Alert archive / Wyoming / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 2, NWS Cheyenne, WY

May 9, 2026Carbon County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at May 9, 2026, 2:43 PM MDT for Carbon County, Wyoming. It was in force for 47 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
May 9, 2026, 2:43 PM MDT (20:43 UTC)
Expired
May 9, 2026, 3:30 PM MDT
In force
47 min
Issued by
NWS Cheyenne, WY
Area
Storm-based polygon
Hail
1.25 in
Wind
60.0 mph

County Carbon County, WY

The radar

The Riverton/Lander radar (KRIW), 133 km from the middle of the area, began a volume at 20:44 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
May 9, 2:45 PM MDTHAIL 13 Ne Muddy Gap, WYLingering hail of 1.00 inch in diameter reported by former NWS meteorologist. Time of report was based/estimated off radar imagery.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched one storm report to this severe thunderstorm warning; the first came 2 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The text

As transmitted.

066 
WUUS55 KCYS 092043
SVRCYS
WYC007-092130-
/O.NEW.KCYS.SV.W.0002.260509T2043Z-260509T2130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Cheyenne WY
243 PM MDT Sat May 9 2026

The National Weather Service in Cheyenne has issued a

* Severe Thunderstorm Warning for...
  North central Carbon County in south central Wyoming...

* Until 330 PM MDT.

* At 242 PM MDT, a severe thunderstorm was located near Muddy Gap, or
  24 miles east of Jeffrey City, moving southeast at 30 mph.

  HAZARD...60 mph wind gusts and half dollar size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* Locations impacted include...
  Muddy Gap and Dome Rock.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4244 10720 4243 10678 4235 10663 4212 10722
      4238 10753 4243 10752
TIME...MOT...LOC 2042Z 299DEG 25KT 4240 10737 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Natoli
2 follow-up statements
732 
WWUS55 KCYS 092104
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
304 PM MDT Sat May 9 2026

WYC007-092130-
/O.CON.KCYS.SV.W.0002.000000T0000Z-260509T2130Z/
Carbon WY-
304 PM MDT Sat May 9 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 330 PM MDT
FOR NORTH CENTRAL CARBON COUNTY...

At 304 PM MDT, a severe thunderstorm was located 8 miles south of
Devil's Gate, or 34 miles east of Jeffrey City, moving southeast at
30 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Dome Rock.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4243 10717 4243 10678 4235 10663 4213 10718
      4229 10733
TIME...MOT...LOC 2104Z 299DEG 25KT 4232 10719 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Natoli
382 
WWUS55 KCYS 092122
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
322 PM MDT Sat May 9 2026

WYC007-092132-
/O.EXP.KCYS.SV.W.0002.000000T0000Z-260509T2130Z/
Carbon WY-
322 PM MDT Sat May 9 2026

...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL CARBON COUNTY
WILL EXPIRE AT 330 PM MDT...

The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning will
be allowed to expire.

&&

LAT...LON 4243 10717 4243 10678 4235 10663 4213 10718
      4229 10733
TIME...MOT...LOC 2122Z 299DEG 25KT 4227 10706 

$$

Natoli

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Cheyenne, WY wrote its last area forecast discussion before this severe thunderstorm warning went out at May 9, 2:08 PM MDT, 35 minutes earlier. Its key messages:

  • Numerous rain showers and widely scattered thunderstorms expected on Saturday. A few strong thunderstorms or an isolated severe storm possible.
  • Mostly dry and warmer weather will prevail for Sunday through Wednesday, with thunderstorms possibly returning late in the week.
Area forecast discussion, May 9, 2:08 PM MDT, 35 minutes before
Area Forecast Discussion
National Weather Service Cheyenne WY
208 PM MDT Sat May 9 2026

.KEY MESSAGES...

- Numerous rain showers and widely scattered thunderstorms
  expected on Saturday. A few strong thunderstorms or an
  isolated severe storm possible.

- Mostly dry and warmer weather will prevail for Sunday through
  Wednesday, with thunderstorms possibly returning late in the
  week.

