Alert archive / Colorado / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 4, NWS Denver/Boulder, CO

May 9, 2026Logan County, Morgan County, Weld County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at May 9, 2026, 5:04 PM MDT for Logan County, Morgan County, Weld County, Colorado. It was in force for 41 min. 2 reports 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, 5:04 PM MDT (23:04 UTC)
Expired
May 9, 2026, 5:45 PM MDT
In force
41 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Damage threat
Considerable
Hail
1.5 in
Wind
70.0 mph

Counties Logan County, CO, Morgan County, CO, Weld County, CO

The radar

The Cheyenne radar (KCYS), 68 km from the middle of the area, began a volume at 23:03 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, 5:46 PM MDTTSTM WND GST 681 Nnw Briggsdale, COMesonet station CO043 Briggsdale.
May 9, 5:46 PM MDTTSTM WND GST 681 Nnw Briggsdale, COMesonet station CO043 Briggsdale.

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

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm 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 text

As transmitted.

763 
WUUS55 KBOU 092304
SVRBOU
COC075-087-123-092345-
/O.NEW.KBOU.SV.W.0004.260509T2304Z-260509T2345Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Denver CO
504 PM MDT Sat May 9 2026

The National Weather Service in Denver has issued a

* Severe Thunderstorm Warning for...
  West Central Logan County in northeastern Colorado...
  North Central Morgan County in northeastern Colorado...
  Northeastern Weld County in northeastern Colorado...

* Until 545 PM MDT.

* At 504 PM MDT, a severe thunderstorm was located near Grover, or 43
  miles northeast of Greeley, moving southeast at 40 mph.

  HAZARD...70 mph wind gusts and ping pong ball size hail.

  SOURCE...Radar indicated.

  IMPACT...People and animals outdoors will be injured. Expect hail
           damage to roofs, siding, windows, and vehicles. Expect
           considerable tree damage. Wind damage is also likely to
           mobile homes, roofs, and outbuildings.

* Locations impacted include...
  Grover, Keota, Pawnee Buttes, New Raymer, Briggsdale, Stoneham,
  Hereford, Pawnee Pass, Logan Corners and Buckingham.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Anyone outdoors should move to shelter inside a well-built structure
and stay away from windows. This storm is capable of producing
widespread damaging winds and large hail.

&&

LAT...LON 4100 10472 4100 10405 4065 10329 4042 10380
      4062 10437
TIME...MOT...LOC 2303Z 296DEG 57KT 4090 10422

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.50 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

09
1 follow-up statement
979 
WWUS55 KBOU 092338
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
538 PM MDT Sat May 9 2026

COC075-087-123-092345-
/O.CON.KBOU.SV.W.0004.000000T0000Z-260509T2345Z/
Logan CO-Morgan CO-Weld CO-
538 PM MDT Sat May 9 2026

...SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 545 PM MDT FOR
WEST CENTRAL LOGAN, NORTH CENTRAL MORGAN AND NORTHEASTERN WELD
COUNTIES...

At 538 PM MDT, a severe thunderstorm was located 4 miles west of
Pawnee Pass, or 19 miles west of Sterling, moving southeast at 65
mph.

HAZARD...70 mph wind gusts and ping pong ball size hail.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect hail
         damage to roofs, siding, windows, and vehicles. Expect
         considerable tree damage. Wind damage is also likely to
         mobile homes, roofs, and outbuildings.

Locations impacted include...
  Grover, New Raymer, Pawnee Buttes, Keota, Stoneham, Pawnee Pass,
  Briggsdale, Logan Corners and Buckingham.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Anyone outdoors should move to shelter inside a well-built structure
and stay away from windows. This storm is capable of producing
widespread damaging winds and large hail.

&&

LAT...LON 4083 10428 4100 10410 4100 10405 4065 10329
      4042 10380 4062 10437
TIME...MOT...LOC 2304Z 296DEG 57KT 4089 10419

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.50 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

09

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 Denver/Boulder, CO wrote its last area forecast discussion before this severe thunderstorm warning went out at May 9, 1:35 PM MDT, 3 hours 29 minutes earlier. Its key messages:

  • Scattered afternoon and evening showers/thunderstorms likely for the northeastern plains this afternoon and evening.
  • Summerlike warmth and drier weather next week, with highs in the 80s for the lower elevations.
Area forecast discussion, May 9, 1:35 PM MDT, 3 hours 29 minutes before
Area Forecast Discussion
National Weather Service Denver/Boulder CO
135 PM MDT Sat May 9 2026

.KEY MESSAGES...

