Laramie, Wyoming 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

615
FXUS65 KCYS 192357
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
557 PM MDT Sat Jul 19 2025

.KEY MESSAGES...

- Scattered PM showers and thunderstorms are expected again
  today. A few storms will have the potential to become strong
  to severe, mainly in the NE Panhandle.

- Expect warm temperatures Sunday and Monday with more limited
  afternoon thunderstorm potential.

- The next surge of monsoon moisture is expected Tuesday through
  Thursday bringing higher chances for PM thunderstorms and near
  average temperatures.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 1200 PM MDT Sat Jul 19 2025

Current visible satellite late this morning shows some high
clouds over the Interstate 80 corridor with a cumulus field
beginning to develop over the high terrain. This cumulus field,
as well as a weak dryline expected to push to the
Wyoming/Nebraska border later this afternoon will be the main
areas for storm development this afternoon. Synoptically, a weak
shortwave will push across Wyoming this afternoon, providing
the needed lift necessary for storms. Surface moisture and
instability will help fuel storms, leading to potentially
severe storms across portions of the CWA. Model soundings show
the most favorable environment for severe storms in the eastern
Nebraska panhandle. MUCAPE values up to 1700 J/kg with around
40 kts of effective shear will lead to a large hail threat this
afternoon. Strong winds could also be possible with DCAPE values
exceeding 1000 J/kg. Cannot rule out an isolated tornado with
elevated MLCAPE values and effective shear values as high as
they are. Flash flooding could also be possible as PWATs in the
Nebraska panhandle exceed 1 inch which is above the 90th
percentile for climatology. Most Hi-Res guidance keeps the
coverage of severe storms relatively low this afternoon, with
more widely scattered run-of-the-mill storms. Storm initiation
will take place by early to mid afternoon, with storms weakening
and moving out the area by later this evening.

A much drier day is expected on Sunday. Quasi-zonal flow will
continue to dominate the mid-levels, ushering in drier and slightly
warmer air aloft. High temperatures will be in the 80s and 90s, a
few degrees above average for this time of year. Once again, a weak
disturbance aloft moving overheard could trigger a few high terrain
showers during the afternoon. However, the very dry surface and low-
levels will likely prevent any showers from making it out of the
high terrain. Any storms that do form will dissipate during the
evening hours, leading to a quiet overnight.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 152 PM MDT Sat Jul 19 2025

A stout ridge aloft will initially hold court over the central
and southern plains early in the period. By midweek the ridge
axis will be shunted east in response to a digging upper trough
along the west coast. Later in the week the shortwave trough
will lift north and dampen along the International Border
allowing the upper ridge to build back into the central Plains.
On Monday a decent plume of mid to upper moisture will advect
across the region on southerly winds along with some weak
perturbations passing through aloft. This should provide
sufficient lift to allow for isolated thunderstorm development,
however boundary layer moisture appears rather anemic. As the
upper wave makes its closest approach around mid week shower and
thunderstorm chances should increase with monsoonal moisture and
an east-west oriented frontal zone dropping into the area from
the north. Things moisten up considerably over the Panhandle by
Wednesday with dewpoints climbing into the lower 60s and
precipitable water values perhaps reaching around 1.25". This
value -- if realized -- surpasses the 90th percentile for this
date using UNR climatology as a proxy. As such, will need to
keep an eye on heavy rain potential in the Panhandle depending
upon how the mesoscale details play out. As the Great Plains
ridge flexes northwest by late week this should limit shower and
thunderstorm chances while leading to a notable warming trend
which will continue into the weekend.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 535 PM MDT Sat Jul 19 2025

Widely scattered showers and isolated thunderstorms should
gradually wane through 02-03Z. Confidence in on-station impacts
is too low for inclusion in the TAFs, with the exception of
KCDR. Otherwise VFR prevails at the terminals with generally
light winds outside of some afternoon gustiness tomorrow
afternoon at KRWL.

&&

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

&&

$$

SHORT TERM...SF
LONG TERM...SPM
AVIATION...SPM