Alert archive / Colorado / Severe Thunderstorm Warnings in 2025

Severe Thunderstorm Warning 166, NWS Denver/Boulder, CO

June 17, 20254 counties in Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jun 17, 2025, 1:46 PM MDT for 4 counties in Colorado. It was in force for 29 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Jun 17, 2025, 1:46 PM MDT (19:46 UTC)
Expired: Jun 17, 2025, 2:15 PM MDT
In force: 29 min
Issued by: NWS Denver/Boulder, CO
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

Counties Adams County, CO, Boulder County, CO, Broomfield County, CO, Weld County, CO

The radar

The Denver radar (KFTG), 42 km from the middle of the area, began a volume at 19:50 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.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jun 17, 10:48 AM MDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Grand Junction, CO (KGJT), launched 12:00Z, 7.8 hours before the alert went out and 337 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 4428 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: -46 m²/s²
0-3 km storm-relative helicity: -44 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

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 Jun 17, 12:56 PM MDT, 50 minutes earlier.

Area forecast discussion, Jun 17, 12:56 PM MDT, 50 minutes before

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Hazardous weather outlook, Jun 17, 10:12 AM MDT, 3 hours 34 minutes before

Hazardous Weather Outlook
National Weather Service Denver/Boulder CO
1012 AM MDT Tue Jun 17 2025

COZ030>051-181615-
Jackson County Below 9000 Feet-
West Jackson and West Grand Counties Above 9000 Feet-
Grand and Summit Counties Below 9000 Feet-
South and East Jackson/Larimer/North and Northeast Grand/
Northwest Boulder Counties Above 9000 Feet-
South and Southeast Grand/West Central and Southwest Boulder/
Gilpin/Clear Creek/Summit/North and West Park Counties Above
9000 Feet-Larimer and Boulder Counties Between 6000 and 9000 Feet-
Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear
Creek/Northeast Park Counties Below 9000 Feet-
Central and Southeast Park County-
Larimer County Below 6000 Feet/Northwest Weld County-
Boulder And Jefferson Counties Below 6000 Feet/West Broomfield
County-
North Douglas County Below 6000 Feet/Denver/West Adams and
Arapahoe Counties/East Broomfield County-
Elbert/Central and East Douglas Counties Above 6000 Feet-
Northeast Weld County-Central and South Weld County-Morgan County-
Central and East Adams and Arapahoe Counties-
North and Northeast Elbert County Below 6000 Feet/North Lincoln
County-
Southeast Elbert County Below 6000 Feet/South Lincoln County-
Logan County-Washington County-Sedgwick County-Phillips County-
1012 AM MDT Tue Jun 17 2025

This hazardous weather outlook is for northeast and north central
Colorado.

.DAY ONE...Today and Tonight

Strong to severe storms are possible early this afternoon. Best
time frame for I-25 corridor and Denver metro is between 12 PM
and 4 PM. Best time frame for eastern plains will be 3 PM - 7 PM.
Large hail and damaging wind gusts (sometimes up to 80 mph) are
the main hazards.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

Hot weather is likely to return by late this week, with high
temperatures in the mid to upper 90s possible from Thursday
through Saturday. Friday will be the warmest day.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today and tonight, but
reports of any hail or gusty winds will be appreciated.

In the hours before

Special weather statement, Jun 17, 11:11 AM MDT, 2 hours 35 minutes before

Special Weather Statement
National Weather Service Denver CO
1111 AM MDT Tue Jun 17 2025

COZ030-033-035-171800-
South and East Jackson/Larimer/North and Northeast
Grand/Northwest Boulder Counties Above 9000 Feet CO-Larimer and
Boulder Counties Between 6000 and 9000 Feet CO-Jackson County
Below 9000 Feet CO-
1111 AM MDT Tue Jun 17 2025

...A STRONG THUNDERSTORM WILL IMPACT NORTHEASTERN JACKSON AND
NORTHWESTERN LARIMER COUNTIES UNTIL NOON MDT...

At 1111 AM MDT, Doppler radar was tracking a strong thunderstorm 9
miles northeast of Cowdrey, or 65 miles northwest of Fort Collins,
moving southeast at 15 mph.

