Several severe storms moved across the region, primarily following the Interstate 80 corridor through Wyoming and into western Nebraska.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS CYS wrote it up.
Several severe storms moved across the region, primarily following the Interstate 80 corridor through Wyoming and into western Nebraska.
The local office's own words before the first event, 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 the first event at May 9, 1:08 PM MST, 37 minutes earlier. Its key messages:
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
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 Riverton/Lander radar (KRIW), 114 km away, was scanning. The volume nearest the first event began at 20:44 UTC.
3 hail, 1 thunderstorm wind. Local standard time, as filed.
Lingering hail of 1 inch in diameter was reported by a former NWS meteorologist. The time of the report was estimated based on radar imagery.
A Trained spotter reported ping-ping ball sized hail 1 mile north of Pine Bluffs.
A former NWS employee observaed quarter-sized hail around 5 miles northeast of Rock River.
A CWOP station recorded a 64 mph wind gust 5 miles east-northeast of Cheyenne at 5 PM.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2026Every state in 2026This day in weather historyWarnings in Wyoming, May 2026
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1330877, 1330879, 1330880, 1330883.