A strong thunderstorm developed west of Cheyenne during the afternoon of the 27th producing a lightning strike injuring an individual at Francis E. Warren Air Force Base.
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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.
A strong thunderstorm developed west of Cheyenne during the afternoon of the 27th producing a lightning strike injuring an individual at Francis E. Warren Air Force Base.
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 Jul 27, 4:52 PM MST, 2 hours 8 minutes earlier.
Area Forecast Discussion National Weather Service Cheyenne WY 552 PM MDT Thu Jul 27 2023 .UPDATE... Issued at 442 PM MDT Thu Jul 27 2023 Based on the latest radar trends, we are sending out a quick update to expand the showers and thunderstorms further east to cover the Chadron and Alliance area late this afternoon. Otherwise, current forecast looks to be on track. && .SHORT TERM...(This evening through Saturday) Issued at 255 PM MDT Thu Jul 27 2023 An active next few days are expected, including this afternoon where showers and thunderstorms will continue through the evening. Hi-Res guidance shows widely scattered showers and thunderstorms impacting most corners of the CWA. Main concern to keep an eye on with these storms are strong winds. Model soundings show very dry low-levels with the passage of a dryline. Current observations do show the dryline currently trekking eastward, so the inverted-V profiles are believable with over 1000 J/kg of DCAPE. Since severe gusts were seen with yesterday's storms with moister low-levels, then it is very plausible that storms today could produce 60 MPH wind gusts. Hi- Res shows storms tapering off by midnight tonight. On Friday, the upper-level ridge starts to retrograde back westward, allowing for drier conditions to persist west of the Laramie Range and for higher dewpoints to sneak back into the High Plains. A weak shortwave Friday afternoon will push a cool front into the northern counties of the CWA which may usher in even higher dewpoints. This extra lift and moisture will likely produce another round of storms Friday afternoon. Hi-Res shows much less precipitation coverage than the last few days, however, what few isolated storms pop up may be more intense than what has been seen the last few days. GFS soundings from the Nebraska panhandle show ~1000 J/kg of MUCAPE and pretty good shear of 30 to 40 kts. Wind will still be a primary threat with these storms as DCAPEs are still elevated, but large hail could also be possible with storms. As the upper-level ridge over the Four Corners region strengthens again to nearly a 600 decameter high on Saturday, the ridge axis will shift back westward, putting the CWA in more unsettled northwesterly flow. On top of this, a surface low sitting over the panhandle of Texas will help advect moist southeasterly flow into the CWA. The northwest flow aloft and southeast flow at the surface will create a greatly sheared environment east of the Laramie Range. This, combined with dewpoints potentially in the 60s, could lead to severe weather. GFS soundings in the Nebraska panhandle on Saturday show ample instability with greater than 1300 J/kg of MLCAPE, 1800 J/kg of MUCAPE, inverted-V profiles, and ~45 kts of shear. These ingredients make all severe weather hazards possible. .LONG TERM...(Sunday through Thursday) Issued at 230 PM MDT Thu Jul 27 2023 A significant (596-598 dam) H5 ridge is expected to translate east from the Four Corners into the southern and central plains late in the weekend through the early to mid portions of next week. Active west-southwest flow aloft will persist across southeast WY and the western NE Panhandle along the western & northern periphery of the ridge. Numerous mid and upper-level disturbances will pivot around the expansive ridge, along with plentiful moisture availability w/ the development of a more favorable monsoonal pattern. As such, do expect daily chances for showers and thunderstorms for much of the area although the timing & intensity of individual waves cannot be discerned at this time. Hot conditions are likely for a large part of the area early in the forecast period (Sunday/Monday) with day- time highs likely in the 90s as the center of the ridge axis makes its closest approach. However, a dramatic increase in mid and high level moisture associated with the monsoon, as well as much cooler thermal profiles, should support a substantial cooling trend later in the forecast period around Wed/Thu. