Alert archive / Colorado / Severe Thunderstorm Warnings in 2023

Severe Thunderstorm Warning 232, NWS Denver/Boulder, CO

June 29, 2023Morgan County, Washington County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jun 29, 2023, 7:38 PM MDT for Morgan County, Washington County, Colorado. It was in force for 37 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: Jun 29, 2023, 7:38 PM MDT (01:38 UTC)
Expired: Jun 29, 2023, 8:15 PM MDT
In force: 37 min
Issued by: NWS Denver/Boulder, CO
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Morgan County, CO, Washington County, CO

The radar

The Denver radar (KFTG), 96 km from the middle of the area, began a volume at 01:38 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
Jun 29, 1:17 PM MDT	Tornado Watch	SPC	8 hr

The nearest sounding before it

N. Platte/Lee Bi, NE (KLBF), launched 00:00Z, 1.6 hours before the alert went out and 270 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: 387 J/kg
Mixed-layer CIN: -202 J/kg
Mixed-layer LCL: 1917 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: -4 m²/s²
0-3 km storm-relative helicity: 112 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 Jun 29, 6:01 PM MDT, 1 hour 37 minutes earlier.

Area forecast discussion, Jun 29, 6:01 PM MDT, 1 hour 37 minutes before

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Hazardous weather outlook, Jun 29, 11:03 AM MDT, 8 hours 35 minutes before

Hazardous Weather Outlook
National Weather Service Denver/Boulder CO
1103 AM MDT Thu Jun 29 2023

COZ030>051-301715-
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-
1103 AM MDT Thu Jun 29 2023

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

.DAY ONE...Today and Tonight

Scattered thunderstorms will develop over and near the Front Range
this afternoon, and move onto the plains in the late afternoon and
evening. Some of the storms will be strong to severe and a Severe
Thunderstorm Watch will likely be needed. The main threat will be
along the I-25 corridor and eastward towards Akron and Sterling.
The strongest storms could produce hail up to baseball ball size
and wind gusts to 70 mph. A couple tornadoes are also possible.
There is a flash flood threat mainly in Morgan and Logan Counties
as well due to heavy rain.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday

Additional scattered to numerous showers and thunderstorms are
expected for Friday. The severe threat decreases as the main
threat shifts south and eastward. However, storm movement will be
slower, which will increase the threat for flash flooding of flood
prone areas.

Saturday will be drier, but an active weather pattern is expected
to resume Sunday and into next week. There may be a possible lull
in thunderstorm activity on Monday, but scattered afternoon and
evening thunderstorms are expected for Tuesday and Wednesday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will likely be needed after 2 PM.

In the hours before

Local storm report, Jun 29, 5:24 PM MDT, 2 hours 14 minutes before

Preliminary Local Storm Report
National Weather Service Denver CO
524 PM MDT Thu Jun 29 2023

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

0516 PM     Hail             2 NNE Watkins           39.77N 104.59W
06/29/2023  M1.50 inch       Adams              CO   Trained Spotter

&&

Local storm report, Jun 29, 5:26 PM MDT, 2 hours 12 minutes before

Preliminary Local Storm Report
National Weather Service Denver CO
526 PM MDT Thu Jun 29 2023

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

0430 PM     Flood            2 ESE Mountain View     39.76N 105.03W
06/29/2023                   Denver             CO   Public

            Extensive street flooding with water depth
            estimated at 1 to 2 feet, covering entire
            intersection and sidewalks.

&&

BR

Local storm report, Jun 29, 5:35 PM MDT, 2 hours 3 minutes before

Preliminary Local Storm Report
National Weather Service Denver CO
535 PM MDT Thu Jun 29 2023

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

0524 PM     Hail             1 W Bennett             39.75N 104.45W
06/29/2023  E1.50 inch       Adams              CO   Public

            Report from mPING: Ping Pong Ball (1.50
            in.).

&&

BR

Local storm report, Jun 29, 5:52 PM MDT, 1 hour 46 minutes before

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Local storm report, Jun 29, 6:12 PM MDT, 1 hour 26 minutes before

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Local storm report, Jun 29, 6:41 PM MDT, 57 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
Jun 29, 6:00 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Morgan	45 min
Jun 29, 6:18 PM MDT	Severe Thunderstorm Warning Considerable damage threat	BOU	Adams	42 min
Jun 29, 6:58 PM MDT	Severe Thunderstorm Warning Considerable damage threat	BOU	Adams, Morgan, Washington	47 min
Jun 29, 7:46 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Morgan	44 min
Jun 29, 8:36 PM MDT	Areal Flood Advisory	BOU	Adams, Morgan, Weld	6 hr
Jun 29, 9:08 PM MDT	Areal Flood Advisory	BOU	Larimer	3 hr
Jun 30, 1:08 AM MDT	Special Weather Statement	BOU	Washington	52 min
Jun 30, 2:29 AM MDT	Areal Flood Advisory	BOU	Adams, Morgan, Weld	6 hr
Jun 30, 9:17 AM MDT	Areal Flood Advisory	BOU	Adams, Morgan, Weld	27 hr
Jun 30, 9:35 AM MDT	Special Weather Statement	BOU	Park	25 min
Jun 30, 10:03 AM MDT	Special Weather Statement	BOU	Denver	42 min
Jun 30, 10:25 AM MDT	Special Weather Statement	BOU	Douglas	50 min
Jun 30, 10:31 AM MDT	Areal Flood Warning	BOU	Weld	25 hr
Jun 30, 10:55 AM MDT	Areal Flood Warning	BOU	Weld	25 hr
Jun 30, 11:03 AM MDT	Areal Flood Advisory	BOU	Larimer	50 min
Jun 30, 11:28 AM MDT	Flash Flood Warning	BOU	Larimer	3 hr
Jun 30, 1:01 PM MDT	Areal Flood Advisory	BOU	Larimer	2 hr
Jun 30, 1:07 PM MDT	Severe Thunderstorm Warning	BOU	Lincoln	15 min
Jun 30, 2:11 PM MDT	Severe Thunderstorm Warning	BOU	Lincoln	28 min
Jun 30, 2:36 PM MDT	Severe Thunderstorm Warning	BOU	Jefferson	24 min
Jun 30, 2:55 PM MDT	Areal Flood Advisory	BOU	Grand	119 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.