&&

.SHORT TERM /THROUGH MONDAY NIGHT/...
Issued at 152 PM MDT Sat May 9 2026

Scattered showers and some weak thunderstorms are noted on radar
across the area as of this afternoon primarily for our northern
zones with much stronger activity seen to the northwest moving
into Central Wyoming. At the surface, a cold front is currently
draped across portion of the northern Nebraska Panhandle and up
into northeastern Wyoming, while aloft an upper level shortwave
is making its way across Wyoming and into Nebraska through the
day. Current expectation for the rest of today is in line with
the morning forecast package, and expecting scattered
thunderstorms with widely scattered strong to possibly severe
activity today.

High resolution guidance remains largely in agreement on this
continuing over the next several hours, with a few thunderstorms
possible but remaining largely sub-severe. Then as the front
drops across the area, we should see an uptick in thunderstorm
activity along this boundary across the I-25 and I-80 corridors,
with an increase in severe parameters fueling stronger to
possibly severe activity. Along this area should be increasing
CAPE values with pockets of 800-1200 J/kg, 0-6 KM shear values
of 40-60 knots but isolated peaking at around 70-80 knots noted
as well on the HRRR, and steepening low and mid level lapse
rates. Storms will likely be clustered in nature with limited
potential for individual supercells, though cannot rule out at
least one to occur early on. By the later part of this
timeframe, most CAMs agree that activity will congeal into more
linear fragments as they move into Nebraska with intensity
waning as the sun sets. Greatest threats will be gusty winds and
isolated large hail with activity being higher based in nature.

Overnight temperatures should actually chill notably behind the
cold front in tandem with clearing skies fueling radiational
cooling, with widespread lows in the 30's expected Sunday
morning. A building ridge will then control the weather across
the area for the remainder of the short term as we see
temperatures rebounding into the 60's and 70's on Sunday, and
then significant warmth on Monday as highs skyrocket into the
80's and 90's. This will be knocking on the door of record highs
for most of our forecast area with highs 20 degrees above
normal. Alongside this record warmth brings the return of
critical fire weather conditions as our RH values bottom out in
the low teens to near single digits on Monday with some breezy
winds possible along the I-25 corridor and along the base of the
Laramie Range. Will have to take a deeper dive into fire fuels
as we move into Sunday and determine if Red Flag products will
be necessary or not.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
Issued at 152 PM MDT Sat May 9 2026

The general pattern going into Tuesday is one of upper level
ridging. A rather large high pressure system will be building over
the Four Corners Region with an axis of it passing through. This
should allow temperatures to reach the mid 70s to low 80s. We do
have fire weather conditions showing up in the interior mountains
near Rawlins this day. Humidities appear very low, possibly getting
into the low teens with gusty conditions. Elsewhere, dry conditions
may favor some elevated concerns. These conditons should persist
into Wednesday where some spots in valleys east of the Laramie Range
could reach the 90s and near daily record temperatures. Humidities
plummet given the favorable environment for deep layer mixing.
Relative humidities reaching the mid and low teens are a
possibility. Attention to conditions these few days should be
maintained for fire weather interests. Thursday a plume of monsoonal
like moisture makes its way north from the Eastern Pacific into our
area. The ridge gets pushed southeast into Texas allowing increasing
chance of isolated to scattered showers and storms. PoPs are low at
this time, and surface layer mixing will still be high creating dry
conditions at the surface. So, the most likely outcome Thursday are
the continued fire weather risk, but maybe throw in a few dry and
windy thunderstorms. About this time a compact, but high amplitude
trough will be passing over the northwestern Pacific Coast. Global
models differ on the speed and strength of this feature. The GFS is
much more aggressive with this trough and is a bit slower/south with
the progression as it reaches our area Friday. ECMWF is a bit more
progressive, weaker and northward with its trajectory. Both have the
general negative tilt form to the trough which tend to be more
dynamic than positive and flatter systems. The timing is somewhat
important from a severe weather angle, a slower and more southward
system may allow for the favorable left exit region of the jet to
the south of the trough to be in phase with the better daytime
heating. At the moment the models make this a more north and
eastward event. A dry slot on the south side of the system will
create sinking air and may tighten pressure gradients in the 700
mbar enough to create strong winds. Indeed our machine learning
models highlight an elevated risk Friday morning and afternoon
(~40%) for west to east mountain gap flow locations. Conditions area
wide continue to by dry and warm, so fire weather is likely to
continue, even going into Saturday. Fuels in our Nebraska Panhandle
zones are not in good shape with little green up reported. The
snowfall received on the eastern slopes and ridges of the Laramie
Range has caused some greenup with vegetation. The periods of recent
rain may stave off more critical fire concerns going into this
period.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1132 AM MDT Sat May 9 2026

