lessening some tonight. West winds will
become gusty again after 17z on Monday.


Issued at 140 PM MDT Sun Oct 15 2017

Sunny skies and breezy west winds will allow for excellent mixing
of dry air aloft on Monday and Tuesday afternoons.  Widespread critical
fire weather conditions are possible both afternoons so went with a Fire
Weather Watch for zones along and in the lee of the Laramie Range Monday
where fuels have been marked as ready.  Would also be concerned about
portions of the Laramie Valley and Carbon County where criteria will also
likely be met but fuel status is a no in these areas.  Some elevated
conditions are also possible into the Nebraska Panhandle Monday but
think the winds and humidity are too marginal right now to warrant
highlights.  Another watch or warning will likely become necessary for
parts of the same region by Tuesday afternoon as well.


WY...Fire Weather Watch from Monday morning through Monday afternoon
     for WYZ301-309-310.



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