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 535 PM MDT Thu Jul 27 2023 The main concern with this TAF issuance is when the thunderstorms will move out of the picture this evening. The latest radar loop was showing numerous outflow boundaries from various thunderstorm complexes affecting areas from Chadron southwest through Scottsbluff into Cheyenne and Laramie. Latest HRRR guidance is showing this convection lingering through much of the evening, but with these storms working over the environment things may conclude a little sooner. The only fly in the ointment is more convection continues to develop over the Sierra Madre mountain range. If this persist, this may allow for things to recover and allow for convection to last through the night. Otherwise, thunderstorm coverage should be a little less tomorrow afternoon. && .FIRE WEATHER... Issued at 255 PM MDT Thu Jul 27 2023 Main fire weather concerns this afternoon will be scattered showers and thunderstorms producing gusty winds and frequent lightning. Cannot rule out erratic gusts to 60 MPH with any stronger storms. Slightly cooler temperatures are expected over the next few days which will also help keep minimum RHs above 20 percent for most locations. Conditions will remain fairly dry in Carbon County through the weekend. Expect near daily chances for showers and thunderstorms Friday through Sunday. A push of monsoon moisture will come Monday through Wednesday which will also diminish fire weather concerns next week. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && UPDATE...REC SHORT TERM...SF LONG TERM...CLH AVIATION...REC FIRE WEATHER...SF
Hazardous Weather Outlook National Weather Service Cheyenne WY 219 PM MDT Thu Jul 27 2023 NEZ002-003-019>021-054-055-095-096-WYZ101>119-282030- Dawes County-Box Butte County-Scotts Bluff County-Banner County- Morrill County-Kimball County-Cheyenne County- Northern Sioux County-Southern Sioux County- Converse County Lower Elevations-Niobrara County- North Laramie Range-Ferris/Seminoe/Shirley Mountains- Shirley Basin-Central Laramie Range and Southwest Platte County- East Platte County-Goshen County-Central Carbon County- North Snowy Range Foothills-Southwest Carbon County- Sierra Madre Range-Upper North Platte River Basin-Snowy Range- Laramie Valley-South Laramie Range-South Laramie Range Foothills- Central Laramie County-East Laramie County- 219 PM MDT Thu Jul 27 2023 This hazardous weather outlook is for portions of panhandle Nebraska...east central Wyoming...south central Wyoming and southeast Wyoming. .DAY ONE...THIS AFTERNOON AND TONIGHT Scattered showers and thunderstorms are expected across the area this afternoon and evening. Storms will have the potential to produce gusty winds. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY Daily chances for afternoon and evening thunderstorms will continue for the week ahead. Strong to severe storms could be possible on Saturday. Confidence is increasing that a significant push of monsoon moisture will arrive early next week, bringing more widespread thunderstorms and rainfall. .Spotter information statement... Spotters are encouraged to report severe weather to the NWS.
Special Weather Statement
National Weather Service Cheyenne WY
419 PM MDT Thu Jul 27 2023
WYZ117-118-272245-
Central Laramie County WY-South Laramie Range Foothills WY-
419 PM MDT Thu Jul 27 2023
...A strong thunderstorm will impact portions of central Laramie
County through 445 PM MDT...
At 418 PM MDT, Doppler radar was tracking a strong thunderstorm near
Ranchettes, or 9 miles north of Cheyenne, moving east at 15 mph.
HAZARD...Outflow winds in excess of 40 mph and pea size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Cheyenne, North Cheyenne, Warren Af Base, Ranchettes, Warren AFB and
Frontier Park.
This includes the following highways...
Interstate 25 in Wyoming between mile markers 11 and 28.
