Alert archive / Wyoming / Severe Thunderstorm Warnings in 2026
Severe Thunderstorm Warning 2, NWS Cheyenne, WY
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
| Time | Report | Where | Remark |
|---|---|---|---|
| May 9, 2:45 PM MDT | HAIL 1 | 3 Ne Muddy Gap, WY | Lingering 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
$$
Natoli2 follow-up statements
732
WWUS55 KCYS 092104
SVSCYS
Severe Weather Statement
National Weather Service Cheyenne WY
304 PM MDT Sat May 9 2026
WYC007-092130-
/O.CON.KCYS.SV.W.0002.000000T0000Z-260509T2130Z/
Carbon WY-
304 PM MDT Sat May 9 2026
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 330 PM MDT
FOR NORTH CENTRAL CARBON COUNTY...
At 304 PM MDT, a severe thunderstorm was located 8 miles south of
Devil's Gate, or 34 miles east of Jeffrey City, moving southeast at
30 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage to
roofs, siding, and trees.
Locations impacted include...
Dome Rock.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4243 10717 4243 10678 4235 10663 4213 10718
4229 10733
TIME...MOT...LOC 2104Z 299DEG 25KT 4232 10719
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Natoli382
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
$$
NatoliWhat 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
NatoliThe office that day
Everything else NWS Cheyenne, WY issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 9, 2:26 PM MDT | Special Weather Statement | CYS | 49 min | |
| May 9, 3:19 PM MDT | Special Weather Statement | CYS | 56 min | |
| May 9, 3:21 PM MDT | Special Weather Statement | CYS | Carbon | 54 min |
| May 9, 4:21 PM MDT | Severe Thunderstorm Warning | CYS | Albany, Carbon | 39 min |
| May 9, 4:27 PM MDT | Special Weather Statement | CYS | Laramie | 48 min |
| May 9, 4:47 PM MDT | Severe Thunderstorm Warning | CYS | Laramie | 43 min |
| May 9, 4:56 PM MDT | Severe Thunderstorm Warning | CYS | Laramie | 34 min |
| May 9, 5:00 PM MDT | Severe Thunderstorm Warning | CYS | Albany, Laramie, Platte | 45 min |
| May 9, 5:39 PM MDT | Special Weather Statement | CYS | Laramie | 36 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.