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Area Forecast Discussion (AFD)

Issued by Cheyenne, WY (CYS)

                            
000
FXUS65 KCYS 252348
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
548 PM MDT Sun Aug 25 2019

.SHORT TERM...(This evening through Monday)
Issued at 154 PM MDT Sun Aug 25 2019

Similar pattern today as it has been over the last few days.
Strong upper level ridge is in place with an associated potent jet
streak. Very dry conditions across the CWA along with gusty winds.
Areas in Carbon and Albany Counties have been gusting between 45
to 50 mph this afternoon. These ingredients are resulting in
dangerous fire weather conditions in fuel-ready zones. A wildfire
is currently ongoing in northern Carbon County at Pedro Mountain.
Based on GOES-16 Fire Temperature RGB has shown fire temperature
over that area increasing rapidly as the day has continued. 

Overnight tonight a front will dig down from the north bringing 
an associated cold front through the area overnight. This will
allow for a reprieve from dry and hot conditions. High 
temperatures tomorrow will be 15 to 20 degrees cooler than today
and additional moisture will be advected into the area. A few
showers and thunderstorms will be possible tonight into early
tomorrow morning. The rest of the day will be quiet. Not 
anticipating any fire weather concerns for Monday due to frontal
influence.

.LONG TERM...(Monday night through Sunday)
Issued at 154 PM MDT Sun Aug 25 2019

Long range models continue to agree that the dry pattern will
return and be the story for the remainder of the week. An upper
level ridge will be locked in place providing more concerns for
dangerous fire weather conditions. Will not be difficult to dry
out after the passage of the front on Monday. Temperatures will
return to normal in the mid 80s to lower 90s. Westerly winds
influenced by the ridge will result in strong downslope flow again
providing gusty winds for prime fire growth and spread conditions.

Late week a trough will move south into our area providing the
next best chance for precipitation. Models are hinting at a
stronger and deeper trough behind it at the beginning of next
week that could potentially provide an even more prime environment
for widespread rainfall. Between the systems temperatures will
quickly bounce back up to the 90s before again dropping with the
passage of a cold front. 

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 523 PM MDT Sun Aug 25 2019

Wyoming TAFS...VFR. Wind gusts from 25 to 38 knots until 02Z. Wind
gusts to 25 knots at Rawlins from 02Z to 05Z. Wind gusts to 25
knots at all terminals after 06Z. 

Nebraska TAFS...VFR. Showers in the vicinity at Chadron and
Alliance from 07Z to 15Z. Wind gusts from 25 to 31 knots after
05Z. 

&&

.FIRE WEATHER...
Issued at 154 PM MDT Sun Aug 25 2019

Dangerous fire weather conditions are prevailing today in above zones. 
Humidity will be between 10 and 15 percent with winds gusting between 30 
and 35 mph with gusts up to 45 mph possible in our western zones. The Haines
Index is 5 to 6 for areas under the Red Flag Warning. Expect any fires that
develop to behave erratically and spread rapidly. There is a wildfire ongoing 
at this time in northern Carbon County at Pedro Mountain at the Pathfinder Dam.
This fire currently covers approximately 1000 acres and with favorable 
conditions today may experience extensive growth. 

A cold front to the north will progress south across the region tonight, 
shifting winds to a northerly direction. Isolated to scattered showers and 
thunderstorms will accompany the front across the northern and eastern districts. 
Noticeably cooler temperatures and slightly higher humidities are
forecast Monday.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Red Flag Warning until 9 PM MDT this evening for WYZ303>305-307-
     309-310.

NE...None.
&&

$$

SHORT TERM...CW
LONG TERM...CW
AVIATION...RUBIN
FIRE WEATHER...CW