Alert archive / Colorado / Tornado Warnings in 2026
Tornado Warning 5, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this tornado warning at May 21, 2026, 6:05 PM MDT for Logan County, Colorado. It was in force for 28 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- May 21, 2026, 6:05 PM MDT (00:05 UTC)
- Expired
- May 21, 2026, 6:33 PM MDT
- In force
- 28 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Storm-based polygon
- Tornado
- Radar indicated
- Hail
- 1.0 in
County Logan County, CO
The radar
The Cheyenne radar (KCYS), 130 km from the middle of the area, began a volume at 00:09 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.
Did it verify
Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this tornado warning while it was in force. That is not proof nothing happened: reports are thin where few people live.
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 watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| May 21, 2:55 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
The nearest sounding before it
N. Platte/Lee Bi, NE (KLBF), launched 00:00Z, 0.1 hours before the alert went out and 244 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1093 m above ground
- 0-6 km bulk shear
- 48 kt
- 0-1 km storm-relative helicity
- 14 m²/s²
- 0-3 km storm-relative helicity
- 149 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
908
WFUS55 KBOU 220005
TORBOU
COC075-220045-
/O.NEW.KBOU.TO.W.0005.260522T0005Z-260522T0045Z/
BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Denver CO
605 PM MDT Thu May 21 2026
The National Weather Service in Denver has issued a
* Tornado Warning for...
West Central Logan County in northeastern Colorado...
* Until 645 PM MDT.
* At 605 PM MDT, a severe thunderstorm capable of producing a tornado
was located over Pawnee Pass, or 13 miles west of Sterling, moving
east at 15 mph.
HAZARD...Tornado and quarter size hail.
SOURCE...Radar indicated rotation.
IMPACT...Flying debris will be dangerous to those caught without
shelter. Mobile homes will be damaged or destroyed. Damage
to roofs, windows and vehicles will occur. Tree damage is
likely.
* Locations impacted include...
Logan Corners and Pawnee Pass.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Move to an interior room on the lowest floor of a well-built building
away from windows. If you are outdoors, in a mobile home, or in a
vehicle, move to the closest substantial shelter and protect yourself
from flying debris.
&&
LAT...LON 4057 10354 4072 10353 4073 10325 4057 10325
TIME...MOT...LOC 0005Z 266DEG 13KT 4062 10345
TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
$$
633 follow-up statements
888
WWUS55 KBOU 220012
SVSBOU
Severe Weather Statement
National Weather Service Denver CO
612 PM MDT Thu May 21 2026
COC075-220045-
/O.CON.KBOU.TO.W.0005.000000T0000Z-260522T0045Z/
Logan CO-
612 PM MDT Thu May 21 2026
...TORNADO WARNING REMAINS IN EFFECT UNTIL 645 PM MDT FOR WEST
CENTRAL LOGAN COUNTY...
At 612 PM MDT, a severe thunderstorm capable of producing a tornado
was located near Logan Corners, or 11 miles west of Sterling, moving
east at 15 mph.
HAZARD...Tornado and quarter size hail.
SOURCE...Radar indicated rotation.
IMPACT...Flying debris will be dangerous to those caught without
shelter. Mobile homes will be damaged or destroyed. Damage
to roofs, windows and vehicles will occur. Tree damage is
likely.
Locations impacted include...
Logan Corners and Pawnee Pass.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Move to an interior room on the lowest floor of a well-built building
away from windows. If you are outdoors, in a mobile home, or in a
vehicle, move to the closest substantial shelter and protect yourself
from flying debris.
&&
LAT...LON 4057 10354 4069 10352 4069 10325 4057 10325
TIME...MOT...LOC 0005Z 279DEG 13KT 4062 10345
TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
$$
63889
WWUS55 KBOU 220027
SVSBOU
Severe Weather Statement
National Weather Service Denver CO
627 PM MDT Thu May 21 2026
COC075-220045-
/O.CON.KBOU.TO.W.0005.000000T0000Z-260522T0045Z/
Logan CO-
627 PM MDT Thu May 21 2026
...TORNADO WARNING REMAINS IN EFFECT UNTIL 645 PM MDT FOR WEST
CENTRAL LOGAN COUNTY...
At 627 PM MDT, a severe thunderstorm capable of producing a tornado
was located over Logan Corners, or 8 miles west of Sterling, moving
east at 15 mph.
HAZARD...Tornado and quarter size hail.
SOURCE...Radar indicated rotation.
IMPACT...Flying debris will be dangerous to those caught without
shelter. Mobile homes will be damaged or destroyed. Damage
to roofs, windows and vehicles will occur. Tree damage is
likely.
Locations impacted include...