Interstate 80 in Wyoming between mile markers 366 and 376.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 4125 10495 4132 10494 4140 10487 4142 10470
4137 10451 4124 10448 4113 10455 4112 10471
4115 10488
TIME...MOT...LOC 2218Z 275DEG 12KT 4129 10477
MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH
CharnickSpecial Weather Statement
National Weather Service Cheyenne WY
447 PM MDT Thu Jul 27 2023
NEZ019-WYZ106>108-115>119-272315-
Scotts Bluff NE-East Platte County WY-South Laramie Range WY-
Central Laramie Range and Southwest Platte County WY-
Goshen County WY-Central Laramie County WY-
South Laramie Range Foothills WY-Laramie Valley WY-
East Laramie County WY-
447 PM MDT Thu Jul 27 2023
...Strong outflow wind gusts will impact portions of western Scotts
Bluff, east central Albany, southern Goshen, northern Laramie and
southern Platte Counties through 515 PM MDT...
At 446 PM MDT, Doppler radar was tracking strong outflow wind gusts
along a line extending from 6 miles southwest of Lingle to 7 miles
east of Chugwater to 16 miles south of Slater to 17 miles north of
Whitaker to near Iron Mountain to near Baldy Peak. Movement was
southeast at 40 mph.
HAZARD...Wind gusts of 50 to 55 mph.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
Locations impacted include...
Chugwater, Yoder, Federal, Hawk Springs, North Crow Campground, Iron
Mountain, Baldy Peak, Hawk Springs Campground, Whitaker, Hawk Springs
Recreation Area, Horse Creek, Meriden Rest Area, Veteran, Huntley and
Slater.
This includes Interstate 25 in Wyoming between mile markers 19 and
59.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
These outflow winds may intensify, so be certain to monitor local
radio stations and available television stations for additional
information and possible warnings from the National Weather Service.
&&
LAT...LON 4169 10413 4149 10433 4135 10458 4127 10477
4121 10503 4117 10533 4159 10564 4164 10539
4170 10515 4176 10497 4181 10481 4196 10464
4216 10451 4184 10401
TIME...MOT...LOC 2246Z 328DEG 33KT 4207 10442 4173 10469 4165 10479
4165 10498 4169 10512 4155 10531 4152 10550
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...55 MPH
CharnickSpecial Weather Statement
National Weather Service Cheyenne WY
458 PM MDT Thu Jul 27 2023
WYZ115>117-272330-
South Laramie Range WY-South Laramie Range Foothills WY-
Laramie Valley WY-
458 PM MDT Thu Jul 27 2023
...A strong thunderstorm will impact portions of southeastern Albany
and far southwestern Laramie Counties through 530 PM MDT...
At 458 PM MDT, Doppler radar was tracking a strong thunderstorm over
Tie Siding, or 15 miles south of Laramie, moving east at 35 mph.
HAZARD...Wind gusts up to 50 mph and pea size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
North Crow Campground, Granite Springs Reservoir, Vedauwoo, Tie
Siding, Granite Springs Campground, Crystal Lake Reservoir, Pumpkin
Vine, Crystal Lake Campground, Vedauwoo Campground, Buford and The
Buttes.
This includes Interstate 80 in Wyoming between mile markers 327 and
348.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 4113 10564 4126 10523 4116 10506 4100 10507
4100 10559
TIME...MOT...LOC 2258Z 255DEG 32KT 4109 10550
MAX HAIL SIZE...0.25 IN
MAX WIND GUST...50 MPH
CharnickSpecial Weather Statement
National Weather Service Cheyenne WY
520 PM MDT Thu Jul 27 2023
WYZ108-116>119-280000-
South Laramie Range WY-Goshen County WY-Central Laramie County WY-
South Laramie Range Foothills WY-East Laramie County WY-
520 PM MDT Thu Jul 27 2023
...Strong thunderstorms will impact portions of northwestern Kimball,
southwestern Banner, southeastern Albany, southwestern Goshen and
Laramie Counties through 600 PM MDT...
At 519 PM MDT, Doppler radar was tracking strong thunderstorms along
a line extending from 7 miles southwest of Hawk Springs Recreation
Area to 6 miles west of Gun Barrel to 9 miles southeast of Whitaker
to near Federal to near Horse Creek to near Yellow Pine Campground.
Movement was southeast at 35 mph.
HAZARD...Wind gusts of 50 to 55 mph.
