Area Forecast Discussion
Issued by NWS Cheyenne, WY

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

FXUS65 KCYS 162207

Area Forecast Discussion
National Weather Service Cheyenne WY
407 PM MDT Sun Oct 16 2016

.SHORT TERM...(This evening through Tuesday)
Issued at 406 PM MDT Sun Oct 16 2016

Cancelled the High Wind Warning for areas west of the Laramie
Range as winds have decreased markedly through the afternoon.
Maintained the Warnings across the southern Laramie Range east to
I-25 as wind gusts were bouncing up and down a bit this afternoon,
but this warning should be able to come down early too. Similarly
with the Red Flag Warning as humidities have been on the steady
rise late this afternoon.

Forecast remains on track for the next upper level system to bring
more widespread strong winds tomorrow along with critical fire
weather concerns for the far southern WY/NE plains. Gradient progs
still look very favorable for strong winds in the wind prone areas
along and west of the Laramie addition to the I-25
corridor from northern Platte County down to the Colorado border
including Cheyenne and vicinity. Looking at winds at the
700-750-800-850 mb levels, GFS remains the bullish model with
widespread 55-60 kt winds in the 750-700mb layer. The NAM and
ECMWF have come up on the wind speeds since yesterday, but are
progging a much smaller area for these stronger winds. Took the
middle ground approach between the models and maintained upwards
of 65 mph wind gusts for tomorrow across portions of southeast
Wyoming, and gusts around 50 mph for Nebraska. Went ahead with the
upgrade to High Wind Warning, adding in eastern Laramie County to
maintain continuity in messaging across I-80. For now, went with
a Wind Advisory for gusty winds in the Panhandle, although there
is a possibility a few locations could peak at 60 mph. Not
confident when or where this will happen though due to the
continued variability in model guidance.

Dry downslope off the Laramie Range will keep the plains on the
dry side through tomorrow afternoon, with critical fire weather
conditions likely especially for areas near the Colorado border.
Upgraded to a Red Flag Warning for these portions of southeast
Wyoming and the southern Nebraska panhandle. Again, very strong
winds could carry fire elsewhere, but humidities will be higher
so will hold off on any Red Flag Warnings elsewhere.

Rain and high elevation snow showers will accompany the upper
level system west of the Laramie Range tomorrow. Accumulations
will remain confined to the higher peaks, with an inch or two
possible. Cooler temps will filter into the area for Tuesday,
along with less wind.

.LONG TERM...(Tuesday night through Sunday)
Issued at 406 PM MDT Sun Oct 16 2016

A Pacific cool front will sweep across the CWA Tuesday night in
association with an upper shortwave that will also move through
the region at that time. Models not as strong or amplified with
this wave as in previous runs with overall QPF lighter.  Should
still have some rain and snow showers across the CWA Tues night
into Weds before ending/moving out late in the day. Cooler Weds
and went a little below guidance for max temps where pcpn/cloud
cover should be greatest. Surface high builds ovr the area Weds
night with clearing skies boding for a chilly morning Thursday.
Thursday through Sunday appearing to be dry and mild as an upper
ridge shifts across the region through Friday before flattening
and leaving a more general zonal flow over the CWA Saturday and
Sunday. Next cool front due about Sunday but looking dry.


.AVIATION...(For the 18Z TAFS through 18Z Monday Morning)
Issued at 1109 AM MDT Sun Oct 16 2016

VFR conditions through the taf period with varying amounts of
mid and high clouds. There will be gusty winds over terminals
this afternoon...especially across the southeast WY sites. Gusts
to 30-45 kts are expected through the afternoon from RWL to CYS.
The winds will decrease after 00Z.


Issued at 406 PM MDT Sun Oct 16 2016

Another low pressure system tracking over the northern rockies on
Monday will bring a return of widespread strong winds to the
district along with increasing moisture. Humidities may still drop
into the teens for southern portions of FWZ 310 and 313 Monday
afternoon, and with strong winds expected over these areas, think
the threat for rapid fire growth will be high. Rain and high
elevation snow showers will reduce fire weather concerns along
and west of the Laramie Range, although winds will be strong.


WY...Red Flag Warning until 6 PM MDT this evening for WYZ309-310.

     Red Flag Warning from 11 AM to 7 PM MDT Monday for WYZ310.

     High Wind Warning from 9 AM to 7 PM MDT Monday for WYZ104-105-

     High Wind Warning until 6 PM MDT this evening for WYZ106-107-116-

     High Wind Warning from 3 AM to 7 PM MDT Monday for WYZ106-110-

NE...Red Flag Warning until 6 PM MDT this evening for NEZ311>313.

     Wind Advisory from 11 AM to 7 PM MDT Monday for NEZ002-003-

     Red Flag Warning from 11 AM to 7 PM MDT Monday for NEZ313.



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