Logan Corners and Pawnee Pass.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Move to an interior room on the lowest floor of a well-built building
away from windows. If you are outdoors, in a mobile home, or in a
vehicle, move to the closest substantial shelter and protect yourself
from flying debris.
&&
LAT...LON 4057 10354 4069 10352 4069 10325 4057 10325
TIME...MOT...LOC 0012Z 279DEG 13KT 4062 10341
TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
$$
63170 WWUS55 KBOU 220033 SVSBOU Severe Weather Statement National Weather Service Denver CO 633 PM MDT Thu May 21 2026 COC075-220043- /O.CAN.KBOU.TO.W.0005.000000T0000Z-260522T0045Z/ Logan CO- 633 PM MDT Thu May 21 2026 ...TORNADO WARNING IS CANCELLED FOR WEST CENTRAL LOGAN COUNTY... The storm which prompted the warning has weakened below severe limits, and no longer appears capable of producing a tornado. Therefore, the warning has been cancelled. However, small hail, gusty winds, and heavy rain are still possible with this thunderstorm. A Severe Thunderstorm Watch remains in effect until 1000 PM MDT Thursday for a portion of northeast Colorado. && LAT...LON 4057 10354 4069 10352 4069 10325 4057 10325 TIME...MOT...LOC 0027Z 279DEG 13KT 4061 10334 $$ 63
What forecasters said that day
The local office's own words before this tornado warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Denver/Boulder, CO wrote its last area forecast discussion before this tornado warning went out at May 21, 1:03 PM MDT, 5 hours 2 minutes earlier. Its key messages:
- Strong to locally severe thunderstorms expected late this afternoon through this evening in the plains, mainly east of I-25.
- Elsewhere, weaker isolated to scattered showers/t-storms can be expected with and behind an early evening cold front.
- Lingering showers into Friday, mainly south of I-70. Remaining cool.
- Warmer and drier this weekend, with isolated showers possible Saturday afternoon.
- Remaining mild next week but with a return of potential afternoon showers and thunderstorms.
Area forecast discussion, May 21, 1:03 PM MDT, 5 hours 2 minutes before
Area Forecast Discussion National Weather Service Denver/Boulder CO 103 PM MDT Thu May 21 2026 .KEY MESSAGES... - Strong to locally severe thunderstorms expected late this afternoon through this evening in the plains, mainly east of I-25. - Elsewhere, weaker isolated to scattered showers/t-storms can be expected with and behind an early evening cold front. - Lingering showers into Friday, mainly south of I-70. Remaining cool. - Warmer and drier this weekend, with isolated showers possible Saturday afternoon. - Remaining mild next week but with a return of potential afternoon showers and thunderstorms. && .DISCUSSION /Through Thursday/... Issued at 1218 PM MDT Thu May 21 2026 Ingredients are coming together as anticipated to provide for an active afternoon and evening for our plains in particular. Cloud cover has reduced considerably across the urban corridor and will continue to thin over the plains in the coming hours, helping to destabilize the environment. Surface moisture remains a potential limiting factor for portions of the I-25 corridor with dewpoints falling below 40F this afternoon, capping MLCAPE below ~400 J/Kg at most. Thunderstorms remain on track to develop mid-afternoon, mainly after 3-4pm, favoring initiation east of I-25 and off the Palmer Divide, where a DCVZ will become increasingly pronounced as the afternoon progresses. These will spread into a much more unstable environment in the eastern plains where an axis of more favorable low-level moisture (dewpoints exceeding 50F) is present, roughly to the east of the north/south line from Fort Morgan to Agate. Ample bulk shear of 45-60 kts should support sustained growth of a few supercells into Lincoln/Washington/Logan Counties late afternoon into early evening, capable of producing large hail to ~2" in diameter with the strongest storms, as well as isolated strong wind gusts and/or a weak tornado. For the urban corridor, the highest chances for showers and thunderstorms will arrive in the evening as a cold front descends south between 5-8pm, although any convection should be sub-severe. However, the front will provide an opportunity for redevelopment of strong thunderstorms into the plains, reinforced by a secondary frontal surge mid/late evening associated with the upper level trough axis. With time, convection should become less discrete in nature, favoring some upscale growth into a broader area of thunderstorms across the northeast plains, exiting into KS/NE roughly after midnight. Post-frontal winds will remain robust overnight across our plains with gusts 25-40 mph. This evening's front will usher in cooler temperatures for Friday, along with a more stable airmass that will significantly reduce precipitation potential for most areas. Nonetheless, some