HAZARD...Wind gusts up to 40 mph and half inch 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...
  Four Corners.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4086 10631 4100 10621 4100 10575 4074 10602
TIME...MOT...LOC 1711Z 306DEG 12KT 4095 10619

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH

Schlatter

Local storm report, Jun 17, 11:28 AM MDT, 2 hours 18 minutes before

Preliminary Local Storm Report
National Weather Service Denver CO
1128 AM MDT Tue Jun 17 2025

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

1116 AM     Hail             7 N Limon               39.36N 103.67W
06/17/2025  M1.00 Inch       Lincoln            CO   Trained Spotter

&&

Special weather statement, Jun 17, 12:59 PM MDT, 47 minutes before

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Special weather statement, Jun 17, 1:10 PM MDT, 36 minutes before

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Special weather statement, Jun 17, 1:37 PM MDT, 9 minutes before

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Local storm report, Jun 17, 1:41 PM MDT, 5 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 16, 6:29 PM MDT	Special Weather Statement	BOU	Washington	16 min
Jun 16, 6:37 PM MDT	Special Weather Statement	BOU	Logan	23 min
Jun 16, 6:50 PM MDT	Special Weather Statement	BOU	Washington	40 min
Jun 16, 7:10 PM MDT	Severe Thunderstorm Warning	BOU	Washington	33 min
Jun 16, 7:19 PM MDT	Severe Thunderstorm Warning	BOU	Washington	11 min
Jun 16, 7:24 PM MDT	Tornado Warning	BOU	Washington	20 min
Jun 17, 1:57 AM MDT	Special Weather Statement	BOU	Weld	33 min
Jun 17, 2:16 AM MDT	Severe Thunderstorm Warning	BOU	Larimer, Weld	29 min
Jun 17, 2:19 AM MDT	Severe Thunderstorm Warning	BOU	Weld	26 min
Jun 17, 2:38 AM MDT	Severe Thunderstorm Warning Considerable damage threat	BOU	Weld	37 min
Jun 17, 2:43 AM MDT	Severe Thunderstorm Warning	BOU	Larimer, Weld	32 min
Jun 17, 3:07 AM MDT	Severe Thunderstorm Warning	BOU	Larimer, Weld	23 min
Jun 17, 3:14 AM MDT	Severe Thunderstorm Warning	BOU	Larimer, Weld	31 min
Jun 17, 3:17 AM MDT	Severe Thunderstorm Warning	BOU	Larimer, Weld	43 min
Jun 17, 3:22 AM MDT	Severe Thunderstorm Warning	BOU	Morgan, Weld	38 min
Jun 17, 3:30 AM MDT	Severe Thunderstorm Warning Considerable damage threat	BOU	Weld	30 min
Jun 17, 3:32 AM MDT	Severe Thunderstorm Warning Destructive damage threat	BOU	Weld	28 min
Jun 17, 3:48 AM MDT	Severe Thunderstorm Warning Destructive damage threat	BOU	Morgan	42 min
Jun 17, 3:52 AM MDT	Severe Thunderstorm Warning Considerable damage threat	BOU	Weld	27 min
Jun 17, 3:54 AM MDT	Severe Thunderstorm Warning	BOU	Adams, Weld	36 min
Jun 17, 4:02 AM MDT	Severe Thunderstorm Warning Destructive damage threat	BOU	Adams, Weld	28 min
Jun 17, 4:06 AM MDT	Severe Thunderstorm Warning	BOU	Adams, Boulder, Broomfield	39 min
Jun 17, 4:15 AM MDT	Severe Thunderstorm Warning Considerable damage threat	BOU	Morgan	45 min
