Area Forecast Discussion
Issued by NWS Cheyenne, WY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS65 KCYS 230313
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
913 PM MDT MON AUG 22 2016

.UPDATE...
Issued at 852 PM MDT Mon Aug 22 2016

Winds remain a bit gusty across the region this evening, but
humidities are back above 20 percent for most locations so let the
Red Flag Warning expire on time. Also, upgraded to a Red Flag
Warning for tomorrow afternoon for all zones in the Fire Weather
Watch except FWZ 301. Latest guidance shows the cold front
through the area soon enough to keep winds below critical
thresholds in the afternoon. Further southwest, expecting very
dry and breezy conditions once again, similar to today.

&&

.SHORT TERM...(This evening through Wednesday night)
Issued at 300 PM MDT Mon Aug 22 2016

Forecast challenges with this forecast package deal with fire
weather concerns.

Currently...Surface analysis showing a cold front off to the
west...roughly laying along a line from western Montana to
southwest Idaho into northern California this afternoon. Leeside
trough lays over the Nebraska Panhandle. Mosaic radar showing
showers mainly south of the Wyoming/Colorado line this afternoon.
Gusty winds being reported across all the areas included in the
Red Flag Warning this afternoon. Looks like the warning is
panning out pretty good and have no plans on changes.

For this afternoon...do expect some of those showers to still make
it up into our area and have continued low chance PoPs for this
afternoon.

Winds should ease tonight...though the will stay up making
humidity recoveries poor once again tonight. This will set the
stage for another critical fire weather day Tuesday. GFS and ECMWF
shows the front hanging up along the Laramie Range Tuesday morning
and not really impacting dry air and winds out west. GFS 700mb
winds quite strong for Tuesday out west. Front really does not get
into areas west of Laramie Range until late Tuesday afternoon.

Fire weather conditions ease Wednesday as the front finally pushes
west and southwest. Moisture return from the south should give us
better chances for showers and thunderstorms especially across our
southern zones.

.LONG TERM...(Thursday through Monday)
Issued at 300 PM MDT Mon Aug 22 2016

Mid-level disturbances embedded w/in the larger scale flow pattern
will promote daily chances for convection over the area through at
least Sunday. Greater potential for more widespread convection may
exist on Thursday afternoon with a stronger wave and stronger low-
level convergence along the Laramie Range. The GFS still shows SFC
CAPES around 1000 J/kg and 0 to 6 km shear of 40 to 50 knots, so a
few stronger storms are certainly possible. Temperatures may start
on the cooler side following the frontal passage on Wednesday with
H7 temperatures only in the single digits. A gradual warming trend
can be expected through Sunday as mid-level heights begin to rise.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 911 PM MDT Mon Aug 22 2016

VFR prevails. Gusts of 23 to 27 knots from 15Z Tuesday to 01Z
Wednesday.

&&

.FIRE WEATHER...
Issued at 300 PM MDT Mon Aug 22 2016

Critical fire weather conditions ongoing this afternoon and are
expected to continue into early this evening. Current Red Flag
Warnings look on track and no changes anticipated. These winds are
due to a low pressure system tracking through northern Montana.
Associated cold front with this low slow to move into southeast
Wyoming and may not move into our western zones (west of Laramie
Range) until Tuesday afternoon. Another critical fire weather day
is therefore expected for areas west of the Laramie Range for
Tuesday and Fire Weather Watches remain in effect for Tuesday.

&&

.CYS Watches/Warnings/Advisories...
WY...Red Flag Warning from 10 AM to 8 PM MDT Tuesday for WYZ302>304-
     306-308.

NE...None.
&&

$$

UPDATE...RJM
SHORT TERM...GCC
LONG TERM...CLH
AVIATION...RUBIN
FIRE WEATHER...GCC



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.