964
FXUS65 KCYS 141729
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
1129 AM MDT Wed Aug 14 2024

.KEY MESSAGES...

- Scattered to numerous afternoon/evening showers and
  thunderstorms are expected the next few days. Storms will
  have the potential to produce torrential rainfall, gusty
  winds, and isolated large hail.

- Seasonable temperatures will continue through the period. Showers
  and thunderstorms will be most likely on Sunday, Monday and
  Tuesday, with dry conditions for Saturday.

- Fire weather concerns begin to increase Friday as well as
  Saturday with warmer temperatures and low afternoon humidity.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 213 AM MDT Wed Aug 14 2024

1006mb surface low across northeastern Wyoming near Gillette.
Cold front extends from this low south through Wheatland and
then west southwest to Laramie and then west to Evanston this
morning. Dewpoints in the low 60s east of this front with 40s
west.

Look for another round of showers and thunderstorms this
afternoon through early evening. NAM/GFS soundings not showing
much in the way of CAPE this afternoon. NAM showing MUCAPE
around 500J/KG this afternoon...while GFS soundings showing
maybe 900-1000J/KG in the Panhandle. So despite the Marginal
Risk area highlighted by SPC...think severe storms will be
minimal today. Much drier today as well with PWATs less than an
inch in the Panhandle and about a half inch out over Carbon
County.

Storms may continue into the evening hours tonight as another
shortwave moves through the northwest flow. Kept PoPs going
through 06Z as this shortwave moves through the CWA.

Storms continue Thursday afternoon...though much less coverage
expected over today. Really dry out Friday as ridge builds over
the CWA. 700mb temperatures +16 to +18C will yield afternoon
highs in the 90s east of the Laramie Range and mid 80s west. May
be dealing with fire weather headlines Friday as GFS 700mb winds
up near 20-25kts west of the Laramie Range that will likely mix
down to the surface.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Issued at 213 AM MDT Wed Aug 14 2024

Friday night/Saturday...West flow aloft will continue to dry out the
airmass and thus we will see correspondingly warmer temperatures
from the mid 80s to mid 90s. With precipitable water values lowering
to 0.4 to 1 inch and warm temperatures aloft increasing the
convective inhibition. it looks dry.

Sunday...Despite ridging aloft developing, we will see an increase
in atmospheric moisture content with precipitable water values
increasing to 0.6 to 1.4 inches. Thus, we expect an increase in
widely scattered to scattered late day showers and thunderstorms,
most numerous from the Snowy Range to far southeast Wyoming.

Monday/Tuesday...Atmospheric moisture content remains about the same
as on Sunday, and thus we expect another round of scattered late day
showers and thunderstorms each day, most numerous near the Colorado
state line from the Snowy Range to far southeast Wyoming. With
similar 700 mb temperatures, maximum temperatures should be about
the same as those from Sunday.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1119 AM MDT Wed Aug 14 2024

Changes once again to the aviation forecast, with details
becoming a bit more clear with the latest HiRes model guidance.
Active weather expected once again today, with another
progressive shortwave expected to dig across the Intermountain
West through the evening hours. Less moisture has been observed
throughout the morning, with dewpoints in the mid to high 40s
for Southeast Wyoming, and into the mid 50s for the Nebraska
Panhandle. At this time, not expecting much to change throughout
the day, with the better moisture advection occurring in the
central CONUS and just out of reach. Regardless, forecast
soundings continue to indicate DCAPE around 1000 J/kg and the
latest HiRes model guidance having convection spark off the
shortwave digging through. Main concerns will be gusty to strong
winds associated with the lines of storms expected to develop.

&&

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

&&

$$

SHORT TERM...GCC
LONG TERM...RUBIN
AVIATION...MRD