Flash Flooding and Flood in Colorado, June 29 to 30, 2023

Name: Flash Flooding and Flood in Colorado, June 29 to 30, 2023
Start: 2023-06-29T00:20
End: 2023-06-30T08:00
Location: Colorado

June 29 to 30, 2023 · NWS BOU · 38 events in 6 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: 5
Property damage: $79,000
Crop damage: None recorded
Events: 38

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.

Severe thunderstorms produced large hail, from penny to tennis ball size across parts of Jefferson, Adams, Arapahoe, Denver and Washington counties. The hail along with heavy rain caused flooding and flash flooding problems. In Adams County, widespread hail accumulated up to 6 inches deep on the roadways between Watkins and Bennett, with localized accumulations up to a foot reported. Highway 36 was closed due to flooding between Watkins and Schumaker Road. Numerous vehicles were stranded with reports of roads washed out and active water rescues. One motorist south of Roggen died when he ignored a barricade and drove into floodwaters. South Strasburg, intense straight-line winds snapped a power pole.

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 28, 7:28 PM MST, 4 hours 52 minutes earlier.

Area forecast discussion, Jun 28, 7:28 PM MST, 4 hours 52 minutes before

Area Forecast Discussion
National Weather Service Denver/Boulder CO
828 PM MDT Wed Jun 28 2023

.UPDATE...
Issued at 824 PM MDT Wed Jun 28 2023

The forecast is performing well with only minor updates this
evening.

The 00Z synoptic dataset shows the trough over the western states
and ridge over the southern and southeastern states, with brisk
southwesterly flow aloft over Colorado. Upstream soundings had
between 0.33 and 0.97 inches of precipitable water, in spite of
all being pretty well mixed to almost 500 mb. GOES water vapor
imagery shows good moisture in the trough and scattered convection
ahead.

Most of that activity stayed north of us but a few severe storms
are moving over our northeast corner this evening. In Wyoming, the
storms produced confirmed tornadoes and very large hail. On our
side of the border, similar hazards are likely but have not been
confirmed.

CAMs suggest more convection on the outflow from these storms
later this evening, to affect mainly Morgan and Washington
counties by 04Z then moving northeast early tonight. Storms are
currently weakening and the air in that area will be pretty well
worked over by late evening, so we don't consider scattered strong
storms later very likely, though some convection over that
outflow is reasonable.

Our partners and CDPHE issued an Ozone Action Day Alert for the
Front Range Urban Corridor valid tomorrow from 4 PM to 12 AM MDT,
as heat and light winds will likely allow ozone concentrations to
reach unhealthy levels. Refer to AQABOU for more information.

&&

.SHORT TERM...(This evening through Thursday)
Issued at 310 PM MDT Wed Jun 28 2023

Key Messages:

1. Chance for a few storms early eve/tonight along near north border
and northeast corner, capable of large hail and damaging winds

2. Higher chances for thunderstorms Thurs. with a severe threat for
large hail and damaging winds

Temperatures are slowly warming into the low 80s this afternoon
across the plains and urban corridor. Main concern and forecast
challenge for the remainder of the afternoon/evening will be the
potential for isolated showers and thunderstorms. SPC mesoscale
analysis shows CIN across the the urban corridor. This will act as a
barrier for convective development, lowering storm chances. Further
east over the plains it is a similar story on whether it will heat
enough to weaken the cap. There is less CIN out there and satellite
shows Cu development in some areas. CAMs continue to settle on the
capping scenario with solutions resolving little to no convection
which is the more likely case. Although a few solutions seem to grab
onto potential for a storm or two across the north border and
northeast corner either early evening or late evening with the
front. Regardless, can't rule out the chance of a storm developing
in the more favored north/northeast corner from an outflow boundary
feature coming from storms to the north. Given the favorable
environment, a strong to severe storm will be favored with large
hail and damaging winds possible. The main cold front moves
southward between 02Z-07Z which may also result in chances for a few
showers or storms to clip the north border in that very early Thurs
timeframe. Bottom line, the environment is favorable for storms, but
it needs something to make it go like a boundary or convergence.

The region remains in a cooler, moist post-frontal airmass Thursday
with weak synoptic ascent. Early Thursday morning, the increase in
low-level moisture behind the front will develop low level stratus.
Model soundings hang onto the low-level moisture keeping stratus
around through late morning, lifting slightly and becoming more
broken by the afternoon. Despite the cloud cover, models are
consistent with indicating a favorable convective environment
tomorrow afternoon with the moist and unstable airmass. MLCAPE
values build into the 1500-2500 J/kg range with 0-6 km bulk shear 40-
55 kts. Soundings show a strong signal for large hail with MUCAPE
2000J/kg+ and a sufficient area of CAPE, dry mid-level air, and
decent area of CAPE along the lifted parcel profile. Storms likely
initiate over the Palmer Divide mid-afternoon to start with storms
developing across the I-25 corridor and then eastward through late
afternoon/early evening. Hail and wind will be the main threats.

.LONG TERM...(Thursday night through Wednesday)
Issued at 310 PM MDT Wed Jun 28 2023

Thunderstorms, some severe, will likely become more numerous and
spread east across the plains through Thursday evening as the cap
weakens further. We think the severe storm threat with large hail,
damaging winds, and a couple tornadoes will last til at least mid
evening given the amount of instability (MLCAPE near 2000 J/kg)
and shear (bulk shear 55-60 kts). However,some of the latest data
suggests tornado threat could be limited by a weaker easterly low
level flow, while other models still have significant 0-1 SRH of
100-150 m2/s2. Would expect locally heavy rain and at least a low
flash flood threat give storm intensity, deeper moisture profile,
and dewpoints in the lower 60s over the eastern plains.
Fortunately, storms should be moving quickly.

Friday will be a cooler and rather wet day. There may be a few
showers around already in the morning as an upper level trough and
deeper moisture arrives from the west. With continued forcing,
we'll see showers and storms become more widespread and probably a
couple hours earlier than normal given the early arrival of the
upper level trough. At this point, the trough axis is still
expected to hold off late enough in the day to bring more
widespread showers and storms. Bulk shear decreases as the upper
level trough arrives, but there's still enough shear and
instability over the eastern plains for a severe storm threat.
That said, main focus will likely shift toward storms with locally
heavy rain and a flash flood threat. More on that in the
Hydrology section below. High temperatures will likely only reach
the lower to mid 70s on the plains, with 60s in most mountain and
foothill locales.

