Preview of NWS' New Version of Forecast
This preview is not operational and should not be used for support decisions.

Area Forecast Discussion (AFD)

Issued by Cheyenne, WY (CYS)

FXUS65 KCYS 172346

Area Forecast Discussion
National Weather Service Cheyenne WY
546 PM MDT Sat Aug 17 2019

Issued at 527 PM MDT Sat Aug 17 2019

...Please see latest 0Z aviation discussion...

UPDATE Issued at 356 PM MDT Sat Aug 17 2019

Dry and breezy conditions expected to continue Sunday for FWZ
310...especially the southwest part of the zone. Cheyenne to
Wheatland should experience these decided to
upgrade the watch to a Red Flag Warning. Updates have been sent.


.SHORT TERM...(This evening through Monday)
Issued at 225 PM MDT Sat Aug 17 2019

Isolated showers and a few storms moving east across mainly far
southern parts of the CWA attm. Little rain likely falling from
these with a rather dry sub-cloud layer. Expect these to 
dissipate this evening with diurnal cooling. Overnight a cool
front will sag south across the area and should produce some low
stratus for a time later tonight into Sunday morning over the
plains. The front will bank up against the mtns early Sunday then
some question as how fast it will move back east. A little cooler
over the plains Sunday then very warm conditions return Monday.

.LONG TERM...(Monday night through Saturday)
Issued at 225 PM MDT Sat Aug 17 2019

Chances for showers and tstms look to return beginning Tuesday
with the best chances looking to be late Tuesday through Weds as a
push of cooler air drops down the plains and banks up against the
mtns creating some upslope flow. A little cooler as well Tuesday
and Weds. Drier air then returns late week reducing convection to
a more isolated basis Thursday, with dry weather Friday and


.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 527 PM MDT Sat Aug 17 2019

Surface layer is very dry with RHs ranging from 10 to 30 percent 
across Wyoming and Nebraska sites. Some reflectivity is being
picked up at mid-levels by radar, but rain is not reaching the
ground due to the lack of moisture. With that evaporation and
collapsing cells, gusty winds are likely. A few stations along
I-80 have measured gusts between 55 to 60 MPH already this evening.
Expect this to be the main concern over the next couple of hours 
along with erratic wind directions. There's a bit more moisture in
the Nebraska Panhandle that could contribute to MVFR ceilings 
early Sunday morning, but fog is not expected. 


Issued at 225 PM MDT Sat Aug 17 2019

Dry and very warm conditions will persist over the districts
through Monday before a trend to a little cooler conditions and
better chances for rain arrive by midweek. Critical fire weather
conditions will persist over parts of southeast Wyoming into this
evening and is likely Sunday afternoon and evening mainly out 
west as winds will be gusty again. Conditions are expected to ease
Monday onward.


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

     Red Flag Warning from noon to 8 PM MDT Sunday for WYZ303-304-310.