Alert archive / Colorado / Severe Thunderstorm Warnings in 2023

Severe Thunderstorm Warning 394, NWS Denver/Boulder, CO

August 3, 2023Logan County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Aug 3, 2023, 7:50 PM MDT for Logan County, Colorado. It was in force for 25 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 3, 2023, 7:50 PM MDT (01:50 UTC)
Expired: Aug 3, 2023, 8:15 PM MDT
In force: 25 min
Issued by: NWS Denver/Boulder, CO
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County Logan County, CO

The radar

The Cheyenne radar (KCYS), 150 km from the middle of the area, began a volume at 01:53 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
Aug 3, 2:57 PM MDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

N. Platte/Lee Bi, NE (KLBF), launched 00:00Z, 1.8 hours before the alert went out and 216 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: 1148 J/kg
Mixed-layer CIN: -8 J/kg
Mixed-layer LCL: 1232 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: -13 m²/s²
0-3 km storm-relative helicity: 43 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 3, 7:22 PM MDT, 28 minutes earlier.

Area forecast discussion, Aug 3, 7:22 PM MDT, 28 minutes before

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Hazardous weather outlook, Aug 3, 10:53 AM MDT, 8 hours 57 minutes before

Hazardous Weather Outlook
National Weather Service Denver/Boulder CO
1053 AM MDT Thu Aug 3 2023

COZ030>051-041700-
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-
1053 AM MDT Thu Aug 3 2023

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

.DAY ONE...Today and Tonight

Severe thunderstorms are expected to develop across the northeast
plains this afternoon. Scattered storms will first develop over
the mountains and near the I-25 Corridor early this afternoon, and
then become more widespread and intensify as they move east over
the plains. Storms that develop initially along the I-25 Corridor
will be capable of producing large hail and isolated damaging wind
gusts. However, the threat of large hail and especially more
widespread damaging winds will increase as the storms organize and
roll east across the plains late this afternoon and early evening.
Wind gusts of 60-80 mph will be possible, along with golfball
sized hail from the strongest storms. A brief tornado is possible.
Storms will also produce very heavy rain, so there is potential
for localized flash flooding in areas that see multiple storms or
storm mergers.

The thunderstorms will end from west to east fairly quickly
through the late afternoon and early evening hours.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday

Friday and Saturday will have decreased storm coverage. However, a
couple stronger or severe storms will still be possible over the
northeast plains. There is just a low threat of flash flooding
mainly over the burn areas, as storms will generally be weaker in
the high country and moving along at a fast pace.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today and tonight. However,
any reports of heavy rainfall, hail, and strong winds will be
appreciated.

In the hours before

Special weather statement, Aug 3, 5:26 PM MDT, 2 hours 24 minutes before

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Special weather statement, Aug 3, 6:22 PM MDT, 1 hour 28 minutes before

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Special weather statement, Aug 3, 7:04 PM MDT, 46 minutes before

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Local storm report, Aug 3, 7:14 PM MDT, 36 minutes before

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Special weather statement, Aug 3, 7:16 PM MDT, 34 minutes before

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Local storm report, Aug 3, 7:27 PM MDT, 23 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
Aug 3, 6:08 PM MDT	Severe Thunderstorm Warning	BOU	Logan, Weld	52 min
Aug 3, 6:22 PM MDT	Special Weather Statement	BOU	Washington	53 min
Aug 3, 6:27 PM MDT	Severe Thunderstorm Warning	BOU	Lincoln	63 min
Aug 3, 6:30 PM MDT	Severe Thunderstorm Warning	BOU	Weld	45 min
Aug 3, 6:55 PM MDT	Severe Thunderstorm Warning	BOU	Logan	50 min
Aug 3, 7:00 PM MDT	Severe Thunderstorm Warning	BOU	Weld	15 min
Aug 3, 7:04 PM MDT	Special Weather Statement	BOU	Lincoln	41 min
Aug 3, 7:16 PM MDT	Special Weather Statement	BOU	Lincoln	44 min
Aug 3, 7:39 PM MDT	Severe Thunderstorm Warning	BOU	Logan	51 min
Aug 3, 8:14 PM MDT	Special Weather Statement	BOU	Logan, Sedgwick	46 min
Aug 3, 8:51 PM MDT	Special Weather Statement	BOU	Phillips, Sedgwick	54 min
Aug 3, 9:19 PM MDT	Severe Thunderstorm Warning	BOU	Phillips	41 min
Aug 4, 2:36 PM MDT	Special Weather Statement	BOU	Elbert	39 min
Aug 4, 3:47 PM MDT	Special Weather Statement	BOU	Morgan	43 min
Aug 4, 4:28 PM MDT	Special Weather Statement	BOU	Lincoln	47 min
Aug 4, 4:44 PM MDT	Severe Thunderstorm Warning	BOU	Elbert, Lincoln	31 min
Aug 4, 4:46 PM MDT	Special Weather Statement	BOU	Sedgwick	44 min
Aug 4, 4:53 PM MDT	Severe Thunderstorm Warning	BOU	Logan, Phillips, Sedgwick	37 min
Aug 4, 5:12 PM MDT	Severe Thunderstorm Warning	BOU	Elbert, Lincoln	48 min
Aug 4, 5:24 PM MDT	Severe Thunderstorm Warning	BOU	Logan, Phillips, Sedgwick	36 min
Aug 4, 5:50 PM MDT	Special Weather Statement	BOU	Lincoln	40 min

Nearby

Severe Thunderstorm Warnings in Colorado, 2023 Every severe thunderstorm warning in 2023

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.