Lagrange, Wyoming Weather Forecast Discussion

581
FXUS65 KCYS 121142
AFDCYS
Area Forecast Discussion
National Weather Service Cheyenne WY
542 AM MDT Fri Sep 12 2025
.KEY MESSAGES...
- Daily chances for afternoon showers and thunderstorms continue
  through Saturday with gusty winds, downpours, and isolated
  hail possible.
- A cold front will impact the area Saturday, bringing cooler
  temperatures through the weekend.
&&
.SHORT TERM /THROUGH SATURDAY/...
Issued at 326 AM MDT Fri Sep 12 2025
Current radar shows a few stray light showers across the forecast
area early this morning. Some leftover energy from a shortwave that
moved through on Thursday has lead to the light showers and will
cause these showers to continue through the morning hours. As the
upper-level trough over the Great Basin continues to push eastward,
more vorticity maxes will be sent into the CWA. This, combined with
some 250 mb jet energy will lead to numerous showers and storms
developing during the afternoon. Instability is rather lacking so
severe storms are unlikely. Although MUCAPE is lacking, DCAPE is
still a bit elevated which could lead to some gusty winds in storms.
As the day progresses into evening, instability will weaken, turning
convection into more stratiform precipitation. PWATs will also
increase as the cold front associated with the trough creeps closer.
Elevated PWATs will lead to heavy rain at times throughout the
afternoon and evening. Hi-Res guidance shows widespread coverage of
storms, so it is likely that most locations will see at least some
precipitation today. As the trough pushes into the CWA, the cold
front will move through the area Friday night. This will cause
showers to linger overnight, but overall should not cause any
impacts.
With the trough over the Rockies on Saturday and the cold front
through the area, high temperatures will be about 5 to 10 degrees
cooler than Friday. Highs will be in the 60s for areas west of the
Laramie Range and 70s to low 80s for areas to the east. These high
temperatures will be near to slightly below normal for mid-
September. As the trough axis continues to shift eastward closer to
the CWA, more precipitation chances will be possible. Saturday looks
like a repeat of Friday with similar instability and PWATs. Showers
and storms will develop during the afternoon, once again turning
more stratiform by the evening hours as instability dies off.
Widespread coverage of precipitation is expected, with most
locations likely to see at least some rain by midnight Saturday
night.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Issued at 219 PM MDT Thu Sep 11 2025
As we start the long term and progress through the weekend,
troughing digs in and slides across our CWA as ridging pushes off to
the east. Within the trough, energy aloft will move through our CWA,
kicking off a few isolated to scattered thunderstorms along with the
potential for heavy rainfall. This trough will slide off to the east
through Sunday, bringing the greatest threat of heavy precipitation
and thunderstorm potential into the Nebraska panhandle. A brief
reprieve Monday as a transit ridge moves in, decreasing
precipitation and storm potential. This ridge will bring in the
warmest temperatures for the long term period, with highs east of
the I-25 corridor soaring once again back into the lower to
mid/upper 80s and into the 70s across our western counties.
Beginning Tuesday, we will see a return of moisture along with
increased precipitation chances that remain possible into Wednesday
as another another upper level low rotates across our CWA. At the
tail end of next week, northwest flow aloft makes a return, ushering
in cooler temperatures that may only top out in the lower to mid
70s. In addition, precipitation chances during this time period
previously mentioned, dwindles into next weekend.
&&
.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 542 AM MDT Fri Sep 12 2025
Numerous showers and storms are expected across all terminals this
afternoon and evening. Storms could contain gusty winds and heavy
rain which could reduce visibility at times. Scattered storms this
afternoon will transition more to stratiform precipitation during
the evening and overnight hours.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&
$$
SHORT TERM...SF
LONG TERM...RZ
AVIATION...SF

NWS CYS Office Area Forecast Discussion