882
FXUS65 KCYS 171100
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
500 AM MDT Fri Jul 17 2026

.KEY MESSAGES...

- Hot, dry, and breezy conditions continue through Sunday before
  a much awaited cold front arrives for the start of the week.

- Monday looks to be the last 100+ day for the upcoming week or
  so, with reduced fire concerns also arriving with cooler
  weather.

- Monsoonal moisture will attempt to return as early as Monday,
  leading to increased precipitation chances through much of
  next week.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 127 AM MDT Fri Jul 17 2026

Upper-level ridging continues to dominant much of the CONUS today
through much of next week. This upper-level high will result in
largely light and variable winds throughout the atmosphere as the
ridge slowly strengthens through the weekend. A 594dm high at 500mb
develops overhead for late Saturday through the day Sunday, leading
to a very hot weekend in store for much of the region. Afternoon
highs on Friday will be in the mid-80s to near-100F, while afternoon
highs on Saturday will be warmer in the upper-80s to 100F+ across
western Nebraska. Sunday does appear to be the hottest day, with
afternoon highs in the upper-80s to 105F in western Nebraska as the
upper-level high strengthens overhead. With dry conditions expected
for most areas today through Sunday, afternoon relative humidity
values will drop into the 15 to 25 percent range everywhere Friday
through Sunday afternoon. Luckily, winds will be just below critical
thresholds, so elevated, but not critical, fire conditions are
anticipated to continue Friday onwards. No fire weather headlines
have been issued at this time. Consideration was given to the
potential need for a Heat Advisory across northern portions of the
region on Sunday, but will defer to future shifts to determine the
necessity as models continue to come into better agreement on
forecast highs for Sunday.

Monsoonal moisture will start to try to return to the region as
early as Saturday afternoon, mainly west of the Laramie Range. As a
result, precipitation chances start increasing Saturday onwards, but
an isolated shower or storm over the mountains cannot be ruled out
this afternoon (~15% chance). More "widespread" precipitation
chances start to return Saturday afternoon, mainly west of the
Laramie Range, with around a 25 to 35% chance for precipitation in
Carbon County. Sunday will see the best chance for precipitation in
the short term forecast, with PoPs in the 35 to 50 percent range
mainly along and west of I-25. Significant precipitation does not
look likely as the best monsoonal moisture will not arrive until
next week, but up to a quarter inch of precipitation will be
possible Sunday afternoon where the majority of showers/storms
develop over northern Albany County. Precipitation chances continue
to improve into the upcoming work week.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
Issued at 127 AM MDT Fri Jul 17 2026

Upper-level ridging is progged to continue through much of the
upcoming week, with little indication of the ridge moving out of the
area anytime soon. Long range models suggest that the ridge will
retrograde slightly and strengthen over the Intermountain West once
again Tuesday into Wednesday, leading to more westerly to
northwesterly flow aloft. 500mb flow suggests that the monsoon will
start to take hold as early as Monday evening into Tuesday, leading
to increasing moisture across the CWA. With northwesterly flow aloft
developing by Wednesday, a favorable setup is expected for daily
thunderstorms chances to return with some severe storms potentially
possible. Severe threat is very uncertain at this time, due to the
best pattern not evolving until Wednesday and after. Luckily, after
another hot day on Monday under the strengthening upper-level high,
a stout cold front will push through Monday evening into Tuesday,
dropping temperatures from highs of the mid-80s to low-100s on
Monday to highs in the low-80s to low-90s Tuesday onwards. With
cooler temperatures and increasing moisture influx due to monsoonal
flow, fire concerns will drop off rapidly Tuesday onwards. Afternoon
minimum humidity values will remain at or above about 30% most day
this upcoming week, which is well above critical thresholds. Winds
will remain breezy, though below Red Flag criteria. Unfortunately,
these winds will not be enough to make temperatures feel cooler than
actual temperatures, due to increasing humidity across the region.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 500 AM MDT Fri Jul 17 2026

VFR conditions expected this morning through the 12Z TAF period.
Some high-level clouds move into all the terminals by mid-day, but
clear skies return after sunset. Breezy conditions develop around
mid-day, with all terminals gusting 20 to 25kts this afternoon and
evening. Calmer winds return for the late evening into the overnight
hours.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.

&&

$$

SHORT TERM...AM
LONG TERM...AM
AVIATION...AM