Tornadoes and Flash Flooding in Colorado, June 17 to 22, 2023

Name: Tornadoes and Flash Flooding in Colorado, June 17 to 22, 2023
Start: 2023-06-17T13:59
End: 2023-06-22T06:15
Location: Colorado

June 17 to 22, 2023 · NWS BOU · 94 events in 13 counties and zones

Where it happened

Every event with a place to put it. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 1
Injuries: 90
Property damage: $325,000
Crop damage: $45,000
Events: 94

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS BOU wrote it up.

Long duration severe weather event across the northeast plains, and most of the Denver metropolitan area beginning during the early afternoon hours. Scores of tornadoes occurred across Washington and Logan counties. Several rounds of hail across the Denver metro, with ping pong ball sized hail in downtown, larger hail up to 2 inches in diameter at concert in Red Rocks Amphitheatre. In all, seven patrons were hospitalized, with 83 treated on scene. A substantial number of attendees suffered welts, bruises and broken fingers trying to protect themselves. Several suffered concussions as well. A total of 33 tornadoes touched down in Washington County, with 3 reported in Logan County. There were reports of at least one home damaged west of Sterling and one commercial building collapse in Sterling. The home was damaged by one of the tornadoes.

Significant flooding and flash flooding also occurred in portions of the plains, including Elbert, Arapahoe, Adams, Logan, Washington and Morgan counties. There were likely several rural roads that flooded due to the heavy rainfall. There was a flood fatality just south of I-70 along Watkins Rd. First responders found two stranded cars swept into a field, but its occupants had either gotten out or had been rescued. The third vehicle ended up west of Watkins and 6th Ave. in what is normally a dry creek bed. South Metro’s water rescue team was then called out to do a water rescue but that operation turned into a recovery by the following morning. Due to flooding, Watkins Road was closed between Interstate 70 and Jewell Ave. Interstate 70 was also closed for several hours until water could recede from flooded underpasses. Minor flooding also occurred in portions of the Denver and the surrounding metro area. Baseball size hail was observed in Washington County. In Clear Creek County, a thunderstorm wind gusts to 68 mph was recorded.

What forecasters said that day

The local office's own words before the first event, 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 the first event at Jun 17, 1:39 PM MST, 20 minutes earlier.

Area forecast discussion, Jun 17, 1:39 PM MST, 20 minutes before

Area Forecast Discussion
National Weather Service Denver/Boulder CO
239 PM MDT Sat Jun 17 2023

.SHORT TERM...(This evening through Sunday)
Issued at 239 PM MDT Sat Jun 17 2023

Developing squall line will pass out of our area late this
afternoon. There's enough CAPE for a threat of large hail, and the
wind field may be getting organized by then. We've had a few
funnel cloud reports with updrafts, but the environment doesn't
look particularly conducive to tornadogenesis in our area as the
winds are still fairly weak.

There's a loosely organized area of scattered storms upstream over
the mountains, but these are weaker and in a drying environment.
They may not do well coming over the mountains, but it's enough to
hand on to low PoPs until about sunset on the plains. After that,
there's still some mid/hi level moisture for partly cloudy skies
overnight and probably through Sunday. The forecast of 10-15
degrees warmer with no PoPs for Sunday looks good, though there
could be some weak convection and maybe some sprinkles over the
mountains mid to late afternoon.

.LONG TERM...(Sunday night through Saturday)
Issued at 239 PM MDT Sat Jun 17 2023

Colorado will spend most of the period between upper level
troughing to our northwest and ridging to our south and southeast.
There will be persistent and generally increasing southwesterly
flow aloft as those features intensify, promoting drier and warmer
weather than in recent weeks. Models maintain good consensus and
have been consistent. Ensemble forecast systems suggest fairly
high confidence in the fundamentals of the long term forecast.