Saturday will see drier conditions with weak subsidence and
downslope flow developing. Still can't rule out an isolated storm
or two, but they would be high based and weaker. Sunday may see a
little moisture build under the flat ridge, but overall storm
intensity should remain weaker with limited CAPE. Temperatures
will show a warming this weekend with highs returning to near
normal (upper 80s for the plains).

Ensembles are still pointing toward somewhat more active weather
and higher afternoon and evening storm coverage toward the 4th.
While it's hard to pin down any specifics, ensembles suggest a
more zonal flow and possibly a weak backdoor cold front or two
that could lead to more low level moisture and instability. Given
that, there is reasonable confidence we should stay at or below
normal temperatures for the middle portion of next week.

&&

.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 824 PM MDT Wed Jun 28 2023

Expect VFR conditions through this evening and much of tonight,
then MVFR conditions are likely before sunrise with low clouds
behind a weak front. Patchy fog is possible in the early morning
as well, but lower confidence and not yet included in the TAF.
Moderate easterly to northeasterly winds likely to persist through
the evening and much of tonight, outflow from storms, then winds
to come around southeasterly in the morning. Scattered showers and
storms in the vicinity tomorrow afternoon and evening.

&&

.HYDROLOGY...
Issued at 310 PM MDT Wed Jun 28 2023

Isolated thunderstorms mainly on the plains this evening could
produce very localized heavy rain. The threat of burn area
flooding is very low because the strong storms are expected to be
east of the burn areas.

Strong to severe thunderstorms are expected to form Thursday
afternoon and evening. In addition to hail and strong winds, very
heavy rainfall will be possible with the storms, which could
produce localized flooding. With a somewhat strong flow aloft most
storms should be moving quickly.

For Friday, the upper level trough moves over Colorado and brings
weaker winds aloft. Numerous showers and thunderstorms are
expected again for Friday, and storm movement will be slower.
Precipitable water values increase to around 1" across the I-25
Corridor and 1.25" over the eastern plains. Meanwhile, warm cloud
depth increase to around 5,000 feet across the Front Range. Thus,
storms will be more efficient rain producers and be capable of
producing 1-2" of rain in less than 45 minutes. The threat of
flash flooding will increase Friday (not just in the recent burn
areas) and a Flash Flood Watch may be eventually be needed over
the Foothills and Plains.

Saturday into early next week will trend to higher based storms
with limited if any threat of flash flooding in the susceptible
areas.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&

UPDATE...EJD
SHORT TERM...Mensch
LONG TERM...Barjenbruch
AVIATION...EJD
HYDROLOGY...Barjenbruch

Hazardous weather outlook, Jun 28, 9:56 AM MST, 14 hours 24 minutes before

Hazardous Weather Outlook
National Weather Service Denver/Boulder CO
1056 AM MDT Wed Jun 28 2023

COZ030>051-291700-
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-
1056 AM MDT Wed Jun 28 2023

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

.DAY ONE...Today and Tonight

A few severe thunderstorms are possible this evening and tonight.
The main threat is north of a line from Fort Collins to Akron
between 6 PM and 2 AM. The strongest storms could produce hail up
to tennis ball size, wind gusts to 70 mph, and tornadoes.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday

Scattered to numerous thunderstorms, some severe, are expected to
form along and east of the foothills Thursday afternoon and
evening. Large hail, damaging winds, and even a few tornadoes
will be possible.

On Friday, additional scattered to numerous showers and
thunderstorms are expected. The severe threat may decrease
somewhat as the main threat shifts slowly south and east.
However, storm movement will be slower, which will increase the
threat for flash flooding.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed after 3 PM.

In the hours before

Local storm report, Jun 28, 8:36 PM MST, 3 hours 44 minutes before

Preliminary Local Storm Report
National Weather Service Denver CO
936 PM MDT Wed Jun 28 2023

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

0932 PM     Hail             Haxtun                  40.64N 102.63W
06/28/2023  E2.75 inch       Phillips           CO   Law Enforcement

0928 PM     Hail             1 N Haxtun              40.66N 102.63W
06/28/2023  E1.75 inch       Phillips           CO   Public

0925 PM     Hail             Iliff                   40.76N 103.06W
06/28/2023  E1.00 inch       Logan              CO   Public

            Report from mPING: Quarter (1.00 in.).

0913 PM     Hail             Fleming                 40.68N 102.84W
06/28/2023  M2.75 inch       Logan              CO   Public

            Report from mPING: Baseball (2.75 in.).

0900 PM     Hail             9 NE Westplains         40.96N 103.38W
06/28/2023  M2.50 inch       Logan              CO   Public

0854 PM     Hail             6 WSW Peetz             40.93N 103.23W
06/28/2023  E2.00 inch       Logan              CO   Public

            Report from mPING: Hen Egg (2.00 in.).

0854 PM     Hail             6 W Peetz               40.95N 103.23W
06/28/2023  E2.25 inch       Logan              CO   Public

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

0834 PM     Hail             3 NE Iliff              40.79N 103.02W
06/28/2023  M3.00 inch       Logan              CO   Public

0813 PM     Tornado          3 ENE Iliff             40.78N 103.01W
06/28/2023                   Logan              CO   Public

            Corrects previous tornado report from 3 ENE
            Iliff. Twitter.

&&

Local storm report, Jun 28, 10:09 PM MST, 2 hours 11 minutes before

Preliminary Local Storm Report
National Weather Service Denver CO
1109 PM MDT Wed Jun 28 2023

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

1105 PM     Hail             12 SE Holyoke           40.46N 102.14W
06/28/2023  M1.75 inch       Phillips           CO   Trained Spotter

1100 PM     Hail             Brush                   40.26N 103.63W
06/28/2023  E2.75 inch       Morgan             CO   Public

            Report from mPING: Baseball (2.75 in.).

1100 PM     Hail             1 NNW Brush             40.27N 103.64W
06/28/2023  E2.50 inch       Morgan             CO   Public

            Report from mPING: Tennis Ball (2.50 in.).

