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 241100

Area Forecast Discussion
National Weather Service Cheyenne WY
500 AM MDT Sat Aug 24 2019

.SHORT TERM...(Today through Sunday night)
Issued at 340 AM MDT Sat Aug 24 2019

Overnight GOES-16 WV/IR loop showed the mid/upper level trough
progressing through eastern WY. Most of the convection observed
earlier over the Nebraska Panhandle had exited to the east. There
were a few weak showers developing ahead of a cool front over
southeast Wyoming. Moist southerly flow ahead of the front with 
dewpoints in the 50s and low 60s and light winds will yield some
low ceilings and patchy fog toward daybreak.

The trough and front will continue their eastward trek across 
High Plains this morning, allowing drier air to spread east
as well. It will be breezy west of the Laramie Range with westerly
700mb winds up to 30 kt. High temperatures will be in the mid 70s
to mid 80s, with 60s for the mountains. Sunday will be 5 to 10 
degrees warmer with 700mb temperatures from 14 to 18 Celsius. 
Westerly winds will increase Sunday afternoon ahead of a stronger 
front and upper trough to the north. Gusts of 35 to 45 mph will be
common west of the Laramie Range, with gusts of 25 to 35 mph 
possible over southeast Wyoming. The cold front moves south 
through the CWA Sunday night, with widely scattered showers and 
thunderstorms developing over the plains.

.LONG TERM...(Monday through Friday)
Issued at 300 AM MDT Sat Aug 24 2019

It's shaping up to be a quieter week ahead with limited chances 
for convection. After very warm temperatures Sunday, Monday will 
be noticeably cooler in the wake of the cold front as 700mb 
temperatures lower to 4 to 8 Celsius. It will be breezy west of 
the Laramie Range. High temperatures will be in the 70s with 50s 
and 60s mountains. A upper trough over the north-central CONUS 
amplifies, with a reinforcing shot of cool air producing a slight 
chance of showers for the plains. High temperatures Tuesday will 
range from the upper 60s to mid 70s. For Wednesday and Thursday, 
it will be warmer as 700mb temperatures rebound to 12 to 16 
Celsius. Isolated late day showers and thunderstorms will be 
possible Thursday as a backdoor front slips south and west into 
the CWA. It will be slightly cooler Friday with widely scattered 
showers and thunderstorms.


.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
Issued at 500 AM MDT Sat Aug 24 2019

Patchy low clouds producing IFR/LIFR cigs will affect the area from 
about KCYS to KSNY early this morning, then VFR areawide late 
morning through tonight as drier air moves into the region.  


Issued at 259 AM MDT Sat Aug 24 2019

Drier air will infiltrate areas along and east of the Laramie Range
today in the wake of a low pressure trough. Warm temperatures and
gusty westerly winds will maintain critical fire weather conditions
for much of Carbon County today. Windier conditions in advance of
a stronger trough and cold front will maintain high fire danger in
much of Carbon County Sunday, with critical fire weather conditions
possible for portions of southeast Wyoming Sunday. Cooler temperatures
are forecast Monday, with higher humidities across the high plains.
Low humidities and gusty winds will maintain the high fire danger for
much of Carbon County Monday. There will be slight chances for showers
and thunderstorms early and late next week.


WY...Red Flag Warning from 11 AM this morning to 8 PM MDT this 
     evening for WYZ303>305.

     Fire Weather Watch from Sunday morning through Sunday evening 
     for WYZ303>305-309-310.