Sunday evening through Tuesday, skies should be partly cloudy to
mostly clear as warm, dry air aloft suppresses cloudiness and
convection. There will be very little precipitation or threat of
thunderstorms. The warming trend still looks to peak on Monday,
though high temperatures are forecast mostly in the 80s across the
plains and 50s to 70s across the high country through the period.
Monday and Tuesday, some areas on the plains may break 90 F,
especially out near the northeast corner. I adjusted forecast high
temperatures up a few degrees for Monday and Tuesday to account
for model bias correction calibrated to the recent weeks of cool,
wet weather. A few areas around the southern Front Range
foothills, South Park and Middle Park may see very marginal Red
Flag humidity and wind conditions during the afternoon, but fuels
are still definitely non-critical and should remain so for quite
some time, which should mitigate fire weather concerns.

Wednesday, it looks like there will be a little disturbance aloft
and a cool front to bring temperatures back down to near normal
and increase humidity. In the afternoon, there will probably be
scattered showers with a few storms which might linger over the
eastern plains in the evening and night. The rest of the period,
moisture and cloudiness should increase again (not like the
previous weeks but better than earlier in the period), with
scattered to widespread showers possible each afternoon and
evening. It's a bit difficult to make reliable predictions of
hazards at this range, but model moisture, instability and shear
values are sufficient to support scattered severe thunderstorms
and potentially a few supercells. Locally heavy rainfall will
likely pose at least a limited risk of flash flooding to burn,
urban and poor drainage areas again.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 1200 PM MDT Sat Jun 17 2023

Scattered showers and thunderstorms will be in the Denver area
this afternoon, with the treat mainly before 22z. Instrument
approaches to KDEN will likely be needed for a few hours. Winds
will likely just switch to west to northwest direction, though
brief variable gusts up to 30 knots are possible. After 23z, VFR
conditions are expected through tonight.

&&

.HYDROLOGY...
Issued at 239 PM MDT Sat Jun 17 2023

Heavy rain with a band of thunderstorms may cause localized
flooding in Elbert and Lincoln counties through early evening.
After that, dry conditions are expected through Sunday.

Monday through about mid week, precipitation will be very
suppressed and there should be little to no threat of burn area
flash flooding.

From about mid week through the rest of the period, there may be
scattered to widespread showers each afternoon and evening; while
the impacts are not very certain at this range, it looks like
locally heavy rainfall will pose at least a limited risk of flash
flooding to the burn areas.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Flood Watch until 6 PM MDT this evening for COZ041-046-047.

&&

SHORT TERM...Gimmestad
LONG TERM...EJD
AVIATION...Gimmestad
HYDROLOGY...EJD/Gimmestad

Hazardous weather outlook, Jun 17, 10:02 AM MST, 3 hours 57 minutes before

Hazardous Weather Outlook
National Weather Service Denver/Boulder CO
1102 AM MDT Sat Jun 17 2023

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-
1102 AM MDT Sat Jun 17 2023

...FLOOD WATCH IN EFFECT TODAY FROM NOON THROUGH 6 PM MDT FOR
ELBERT AND LINCOLN COUNTIES...

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

.DAY ONE...Today and Tonight

Scattered showers and thunderstorms will move east from the
mountains across the plains this afternoon. A few severe
thunderstorms are possible on the plains south of Interstate 70.
Hail up to 2 inches in diameter and wind gusts to 60 mph may occur
with the strongest storms.

In addition, flash flooding will remain a threat across Elbert and
Lincoln counties this afternoon. Heavy rainfall from Friday
coupled with another round of strong storms could cause flash
flooding along creeks and streams that are already running high.
Storms will end in the mountains by early evening and on the
eastern plains a few hours later.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

Hazardous weather is not expected through Tuesday. There will be
scattered late day showers and thunderstorms Wednesday through
Friday, which could pose a limited threat of burn area flash
flooding.

.SPOTTER INFORMATION STATEMENT...

Formal spotter activation will not be needed, but reports of hail, heavy
rain or flooding will be appreciated.