1054 PM     Hail             1 WNW Log Lane Village  40.28N 103.85W
06/28/2023  M2.75 inch       Morgan             CO   Trained Spotter

1047 PM     Hail             2 NNE Fort Morgan       40.29N 103.78W
06/28/2023  M2.00 inch       Morgan             CO   Trained Spotter

1045 PM     Hail             6 SE Holyoke            40.53N 102.22W
06/28/2023  M1.75 inch       Phillips           CO   Trained Spotter

1045 PM     Tstm Wnd Gst     6 SE Holyoke            40.53N 102.22W
06/28/2023  M82 MPH          Phillips           CO   Trained Spotter

1037 PM     Hail             1 WNW Log Lane Village  40.28N 103.85W
06/28/2023  M2.50 inch       Morgan             CO   Trained Spotter

1032 PM     Hail             Holyoke                 40.58N 102.30W
06/28/2023  M1.75 inch       Phillips           CO   Law Enforcement

1022 PM     Tstm Wnd Gst     8 S Holyoke             40.47N 102.30W
06/28/2023  M81 MPH          Phillips           CO   Mesonet

1012 PM     Hail             1 NE Sterling           40.64N 103.20W
06/28/2023  E1.00 inch       Logan              CO   Public

            Report from mPING: Quarter (1.00 in.).

1011 PM     Hail             Sterling                40.62N 103.21W
06/28/2023  E1.25 inch       Logan              CO   Trained Spotter

1008 PM     Hail             Sterling                40.63N 103.21W
06/28/2023  M1.00 inch       Logan              CO   Trained Spotter

1003 PM     Hail             Sterling                40.63N 103.21W
06/28/2023  E1.00 inch       Logan              CO   Trained Spotter

0937 PM     Hail             1 N Haxtun              40.66N 102.63W
06/28/2023  E1.00 inch       Phillips           CO   Public

0932 PM     Hail             Haxtun                  40.64N 102.63W
06/28/2023  E2.75 inch       Phillips           CO   Law Enforcement

0928 PM     Hail             1 N Haxtun              40.66N 102.63W
06/28/2023  E1.75 inch       Phillips           CO   Public

0925 PM     Hail             Iliff                   40.76N 103.06W
06/28/2023  E1.00 inch       Logan              CO   Public

            Report from mPING: Quarter (1.00 in.).

0913 PM     Hail             Fleming                 40.68N 102.84W
06/28/2023  M2.75 inch       Logan              CO   Public

            Report from mPING: Baseball (2.75 in.).

0900 PM     Hail             9 NE Westplains         40.96N 103.38W
06/28/2023  M2.50 inch       Logan              CO   Public

0854 PM     Hail             6 W Peetz               40.95N 103.23W
06/28/2023  E2.25 inch       Logan              CO   Public

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

0854 PM     Hail             6 WSW Peetz             40.93N 103.23W
06/28/2023  E2.00 inch       Logan              CO   Public

            Report from mPING: Hen Egg (2.00 in.).

0834 PM     Hail             Iliff                   40.76N 103.07W
06/28/2023  M4.00 inch       Logan              CO   Trained Spotter

            Radar used to estimate time.

0834 PM     Hail             3 NE Iliff              40.79N 103.02W
06/28/2023  M3.00 inch       Logan              CO   Public

0813 PM     Tornado          3 ENE Iliff             40.78N 103.01W
06/28/2023                   Logan              CO   Public

            Corrects previous tornado report from 3 ENE
            Iliff. Twitter.

&&

Local storm report, Jun 28, 10:33 PM MST, 1 hour 47 minutes before

Preliminary Local Storm Report
National Weather Service Denver CO
1133 PM MDT Wed Jun 28 2023

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

1116 PM     Hail             1 NNE Brush             40.27N 103.62W
06/28/2023  M2.75 inch       Morgan             CO   Public

            Report from mPING: Baseball (2.75 in.).

1107 PM     Hail             Brush                   40.26N 103.63W
06/28/2023  M3.00 inch       Morgan             CO   Public

            Twitter post of hail slightly larger than a
            baseball.

1105 PM     Hail             3 WSW Brush             40.25N 103.69W
06/28/2023  M2.75 inch       Morgan             CO   Trained Spotter

1105 PM     Hail             12 SE Holyoke           40.46N 102.14W
06/28/2023  M1.75 inch       Phillips           CO   Trained Spotter

1100 PM     Hail             Roggen                  40.17N 104.37W
06/28/2023  M1.00 inch       Weld               CO   Public

            Time estimate based on radar.

1100 PM     Hail             1 NNW Brush             40.27N 103.64W
06/28/2023  E2.50 inch       Morgan             CO   Public

            Report from mPING: Tennis Ball (2.50 in.).

1100 PM     Hail             Brush                   40.26N 103.63W
06/28/2023  E2.75 inch       Morgan             CO   Public

            Report from mPING: Baseball (2.75 in.).

1054 PM     Hail             1 WNW Log Lane Village  40.28N 103.85W
06/28/2023  M2.75 inch       Morgan             CO   Trained Spotter

1047 PM     Hail             2 NNE Fort Morgan       40.29N 103.78W
06/28/2023  M2.00 inch       Morgan             CO   Trained Spotter

1045 PM     Tstm Wnd Gst     6 SE Holyoke            40.53N 102.22W
06/28/2023  M82 MPH          Phillips           CO   Trained Spotter

1045 PM     Hail             6 SE Holyoke            40.53N 102.22W
06/28/2023  M1.75 inch       Phillips           CO   Trained Spotter

1037 PM     Hail             1 WNW Log Lane Village  40.28N 103.85W
06/28/2023  M2.50 inch       Morgan             CO   Trained Spotter

1032 PM     Hail             Holyoke                 40.58N 102.30W
06/28/2023  M1.75 inch       Phillips           CO   Law Enforcement

1028 PM     Hail             Fort Lupton             40.09N 104.81W
06/28/2023  M1.50 inch       Weld               CO   Public

            Time estimate based on radar.

1025 PM     Hail             .6 SW Holyoke           40.58N 102.31W
06/28/2023  M1.25 inch       Phillips           CO   Trained Spotter

1022 PM     Tstm Wnd Gst     8 S Holyoke             40.47N 102.30W
06/28/2023  M81 MPH          Phillips           CO   Mesonet

1012 PM     Hail             1 NE Sterling           40.64N 103.20W
06/28/2023  E1.00 inch       Logan              CO   Public

            Report from mPING: Quarter (1.00 in.).

