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Area Forecast Discussion (AFD)

Issued by Cheyenne, WY (CYS)

FXUS65 KCYS 182028

Area Forecast Discussion
National Weather Service Cheyenne WY
228 PM MDT Sun Aug 18 2019

.SHORT TERM...(This evening through Tuesday)
Issued at 228 PM MDT Sun Aug 18 2019

Quiet weather seen across the CWA through early Tuesday outside of
fire weather concerns. Skies will be clear for the most part
though some low clouds may develop for a time later tonight into
Monday morning over the Panhandle in southerly flow. Otherwise 
very warm again Monday with max temps in the 90s over many areas 
east of the mtns. Tuesday should see a cool front drop south over
the plains in the afternoon. This could set off some convection 
in post-frontal upslope flow though capping may hinder this.
Latest NAM not showing anything yet but would not be surprised to
see some initiate especially near the mtns.

.LONG TERM...(Tuesday night through Sunday)
Issued at 228 PM MDT Sun Aug 18 2019

Cooler Weds and Thursday with the best chance of the week for
showers and tstms as a surface high slips east over the northern
plains and a couple shortwaves clip the CWA. A return to warmer
and mainly dry weather expected Friday through the weekend as
drier air moves back in under a flat upper high centered over the
desert southwest.


.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1155 AM MDT Sun Aug 18 2019

IFR/MVFR stratus continues to mix out as of 18Z with VFR mostly
SKC now prevailing across most locations other than KCDR. KCDR
will continue to mix out the SCT040 towards SKC next 1-2 hours.
Main aviation message next 6-10 hours will be the elevated winds
for WY sites, especially KRWL/KLAR that will gust upwards of 30 to
35 knots from the west/southwest. Slightly lower winds at KCYS 
but some gusts could reach 30 knots and cause local wind shear on 
approach or take off. NE Panhandle will have south to southeast 
winds 10-15 knots. All wind will subside tonight 10 knots or 
below. Aviation concern overnight will be in the NE Panhandle for
the possibility of patchy fog and low ceilings to develop once
again. NAM is more more bullish but there are some indications in
the GFS model soundings as well. HRRR keeps low ceilings/fog
farther east into Central Nebraska. Have trended towards lower
ceilings with SCT010 for now and will need to monitor trends next
two TAF cycles. 


Issued at 228 PM MDT Sun Aug 18 2019

Red Flag conditions will continue into this evening over parts of
the area with critical conditions expected once again Monday
afternoon and evening, due to gusty winds and dry air. Fire
weather conditions should improve beginning on Tuesday as moisture
increases with at least scattered showers and storms expected
Tuesday night into Thursday, along with cooler temperatures.  


WY...Red Flag Warning until 8 PM MDT this evening for WYZ303-304-310.

     Red Flag Warning from noon to 8 PM MDT Monday for WYZ303-304.

     Fire Weather Watch from Monday afternoon through Monday evening 
     for WYZ310.