Alert archive / Colorado / Severe Thunderstorm Warnings in 2023

Severe Thunderstorm Warning 372, NWS Denver/Boulder, CO

August 2, 20235 counties in Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Aug 2, 2023, 8:56 PM MDT for 5 counties in Colorado. It was in force for 28 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 2, 2023, 8:56 PM MDT (02:56 UTC)
Expired: Aug 2, 2023, 9:24 PM MDT
In force: 28 min
Issued by: NWS Denver/Boulder, CO
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Adams County, CO, Arapahoe County, CO, Denver County, CO, Elbert County, CO, Weld County, CO

The radar

The Denver radar (KFTG), 12 km from the middle of the area, began a volume at 02:57 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, 2.9 hours before the alert went out and 354 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: 1555 J/kg
Mixed-layer CIN: -15 J/kg
Mixed-layer LCL: 1582 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 7 m²/s²
0-3 km storm-relative helicity: 57 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 2, 3:22 PM MDT, 5 hours 34 minutes earlier.

Area forecast discussion, Aug 2, 3:22 PM MDT, 5 hours 34 minutes before

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Hazardous weather outlook, Aug 2, 6:10 PM MDT, 2 hours 46 minutes before

Outdoor Activities Forecast
National Weather Service Denver/Boulder CO
610 PM MDT Wed Aug 2 2023

IT WILL REMAIN UNSETTLED THROUGH MUCH OF THE PERIOD WITH A CHANCE OF
MAINLY AFTERNOON AND EVENING THUNDERSTORMS THROUGH THE PERIOD. AS A
RESULT, TEMPERATURES ARE EXPECTED TO RUN ON THE COOLER SIDE,
GENERALLY BELOW SEASONAL NORMALS.

...The forecast for the central Colorado mountains east of Vail Pass...

.TONIGHT...Mostly cloudy. Chance of thunderstorms in the evening,
then a chance of showers and slight chance of thunderstorms after
midnight. Lows in the mid 40s. Chance of rain 50 percent.
.THURSDAY...Partly cloudy with a slight chance of thunderstorms
in the morning, then mostly cloudy with a chance of thunderstorms
in the afternoon. Highs in the upper 60s. West winds 10 to 20 mph
with gusts up to 30 mph. Chance of precipitation 50 percent.
.THURSDAY NIGHT...Mostly cloudy with a slight chance of
thunderstorms in the evening, then partly cloudy after midnight.
Lows in the mid 40s. West winds 10 to 15 mph with gusts up to
25 mph in the evening, becoming light. Chance of precipitation
20 percent.
.FRIDAY...Partly cloudy with a 40 percent chance of
thunderstorms. Highs in the mid 60s. West winds 10 to 20 mph with
gusts up to 30 mph.
.FRIDAY NIGHT...Mostly clear with a 10 percent chance of
thunderstorms. Lows in the mid 40s.

...Looking further ahead for the mountain areas...

.SATURDAY...Partly cloudy with a 40 percent chance of
thunderstorms. Highs in the upper 60s.
.SATURDAY NIGHT...Partly cloudy with a 20 percent chance of
thunderstorms. Lows in the lower 40s.
.SUNDAY THROUGH MONDAY...Partly cloudy with a 40 percent chance
of thunderstorms. Highs in the mid 60s. Lows in the lower 40s.
.MONDAY NIGHT...Partly cloudy with a chance of rain showers and
slight chance of thunderstorms. Lows in the lower 40s. Chance of
rain 40 percent.
.TUESDAY...Partly cloudy with a 40 percent chance of
thunderstorms. Highs in the mid 60s.
.TUESDAY NIGHT...Mostly clear with a 10 percent chance of
thunderstorms. Lows in the lower 40s.
.WEDNESDAY...Partly cloudy with a 20 percent chance of
thunderstorms. Highs in the upper 60s.

The ultraviolet index for Denver on Thursday is a 11
which is in the extreme category.

The forecast weather and high temperature for Thursday
at a few cities around the country...

Seattle...Sunny and 84.
San Francisco...Mostly Cloudy and 63.
Los Angeles...Sunny and 75.
Salt Lake City...Thunderstorms and 86.
Las Vegas...Sunny and 103.
Chicago...Partly Cloudy and 87.
Dallas...Very hot and 106.
Boston...Sunny and 80.
New York City...Partly Cloudy and 80.
Washington DC...Partly Cloudy and 87.
Atlanta...Thunderstorms and 87.
Miami...Thunderstorms and 91.

In the hours before

Special weather statement, Aug 2, 3:18 PM MDT, 5 hours 38 minutes before

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Special weather statement, Aug 2, 4:11 PM MDT, 4 hours 45 minutes before

Special Weather Statement
National Weather Service Denver CO
411 PM MDT Wed Aug 2 2023

COZ050-051-022300-
Phillips County CO-Sedgwick County CO-
411 PM MDT Wed Aug 2 2023

...A strong thunderstorm will impact portions of Phillips and
Sedgwick Counties through 500 PM MDT...

At 411 PM MDT, Doppler radar was tracking a strong thunderstorm near
Fairfield, or 11 miles northwest of Holyoke, moving east at 25 mph.

HAZARD...Wind gusts up to 50 mph and nickel size hail.

SOURCE...Radar indicated.

