National Weather Service Raw Text Product

329 
FXUS65 KCYS 282047
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
247 PM MDT Sat Jun 28 2025

.KEY MESSAGES...

- Scattered showers and thunderstorms expected Saturday and
  Sunday with a marginal to slight risk of severe weather
  including large hail and damaging winds.

- Critical fire weather conditions are expected in central and
  northern Carbon County on Saturday; elevated fire weather
  concerns are expected on Sunday.

- Warm temperatures and daily coverage of isolated to scattered
  afternoon and evening showers and thunderstorms expected for
  Monday through Saturday.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 150 PM MDT Sat Jun 28 2025

Cumulus field beginning to setup across the CWA with a few
echoes noted just east to southeast of Laramie County, with
activity in Colorado already producing a few strikes of
lightning. Lapse rates remain steep on environmental analysis,
but noteworthy instability is limited to just the Nebraska
Panhandle with 500 J/kg or less for Wyoming border and westward,
and shear is near non-existant. Heating and mixing should 
continue to contribute to development through this evening, with
high based thunderstorms expected (surface moisture remains 
abysmal, with most RH values in the 20's to teens and dewpoints 
struggling to make it past 50 degrees). High resolution guidance
is indicating we'll see our initial rounds developing over the 
next few hours and spread eastwards, particularly across 
Niobrara and Goshen Counties in Wyoming and the northern half of
the Nebraska Panhandle, but the NAM Nest is also pinging 
additional development spreading into these areas beginning 
again this evening and into the nighttime hours and re-igniting 
another round of stronger to severe storms. Regardless, any 
storms that do form will have the potential for hail and strong 
wind gusts, and activity even along and west of the I-25 
corridor can't rule out stronger wind gusts due to the inverted 
V soundings thanks to the dry conditions at the surface. On the 
note of dry conditions, breezy winds and low relative humidities
are continuing to fuel the ongoing Red Flag Warning for Carbon 
County, continuing into this evening before winds lessen and RH 
values rise back above critical thresholds.

Moisture should overspread the region on Sunday and, alongside
the slowly propagating backdoor cold front, should bring more
temperate conditions as highs drop back down into the 70's to
80's, alongside a more widespread shower and thunderstorm risk
for the day. High resolution models are much more excited for
areas in Laramie County for the day, with the HREF paintball for
reflectivity 40 dBZ or greater coloring in almost the entire
county. While overall instability will be a bit lower for the 
day compared to Saturday, soundings show a favorable profile for
hail development, so expect the potential for strong winds and 
large hail, encompassing from the Laramie Range eastwards. 
Further west though, another round of dry surface conditions 
with RH values into the teens and breezy winds could bring 
another round of enhanced fire weather conditions. On the fence 
currently if we'll see 3 hours of critical conditions though, 
and will coordinate with the evening shift to determine if 
smaller red flag warning may be needed tomorrow or not.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Issued at 150 PM MDT Sat Jun 28 2025

Monday...Temperatures about the same as on Sunday, with low level 
upslope east winds and 700 mb temperatures near 10 Celsius. Despite 
adequate low and mid level moisture, we should see a decrease in 
coverage of showers and thunderstorms due to ridging aloft.

Tuesday...A warming trend develops as 700 mb temperatures rise to 
near 15 Celsius. Adequate moisture aloft for isolated to widely 
scattered late day showers and thunderstorms, mainly east of I-25.

Wednesday...The warming trend continues as 700 mb temperatures reach 
16 Celsius. Moisture looks similar to Tuesday, thus we anticipate 
isolated late day showers and thunderstorms.

Thursday-July 4th...Similar temperatures to Wednesday with 700 mb 
temperatures near 16 Celsius. Adequate low and mid level moisture 
again, thus isolated to scattered late day showers and thunderstorms 
expected. Looks like decent weather for outdoor holiday activities.

Saturday...Although ridging aloft builds overhead, there should 
still be adequate low and mid level moisture for scattered afternoon 
and evening showers and thunderstorms. Slightly cooler temperatures 
expected for most locations.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1155 AM MDT Sat Jun 28 2025

Mostly VFR conditions expected over the next 24 hours, with
this visibility disrupted primarily by strong thunderstorms.
Storms are expected to be possible at all sites, though most
likely for KBFF/KCDR, while storms are KRWL may be high based
and dry with just thunder. Any storms that move over or near
sites will cause winds to become gusty and erratic. Cloud bases
drop to around 10k feet with precipitation today, but could
lower further near or under any storms. Storms will linger the
longest tonight for KCDR/KAIA, with precipitation possible
through 08Z. Winds should lessen later tonight into tomorrow
morning after activity settles. Finally, a surge of moisture
plus a stalling boundary could produce lowered CIGs in the
Nebraska Panhandle for the sites impacted by lingering
precipitation, with decks dropping to around 30-50k feet; other
sites meanwhile should see higher based clouds into tomorrow
morning.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Red Flag Warning until 9 PM MDT this evening for WYZ421-422-
     427.
NE...None.

&&

$$

SHORT TERM...CG
LONG TERM...RUBIN
AVIATION...CG