Alert archive / Colorado / Severe Thunderstorm Warnings in 2024

Severe Thunderstorm Warning 293, NWS Denver/Boulder, CO

September 17, 20244 counties in Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Sep 17, 2024, 4:39 PM MDT for 4 counties in Colorado. It was in force for 36 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: Sep 17, 2024, 4:39 PM MDT (22:39 UTC)
Expired: Sep 17, 2024, 5:15 PM MDT
In force: 36 min
Issued by: NWS Denver/Boulder, CO
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

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

The radar

The Denver radar (KFTG), 102 km from the middle of the area, began a volume at 22:42 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
Sep 17, 2:54 PM MDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Dodge City, (KDDC), launched 12:00Z, 10.7 hours before the alert went out and 433 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: 518 J/kg
Mixed-layer CIN: -179 J/kg
Mixed-layer LCL: 1237 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 149 m²/s²
0-3 km storm-relative helicity: 154 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.9

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 Sep 17, 2:15 PM MDT, 2 hours 24 minutes earlier.

Area forecast discussion, Sep 17, 2:15 PM MDT, 2 hours 24 minutes before

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Hazardous weather outlook, Sep 17, 11:09 AM MDT, 5 hours 30 minutes before

Hazardous Weather Outlook
National Weather Service Denver/Boulder CO
1109 AM MDT Tue Sep 17 2024

COZ030>051-181715-
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-
1109 AM MDT Tue Sep 17 2024

...HIGH AND POTENTIALLY DAMAGING WINDS FROM SEVERE STORMS THIS
AFTERNOON...

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

.DAY ONE...This Afternoon and Tonight

A line of thunderstorms will race across the area this afternoon.
As this line of thunderstorms moves through, wind gusts of 40 to
60 mph are expected. Isolated wind gusts of 70 to 80 mph will be
possible with the stronger thunderstorms over the plains. The last
of the storms will move out of the far northeast corner of
Colorado by 7-8 mph. Impact will include significant danger to
boaters and outdoor water enthusiasts, who should get off the
water well before storms and gusty winds arrive. Scattered power
outages are also possible.

Breezy to windy conditions will likely linger over the higher
foothills and Front Range Mountains through the evening, while
other locations will see winds subside quickly behind the line of
storms.

Fire danger will be elevated due to very warm temperatures and
gusty winds on the plains ahead of the front.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

Dry conditions and above normal temperatures are expected both
Wednesday and Thursday. This may lead to elevated fire weather
conditions. By Friday, isolated to scattered chances for storms and
showers return.

The next storm system arriving this weekend will bring cooler
unsettled weather to the region with rainfall on the plains and
the potential for accumulating snow across the higher Front Range
Mountains.

.SPOTTER INFORMATION STATEMENT...

Spotter are encouraged to provide any reports of severe wind gusts
or wind damage this afternoon.

In the hours before

Local storm report, Sep 17, 3:05 PM MDT, 1 hour 34 minutes before

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Special weather statement, Sep 17, 3:05 PM MDT, 1 hour 34 minutes before

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Local storm report, Sep 17, 4:08 PM MDT, 31 minutes before

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Local storm report, Sep 17, 4:10 PM MDT, 29 minutes before

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Local storm report, Sep 17, 4:12 PM MDT, 27 minutes before

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Local storm report, Sep 17, 4:39 PM MDT, 0 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
Sep 17, 1:50 PM MDT	Special Weather Statement	BOU	Jefferson	25 min
Sep 17, 2:07 PM MDT	Special Weather Statement	BOU	Boulder, Broomfield	23 min
Sep 17, 2:11 PM MDT	Special Weather Statement	BOU	Denver, Jefferson	34 min
Sep 17, 2:36 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Arapahoe, Denver, Douglas, Weld	39 min
Sep 17, 2:41 PM MDT	Special Weather Statement	BOU	Weld	49 min
Sep 17, 3:05 PM MDT	Special Weather Statement	BOU	Adams, Arapahoe, Weld	40 min
Sep 17, 3:23 PM MDT	Severe Thunderstorm Warning	BOU	Elbert	52 min
Sep 17, 3:33 PM MDT	Severe Thunderstorm Warning	BOU	Elbert, Lincoln	42 min
Sep 17, 4:04 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Arapahoe, Elbert, Morgan, Washington, Weld	41 min
Sep 17, 4:11 PM MDT	Severe Thunderstorm Warning	BOU	Elbert, Lincoln	49 min
Sep 17, 4:29 PM MDT	Severe Thunderstorm Warning	BOU	Arapahoe, Elbert, Lincoln, Washington	28 min
Sep 17, 5:09 PM MDT	Special Weather Statement	BOU	Logan	51 min
Sep 17, 5:56 PM MDT	Special Weather Statement	BOU	Phillips, Sedgwick	64 min

Nearby

Severe Thunderstorm Warnings in Colorado, 2024 Every 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.