1011 PM     Hail             Sterling                40.62N 103.21W
06/28/2023  E1.25 inch       Logan              CO   Trained Spotter

1008 PM     Hail             Sterling                40.63N 103.21W
06/28/2023  M1.00 inch       Logan              CO   Trained Spotter

1003 PM     Hail             Sterling                40.63N 103.21W
06/28/2023  E1.00 inch       Logan              CO   Trained Spotter

0937 PM     Hail             1 N Haxtun              40.66N 102.63W
06/28/2023  E1.00 inch       Phillips           CO   Public

0932 PM     Hail             Haxtun                  40.64N 102.63W
06/28/2023  E2.75 inch       Phillips           CO   Law Enforcement

0928 PM     Hail             1 N Haxtun              40.66N 102.63W
06/28/2023  E1.75 inch       Phillips           CO   Public

0925 PM     Hail             Iliff                   40.76N 103.06W
06/28/2023  E1.00 inch       Logan              CO   Public

            Report from mPING: Quarter (1.00 in.).

0913 PM     Hail             Fleming                 40.68N 102.84W
06/28/2023  M2.75 inch       Logan              CO   Public

            Report from mPING: Baseball (2.75 in.).

0900 PM     Hail             9 NE Westplains         40.96N 103.38W
06/28/2023  M2.50 inch       Logan              CO   Public

0854 PM     Hail             6 WSW Peetz             40.93N 103.23W
06/28/2023  E2.00 inch       Logan              CO   Public

            Report from mPING: Hen Egg (2.00 in.).

0854 PM     Hail             6 W Peetz               40.95N 103.23W
06/28/2023  E2.25 inch       Logan              CO   Public

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

0834 PM     Hail             3 NE Iliff              40.79N 103.02W
06/28/2023  M3.00 inch       Logan              CO   Public

0834 PM     Hail             Iliff                   40.76N 103.07W
06/28/2023  M4.00 inch       Logan              CO   Trained Spotter

            Radar used to estimate time.

0813 PM     Tornado          3 ENE Iliff             40.78N 103.01W
06/28/2023                   Logan              CO   Public

            Corrects previous tornado report from 3 ENE
            Iliff. Twitter.

&&

Local storm report, Jun 28, 11:17 PM MST, 1 hour 3 minutes before

Preliminary Local Storm Report...Summary
National Weather Service Denver CO
1217 AM MDT Thu Jun 29 2023

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

1201 AM     Hail             2 SE Akron              40.14N 103.18W
06/29/2023  M2.50 inch       Washington         CO   Public

1154 PM     Hail             5 W Akron               40.16N 103.31W
06/28/2023  M2.50 inch       Washington         CO   Storm Chaser

1137 PM     Hail             Wiggins                 40.23N 104.07W
06/28/2023  M1.00 inch       Morgan             CO   Public

1116 PM     Hail             1 NNE Brush             40.27N 103.62W
06/28/2023  M2.75 inch       Morgan             CO   Public

            Report from mPING: Baseball (2.75 in.).

1107 PM     Hail             Brush                   40.26N 103.63W
06/28/2023  M3.00 inch       Morgan             CO   Public

            Twitter post of hail slightly larger than a
            baseball.

1105 PM     Hail             12 SE Holyoke           40.46N 102.14W
06/28/2023  M1.75 inch       Phillips           CO   Trained Spotter

1105 PM     Hail             3 WSW Brush             40.25N 103.69W
06/28/2023  M2.75 inch       Morgan             CO   Trained Spotter

1100 PM     Hail             Brush                   40.26N 103.63W
06/28/2023  E2.75 inch       Morgan             CO   Public

            Report from mPING: Baseball (2.75 in.).

1100 PM     Hail             1 NNW Brush             40.27N 103.64W
06/28/2023  E2.50 inch       Morgan             CO   Public

            Report from mPING: Tennis Ball (2.50 in.).

1100 PM     Hail             Roggen                  40.17N 104.37W
06/28/2023  M1.00 inch       Weld               CO   Public

            Time estimate based on radar.

1054 PM     Hail             1 WNW Log Lane Village  40.28N 103.85W
06/28/2023  M2.75 inch       Morgan             CO   Trained Spotter

1052 PM     Hail             2 N Fort Morgan         40.29N 103.79W
06/28/2023  M3.00 inch       Morgan             CO   Public

1047 PM     Hail             2 NNE Fort Morgan       40.29N 103.78W
06/28/2023  M2.00 inch       Morgan             CO   Trained Spotter

1045 PM     Hail             6 SE Holyoke            40.53N 102.22W
06/28/2023  M1.75 inch       Phillips           CO   Trained Spotter

1045 PM     Tstm Wnd Gst     6 SE Holyoke            40.53N 102.22W
06/28/2023  M82 MPH          Phillips           CO   Trained Spotter

1041 PM     Hail             2.5 N Fort Morgan       40.30N 103.79W
06/28/2023  M3.00 inch       Morgan             CO   Public

            Twitter post showing 3 inch hail.

1037 PM     Hail             1 WNW Log Lane Village  40.28N 103.85W
06/28/2023  M2.50 inch       Morgan             CO   Trained Spotter

1032 PM     Hail             Holyoke                 40.58N 102.30W
06/28/2023  M1.75 inch       Phillips           CO   Law Enforcement

1028 PM     Hail             Fort Lupton             40.09N 104.81W
06/28/2023  M1.50 inch       Weld               CO   Public

            Time estimate based on radar.

1025 PM     Hail             .6 SW Holyoke           40.58N 102.31W
06/28/2023  M1.25 inch       Phillips           CO   Trained Spotter

1022 PM     Tstm Wnd Gst     8 S Holyoke             40.47N 102.30W
06/28/2023  M81 MPH          Phillips           CO   Mesonet

1012 PM     Hail             1 NE Sterling           40.64N 103.20W
06/28/2023  E1.00 inch       Logan              CO   Public

            Report from mPING: Quarter (1.00 in.).

1011 PM     Hail             Sterling                40.62N 103.21W
06/28/2023  E1.25 inch       Logan              CO   Trained Spotter

1008 PM     Hail             Sterling                40.63N 103.21W
06/28/2023  M1.00 inch       Logan              CO   Trained Spotter

1003 PM     Hail             Sterling                40.63N 103.21W
06/28/2023  E1.00 inch       Logan              CO   Trained Spotter

0937 PM     Hail             1 N Haxtun              40.66N 102.63W
06/28/2023  E1.00 inch       Phillips           CO   Public

0932 PM     Hail             Haxtun                  40.64N 102.63W
06/28/2023  E2.75 inch       Phillips           CO   Law Enforcement

0928 PM     Hail             1 N Haxtun              40.66N 102.63W
06/28/2023  E1.75 inch       Phillips           CO   Public

0925 PM     Hail             Iliff                   40.76N 103.06W
06/28/2023  E1.00 inch       Logan              CO   Public

            Report from mPING: Quarter (1.00 in.).