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

Locations impacted include...
Holyoke, Haxtun, Sedgwick, Paoli, Amherst, Highland Center,
Fairfield, Marks Butte and Sixteen-Mile Corner.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4044 10266 4075 10265 4098 10265 4093 10212
      4045 10216
TIME...MOT...LOC 2211Z 249DEG 21KT 4067 10250

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...50 MPH

ENTREKIN

Special weather statement, Aug 2, 6:32 PM MDT, 2 hours 24 minutes before

Special Weather Statement
National Weather Service Denver CO
632 PM MDT Wed Aug 2 2023

COZ037-030115-
Central and Southeast Park County CO-
632 PM MDT Wed Aug 2 2023

...A strong thunderstorm will impact portions of southeastern Park
County through 715 PM MDT...

At 631 PM MDT, Doppler radar was tracking a strong thunderstorm 4
miles southwest of Guffey, or 29 miles northeast of Hayden Pass Burn
Scar, moving east at 20 mph.

HAZARD...Winds in excess of 40 mph and half inch hail.

SOURCE...Radar indicated.

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

Locations impacted include...
Guffey.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3874 10566 3883 10533 3870 10533 3870 10566
TIME...MOT...LOC 0031Z 262DEG 18KT 3869 10556

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...30 MPH

ENTREKIN

Special weather statement, Aug 2, 7:58 PM MDT, 58 minutes before

Special Weather Statement
National Weather Service Denver CO
758 PM MDT Wed Aug 2 2023

COZ036-030245-
Jefferson and West Douglas Counties Above  6000 Feet/Gilpin/Clear
Creek/Northeast Park Counties Below 9000 Feet CO-
758 PM MDT Wed Aug 2 2023

...A strong thunderstorm will impact portions of southwestern Douglas
and southeastern Jefferson Counties through 845 PM MDT...

At 758 PM MDT, Doppler radar was tracking a strong thunderstorm near
Sprucewood, or 30 miles south of Denver, moving northeast at 20 mph.

HAZARD...Winds in excess of 45 mph and penny size hail.

SOURCE...Radar indicated.

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

Locations impacted include...
Roxborough Park, Sprucewood, South Platte and Devil's Head.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3930 10527 3946 10511 3940 10495 3938 10495
      3935 10497 3930 10497 3921 10516
TIME...MOT...LOC 0158Z 220DEG 18KT 3931 10512

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...40 MPH

ENTREKIN

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 2, 6:32 PM MDT	Special Weather Statement	BOU	Teller	43 min
Aug 2, 7:58 PM MDT	Special Weather Statement	BOU	Douglas	47 min
Aug 2, 8:18 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Arapahoe, Denver, Douglas, Elbert, Jefferson	42 min
Aug 2, 8:34 PM MDT	Severe Thunderstorm Warning	BOU	Douglas, Elbert	41 min
Aug 2, 9:32 PM MDT	Special Weather Statement	BOU	Lincoln	43 min
Aug 2, 9:52 PM MDT	Severe Thunderstorm Warning	BOU	Weld	23 min
Aug 2, 10:03 PM MDT	Severe Thunderstorm Warning	BOU	Elbert	27 min
Aug 2, 10:13 PM MDT	Special Weather Statement	BOU	Lincoln	47 min
Aug 2, 10:14 PM MDT	Special Weather Statement	BOU	Broomfield	46 min
Aug 2, 10:32 PM MDT	Severe Thunderstorm Warning	BOU	Arapahoe, Elbert	43 min
Aug 2, 10:55 PM MDT	Special Weather Statement	BOU	Lincoln	50 min
Aug 2, 11:03 PM MDT	Areal Flood Advisory	BOU	Larimer	21 min
Aug 2, 11:24 PM MDT	Flash Flood Warning Considerable damage threat	BOU	Larimer	5 hr
Aug 2, 11:57 PM MDT	Special Weather Statement	BOU	Washington	48 min
Aug 3, 3:01 PM MDT	Special Weather Statement	BOU	Larimer	44 min
Aug 3, 3:20 PM MDT	Special Weather Statement	BOU	Denver	40 min
Aug 3, 3:23 PM MDT	Special Weather Statement	BOU	Douglas	52 min
Aug 3, 3:34 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Denver	41 min
Aug 3, 3:36 PM MDT	Severe Thunderstorm Warning	BOU	Adams	39 min
Aug 3, 3:59 PM MDT	Severe Thunderstorm Warning	BOU	Larimer	46 min
Aug 3, 4:02 PM MDT	Severe Thunderstorm Warning	BOU	Elbert	43 min
Aug 3, 4:24 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Arapahoe	51 min
Aug 3, 4:29 PM MDT	Severe Thunderstorm Warning	BOU	Weld	46 min
Aug 3, 4:45 PM MDT	Special Weather Statement	BOU	Elbert	45 min
Aug 3, 4:46 PM MDT	Special Weather Statement	BOU	Weld	44 min
Aug 3, 4:54 PM MDT	Areal Flood Advisory	BOU	Larimer	3 hr
Aug 3, 4:54 PM MDT	Severe Thunderstorm Warning	BOU	Elbert	51 min
Aug 3, 4:57 PM MDT	Severe Thunderstorm Warning	BOU	Adams	48 min
Aug 3, 5:00 PM MDT	Special Weather Statement	BOU	Weld	45 min
Aug 3, 5:11 PM MDT	Severe Thunderstorm Warning	BOU	Larimer	34 min
Aug 3, 5:17 PM MDT	Flash Flood Warning	BOU	Larimer	104 min
Aug 3, 5:26 PM MDT	Special Weather Statement	BOU	Denver	49 min
Aug 3, 5:40 PM MDT	Severe Thunderstorm Warning	BOU	Elbert, Lincoln	50 min
Aug 3, 5:43 PM MDT	Severe Thunderstorm Warning	BOU	Larimer, Weld	47 min
Aug 3, 5:48 PM MDT	Severe Thunderstorm Warning	BOU	Lincoln	42 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.