Gimmestad/EJD

In the hours before

Special weather statement, Jun 17, 11:52 AM MST, 2 hours 7 minutes before

Special Weather Statement
National Weather Service Denver CO
1252 PM MDT Sat Jun 17 2023

COZ041-046-171930-
Elbert/Central and East Douglas Counties Above 6000 Feet CO-
North and Northeast Elbert County Below 6000 Feet/North Lincoln
County CO-
1252 PM MDT Sat Jun 17 2023

...Strong thunderstorms will impact portions of central Elbert County
through 130 PM MDT...

At 1250 PM MDT, trained weather spotters reported funnel clouds
along a line extending from 11 miles southwest of Agate to 5 miles
southwest of Elbert, or along a line extending from 24 miles west of
Limon to 22 miles northeast of Colorado Springs.
Movement was east at 10 mph.

HAZARD...Pea size hail.

SOURCE...Trained weather spotters.

IMPACT...Minor damage to outdoor objects is possible.

These storms will remain over mainly rural areas of central Elbert
County, which includes Fondis.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

If a tornado is spotted seek shelter inside a sturdy building.

Torrential rainfall is also occurring with these storms and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

A Severe Thunderstorm Watch remains in effect until 800 PM MDT for
east central Colorado.

&&

LAT...LON 3913 10469 3940 10415 3943 10386 3913 10449
TIME...MOT...LOC 1850Z 256DEG 5KT 3937 10413 3915 10459

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...<30 MPH

BARJENBRUCH

Special weather statement, Jun 17, 12:19 PM MST, 1 hour 40 minutes before

Special Weather Statement
National Weather Service Denver CO
119 PM MDT Sat Jun 17 2023

COZ038-172000-
Larimer County Below 6000 Feet/Northwest Weld County CO-
119 PM MDT Sat Jun 17 2023

...A strong thunderstorm will impact portions of north central Weld
County through 200 PM MDT...

At 119 PM MDT, Doppler radar was tracking a strong thunderstorm
capable of producing a landspout tornado 9 miles northeast of
Rockport, or 13 miles southeast of Cheyenne, moving east at 20 mph.

HAZARD...Landspouts possible, winds in excess of 40 mph, and pea
         size hail.

SOURCE...Radar indicated.

IMPACT...Landspout tornadoes can damage mobile homes, roofs,
         vehicles, and trees. Outdoor objects may be tossed about.
         Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Hereford.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

If a tornado is spotted seek shelter inside a sturdy building.

&&

LAT...LON 4099 10428 4088 10442 4096 10478 4100 10476
      4100 10428
TIME...MOT...LOC 1919Z 277DEG 17KT 4098 10465

LANDSPOUT...POSSIBLE
MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

BARJENBRUCH

The radar

The Pueblo radar (KPUX), 43 km away, was scanning. The volume nearest the first event began at 20:56 UTC.

Open the radar archive at this moment

Event by event

48 hail, 37 tornado, 4 flash flood, 3 thunderstorm wind, 2 flood. Local standard time, as filed.

Thunderstorm Wind, Lincoln

When: June 17, 1:59 PM MST
Where: Lincoln County, 16.02 mi SW of Karval
Measured: 52 kt (60 mph) measured gust
Reported by: Trained Spotter
Coordinates: 38.540, -103.700

Tornado, Logan

When: June 21, 12:44 PM MST to 12:47 PM MST
Where: Logan County, 4.35 mi SSW of Padroni to 4.28 mi SSW of Padroni
Rating: EFU
Path length: 0.46 mi
Path width: 25 yd
Reported by: Trained Spotter
Coordinates: 40.711, -103.199

A tornado touched down briefly in an open field. No damage was observed.

Hail, Logan

When: June 21, 1:08 PM MST
Where: Logan County, 3.91 mi WNW of Padroni
Measured: 1.75 in hail
Reported by: Law Enforcement
Coordinates: 40.790, -103.240

Hail, Logan

When: June 21, 2:03 PM MST
Where: Logan County, 5.8 mi W of Padroni
Measured: 2 in hail
Reported by: Trained Spotter
Coordinates: 40.760, -103.280

Tornado, Washington

When: June 21, 2:05 PM MST to 2:10 PM MST
Where: Washington County, 5.68 mi SE of Platner to 5.66 mi SSW of Otis
Rating: EFU
Path length: 0.66 mi
Path width: 25 yd
Reported by: Storm Chaser
Coordinates: 40.066, -102.989

A tornado touched down briefly in an open field. No damage was observed.