0913 PM     Hail             Fleming                 40.68N 102.84W
06/28/2023  M2.75 inch       Logan              CO   Public

            Report from mPING: Baseball (2.75 in.).

0900 PM     Hail             9 NE Westplains         40.96N 103.38W
06/28/2023  M2.50 inch       Logan              CO   Public

0854 PM     Hail             6 W Peetz               40.95N 103.23W
06/28/2023  E2.25 inch       Logan              CO   Public

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

0854 PM     Hail             6 WSW Peetz             40.93N 103.23W
06/28/2023  E2.00 inch       Logan              CO   Public

            Report from mPING: Hen Egg (2.00 in.).

0834 PM     Hail             Iliff                   40.76N 103.07W
06/28/2023  M4.00 inch       Logan              CO   Trained Spotter

            Radar used to estimate time.

0834 PM     Hail             3 NE Iliff              40.79N 103.02W
06/28/2023  M3.00 inch       Logan              CO   Public

0813 PM     Tornado          3 ENE Iliff             40.78N 103.01W
06/28/2023                   Logan              CO   Public

            Corrects previous tornado report from 3 ENE
            Iliff. Twitter.

&&

Local storm report, Jun 28, 11:35 PM MST, 45 minutes before

Preliminary Local Storm Report...Summary
National Weather Service Denver CO
1235 AM MDT Thu Jun 29 2023

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

1228 AM     Hail             Otis                    40.15N 102.96W
06/29/2023  M2.00 inch       Washington         CO   Public

1201 AM     Hail             2 SE Akron              40.14N 103.18W
06/29/2023  M2.50 inch       Washington         CO   Public

1200 AM     Hail             Akron                   40.16N 103.21W
06/29/2023  M3.00 inch       Washington         CO   Public

1158 PM     Hail             1 NW Akron              40.17N 103.23W
06/28/2023  M3.00 inch       Washington         CO   Public

1154 PM     Hail             1 NW Akron              40.17N 103.23W
06/28/2023  M3.00 inch       Washington         CO   Public

1154 PM     Hail             5 W Akron               40.16N 103.31W
06/28/2023  M2.50 inch       Washington         CO   Storm Chaser

1137 PM     Hail             Wiggins                 40.23N 104.07W
06/28/2023  M1.00 inch       Morgan             CO   Public

1116 PM     Hail             1 NNE Brush             40.27N 103.62W
06/28/2023  M2.75 inch       Morgan             CO   Public

            Report from mPING: Baseball (2.75 in.).

1107 PM     Hail             Brush                   40.26N 103.63W
06/28/2023  M3.00 inch       Morgan             CO   Public

            Twitter post of hail slightly larger than a
            baseball.

1105 PM     Hail             3 WSW Brush             40.25N 103.69W
06/28/2023  M2.75 inch       Morgan             CO   Trained Spotter

1105 PM     Hail             12 SE Holyoke           40.46N 102.14W
06/28/2023  M1.75 inch       Phillips           CO   Trained Spotter

1100 PM     Hail             Roggen                  40.17N 104.37W
06/28/2023  M1.00 inch       Weld               CO   Public

            Time estimate based on radar.

1100 PM     Hail             1 NNW Brush             40.27N 103.64W
06/28/2023  E2.50 inch       Morgan             CO   Public

            Report from mPING: Tennis Ball (2.50 in.).

1100 PM     Hail             Brush                   40.26N 103.63W
06/28/2023  E2.75 inch       Morgan             CO   Public

            Report from mPING: Baseball (2.75 in.).

1054 PM     Hail             1 WNW Log Lane Village  40.28N 103.85W
06/28/2023  M2.75 inch       Morgan             CO   Trained Spotter

1052 PM     Hail             2 N Fort Morgan         40.29N 103.79W
06/28/2023  M3.00 inch       Morgan             CO   Public

1047 PM     Hail             2 NNE Fort Morgan       40.29N 103.78W
06/28/2023  M2.00 inch       Morgan             CO   Trained Spotter

1045 PM     Tstm Wnd Gst     6 SE Holyoke            40.53N 102.22W
06/28/2023  M82 MPH          Phillips           CO   Trained Spotter

1045 PM     Hail             6 SE Holyoke            40.53N 102.22W
06/28/2023  M1.75 inch       Phillips           CO   Trained Spotter

1041 PM     Hail             2.5 N Fort Morgan       40.30N 103.79W
06/28/2023  M3.00 inch       Morgan             CO   Public

            Twitter post showing 3 inch hail.

1037 PM     Hail             1 WNW Log Lane Village  40.28N 103.85W
06/28/2023  M2.50 inch       Morgan             CO   Trained Spotter

1032 PM     Hail             Holyoke                 40.58N 102.30W
06/28/2023  M1.75 inch       Phillips           CO   Law Enforcement

1028 PM     Hail             Fort Lupton             40.09N 104.81W
06/28/2023  M1.50 inch       Weld               CO   Public

            Time estimate based on radar.

1025 PM     Hail             .6 SW Holyoke           40.58N 102.31W
06/28/2023  M1.25 inch       Phillips           CO   Trained Spotter

1022 PM     Tstm Wnd Gst     8 S Holyoke             40.47N 102.30W
06/28/2023  M81 MPH          Phillips           CO   Mesonet

1012 PM     Hail             1 NE Sterling           40.64N 103.20W
06/28/2023  E1.00 inch       Logan              CO   Public

            Report from mPING: Quarter (1.00 in.).

1011 PM     Hail             Sterling                40.62N 103.21W
06/28/2023  E1.25 inch       Logan              CO   Trained Spotter

1008 PM     Hail             Sterling                40.63N 103.21W
06/28/2023  M1.00 inch       Logan              CO   Trained Spotter

1003 PM     Hail             Sterling                40.63N 103.21W
06/28/2023  E1.00 inch       Logan              CO   Trained Spotter

0937 PM     Hail             1 N Haxtun              40.66N 102.63W
06/28/2023  E1.00 inch       Phillips           CO   Public

0932 PM     Hail             Haxtun                  40.64N 102.63W
06/28/2023  E2.75 inch       Phillips           CO   Law Enforcement

0928 PM     Hail             1 N Haxtun              40.66N 102.63W
06/28/2023  E1.75 inch       Phillips           CO   Public

0925 PM     Hail             Iliff                   40.76N 103.06W
06/28/2023  E1.00 inch       Logan              CO   Public

            Report from mPING: Quarter (1.00 in.).