pockets of marginal instability could remain south of I-70, and upslope flow combined with the passage of another (weaker) shortwave aloft will promote some showers and potentially a few weak thunderstorms in the late afternoon and evening, focused across the Palmer Divide. We'll trend noticeably warmer Saturday into Sunday, with the latter seeing highs climb into the lower 80's for the plains and urban corridor. Some lingering mid-level moisture and yet another weak shortwave may support isolated and weak high-based convection on Saturday, although most will stay dry, and that will certainly be the case on Sunday as higher pressure settles in. A more unsettled pattern looks to return as early as Monday with renewed potential for diurnal showers and thunderstorms through much of the week. && .AVIATION /18Z TAFS through 18Z Friday/... Issued at 1151 AM MDT Thu May 21 2026 VFR conditions expected through the TAF period. Winds are currently light and VRB at all TAF sites and will continue for the next hour or two. By 20Z, winds should become more easterly (easterly to southeasterly and DEN) around 10-15 kts. Precipitation chances increases at this time, however convection should be isolated-to-scattered through 00Z and may not impact the airports besides gusty outflows. For this reason, have decided to keep the PROB30 for all terminals. Between 00Z and 05Z convection should increase with the arrival of the cold front, however the bulk of the precipitation looks to stay east of the airports. Have decided to keep the PROB30 in the TAF instead of TEMPO due to this uncertainty. However, gusty VRB outflow winds are still possible. With the arrival of the cold front (around 01Z/02Z), expect northerly winds gusting up to 30 kts, before gradually weakening and turning more easterly by 05Z and through the morning. There is a low chance (<30% chance) that ceilings could drop down to MVFR conditions (between 2500 and 3000 ft) behind that front. However, expect lifting between 05Z-08Z. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && DISCUSSION...BRQ AVIATION...MAI
In the hours before
Local storm report, May 21, 5:11 PM MDT, 54 minutes before
Preliminary Local Storm Report
National Weather Service Denver CO
511 PM MDT Thu May 21 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0450 PM Hail 5 S Last Chance 39.65N 103.59W
05/21/2026 E1.00 Inch Washington CO Storm Chaser
Report from mPING: Quarter (1.00 in.).
&&Local storm report, May 21, 5:19 PM MDT, 46 minutes before
Preliminary Local Storm Report
National Weather Service Denver CO
519 PM MDT Thu May 21 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0506 PM Hail 5 SSE Last Chance 39.67N 103.53W
05/21/2026 M2.50 Inch Washington CO Trained Spotter
&&Local storm report, May 21, 5:23 PM MDT, 42 minutes before
Preliminary Local Storm Report
National Weather Service Denver CO
523 PM MDT Thu May 21 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0519 PM Hail 6 S Lindon 39.64N 103.41W
05/21/2026 M2.50 Inch Washington CO Storm Chaser
Report from mPING: Tennis Ball (2.50 in.).
&&Local storm report, May 21, 5:46 PM MDT, 19 minutes before
Preliminary Local Storm Report
National Weather Service Denver CO
546 PM MDT Thu May 21 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0535 PM Tornado 3 WNW Thurman 39.61N 103.27W
05/21/2026 Washington CO Trained Spotter
Brief ground circulation. Report via
NWSChat.
&&Local storm report, May 21, 5:48 PM MDT, 17 minutes before
Preliminary Local Storm Report
National Weather Service Denver CO
548 PM MDT Thu May 21 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0544 PM Hail 2 WNW Thurman 39.61N 103.24W
05/21/2026 M2.75 Inch Washington CO Trained Spotter
&&Local storm report, May 21, 5:56 PM MDT, 9 minutes before
Preliminary Local Storm Report
National Weather Service Denver CO
556 PM MDT Thu May 21 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0547 PM Hail 1 S Thurman 39.58N 103.22W
05/21/2026 E3.00 Inch Washington CO Trained Spotter
Report from mPING: Tea Cup (3.00 in.).
&&The office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 21, 6:25 PM MDT | Severe Thunderstorm Warning | BOU | Washington | 35 min |
| May 21, 6:30 PM MDT | Severe Thunderstorm Warning | BOU | Washington | 30 min |
| May 21, 6:51 PM MDT | Flash Flood Warning | BOU | Washington | 6 hr |
| May 21, 7:01 PM MDT | Severe Thunderstorm Warning | BOU | Washington | 18 min |
| May 21, 7:09 PM MDT | Severe Thunderstorm Warning | BOU | Adams, Arapahoe, Washington | 36 min |
| May 21, 7:26 PM MDT | Special Weather Statement | BOU | Elbert | 49 min |
| May 21, 7:57 PM MDT | Special Weather Statement | BOU | Lincoln | 48 min |
| May 21, 8:39 PM MDT | Severe Thunderstorm Warning | BOU | Lincoln | 36 min |
Nearby
Tornado Warnings in Colorado, 2026Every tornado warning in 2026Tornadoes 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.