Hail, Logan

When: June 21, 2:32 PM MST
Where: Logan County, 3.15 mi W of Sterling Arpt
Measured: 1.25 in hail
Reported by: Trained Spotter
Coordinates: 40.620, -103.330

Tornado, Logan

When: June 21, 2:35 PM MST to 2:46 PM MST
Where: Logan County, 9.88 mi WNW of Sterling Arpt to 10.79 mi N of Willard
Rating: EFU
Path length: 1.44 mi
Path width: 25 yd
Reported by: Trained Spotter
Coordinates: 40.699, -103.427

A tornado touched down briefly in an open field. No damage was observed.

Hail, Washington

When: June 21, 2:42 PM MST
Where: Washington County, 5.78 mi SSW of Platner
Measured: 2.75 in hail
Reported by: Trained Spotter
Coordinates: 40.050, -103.130

Tornado, Washington

When: June 21, 3:10 PM MST to 3:11 PM MST
Where: Washington County, 5.49 mi N of Elba to 5.47 mi N of Elba
Rating: EFU
Path length: 0.3 mi
Path width: 25 yd
Reported by: Trained Spotter
Coordinates: 39.999, -103.190

A tornado touched down briefly in an open field. No damage was observed.

Tornado, Washington

When: June 21, 3:18 PM MST to 3:22 PM MST
Where: Washington County, 6.85 mi N of Elba to 7.07 mi N of Elba
Rating: EFU
Path length: 0.51 mi
Path width: 25 yd
Reported by: Storm Chaser
Coordinates: 40.019, -103.194

A tornado briefly touched down in open country. No damage was observed.

Tornado, Washington

When: June 21, 3:25 PM MST to 3:26 PM MST
Where: Washington County, 6.72 mi N of Elba to 6.97 mi N of Elba
Rating: EFU
Path length: 0.69 mi
Path width: 50 yd
Reported by: Storm Chaser
Coordinates: 40.017, -103.186

A tornado briefly touched down in open country. No damage was observed.

Tornado, Washington

When: June 21, 3:28 PM MST to 3:29 PM MST
Where: Washington County, 6.97 mi N of Elba to 7.08 mi N of Elba
Rating: EFU
Path length: 0.24 mi
Path width: 50 yd
Reported by: Storm Chaser
Coordinates: 40.020, -103.197

A tornado briefly touched down in open country. No damage was observed.

Tornado, Washington

When: June 21, 3:28 PM MST to 3:35 PM MST
Where: Washington County, 7.12 mi N of Elba to 7.95 mi NNW of Elba
Rating: EF2
Path length: 1.85 mi
Path width: 400 yd
Property damage: $15,000
Reported by: Storm Chaser
Coordinates: 40.022, -103.202

A large tornado with estimated peak winds to 118 mph, snapped power poles as it crossed Highway 63.

Tornado, Washington

When: June 21, 3:29 PM MST to 3:30 PM MST
Where: Washington County, 6.96 mi N of Elba to 7.05 mi N of Elba
Rating: EFU
Path length: 0.2 mi
Path width: 25 yd
Reported by: Storm Chaser
Coordinates: 40.020, -103.196

A second weaker satellite tornado, formed in close proximity to the EF2 tornado, briefly touched down in open country. No damage was observed.

Tornado, Washington

When: June 21, 3:31 PM MST to 3:34 PM MST
Where: Washington County, 6.96 mi N of Elba to 7.48 mi NNW of Elba
Rating: EFU
Path length: 1.6 mi
Path width: 50 yd
Reported by: Trained Spotter
Coordinates: 40.020, -103.189

Another satellite tornado, formed in open country near the EF2 tornado, and eventually wrapped into it. No damage was observed.