Rock River, Wyoming Weather Forecast Discussion

950
FXUS65 KCYS 080627
AFDCYS
Area Forecast Discussion
National Weather Service Cheyenne WY
1227 AM MDT Mon Sep 8 2025
.KEY MESSAGES...
- A lull in shower and thunderstorm activity for Monday, with
  temperatures continuing to warm to near 90 in spots across
  eastern Wyoming and the Nebraska panhandle.
- Daily afternoon thunderstorm chances return Tuesday onwards
  with primary threats being wind and hail.
- A cold front will impact the area later this week, dropping
  temperatures a few degrees.
&&
.SHORT TERM /THROUGH TUESDAY/...
Issued at 145 PM MDT Sun Sep 7 2025
An upper-level shortwave will slide across the CWA providing the
needed lift in the atmosphere along with adequate moisture for
storm initiation that we are currently seeing on radar. These
storms will become more widespread as the afternoon progresses,
developing over Wyoming and spreading into the Nebraska
panhandle. Instability parameters are meager at best, but
enough for small hail along with gusty and erratic winds to be
of some concern, this activity will continue into the evening
hours. SPC earlier had a Marginal Risk (Level 1 of 5) nosing
into the southern Nebraska panhandle, they since removed it to
just south of the border. However, we still can`t rule out some
low end severe storms in this area of Nebraska. Winds are
ramping up across portions of the CWA, expect gusty winds
primarily in to 20-25 MPH range, with a few locations possibly
gusting to 30-35. Temperatures will continue to warm into Monday
as 700MB temperatures will climb into the double digits, expect
highs to top out mid to upper 70s to near 80 west of the I-25
and lower 80s to upper 80s east of I-25 for this afternoon. More
of the same for Monday in terms of temperatures, although
slightly warmer across easter Wyoming and the Nebraska Panhandle
where temperatures may soar to near 90 in a few spots.
Thunderstorm activity decreases for Monday with a more active
pattern leading into the long term.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Issued at 155 PM MDT Sun Sep 7 2025
Mid-level water vapor shows the next low pressure system of the
coast of California/Oregon now. This system will be responsible for
our overall wet pattern. Cluster analysis show majority of the
ensembles stalling the system as it collides with the ridging
pattern to give us a wet work week. As this system stalls over the
West Coast it will send multiple shortwave disturbances across
Southeast Wyoming and the Nebraska Panhandle. These shortwaves will
develop chances for afternoon and evening precipitation and
thunderstorm development. By Thursday the next wave is progged to
push its way into the Pacific Northwest. This oncoming wave is
expected to make the pattern progressive again and help lift the
previous low pressure system up and over the ridge centered on the
high plains during this time period. As the low pressure system
lifts it will change our flow pattern from southerly to a more
westerly pattern, cutting off some of the moisture advection into
the region. Friday and weekend is expected to be wet and cool as
some arctic air escapes from Canada to give us daily highs in the
70`s and overnight temperatures in the 40`s and 50`s.
&&
.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1105 PM MDT Sun Sep 7 2025
Isolated showers and storms continue to drift across the region
tonight, but should come to an end in the next 1 to 3 hours. KCYS
and KLAR have the best chance to see showers in the vicinity, while
KSNY may see thunderstorms in the vicinity and potentially impacting
the terminal. Showers and storms clear by 09Z. Primary aviation
concerns for the afternoon hours will be another round of isolated
to scattered showers and storms, as well as gusty winds across the
terminals. Light smoke may be in the area around KCDR, KAIA, and
KSNY late this morning into the afternoon hours, though major
visibility reductions are not expected.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&
$$
SHORT TERM...RZ
LONG TERM...MM
AVIATION...AM

NWS CYS Office Area Forecast Discussion