Alert archive / Colorado / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 7, NWS Denver/Boulder, CO

May 9, 2026Washington County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at May 9, 2026, 7:20 PM MDT for Washington County, Colorado. It was in force for 40 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 9, 2026, 7:20 PM MDT (01:20 UTC)
Expired
May 9, 2026, 8:00 PM MDT
In force
40 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Washington County, CO

The radar

The Goodland radar (KGLD), 130 km from the middle of the area, began a volume at 01:20 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 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 nearest sounding before it

N. Platte/Lee Bi, NE (KLBF), launched 00:00Z, 1.3 hours before the alert went out and 245 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.

Skew-T log-pSkew-T log-p diagram, N. Platte/Lee Bi, NE at 00:00Z on 2026-05-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, N. Platte/Lee Bi, NE at 00:00Z on 2026-05-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -87 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1855 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
-87 m²/s²
0-3 km storm-relative helicity
56 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.2

Open this sounding in Storm Lab

The text

As transmitted.

957 
WUUS55 KBOU 100120
SVRBOU
COC121-100200-
/O.NEW.KBOU.SV.W.0007.260510T0120Z-260510T0200Z/

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

The National Weather Service in Denver has issued a

* Severe Thunderstorm Warning for...
  Southeastern Washington County in northeastern Colorado...

* Until 800 PM MDT.

* At 720 PM MDT, a severe thunderstorm was located 9 miles northeast
  of Elba, or 13 miles southeast of Akron, moving southeast at 60
  mph.

  HAZARD...60 mph wind gusts and small hail.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Locations impacted include...
  Arickaree School, Elba, Anton, Cope and Platner.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Seek shelter inside a well-built structure and stay away from
windows. This storm is capable of producing damaging winds.

&&

LAT...LON 3998 10341 4017 10311 4011 10279 4000 10279
      4000 10280 3957 10280 3958 10313
TIME...MOT...LOC 0119Z 316DEG 49KT 4002 10308

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

09
2 follow-up statements
998 
WWUS55 KBOU 100139
SVSBOU

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

COC121-100200-
/O.CON.KBOU.SV.W.0007.000000T0000Z-260510T0200Z/
Washington CO-
739 PM MDT Sat May 9 2026

...SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 8 PM MDT FOR
SOUTHEASTERN WASHINGTON COUNTY...

At 739 PM MDT, a severe thunderstorm was located 12 miles northeast
of Arickaree School, or 26 miles southeast of Akron, moving southeast
at 40 mph.

HAZARD...60 mph wind gusts and small hail.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
  Arickaree School, Cope and Anton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Seek shelter inside a well-built structure and stay away from
windows. This storm is capable of producing damaging winds.

&&

LAT...LON 3981 10329 4005 10303 4011 10279 4000 10279
      4000 10280 3957 10280 3958 10313
TIME...MOT...LOC 0120Z 313DEG 36KT 4001 10306

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

09
482 
WWUS55 KBOU 100158
SVSBOU

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

COC121-100208-
/O.EXP.KBOU.SV.W.0007.000000T0000Z-260510T0200Z/
Washington CO-
758 PM MDT Sat May 9 2026

...SEVERE THUNDERSTORM WARNING WILL EXPIRE AT 8 PM MDT FOR
SOUTHEASTERN WASHINGTON COUNTY...

The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire. However, gusty
winds are still possible with this thunderstorm.

&&

LAT...LON 3981 10329 4005 10303 4011 10279 4000 10279
      4000 10280 3957 10280 3958 10313
TIME...MOT...LOC 0139Z 313DEG 36KT 3988 10287

$$

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, 5:38 PM MDT, 1 hour 42 minutes earlier. Its key messages:

  • Scattered afternoon and evening showers/thunderstorms likely for the northeastern plains this evening.
  • Summerlike warmth and drier weather next week, with highs in the 80s for the lower elevations.
Area forecast discussion, May 9, 5:38 PM MDT, 1 hour 42 minutes before
Area Forecast Discussion
National Weather Service Denver/Boulder CO
538 PM MDT Sat May 9 2026

.KEY MESSAGES...

