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

FXUS65 KCYS 240832

Area Forecast Discussion
National Weather Service Cheyenne WY
232 AM MDT Mon Apr 24 2017

.SHORT TERM...(Today through Wednesday)
Issued at 300 AM MDT Mon Apr 24 2017

Today...Cold front will continue to move from west to east across
our forecast area this morning. Next shortwave trough aloft moves
over southern Wyoming this afternoon, helping to produce isolated to
scattered showers and isolated thunderstorms to the west of a
Cheyenne to Chadron line. Somewhat cooler temperatures today, though
relatively mild for late April.

Tonight...Scattered to numerous showers and isolated evening
thunderstorms expected as the shortwave trough aloft rotates across
our counties, along with plenty of low and mid level moisture to
fuel showers and thunderstorms. Best coverage of showers to the
north of a Douglas to Scottsbluff line along a low level convergence
axis. Based on low and mid level gradients, winds may approach high
wind criteria across our wind prone locations such as Arlington,
though confidence and duration not high enough now for a high wind
watch issuance.

Tuesday...Next push of colder air sweeps southward across our
counties in the wake of another stronger cold front producing a
quite cool day, especially across our northern counties from Douglas
to Alliance. With plenty of low and mid level moisture, cyclonic
flow aloft and another shortwave trough aloft overhead, expect
scattered to numerous showers again, especially in the afternoon.

Tuesday night...Flow aloft turns northwest with drying noted in the
low and mid levels, thus will see a significant decrease in areal
coverage of showers during the evening and late night hours.

Wednesday...Another cool and breezy day with northwest flow aloft
and decent low and mid level gradients. Best low and mid level
moisture will be across our western counties, thus necessitating a
chance of showers mainly along and west of a Douglas to Laramie

.LONG TERM...(Wednesday night through Sunday)
Issued at 300 AM MDT Mon Apr 24 2017

Very unsettled weather in the long term as the area stays under
cyclonic flow aloft. Southeast Wyoming and Nebraska Panhandle will
see daily chances for rain and at times snow.

Best time for snow across southeast Wyoming looks to be Thursday
night into Friday with 700mb temperatures falling to -8 to -10C.
ECMWF showing a closed low tracking across northern Colorado
Friday afternoon/evening while the GFS keeps an open wave. Should
the ECMWF solution come true, we could be in for a pretty major
winter storm. Right now, its showing majority of the snow in
eastern Colorado that tracks up into central Nebraska by Saturday

Should the low track 50-60 miles further north, southeast Wyoming
and Nebraska Panhandle will be in the cold wrap around moisture
(TROWAL) feature of this low. Definitely something we need to be


.AVIATION...(For the 06Z TAFS through Monday night)
Issued at 1135 PM MDT Sun Apr 23 2017

VFR conditions will prevail tonight and Monday. A cold front will
push through the area tonight. Surface winds will shift from S-SW to
W-NW, with gusts between 30 and 40 kt Monday. Ceilings will lower
throughout the daylight hours Monday, with MVFR developing across
Carbon County including Rawlins Monday evening. Occasional showers
and perhaps a few t-storms will continue tonight and Monday morning
west of the Laramie Range, and Monday afternoon for the WY plains.


Issued at 135 AM MDT Mon Apr 24 2017

No concerns this week due to the cooler and wetter
conditions expected, as well as the projected winds and humidities.




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