518
FXUS65 KCYS 212325
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
525 PM MDT Thu Aug 21 2025

.KEY MESSAGES...

- A marginal risk (1 of 5) of severe weather is expected today,
  with the most likely area for stronger storms across the
  northern counties of the CWA.

- One last day of hot temperatures will continue through this
  afternoon, with the hottest across eastern Wyoming and the
  Nebraska Panhandle.

- A cooler and wetter period is expected to begin Friday through
  Wednesday due to abundant cloud cover along with scattered to
  numerous showers and thunderstorm activity for most days.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 105 PM MDT Thu Aug 21 2025

One last day of warm temperatures across the CWA, with highs topping
out in the mid 80s to upper 90s, with the warmest temperatures
holding strong across eastern Wyoming and the Nebraska Panhandle. A
front, as evident on VIS satellite, is starting to impact and move
through northwestern portions of the CWA. As the day progresses, so
will this front as it sweeps across the region through the afternoon
into the evening hours. This frontal boundary will bring much needed
precipitation chances to the CWA along with a few embedded
thunderstorms. As we move into the afternoon, storms will begin to
develop and increase in area with the greatest threat of severe
storms impacting our northern counties, such as Converse and
Niobrara, due to upslope flow aiding in thunderstorm development.
Most of the CWA will remain in meager severe weather parameters;
however, the two aforementioned counties may have the best
chances of severe weather, with primarily strong winds and
larger hail, due to stronger wind shear.

An upper level low that is bringing this frontal boundary to our CWA
today along with a pattern change, will continue on its east-
southeast trek through Canada through the day on Friday. Upslope
flow will once again bring a threat of thunderstorm activity, a
Marginal Risk (1 of 5) from the Laramie Range, a line north/south,
east into the Nebraska Panhandle. The biggest threat with this
thunderstorm activity on Friday will be hail and gusty winds.
Heading into the weekend, high temperatures will continue to drop
into the mid 70s to low 80s. This decrease in temperatures should
continue into next week as we begin our first fall pattern
across the CWA.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 105 PM MDT Thu Aug 21 2025

A cool and wet pattern is the primary story for the long term
forecast as northwesterly flow aloft moves overhead and 700mb
temperatures drop into the single digits. A broad ridge will set up
over the Four Corners region this weekend and remain in place
through much of next week. With the 500mb high positioned over the
Four Corners region, monsoonal moisture will continuously advect
into the region, fueling a very wet pattern. With northwesterly flow
advecting in cooler Canadian air, 70mb temperatures will drop into
the 7 to 10C range throughout the week, leading to daytime high
temperatures in the 60s and 70s for most of the region, with only a
few places seeing highs in the low 80s. Monday looks to be the
coolest day behind a cold front, wit temperatures in the mid-60s to
low-70s area wide, except a few locations that will be in the mid-
70s. Northwesterly flow aloft will leave the door open for multiple
disturbances to pass through the flow. As a result, day
precipitation chances are expected throughout the week, leading to a
cool and fairly dreary week for late August. The cooler temperatures
and increased precipitation will be a welcome reprieve after the
warm and dry week the region has been seeing. Additionally, daily
precipitation will limit fire weather concerns for much of the area,
another welcome addition from the incoming cooler and wetter weather.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 520 PM MDT Thu Aug 21 2025

West flow aloft tonight will turn to northwest on Friday as a
cold front enters the terminals.

Wyoming TAFS...Scattered to broken clouds from 5000 to
10000 feet will occur. Thunderstorms will be in the vicinity of
Laramie until 02Z. Winds will gust to 25 knots at all the
terminals until 02Z, and will gust to 25 knots after 15Z Friday.

Nebraska TAFS...Scattered to broken clouds from 5000 to
10000 feet will occur. Winds will gust to 30 knots until 04Z,
and will gust to 25 knots at Alliance and Sidney after 15Z
Friday.

&&

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

&&

$$

SHORT TERM...RZ
LONG TERM...AM
AVIATION...RUBIN