- Scattered afternoon and evening showers/thunderstorms likely for
  the northeastern plains this 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 /00Z TAFS through 00Z Monday/...
Issued at 528 PM MDT Sat May 9 2026

Cold front will move across between 0030z and 01z with gusty north
to northeast winds behind it. Wind gusts up to 40 mph will occur
with its passage for a few hours.  Winds will decrease by 03z and
have a N/NNE direction. Will see stratus develop after 03z with
ceilings down to 1200 ft. There will be a chance of rain showers
between 04z and 08z with ceilings down to 500 feet accompanying
the rain. Should see 1200 ft ceilings scatter out by 13z Sun.
Winds by 08z will be north and then go light and variable by 13z.
Winds by 18Z will be light from the NNE.

&&

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

&&

DISCUSSION...MV
AVIATION...RPK

In the hours before

Special weather statement, May 9, 2:32 PM MDT, 4 hours 48 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
Special weather statement, May 9, 6:08 PM MDT, 1 hour 12 minutes before
Special Weather Statement
National Weather Service Denver CO
608 PM MDT Sat May 9 2026

COZ048-100045-
Logan County CO-
608 PM MDT Sat May 9 2026

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

At 608 PM MDT, Doppler radar was tracking a strong thunderstorm near
Logan Corners, or 10 miles west of Sterling, moving southeast at 25
mph.

HAZARD...Wind gusts up to 50 mph and penny 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...
  Sterling, Atwood, Logan Corners, North Sterling Reservoir and
  Pawnee Pass.

This includes Interstate 76 between mile markers 113 and 135.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4060 10354 4081 10338 4071 10296 4044 10318
      4044 10325
TIME...MOT...LOC 0007Z 303DEG 22KT 4068 10337

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...50 MPH

09
Local storm report, May 9, 6:32 PM MDT, 48 minutes before
Preliminary Local Storm Report
National Weather Service Denver CO
632 PM MDT Sat May 9 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0546 PM     Tstm Wnd Gst     1 NNW Briggsdale        40.64N 104.33W
05/09/2026  M68 MPH          Weld               CO   Mesonet

            Mesonet station CO043 Briggsdale.

&&
Special weather statement, May 9, 6:45 PM MDT, 35 minutes before
Special Weather Statement
National Weather Service Denver CO
645 PM MDT Sat May 9 2026

COZ048-049-100130-
Logan County CO-Washington County CO-
645 PM MDT Sat May 9 2026

...A STRONG THUNDERSTORM WILL IMPACT SOUTH CENTRAL LOGAN AND
NORTHEASTERN WASHINGTON COUNTIES UNTIL 730 PM MDT...

At 645 PM MDT, Doppler radar was tracking a strong thunderstorm 10
miles south of Sterling, moving southeast at 25 mph.

HAZARD...Wind gusts up to 40 mph and nickel 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...
  Burdett and Lone Star.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4044 10329 4056 10310 4044 10271 4044 10278
      4039 10278 4012 10313
TIME...MOT...LOC 0045Z 299DEG 23KT 4049 10314

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...40 MPH

09
Local storm report, May 9, 7:05 PM MDT, 15 minutes before
Preliminary Local Storm Report
National Weather Service Denver CO
705 PM MDT Sat May 9 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0436 PM     Tstm Wnd Gst     7 N Rockport            41.00N 104.77W
05/09/2026  M64 MPH          Weld               CO   Mesonet

            Mesonet station CO128 085s30935rws1rhs - 0.2
            Mi S Of W.

&&

The office that day

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

IssuedProductOfficeCountiesLasted
May 9, 6:08 PM MDTSpecial Weather StatementBOULogan37 min
May 9, 6:45 PM MDTSpecial Weather StatementBOULogan45 min
May 9, 7:23 PM MDTSpecial Weather StatementBOUWashington22 min
May 9, 8:19 PM MDTSpecial Weather StatementBOUElbert41 min
May 9, 9:45 PM MDTSpecial Weather StatementBOULincoln45 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.