Area Forecast Discussion
Issued by NWS Cheyenne, WY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
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
FXUS65 KCYS 241024

Area Forecast Discussion
National Weather Service Cheyenne WY
424 AM MDT Thu Aug 24 2017

.SHORT TERM...(Today - Saturday)
Issued at 231 AM MDT Thu Aug 24 2017

The upper-level pattern will be characterized by weak, quasi-zonal
flow through the remainder of the week. Multiple disturbances will
traverse the flow over the next several days, each resulting in at
least isolated shower/thunderstorm activity. Shortwave ridging may
keep convection at bay until 21z this afternoon, when stronger mid
level forcing looks to overspread the CWA. Afternoon CAPEs of 1000
J/kg could support small hail with stronger cells, but 500 mb flow
less than 20 knots is expected to limit the potential for anything
organized. The latest MRGL risk from SPC looks justified w/current
instability progs, but anything severe today/tonight would be very
short lived. The passage of multiple disturbances on Fri/Sat could
aid in convective development as well, mainly over the high plains
with lee troughing in place and a couple of weak fropas. Given the
fairly normal upper-level pattern for this time of year, we expect
daytime high temperatures to continue to hover around the seasonal

.LONG TERM...(Saturday night through Wednesday)
Issued at 410 PM MDT Wed Aug 23 2017

Long Range models in good agreement, showing no significant
weather concerns through early next week. Upper level high is
expected to build near the four corners region this weekend and
drift slightly west early in the period, and then eventually
eastward into Utah and western Colorado by the middle of next
week. A strong ridge axis will extend northeast across the state
of Wyoming as well, limiting chances for convection due to
subsidence aloft. A weak shortwave and associated cool front are
expected to move across the eastern plains on Saturday, with the
front stalling along the Laramie Range into Sunday. This may be
just enough forcing to trigger afternoon and evening thunderstorms
across the southern and eastern zone, mainly along the I-80
corridor, but confidence is still low at this time. Otherwise,
mainly dry weather can be expected with little chance for
precipitation through Wednesday. High temperatures will be
seasonable and slightly above average for this time of the year,
with highs mainly in the 80`s to low 90`s for most locations. Mid
to upper 70`s are possible in the higher elevations around Laramie
with cool overnight lows in the 40`s and low 50`s.


.AVIATION...(For the 12Z TAFS through Thursday night) Issued at
231 AM MDT Thu Aug 24 2017

VFR conditions expected to continue today and tonight with another
round of scattered showers and isolated thunderstorms this
afternoon through this evening, mainly along and east of the
Interstate 25 corridor.


Issued at 231 AM MDT Thu Aug 24 2017

In general, dry conditions will prevail over the next several days
with minimum RH values frequently below 20 percent, especially for
areas along/west of the Laramie Range. However, winds are expected
to be light, limiting fire weather concerns through Saturday.




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