Alert archive / Colorado / Severe Thunderstorm Warnings in 2024

Severe Thunderstorm Warning 225, NWS Denver/Boulder, CO

August 10, 2024Jackson County, Larimer County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Aug 10, 2024, 12:55 PM MDT for Jackson County, Larimer County, Colorado. It was in force for 35 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 10, 2024, 12:55 PM MDT (18:55 UTC)
Expired
Aug 10, 2024, 1:30 PM MDT
In force
35 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Jackson County, CO, Larimer County, CO

The radar

The Cheyenne radar (KCYS), 107 km from the middle of the area, began a volume at 18:59 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 nearest sounding before it

Grand Junction, CO (KGJT), launched 12:00Z, 6.9 hours before the alert went out and 280 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, Grand Junction, CO at 12:00Z on 2024-08-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 38 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, Grand Junction, CO at 12:00Z on 2024-08-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 132 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
38 J/kg
Mixed-layer CIN
-300 J/kg
Mixed-layer LCL
1362 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
132 m²/s²
0-3 km storm-relative helicity
294 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 Aug 10, 12:02 PM MDT, 53 minutes earlier.

Area forecast discussion, Aug 10, 12:02 PM MDT, 53 minutes before
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Hazardous weather outlook, Aug 10, 11:14 AM MDT, 1 hour 41 minutes before
Hazardous Weather Outlook
National Weather Service Denver/Boulder CO
1114 AM MDT Sat Aug 10 2024

COZ030>051-111715-
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-
1114 AM MDT Sat Aug 10 2024

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

.DAY ONE...This Afternoon and Tonight

Thunderstorms will develop in the mountains through early
afternoon, with scattered storms spreading east across the plains
through the rest of the afternoon and evening. Locally heavy rain
can be expected with some of the storms, resulting in a threat of
flooding in recent burn areas. A couple strong to severe storms
will develop on the plains, with some hail and wind gusts to
around 60 mph the main threats.

A few showers and storms will likely linger into the overnight
hours, but these will be less intense.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

Scattered to numerous showers and storms are expected Sunday into
early next week, most numerous over the high country. Locally
heavy rainfall is possible with the stronger storms that could
elevate the flash flood threat for sensitive areas like our burn
scars. There is a marginal severe threat for gusty winds and hail
for portions of the plains.

There will be a gradual warming and drying trend Wednesday through
Friday, with thunderstorm activity returning to a more typical
summer convective pattern as the week persists.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today or tonight. However,
any reports of heavy rainfall or strong wind gusts will be
appreciated.

In the hours before

Special weather statement, Aug 10, 12:35 PM MDT, 20 minutes before
Special Weather Statement
National Weather Service Denver CO
1235 PM MDT Sat Aug 10 2024

COZ030-033-035-101900-
Jackson County Below 9000 Feet CO-
Larimer and Boulder Counties Between 6000 and 9000 Feet CO-
South and East Jackson/Larimer/North and Northeast Grand/Northwest
Boulder Counties Above 9000 Feet CO-
1235 PM MDT Sat Aug 10 2024

...A STRONG THUNDERSTORM WILL IMPACT NORTHEASTERN JACKSON AND
NORTHWESTERN LARIMER COUNTIES THROUGH 100 PM MDT...

At 1234 PM MDT, Doppler radar was tracking a strong thunderstorm 6
miles south of Wyocolo, or 42 miles southwest of Laramie, moving
southeast at 20 mph.

HAZARD...Wind gusts of 50 to 55 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor hail damage to vegetation is
         possible.

This storm will remain over mainly rural areas of northeastern
Jackson and northwestern Larimer Counties.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare for sudden gusty winds. Secure loose objects and move to a
safe shelter inside a building or vehicle.

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4100 10613 4088 10595 4074 10619 4092 10635
      4100 10623
TIME...MOT...LOC 1834Z 318DEG 17KT 4091 10620

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...55 MPH

RPK

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 10, 12:35 PM MDTSpecial Weather StatementBOUJackson25 min
Aug 10, 1:16 PM MDTSpecial Weather StatementBOULarimer29 min
Aug 10, 2:04 PM MDTAreal Flood AdvisoryBOULarimer116 min
Aug 10, 4:34 PM MDTFlash Flood Warning Considerable damage threatBOUJefferson3 hr
Aug 10, 4:43 PM MDTSpecial Weather StatementBOUDouglas47 min
Aug 10, 4:47 PM MDTSevere Thunderstorm WarningBOUDouglas, Elbert43 min
Aug 10, 5:29 PM MDTAreal Flood AdvisoryBOUDouglas, Elbert3 hr

Nearby

Severe Thunderstorm Warnings in Colorado, 2024Every severe thunderstorm warning in 2024

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.