- Scattered afternoon and evening showers/thunderstorms likely for
  the northeastern plains this afternoon and evening.

- Summerlike warmth and drier weather next week, with highs in the
  80s for the lower elevations.

&&

.DISCUSSION /Through Saturday/...
Issued at 134 PM MDT Sat May 9 2026

Latest satellite imagery shows the shortwave of interest for today
moving through Montana and Wyoming with cumulus clouds developing
across eastern WY. Today will be a bit warmer than yesterday with
highs generally in the mid 70s across the plains. A few showers and
thunderstorms are expected for this afternoon, especially for the
northeast plains, starting around 3pm. These showers/thunderstorms
will be associated with the aforementioned mid-level shortwave
embedded in the northwest flow aloft as it moves across NE CO. DCAPE
values are expected to be between 1000 and 1300 J/kg this afternoon,
meaning any stronger storms could produce gusty outflow winds. A low
risk for small hail also exists for the northeast plains given
strong shear and modest instability in place as noted in model
soundings. These areas are in a marginal (1/5) risk for severe
storms.

The precipitation chances will transition southward throughout the
evening as a cold front moves through the forecast area, but storms
should decrease in coverage and intensity with the loss of daytime
heating as they approach the Denver metro. The highest chances for
showers in the Denver metro - between 30 and 40 percent - will be
between 10pm and 2am tonight. Wind gusts could briefly reach 35 to
45 mph as the cold front passes through. Despite tonight's cold
front, warm air advection should allow high temperatures on Sunday
across the plains to return to the upper 60s and low 70s.

A strong ridge of high pressure is still on track to setup near or
over our forecast area for most of next week leading to well above-
average temperatures through the rest of the forecast period. Highs
for the work week will be in the mid to upper 80s for the plains
with the northeast plains even having the possibility of reaching
the low 90s during the middle of week. The hottest temperatures of
the week are expected on Wednesday when the ridge is at its
strongest. As noted in the previous discussion, the record high for
Denver is 90 degrees F and we have an outside chance of tying or
breaking that record. Precipitation chances could increase again by
the end of the week, but there is disagreement among the global
models on the evolution of a potential shortwave pivoting into
Colorado. Elevated to critical fire weather conditions are possible
through the week given the dry conditions, but there is quite a bit
of uncertainty with how much wind there will be on any given
afternoon.

&&

.AVIATION /18Z TAFS through 18Z Sunday/...
Issued at 1207 PM MDT Sat May 9 2026

Models are generally showing NW to NNE wind directions at DIA
through the afternoon. Gusts to 25 knot look to be as strong as
they will get. The advertised cold front looks to arrive at DIA
around 00Z. Wind gusts behind the cold front could reach 35 knots.
I will leave the TS out for now with the best instability well
north of DIA. Once the front passes, the precipitation will be
more Stratiform in nature.  So far as ceilings go, will get them
down into the BKN-OVC010-025 range after 03z, with a TEMPO group
down to BKN005 along with -RA. Ceiling will improve by 12Z-13Z.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
None.

&&

DISCUSSION...MV
AVIATION...66

In the hours before

Special weather statement, May 9, 2:32 PM MDT, 2 hours 32 minutes before
Special Weather Statement
National Weather Service Denver CO
232 PM MDT Sat May 9 2026

COZ048-092115-
Logan County CO-
232 PM MDT Sat May 9 2026

...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN LOGAN COUNTY UNTIL
315 PM MDT...

At 232 PM MDT, Doppler radar was tracking a strong thunderstorm 4
miles south of Logan Corners, or 9 miles southwest of Sterling,
moving southeast at 15 mph.

HAZARD...Nickel size hail.

SOURCE...Radar indicated.

IMPACT...Minor damage to outdoor objects is possible.

Locations impacted include...
  Merino, Atwood and Logan Corners.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the weather situation closely and be alert for threatening
weather conditions.

&&

LAT...LON 4061 10343 4064 10334 4057 10305 4044 10304
      4044 10339
TIME...MOT...LOC 2032Z 330DEG 13KT 4057 10334

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...<30 MPH

09

The office that day

Everything else NWS Denver/Boulder, CO issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 9, 2:32 PM MDTSpecial Weather StatementBOULogan43 min
May 9, 5:10 PM MDTSevere Thunderstorm WarningBOULogan, Weld50 min
May 9, 5:45 PM MDTSevere Thunderstorm WarningBOULogan, Morgan, Weld30 min

Nearby

Severe Thunderstorm Warnings in Colorado, 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.