0913 PM     Hail             Fleming                 40.68N 102.84W
06/28/2023  M2.75 inch       Logan              CO   Public

            Report from mPING: Baseball (2.75 in.).

0900 PM     Hail             9 NE Westplains         40.96N 103.38W
06/28/2023  M2.50 inch       Logan              CO   Public

0854 PM     Hail             6 WSW Peetz             40.93N 103.23W
06/28/2023  E2.00 inch       Logan              CO   Public

            Report from mPING: Hen Egg (2.00 in.).

0854 PM     Hail             6 W Peetz               40.95N 103.23W
06/28/2023  E2.25 inch       Logan              CO   Public

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

0834 PM     Hail             3 NE Iliff              40.79N 103.02W
06/28/2023  M3.00 inch       Logan              CO   Public

0834 PM     Hail             Iliff                   40.76N 103.07W
06/28/2023  M4.00 inch       Logan              CO   Trained Spotter

            Radar used to estimate time.

0813 PM     Tornado          3 ENE Iliff             40.78N 103.01W
06/28/2023                   Logan              CO   Public

            Corrects previous tornado report from 3 ENE
            Iliff. Twitter.

&&

Local storm report, Jun 28, 11:49 PM MST, 31 minutes before

Preliminary Local Storm Report...Summary
National Weather Service Denver CO
1249 AM MDT Thu Jun 29 2023

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

1240 AM     Hail             1 E Masters             40.29N 104.23W
06/29/2023  E1.00 inch       Weld               CO   Public

            Report from mPING: Quarter (1.00 in.).

1229 AM     Hail             Otis                    40.15N 102.96W
06/29/2023  M2.50 inch       Washington         CO   Public

1228 AM     Hail             Otis                    40.15N 102.96W
06/29/2023  M2.00 inch       Washington         CO   Public

1226 AM     Hail             Otis                    40.15N 102.96W
06/29/2023  M2.50 inch       Washington         CO   Public

1201 AM     Hail             2 SE Akron              40.14N 103.18W
06/29/2023  M2.50 inch       Washington         CO   Public

1200 AM     Hail             Akron                   40.16N 103.21W
06/29/2023  M3.00 inch       Washington         CO   Public

1158 PM     Hail             1 NW Akron              40.17N 103.23W
06/28/2023  M3.00 inch       Washington         CO   Public

1154 PM     Hail             5 W Akron               40.16N 103.31W
06/28/2023  M2.50 inch       Washington         CO   Storm Chaser

1154 PM     Hail             1 NW Akron              40.17N 103.23W
06/28/2023  M3.00 inch       Washington         CO   Public

1137 PM     Hail             Wiggins                 40.23N 104.07W
06/28/2023  M1.00 inch       Morgan             CO   Public

1130 PM     Hail             Wiggins                 40.23N 104.07W
06/28/2023  M2.00 inch       Morgan             CO   Public

1116 PM     Hail             1 NNE Brush             40.27N 103.62W
06/28/2023  M2.75 inch       Morgan             CO   Public

            Report from mPING: Baseball (2.75 in.).

1107 PM     Hail             Brush                   40.26N 103.63W
06/28/2023  M3.00 inch       Morgan             CO   Public

            Twitter post of hail slightly larger than a
            baseball.

1105 PM     Hail             12 SE Holyoke           40.46N 102.14W
06/28/2023  M1.75 inch       Phillips           CO   Trained Spotter

1105 PM     Hail             3 WSW Brush             40.25N 103.69W
06/28/2023  M2.75 inch       Morgan             CO   Trained Spotter

1100 PM     Hail             Roggen                  40.17N 104.37W
06/28/2023  M1.00 inch       Weld               CO   Public

            Time estimate based on radar.

1100 PM     Hail             1 NNW Brush             40.27N 103.64W
06/28/2023  E2.50 inch       Morgan             CO   Public

            Report from mPING: Tennis Ball (2.50 in.).

1100 PM     Hail             Brush                   40.26N 103.63W
06/28/2023  E2.75 inch       Morgan             CO   Public

            Report from mPING: Baseball (2.75 in.).

1054 PM     Hail             1 WNW Log Lane Village  40.28N 103.85W
06/28/2023  M2.75 inch       Morgan             CO   Trained Spotter

1052 PM     Hail             2 N Fort Morgan         40.29N 103.79W
06/28/2023  M3.00 inch       Morgan             CO   Public

1047 PM     Hail             2 NNE Fort Morgan       40.29N 103.78W
06/28/2023  M2.00 inch       Morgan             CO   Trained Spotter

1045 PM     Hail             6 SE Holyoke            40.53N 102.22W
06/28/2023  M1.75 inch       Phillips           CO   Trained Spotter

1045 PM     Tstm Wnd Gst     6 SE Holyoke            40.53N 102.22W
06/28/2023  M82 MPH          Phillips           CO   Trained Spotter

1041 PM     Hail             2.5 N Fort Morgan       40.30N 103.79W
06/28/2023  M3.00 inch       Morgan             CO   Public

            Twitter post showing 3 inch hail.

1037 PM     Hail             1 WNW Log Lane Village  40.28N 103.85W
06/28/2023  M2.50 inch       Morgan             CO   Trained Spotter

1032 PM     Hail             Holyoke                 40.58N 102.30W
06/28/2023  M1.75 inch       Phillips           CO   Law Enforcement

1028 PM     Hail             Fort Lupton             40.09N 104.81W
06/28/2023  M1.50 inch       Weld               CO   Public

            Time estimate based on radar.

1025 PM     Hail             .6 SW Holyoke           40.58N 102.31W
06/28/2023  M1.25 inch       Phillips           CO   Trained Spotter

1022 PM     Tstm Wnd Gst     8 S Holyoke             40.47N 102.30W
06/28/2023  M81 MPH          Phillips           CO   Mesonet

1012 PM     Hail             1 NE Sterling           40.64N 103.20W
06/28/2023  E1.00 inch       Logan              CO   Public

            Report from mPING: Quarter (1.00 in.).

