672
FXUS65 KCYS 172346
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
545 PM MDT Thu Jul 17 2025

.KEY MESSAGES...

- Critical fire weather conditions are expected this afternoon
  for portions of Carbon county.

- Warmer temperatures and daily chances for PM showers and
  thunderstorms will continue into early next week.

&&

.SHORT TERM /THROUGH SATURDAY/...
Issued at 316 PM MDT Thu Jul 17 2025

Dry air is pushing into the region at the lower levels with some
moisture pushing into the region at the mid-levels. There`s more
sufficient moisture along the Colorado/Wyoming border that will
advect northward as the dryline retreats back to the North. This
moisture will help develop thunderstorms on Friday as a weak trough
pushes through in the afternoon and evening. There is an associated
vort-max that would help further support the development storms as
it amplifies the lifting of the moisture being advected in from the
south. There is the possibility of severe thunderstorms as
thunderstorms collide with the dryline. SPC did place a marginal
risk for severe winds and hail towards the middle to northern
portion of our CWA right about the location where the dryline may
retreat to. Depending on the arrival of the trough axis these
showers/thunderstorms may continue into the overnight period.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
Issued at 316 PM MDT Thu Jul 17 2025

A mid level ridge will remain prominent across the southern
Plains while mean troughing prevails across the Pacific
Northwest. This will promote southwesterly winds aloft and
transport of mid to high level moisture across the region.
Periodic ripples within the mean flow should provide sufficient
lift for widely scattered PM thunderstorm development, however
boundary layer moisture appears rather meager with the dryline
largely retreating to the east. Given this setup the primary
thunderstorm related hazards through the period are lightning
and gusty winds. The other story will be gradually warming
temperatures into early next week. Highs climb well into the 80s
and 90s for many areas on Sunday into Monday, with portions of
the Nebraska Panhandle possibly eclipsing the 100 degree mark on
Tuesday. This will produce a moderate HeatRisk, suggesting
potentially adverse impacts to heast-sensitive individuals and
vulnerable groups. The forecast picture becomes a little murkier
thereafter, with some suggestion of a cooling trend and perhaps
a little better moisture entering the picture.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 545 PM MDT Thu Jul 17 2025

Surface stationary front near the Laramie Range mountains is
forecast to eject eastward as a warm front late this evening. Some
showers and thunderstorms are expected near and just behind the
front until 03z.

HAZARDS/WEATHER TRENDS: VFR conditions will prevail tonight and
through Friday morning. Isolated thunderstorms with brief wind gusts
up to 40 knots possible near KLAR and KCYS, but will continue to
handle with PROB30 groups due to limited coverage. Can`t rule out
some low CIGS returning to KSNY late tonight after 08z, but
confidence is less than 20 percent.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Red Flag Warning until 8 PM MDT this evening for WYZ421-422-
     427.
NE...None.

&&

$$

SHORT TERM...MM
LONG TERM...SPM
AVIATION...TJT