SOURCE...Radar indicated. Highway weather stations recorded wind
gusts 50-55 mph along I-25 south of Chugwater.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
Locations impacted include...
Cheyenne, Pine Bluffs, Burns, Albin, South Greeley, Federal, Vedauwoo
Campground, North Crow Campground, Ranchettes, Granite Springs
Campground, Warren AFB, Frontier Park, North Cheyenne, Horse Creek,
Gun Barrel, Hillsdale, Crystal Lake Reservoir, Crystal Lake
Campground, Buford and Granite Springs Reservoir.
This includes the following highways...
Interstate 25 in Wyoming between mile markers 1 and 39.
Interstate 80 in Wyoming between mile markers 331 and 402.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 4100 10533 4144 10547 4144 10528 4157 10481
4160 10458 4175 10432 4149 10405 4100 10405
TIME...MOT...LOC 2319Z 330DEG 32KT 4166 10433 4146 10448 4135 10470
4133 10502 4133 10517 4129 10541
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...55 MPH
CharnickSpecial Weather Statement
National Weather Service Cheyenne WY
557 PM MDT Thu Jul 27 2023
WYZ117>119-280015-
Central Laramie County WY-South Laramie Range Foothills WY-
East Laramie County WY-
557 PM MDT Thu Jul 27 2023
...Strong outflow winds from thunderstorms will impact portions of
southwestern Kimball and southeastern Laramie Counties through 615
PM MDT...
At 556 PM MDT, Doppler radar was tracking strong outflow wind from
thunderstorms along a line extending from 9 miles northeast of Burns
to near Carpenter to 9 miles southeast of Cheyenne to near South
Greeley. Movement was southeast at 40 mph.
HAZARD...Winds in excess of 40 mph.
SOURCE...Radar indicated. 40-50 mph wind gusts have been reported
across Cheyenne.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
Locations impacted include...
Cheyenne, Pine Bluffs, Burns, South Greeley, Hillsdale, Warren AFB,
Frontier Park, Warren Af Base, Carpenter, Ranchettes, Fox
Farm-College and South Greeley High.
This includes the following highways...
Interstate 25 in Wyoming between mile markers 5 and 13.
Interstate 80 in Wyoming between mile markers 356 and 402.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 4118 10498 4118 10473 4124 10449 4137 10426
4127 10405 4100 10405 4100 10484
TIME...MOT...LOC 2356Z 313DEG 37KT 4127 10422 4108 10443 4104 10467
4107 10486
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH
CharnickSpecial Weather Statement
National Weather Service Cheyenne WY
602 PM MDT Thu Jul 27 2023
WYZ104-109-110-280030-
North Snowy Range Foothills WY-Central Carbon County WY-
Ferris/Seminoe/Shirley Mountains WY-
602 PM MDT Thu Jul 27 2023
...Strong outflow winds will impact portions of central Carbon
County through 630 PM MDT...
At 601 PM MDT, Doppler radar was tracking strong outflow winds over
Sinclair, or near Rawlins, moving northeast at 40 mph.
HAZARD...Wind gusts of 50 to 55 mph.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
Locations impacted include...
Rawlins, Sinclair, Seminoe Campground, Seminoe Dam and Separation
Lake.
This includes Interstate 80 in Wyoming between mile markers 204 and
247.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 4190 10750 4198 10750 4227 10704 4206 10671
4170 10658 4168 10733 4187 10752
TIME...MOT...LOC 0001Z 239DEG 36KT 4181 10711
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...55 MPH
CharnickThe Cheyenne radar (KCYS), 4 km away, was scanning. The volume nearest the first event began at 02:01 UTC.
1 lightning. Local standard time, as filed.
An active-duty member of the U.S. Air Force was struck by lightning while outdoors on the grounds at Francis E. Warren Air Force Base. The lightning strike hit a military vehicle while the individual was in contact with the vehicle frame.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2023Every state in 2023This day in weather historyWarnings in Wyoming, July 2023
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: 1106057.