1011 PM     Hail             Sterling                40.62N 103.21W
06/28/2023  E1.25 inch       Logan              CO   Trained Spotter

1008 PM     Hail             Sterling                40.63N 103.21W
06/28/2023  M1.00 inch       Logan              CO   Trained Spotter

1003 PM     Hail             Sterling                40.63N 103.21W
06/28/2023  E1.00 inch       Logan              CO   Trained Spotter

0937 PM     Hail             1 N Haxtun              40.66N 102.63W
06/28/2023  E1.00 inch       Phillips           CO   Public

0932 PM     Hail             Haxtun                  40.64N 102.63W
06/28/2023  E2.75 inch       Phillips           CO   Law Enforcement

0928 PM     Hail             1 N Haxtun              40.66N 102.63W
06/28/2023  E1.75 inch       Phillips           CO   Public

0925 PM     Hail             Iliff                   40.76N 103.06W
06/28/2023  E1.00 inch       Logan              CO   Public

            Report from mPING: Quarter (1.00 in.).

0913 PM     Hail             Fleming                 40.68N 102.84W
06/28/2023  M2.75 inch       Logan              CO   Public

            Report from mPING: Baseball (2.75 in.).

0900 PM     Hail             9 NE Westplains         40.96N 103.38W
06/28/2023  M2.50 inch       Logan              CO   Public

0854 PM     Hail             6 WSW Peetz             40.93N 103.23W
06/28/2023  E2.00 inch       Logan              CO   Public

            Report from mPING: Hen Egg (2.00 in.).

0854 PM     Hail             6 W Peetz               40.95N 103.23W
06/28/2023  E2.25 inch       Logan              CO   Public

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

0834 PM     Hail             3 NE Iliff              40.79N 103.02W
06/28/2023  M3.00 inch       Logan              CO   Public

0834 PM     Hail             Iliff                   40.76N 103.07W
06/28/2023  M4.00 inch       Logan              CO   Trained Spotter

            Radar used to estimate time.

0813 PM     Tornado          3 ENE Iliff             40.78N 103.01W
06/28/2023                   Logan              CO   Public

            Corrects previous tornado report from 3 ENE
            Iliff. Twitter.

&&

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

32 hail, 4 flash flood, 1 thunderstorm wind, 1 flood. Local standard time, as filed.

Hail, Washington

When: June 29, 12:20 AM MST
Where: Washington County, 9 mi S of Otis
Measured: 2.5 in hail
Reported by: Public
Coordinates: 40.020, -102.960

Flash Flood, Denver

When: June 29, 2:20 PM MST to 3:20 PM MST
Where: Denver County, 6.41 mi NW of Denver to 6.24 mi NW of Denver
Cause: Heavy Rain
Property damage: $10,000
Reported by: Broadcast Media
Coordinates: 39.785, -105.027

A car was stranded on Interstate 70 below Federal Blvd overpass, with approximately 1 foot of water covering several lanes.

Flash Flood, Denver

When: June 29, 2:21 PM MST to 3:21 PM MST
Where: Denver County, 4.98 mi WNW of Denver to 5.01 mi WNW of Denver
Cause: Heavy Rain
Property damage: $5,000
Reported by: Broadcast Media
Coordinates: 39.750, -105.020

Heavy rain produced up to a foot of standing water at 23rd Avenue and I-25.

Flash Flood, Denver

When: June 29, 2:30 PM MST to 3:30 PM MST
Where: Denver County, 5.72 mi WNW of Denver to 5.7 mi WNW of Denver
Cause: Heavy Rain
Property damage: $10,000
Reported by: Public
Coordinates: 39.760, -105.030

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

Hail, Jefferson

When: June 29, 2:34 PM MST
Where: Jefferson County, 1.27 mi ESE of Morrison
Measured: 1.5 in hail
Reported by: NWS Employee
Coordinates: 39.640, -105.160

Hail, Jefferson

When: June 29, 2:42 PM MST
Where: Jefferson County, 3.79 mi E of Morrison
Measured: 1 in hail
Reported by: Trained Spotter
Coordinates: 39.660, -105.110

Hail, Denver

When: June 29, 2:45 PM MST
Where: Denver County, 3.97 mi WNW of Denver
Measured: 1 in hail
Reported by: Public
Coordinates: 39.750, -105.000

Hail, Denver

When: June 29, 2:46 PM MST
Where: Denver County, 5.07 mi WNW of Denver
Measured: 1 in hail
Reported by: Trained Spotter
Coordinates: 39.770, -105.010

Hail, Denver

When: June 29, 2:46 PM MST
Where: Denver County, 3.47 mi WNW of Denver
Measured: 0.75 in hail
Reported by: Trained Spotter
Coordinates: 39.750, -104.990

Hail, Denver

When: June 29, 2:48 PM MST
Where: Denver County, 6.79 mi WNW of Denver
Measured: 0.75 in hail
Reported by: Storm Chaser
Coordinates: 39.780, -105.040

Hail, Jefferson

When: June 29, 2:54 PM MST
Where: Jefferson County, 1.06 mi E of Lakewood
Measured: 1.25 in hail
Reported by: Trained Spotter
Coordinates: 39.730, -105.080

Hail, Denver

When: June 29, 2:57 PM MST
Where: Denver County, 3.47 mi WNW of Denver
Measured: 1 in hail
Reported by: Trained Spotter
Coordinates: 39.750, -104.990

Hail, Denver

When: June 29, 3:07 PM MST
Where: Denver County, 6.46 mi WNW of Denver
Measured: 1.75 in hail
Reported by: Trained Spotter
Coordinates: 39.770, -105.040

Hail, Denver

When: June 29, 3:07 PM MST
Where: Denver County, 5.85 mi W of Denver
Measured: 1.25 in hail
Reported by: Public
Coordinates: 39.730, -105.040

Hail, Denver

When: June 29, 3:07 PM MST
Where: Denver County, 7.16 mi NW of Denver
Measured: 1 in hail
Reported by: Public
Coordinates: 39.790, -105.040

Hail, Jefferson

When: June 29, 3:07 PM MST
Where: Jefferson County, 1.27 mi ENE of Wheat Ridge
Measured: 1.25 in hail
Reported by: Public
Coordinates: 39.760, -105.060

Hail, Denver

When: June 29, 3:08 PM MST
Where: Denver County, 6.95 mi WNW of Denver
Measured: 1 in hail
Reported by: Trained Spotter
Coordinates: 39.770, -105.050

Hail, Jefferson

When: June 29, 3:10 PM MST
Where: Jefferson County, 1.74 mi ESE of Wheat Ridge
Measured: 1.5 in hail
Reported by: Public
Coordinates: 39.740, -105.050

