Alert archive / Colorado / Severe Thunderstorm Warnings in 2025

Severe Thunderstorm Warning 336, NWS Denver/Boulder, CO

August 18, 2025Logan County, Washington County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Aug 18, 2025, 5:05 PM MDT for Logan County, 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 counties it named.

The facts

Issued
Aug 18, 2025, 5:05 PM MDT (23:05 UTC)
Expired
Aug 18, 2025, 5:45 PM MDT
In force
40 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Logan County, CO, Washington County, CO

The radar

The Denver radar (KFTG), 134 km from the middle of the area, began a volume at 23:07 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.

IssuedProductOfficeLasted
Aug 18, 4:25 PM MDTSevere Thunderstorm WatchSPC4 hr

The nearest sounding before it

Dodge City, (KDDC), launched 12:00Z, 11.1 hours before the alert went out and 401 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, Dodge City, at 12:00Z on 2025-08-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 566 joules per kilogram.LCLLFCEL10008507005003002001001 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, Dodge City, at 12:00Z on 2025-08-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 18 square meters per square second.1939Sfc1 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
566 J/kg
Mixed-layer CIN
-303 J/kg
Mixed-layer LCL
1798 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
18 m²/s²
0-3 km storm-relative helicity
90 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

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 Aug 18, 2:30 PM MDT, 2 hours 35 minutes earlier.

Area forecast discussion, Aug 18, 2:30 PM MDT, 2 hours 35 minutes before
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Hazardous weather outlook, Aug 18, 7:37 AM MDT, 9 hours 28 minutes before
Hazardous Weather Outlook
National Weather Service Denver/Boulder CO
737 AM MDT Mon Aug 18 2025

COZ030>051-191345-
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-
737 AM MDT Mon Aug 18 2025

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

.DAY ONE...Today and Tonight

SPC has upgraded our northeast plains to a slight risk (2 out of
5) for severe weather potential today. While the highest concern
is for these locations, there will still be a marginal threat
pushing as far west as the southern urban corridor and along the
Palmer Divide. Main hazards will be strong winds (up to 70 mph)
and large hail (between 1-2").

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

Warmer and drier conditions will be in place through the work
week, with limited precipitation chances for Tuesday and
Wednesday. Moisture will start to increase by the end of the week
and cooler temperatures and increasing shower and storm coverage
is expected for the weekend.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today or tonight, but any
and all severe reports are encouraged and appreciated!

In the hours before

Special weather statement, Aug 18, 3:34 PM MDT, 1 hour 31 minutes before
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Special weather statement, Aug 18, 3:54 PM MDT, 1 hour 11 minutes before
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Special weather statement, Aug 18, 4:02 PM MDT, 1 hour 3 minutes before
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Special weather statement, Aug 18, 4:24 PM MDT, 41 minutes before
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Special weather statement, Aug 18, 4:37 PM MDT, 28 minutes before
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Special weather statement, Aug 18, 4:55 PM MDT, 10 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
Aug 18, 1:04 PM MDTSpecial Weather StatementBOUWashington26 min
Aug 18, 1:46 PM MDTSpecial Weather StatementBOUDouglas29 min
Aug 18, 1:59 PM MDTSpecial Weather StatementBOUElbert46 min
Aug 18, 2:09 PM MDTAreal Flood AdvisoryBOUElbert3 hr
Aug 18, 2:16 PM MDTSevere Thunderstorm WarningBOULincoln29 min
Aug 18, 2:21 PM MDTSpecial Weather StatementBOUArapahoe24 min
Aug 18, 2:42 PM MDTSpecial Weather StatementBOULincoln33 min
Aug 18, 2:50 PM MDTAreal Flood AdvisoryBOUElbert, Lincoln3 hr
Aug 18, 2:53 PM MDTSpecial Weather StatementBOUAdams37 min
Aug 18, 3:02 PM MDTSevere Thunderstorm Warning Considerable damage threatBOULincoln28 min
Aug 18, 3:10 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe24 min
Aug 18, 3:22 PM MDTSpecial Weather StatementBOULincoln38 min
Aug 18, 3:26 PM MDTSpecial Weather StatementBOULincoln49 min
Aug 18, 3:34 PM MDTSpecial Weather StatementBOUMorgan41 min
Aug 18, 3:38 PM MDTAreal Flood AdvisoryBOUElbert, Lincoln, Washington3 hr
Aug 18, 3:50 PM MDTSevere Thunderstorm WarningBOULincoln40 min
Aug 18, 3:54 PM MDTSpecial Weather StatementBOUMorgan36 min
Aug 18, 4:02 PM MDTSpecial Weather StatementBOULincoln58 min
Aug 18, 4:24 PM MDTSpecial Weather StatementBOUWashington51 min
Aug 18, 4:37 PM MDTSpecial Weather StatementBOUMorgan38 min
Aug 18, 5:27 PM MDTSpecial Weather StatementBOULogan48 min

Nearby

Severe Thunderstorm Warnings in Colorado, 2025Every 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.