Showers are developing across the Nebraska Panhandle and within
the vicinity of KCDR, KBFF, and KAIA. This activity is expected
to become more widespread before the arrival of a mid level
shortwave. Widespread showers and thunderstorms are expected to
form over the mountain ranges and spread southeast into the
high plains. Impacts to terminals may include variable surface
winds and gusts above 50 kts, hail, lightning, and reduced
visibilities down to two statue miles or less. KBFF, KAIA, and
KSNY have the highest confidence of thunderstorms this
afternoon. Storms are possible at all other terminals with the
same threats to aviation. A few hour lull in storms is expected
after sunset before more shower and storm development is
possible for the Nebraska Panhandle terminals. The intensity of
this convection is expected to be less than the afternoons,
however ceilings could be lower. Elsewhere, weak, variable winds
and high humidity may create fog near sunrise. Probabilities
are too uncertain at the moment and were left out of the TAFS
for this synoptic forecast period. Cloud coverage is expected to
diminish going into tomorrow afternoon.

&&

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

&&

SHORT TERM...CG
LONG TERM...RV
AVIATION...RV

In the hours before

Special weather statement, May 9, 2:26 PM MDT, 17 minutes before
Special Weather Statement
National Weather Service Cheyenne WY
226 PM MDT Sat May 9 2026

WYZ104-109-092115-
Central Carbon County WY-Ferris/Seminoe/Shirley Mountains WY-
226 PM MDT Sat May 9 2026

...STRONG THUNDERSTORMS WILL IMPACT NORTH CENTRAL CARBON COUNTY
THROUGH 315 PM MDT...

At 226 PM MDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Split Rock to near Independence Rock.
Movement was southeast at 30 mph.

HAZARD...Wind gusts up to 50 mph and nickel size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor hail damage to vegetation is
         possible.

Locations impacted include...
Muddy Gap, Dome Rock, and Miracle Mile.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4243 10752 4244 10720 4243 10671 4226 10657
      4209 10737 4235 10753
TIME...MOT...LOC 2026Z 324DEG 26KT 4247 10749 4250 10719

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...50 MPH

Natoli

The office that day

Everything else NWS Cheyenne, WY issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 9, 2:26 PM MDTSpecial Weather StatementCYS49 min
May 9, 3:19 PM MDTSpecial Weather StatementCYS56 min
May 9, 3:21 PM MDTSpecial Weather StatementCYSCarbon54 min
May 9, 4:21 PM MDTSevere Thunderstorm WarningCYSAlbany, Carbon39 min
May 9, 4:27 PM MDTSpecial Weather StatementCYSLaramie48 min
May 9, 4:47 PM MDTSevere Thunderstorm WarningCYSLaramie43 min
May 9, 4:56 PM MDTSevere Thunderstorm WarningCYSLaramie34 min
May 9, 5:00 PM MDTSevere Thunderstorm WarningCYSAlbany, Laramie, Platte45 min
May 9, 5:39 PM MDTSpecial Weather StatementCYSLaramie36 min

Nearby

Severe Thunderstorm Warnings in Wyoming, 2026Every severe thunderstorm warning in 2026

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; radar from the NEXRAD Level II archive.