Hail, Adams

When: June 29, 3:18 PM MST
Where: Adams County, 4.31 mi E of Aurora
Measured: 1 in hail
Reported by: Public
Coordinates: 39.740, -104.770

Hail, Adams

When: June 29, 3:20 PM MST
Where: Adams County, 4.31 mi E of Aurora
Measured: 1.25 in hail
Reported by: Trained Spotter
Coordinates: 39.740, -104.770

Hail, Arapahoe

When: June 29, 3:23 PM MST
Where: Arapahoe County, 4.73 mi WNW of (Bkf)buckley Air Force Base
Measured: 1.5 in hail
Reported by: Public
Coordinates: 39.730, -104.830

Hail, Adams

When: June 29, 3:24 PM MST
Where: Adams County, 0.87 mi NE of Aurora
Measured: 0.75 in hail
Reported by: Trained Spotter
Coordinates: 39.740, -104.840

Hail, Arapahoe

When: June 29, 3:25 PM MST
Where: Arapahoe County, 3.49 mi NW of (Bkf)buckley Air Force Base
Measured: 1.5 in hail
Reported by: Public
Coordinates: 39.740, -104.790

Hail, Adams

When: June 29, 3:28 PM MST
Where: Adams County, 4.31 mi E of Aurora
Measured: 1.25 in hail
Reported by: Public
Coordinates: 39.740, -104.770

Hail, Arapahoe

When: June 29, 3:30 PM MST
Where: Arapahoe County, 2.97 mi NW of (Bkf)buckley Air Force Base
Measured: 0.75 in hail
Reported by: Public
Coordinates: 39.730, -104.790

Hail, Arapahoe

When: June 29, 3:35 PM MST
Where: Arapahoe County, 2.54 mi ENE of (Bkf)buckley Air Force Base
Measured: 2 in hail
Reported by: Public
Coordinates: 39.720, -104.710

Hail, Arapahoe

When: June 29, 3:41 PM MST
Where: Arapahoe County, 2.54 mi ENE of (Bkf)buckley Air Force Base
Measured: 1 in hail
Reported by: Public
Coordinates: 39.720, -104.710

Hail, Adams

When: June 29, 3:58 PM MST to 4:28 PM MST
Where: Adams County, 0.69 mi N of Denver Front Range A
Measured: 1.25 in hail
Reported by: Public
Coordinates: 39.790, -104.550

Hail, Adams

When: June 29, 4:16 PM MST
Where: Adams County, 1.48 mi NNE of Watkins
Measured: 1.5 in hail
Reported by: Trained Spotter
Coordinates: 39.770, -104.590

Hail, Arapahoe

When: June 29, 4:20 PM MST
Where: Arapahoe County, 4.63 mi NW of (Bkf)buckley Air Force Base
Measured: 1.75 in hail
Reported by: Trained Spotter
Coordinates: 39.740, -104.820

Hail, Adams

When: June 29, 4:24 PM MST
Where: Adams County, 1.06 mi W of Bennett
Measured: 1.5 in hail
Reported by: Public
Coordinates: 39.750, -104.450

Thunderstorm Wind, Arapahoe

When: June 29, 4:30 PM MST
Where: Arapahoe County, 7.44 mi W of Byers
Measured: 70 kt (81 mph) estimated gust
Property damage: $4,000
Reported by: Public
Coordinates: 39.720, -104.360

Intense thunderstorm winds snapped a power pole.

Hail, Adams

When: June 29, 5:00 PM MST
Where: Adams County, 1.27 mi WSW of Manila
Measured: 1.25 in hail
Reported by: Trained Spotter
Coordinates: 39.760, -104.520

Hail, Denver

When: June 29, 5:19 PM MST
Where: Denver County, 3.45 mi S of Glendale
Measured: 0.75 in hail
Reported by: Public
Coordinates: 39.650, -104.900

Hail, Adams

When: June 29, 5:24 PM MST
Where: Adams County, 0.69 mi N of Bennett
Measured: 2 in hail
Reported by: Trained Spotter
Coordinates: 39.760, -104.430

Flash Flood, Adams

When: June 29, 6:00 PM MST
Where: Adams County, 1.09 mi SSE of Denver Front Range A to 0.32 mi S of Denver Front Range A
Cause: Heavy Rain
Property damage: $50,000
Reported by: Fire Department/Rescue
Coordinates: 39.765, -104.544

Highway 36 was closed due to flooding between Watkins and Schumaker Road. At least 6 vehicles were stranded with reports of roads washed out and active water rescues in progress.

Hail, Adams

When: June 29, 6:05 PM MST
Where: Adams County, 5.56 mi NE of Shamrock
Measured: 1 in hail
Reported by: Public
Coordinates: 39.950, -103.740

Flood, Weld

When: June 30, 7:00 AM MST to 8:00 AM MST
Where: Weld County, 2.88 mi NNE of Prospect Valley to 3.28 mi NE of Prospect Valley
Cause: Heavy Rain
Deaths: 1 direct, 0 indirect
Injuries: 0 direct, 5 indirect
Reported by: Broadcast Media
Coordinates: 40.106, -104.382

A person was killed after the car they were driving was swept away by floodwaters. The accident occurred near Weld County Roads 73 and 16 . The occupant of the car drove past the roadblocks that are there to prevent vehicles from entering the dangerous floodwaters in the area. The car was found floating in the water with a driver inside the car. In total, there were six vehicles submerged into floodwaters, six human rescues, and five police dog rescues performed by deputies.

The people who died

As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.

Event	Date	Age	Sex	Where	Kind
Flood, Weld	2023-06-30			Vehicle/Towed Trailer	Direct

What these are

Hail: Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
Flash Flood: Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.
Thunderstorm Wind: Winds from a thunderstorm of 50 knots (58 mph) or more, or lower winds that caused damage or casualties. Measured gusts are marked MG, estimated EG.
Flood: Flooding that develops more slowly than a flash flood: rivers leaving their banks, or water standing over land for an extended time.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Colorado in 2023 Every state in 2023 This day in weather history Warnings in Colorado, June 2023

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1109263, 1116727, 1116713, 1116725, 1109260, 1109254, 1109243, 1109239, 1109250, 1109242, 1109261, 1109240, 1109245, 1109247, 1109248, 1109256, 1109244, 1109258, 1109231, 1109218, 1109234, 1109219, 1109233, 1109220, 1109235, 1109238, 1109236, 1109227, 1109222, 1109232, 1109226, 1109237, 1109229, 1109253, 1109224, 1116714, 1109230, 1116715.