Alert archive / Colorado / Severe Thunderstorm Warnings in 2023

Severe Thunderstorm Warning 458, NWS Denver/Boulder, CO

August 8, 2023Arapahoe County, Douglas County, Elbert County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Aug 8, 2023, 11:14 PM MDT for Arapahoe County, Douglas County, Elbert County, Colorado. It was in force for 31 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 8, 2023, 11:14 PM MDT (05:14 UTC)
Expired: Aug 8, 2023, 11:45 PM MDT
In force: 31 min
Issued by: NWS Denver/Boulder, CO
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

Counties Arapahoe County, CO, Douglas County, CO, Elbert County, CO

The radar

The Denver radar (KFTG), 41 km from the middle of the area, began a volume at 05:15 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

N. Platte/Lee Bi, NE (KLBF), launched 00:00Z, 5.2 hours before the alert went out and 379 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: 1804 J/kg
Mixed-layer CIN: -29 J/kg
Mixed-layer LCL: 1179 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 38 m²/s²
0-3 km storm-relative helicity: 106 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 4.6

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 8, 10:06 PM MDT, 1 hour 8 minutes earlier.

Area forecast discussion, Aug 8, 10:06 PM MDT, 1 hour 8 minutes before

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Hazardous weather outlook, Aug 8, 11:16 AM MDT, 11 hours 58 minutes before

Hazardous Weather Outlook
National Weather Service Denver/Boulder CO
1116 AM MDT Tue Aug 8 2023

COZ030>051-091730-
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-
1116 AM MDT Tue Aug 8 2023

...SEVERE STORM THREAT IS ENHANCED TODAY OVER PORTIONS OF
NORTHEAST COLORADO...

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

.DAY ONE...Today and Tonight

Severe thunderstorms are likely late this afternoon, and at least
into the late evening hours. The most likely area for these
severe storms will be along and east of a line from Kimball,
Nebraska to Fort Morgan to Limon, although there is a non zero
threat farther to the west including the I-25 Corridor.
Destructive hail up to baseball size and wind gusts of 60-70 mph
will be possible from the strongest storms over the northeastern
plains, along with a tornado or two.

There may be one round of severe storms between 3 and 7 pm - most
likely over the northern tier of Counties, while another round is
possible later in the evening into the overnight hours. Those
storms will also have locally heavy rain, and training storms
could produce some flooding concerns over portions of the east
central Colorado plains.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

Wednesday will be dry. Afternoon and evening thunderstorm chances
will return Thursday and Friday with storm coverage staying
isolated. Better monsoonal moisture will arrive this weekend which
will increase storm coverage and strength. The flash flood threat
for recent burn areas will be increasing this upcoming weekend.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will be needed over the northeast plains by 3
pm. Activation will likely remain in effect through the evening
hours, and possibly after midnight for portions of east central
Colorado.

In the hours before

Local storm report, Aug 8, 5:24 PM MDT, 5 hours 50 minutes before

Preliminary Local Storm Report...Summary
National Weather Service Denver CO
524 PM MDT Tue Aug 8 2023

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

0408 PM     Hail             6 S Burdett             40.28N 102.97W
08/08/2023  M1.75 inch       Washington         CO   Storm Chaser

0457 PM     Tornado          2 NW Hyde               40.15N 102.85W
08/08/2023                   Washington         CO   Trained Spotter

            WA298, seen from Yuma.

0500 PM     Tstm Wnd Dmg     1 WNW Hyde              40.13N 102.85W
08/08/2023                   Washington         CO   Law Enforcement

            Pub State patrol.

0502 PM     Hail             Hyde                    40.13N 102.83W
08/08/2023  M3.00 inch       Washington         CO   Trained Spotter

            DE175.

0505 PM     Hail             1 WNW Hyde              40.13N 102.84W
08/08/2023  E2.25 inch       Washington         CO   Public

            Report from mPING: Hen Egg+ (2.25 in.).

0507 PM     Hail             Hyde                    40.13N 102.83W
08/08/2023  E3.00 inch       Washington         CO   Public

            Report from mPING: Tea Cup (3.00 in.).

0517 PM     Hail             4 N Sterling            40.69N 103.21W
08/08/2023  M4.00 inch       Logan              CO   Trained Spotter

            L06.

&&

Local storm report, Aug 8, 5:31 PM MDT, 5 hours 43 minutes before

Preliminary Local Storm Report
National Weather Service Denver CO
531 PM MDT Tue Aug 8 2023

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

0517 PM     Hail             4 N Sterling            40.69N 103.21W
08/08/2023  M1.75 inch       Logan              CO   Trained Spotter

            Corrects previous hail report from 4 N
            Sterling. L06.

&&

Local storm report, Aug 8, 6:10 PM MDT, 5 hours 4 minutes before

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Special weather statement, Aug 8, 7:34 PM MDT, 3 hours 40 minutes before

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Special weather statement, Aug 8, 9:47 PM MDT, 1 hour 27 minutes before

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Special weather statement, Aug 8, 10:37 PM MDT, 37 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 8, 6:01 PM MDT	Severe Thunderstorm Warning	BOU	Logan, Phillips	44 min
Aug 8, 6:06 PM MDT	Severe Thunderstorm Warning	BOU	Washington	24 min
Aug 8, 6:13 PM MDT	Severe Thunderstorm Warning	BOU	Washington	31 min
Aug 8, 6:33 PM MDT	Severe Thunderstorm Warning Considerable damage threat	BOU	Lincoln	42 min
Aug 8, 6:43 PM MDT	Severe Thunderstorm Warning Considerable damage threat	BOU	Lincoln	47 min
Aug 8, 6:46 PM MDT	Severe Thunderstorm Warning	BOU	Phillips, Sedgwick	33 min
Aug 8, 7:17 PM MDT	Tornado Warning	BOU	Lincoln	28 min
Aug 8, 7:34 PM MDT	Special Weather Statement	BOU	Larimer	41 min
Aug 8, 7:45 PM MDT	Severe Thunderstorm Warning	BOU	Lincoln	45 min
Aug 8, 8:22 PM MDT	Severe Thunderstorm Warning	BOU	Lincoln	38 min
Aug 8, 8:38 PM MDT	Severe Thunderstorm Warning	BOU	Elbert, Lincoln	37 min
Aug 8, 9:47 PM MDT	Special Weather Statement	BOU	Washington	43 min
Aug 8, 10:13 PM MDT	Severe Thunderstorm Warning	BOU	Lincoln	21 min
Aug 8, 10:37 PM MDT	Special Weather Statement	BOU	Washington	38 min
Aug 8, 10:50 PM MDT	Severe Thunderstorm Warning	BOU	Washington	25 min
Aug 8, 11:42 PM MDT	Severe Thunderstorm Warning	BOU	Elbert	33 min
Aug 8, 11:57 PM MDT	Special Weather Statement	BOU	Adams	48 min
Aug 9, 12:12 AM MDT	Severe Thunderstorm Warning Considerable damage threat	BOU	Elbert	33 min
Aug 9, 4:01 AM MDT	Special Weather Statement	BOU	Weld	44 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.