Area Forecast Discussion
Issued by NWS Cheyenne, WY

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FXUS65 KCYS 091026

Area Forecast Discussion
National Weather Service Cheyenne WY
326 AM MST Sat Dec 9 2017

.SHORT TERM...(Today through Monday)
Issued at 330 AM MST Sat Dec 9 2017

Fire weather issues today with gusty winds and low humidity.

Currently...Surface high over southern Idaho this morning with
pretty strong pressure gradient over the CWFA. Elevated winds all
night has kept humidity pretty low east of the Laramie Range. At
Cheyenne...we are at 21 percent with 20 and low 30 percent in the
Panhandle at 3AM this morning.

For today...Downsloping winds continue though a little less on
speeds from what we saw yesterday. Tds this morning already 4-5
degrees under MOS guidance. MAV MOS showing Tds tanking to 0F this
afternoon. Decided to go with a Red Flag Warning for the southern
2 fire weather zones in the Panhandle. Dry conditions for FWZ 310
(Laramie/Platte and Goshen Counties) but fuels are reported as NO,
so held off on the warning for this zone.

Pretty dry for Sunday with even lower humidity as downsloping
winds continue. Looking at less wind for Sunday though that may
preclude and fire headlines in the Panhandle.

Winds on the increase for Monday as a Clipper system tracks across
eastern South Dakota, so may see fire headlines returning to the
Panhandle as early as Monday. Right now though, have afternoon min
humidity in the 20 percent range.

.LONG TERM...(Monday night through Friday)
Issued at 330 AM MST Sat Dec 9 2017

Northwest flow will prevail through the week as amplified ridge of
high pressure exists across the western U.S., with deep troughing
across the northeast. The result will be for a dry week with above
normal temperatures. Tuesday will be the warmest day of the week, as
H7 temperatures in the 0-2C range combines with westerly downslope
winds to warm highs into the 50s to near 60 across the eastern
plains. Would not at all be surprised if these need to be trended up
over the coming days too. Medium range guidance is consistent in
diving a fast-moving clipper system (and associated cold front) thru
the CWA on Wednesday. Moisture will be very limited, so no
anticipating any precip chances. Temperatures will cool however,
back generally in the 40s for highs Wed-Thu. Temps look to warm back
into the 50s again east of the mountains on Friday. Early
indications of another fast-moving clipper system to bring a period
of light snow to the region on Saturday. Although uncertainty
remains high this far in advance, there is some suggestion that high
winds may make a return on Friday and again on Sunday.


.AVIATION...(For the 06Z TAFS through Saturday evening)

VFR conditions are expected through Saturday evening with gusty
northwest winds over the eastern plains tonight. Although it will
continue to be breezy into Saturday, winds will be weaker compared
to the last few days over the eastern plains.


Issued at 251 AM MST Sat Dec 9 2017

Gusty winds today with poor overnight humidity recoveries so far
this morning. Will see critical fire weather conditions for FWZ
312 and 313 today with afternoon minimum humidity in the upper
teens. Red Flag Warnings in effect for these two zones today.
Even drier for Sunday with humidity falling into the low teens
across the southern Panhandle and across extreme southeast
Wyoming. May not see the strong winds that we will see today
though. Stronger winds look to return Wednesday as a Clipper
System tracks across central Nebraska.


NE...Red Flag Warning from 11 AM this morning to 5 PM MST this
     afternoon for NEZ312-313.



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