Jun 17, 4:26 AM MDT	Severe Thunderstorm Warning Considerable damage threat	BOU	Morgan	34 min
Jun 17, 4:36 AM MDT	Severe Thunderstorm Warning	BOU	Weld	24 min
Jun 17, 4:40 AM MDT	Severe Thunderstorm Warning	BOU	Adams, Denver	19 min
Jun 17, 4:52 AM MDT	Severe Thunderstorm Warning	BOU	Adams	38 min
Jun 17, 4:58 AM MDT	Severe Thunderstorm Warning	BOU	Morgan, Washington	32 min
Jun 17, 5:19 AM MDT	Severe Thunderstorm Warning	BOU	Washington	41 min
Jun 17, 5:21 AM MDT	Severe Thunderstorm Warning	BOU	Arapahoe, Douglas, Elbert	39 min
Jun 17, 5:31 AM MDT	Severe Thunderstorm Warning	BOU	Adams, Arapahoe	44 min
Jun 17, 5:53 AM MDT	Severe Thunderstorm Warning	BOU	Washington	37 min
Jun 17, 5:56 AM MDT	Severe Thunderstorm Warning	BOU	Arapahoe, Douglas, Elbert	34 min
Jun 17, 6:35 AM MDT	Special Weather Statement	BOU	Washington	40 min
Jun 17, 9:45 AM MDT	Special Weather Statement	BOU	Elbert	30 min
Jun 17, 10:11 AM MDT	Severe Thunderstorm Warning	BOU	Elbert, Lincoln	34 min
Jun 17, 10:42 AM MDT	Severe Thunderstorm Warning	BOU	Elbert, Lincoln, Washington	48 min
Jun 17, 10:54 AM MDT	Special Weather Statement	BOU	Jackson	36 min
Jun 17, 11:11 AM MDT	Special Weather Statement	BOU	Jackson	49 min
Jun 17, 11:19 AM MDT	Severe Thunderstorm Warning Considerable damage threat	BOU	Elbert, Lincoln	41 min
Jun 17, 11:25 AM MDT	Severe Thunderstorm Warning	BOU	Larimer	50 min
Jun 17, 11:35 AM MDT	Severe Thunderstorm Warning	BOU	Douglas, Jefferson	40 min
Jun 17, 11:40 AM MDT	Flash Flood Warning Considerable damage threat	BOU	Larimer	3 hr
Jun 17, 11:57 AM MDT	Severe Thunderstorm Warning	BOU	Lincoln	48 min
Jun 17, 12:11 PM MDT	Severe Thunderstorm Warning	BOU	Larimer	34 min
Jun 17, 12:28 PM MDT	Severe Thunderstorm Warning	BOU	Larimer	32 min
Jun 17, 12:31 PM MDT	Severe Thunderstorm Warning	BOU	Elbert	19 min
Jun 17, 12:39 PM MDT	Severe Thunderstorm Warning Considerable damage threat	BOU	Lincoln	51 min
Jun 17, 12:48 PM MDT	Severe Thunderstorm Warning	BOU	Larimer	17 min
Jun 17, 12:59 PM MDT	Special Weather Statement	BOU	Larimer	46 min
Jun 17, 1:10 PM MDT	Special Weather Statement	BOU	Weld	50 min
Jun 17, 1:35 PM MDT	Severe Thunderstorm Warning	BOU	Lincoln	40 min
Jun 17, 1:37 PM MDT	Special Weather Statement	BOU	Broomfield	38 min
Jun 17, 1:43 PM MDT	Severe Thunderstorm Warning	BOU	Weld	32 min
Jun 17, 1:58 PM MDT	Special Weather Statement	BOU	Denver, Jefferson	47 min
Jun 17, 2:05 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Denver, Weld	40 min
Jun 17, 2:14 PM MDT	Severe Thunderstorm Warning	BOU	Lincoln	46 min
Jun 17, 2:39 PM MDT	Special Weather Statement	BOU	Adams, Morgan	51 min
Jun 17, 2:44 PM MDT	Special Weather Statement	BOU	Logan	46 min
Jun 17, 2:50 PM MDT	Severe Thunderstorm Warning	BOU	Lincoln	25 min
Jun 17, 3:59 PM MDT	Special Weather Statement	BOU	Sedgwick	46 min
Jun 17, 4:08 PM MDT	Severe Thunderstorm Warning	BOU	Sedgwick	22 min

Nearby

Severe Thunderstorm Warnings in Colorado, 2025 Every severe thunderstorm warning in 2025

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.