Flash Flood Warning 15, NWS Denver/Boulder, CO

029 
WGUS75 KBOU 290345
FFSBOU

Flash Flood Statement
National Weather Service Denver CO
945 PM MDT Tue Jul 28 2026

COC075-290515-
/O.CON.KBOU.FF.W.0015.000000T0000Z-260729T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Logan CO-
945 PM MDT Tue Jul 28 2026

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1115 PM MDT THIS
EVENING FOR SOUTHWESTERN LOGAN COUNTY...

At 945 PM MDT, Doppler radar indicated thunderstorms producing heavy
rain across the warned area. Between 1.5 and 3 inches of rain have
fallen. Flash flooding is ongoing or expected to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar indicated.

IMPACT...Flash flooding of small creeks and streams, gulches, roads,
         and poor drainage and low-lying areas.

Some locations that will experience flash flooding include...
  Logan Corners, Atwood and Pawnee Pass.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 4066 10358 4049 10328 4044 10314 4055 10303
      4059 10321 4062 10331 4074 10338 4073 10356

FLASH FLOOD...RADAR INDICATED

$$

Meier

526 
WGUS75 KBOU 290522
FFSBOU

Flash Flood Statement
National Weather Service Denver CO
1122 PM MDT Tue Jul 28 2026

COC075-290532-
/O.EXP.KBOU.FF.W.0015.000000T0000Z-260729T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Logan CO-
1122 PM MDT Tue Jul 28 2026

...FLASH FLOOD WARNING HAS EXPIRED FOR SOUTHWESTERN LOGAN COUNTY...

The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed any remaining closures.

&&

LAT...LON 4066 10358 4049 10328 4044 10314 4055 10303
      4059 10321 4062 10331 4074 10338 4073 10356

$$

MAI

Area Forecast Discussion
National Weather Service Denver/Boulder CO
543 PM MDT Tue Jul 28 2026

.KEY MESSAGES...

- Threat of flash flooding over portions of northeast Colorado
  this afternoon and evening. Numerous showers and storms.

- A couple severe storms possible on the plains with damaging
  winds and marginal hail threat.

- Similar weather setup for Wednesday with more storms.

- Temperatures holding closer to normal today and Wednesday.

- Drying out again later in the week. Heat returns for next
  weekend.

&&

.DISCUSSION /Through Tuesday/...
Issued at 1228 PM MDT Tue Jul 28 2026

GOES-18 satellite data early this afternoon show that robust
convective initiation is ongoing across the Front Range Foothills.
Radar estimates and precipitation gauges suggest that some of
these initial storms have still been efficient rainfall producers
across the foothills... meaning that burn area flash flooding is
still a concern this afternoon.

However, much like the past several days... initial convection
has struggled once making it into the urban corridor. Why is this?
There are several possible explanations. Despite a relatively
favorable environment (T/Td of 90/57 at DEN), ACARS soundings
still maintain a subtle stable layer between roughly 750-675 mb.
While there's still 1500-2000 J/kg MLCAPE in that sounding there's
also a relatively deep, weakly buoyant region above the LFC that
would be prone to some entrainment. With little/no synoptic
ascent through this layer, it would likely take larger, mature
updrafts to overcome this. It's possible additional CI attempts
across the Foothills will lead to more sustained convection across
the Denver metro, but it appears more likely that our favored
terrain (northern Front Range and Palmer Divide) will see the
bulk of the rainfall this afternoon, with gradual upscale growth
towards east of the I-25 corridor later this afternoon and
evening.

As that cluster of convection shifts eastward, the increased
precipitable water and deeper warm cloud layer depths would favor
the potential for some brief but rather heavy rainfall rates this
evening. Recent REFS 3hr PMM QPF hints at as much as 3-5" of
rainfall this evening in Washington county... with broad support
from today's HREF members as well. I saw no reason to adjust the
existing Flood Watch across the plains, which will remain in
effect from 3-10 PM. As the midnight shift noted, there is still a
slim possibility that this cluster of storms eventually sends some
outflow back towards the metro, which would provide another
opportunity for some showers/storms that would be capable of
producing some heavy rain.

Wednesday looks to be the last day of well above normal moisture,
though similar concerns remain about the coverage of storms across
the region. Overall we expect a fairly similar convective setup
compared to today, with perhaps a bit more coverage along/west of
I-25. Storm chances will be dictated by the amount of moisture
return tonight/tomorrow morning. Assuming we do see low/mid 60s
dew points across the urban corridor tomorrow morning, there would
be some heavy rain potential once again.

The latter half of the week will feature a quick drying trend,
with warmer temperatures likely returning by the weekend. Chances
for showers/storms will continue for Thursday but should quickly
diminish by Saturday or Sunday as a 600 dam ridge at 500mb
develops near the Four Corners region. Guidance hints that we
could see a return of upper 90s/low 100s by the end of the
weekend, which then persist through early next week.

&&

.AVIATION /00Z TAFS through 00Z Thursday/...
Issued at 542 PM MDT Tue Jul 28 2026

The latest radar imagery as of 2330z shows convection ongoing
well to the east of KDEN. Gusty winds between 15 and 25 kts have
been occurring at times at all three TAF sites for the last
several hours. The convection has sent off an outflow boundary in
southeast Weld County that is currently moving to the west. There
is a low chance (~30%) that showers/thunderstorms occur this
evening, but if they were to form they would likely be behind this
outflow boundary. So, we have gone ahead and kept the PROB30
through 5z tonight.

Winds should turn to drainage and remain under 12 kts by about
6z. There is still a low (10%) chance of a brief period of low
stratus clouds below 3000 feet tonight roughly between 9z and 15z
depending on how outflow boundaries from storms well to the east
behave overnight. Otherwise, we only expect a few clouds below
12,000 feet AGL tonight. Winds will slowly turn clockwise as the
morning progresses and should be NE to E by late tomorrow morning.

Tomorrow will be a similar setup to today with showers and
thunderstorms moving from west to east through all three TAF sites
between about 20z and 5z. TEMPO and PROB30 groups are in place to
cover this potential. Gusty winds of at least 30 knots,
TSRA/SHRA, and lowered visibility to about 4 SM are possible with
any showers or thunderstorms that pass near/over any of the TAF
sites.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Flood Watch until 10 PM MDT this evening for COZ042-044>049.

&&

DISCUSSION...Hiris
AVIATION...MV

Preliminary Local Storm Report
National Weather Service Denver CO
337 PM MDT Tue Jul 28 2026

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

0310 PM     Tstm Wnd Gst     6 S Manila Village      39.67N 104.53W
07/28/2026  M61 MPH          Arapahoe           CO   Public

            Personal weather station.

0310 PM     Tstm Wnd Gst     5 S Manila Village      39.69N 104.50W
07/28/2026  M58 MPH          Arapahoe           CO   Mesonet

            Mesonet station AX443 BENNETT.

0302 PM     Tstm Wnd Gst     5 SSE Watkins           39.69N 104.58W
07/28/2026  M66 MPH          Arapahoe           CO   Public

0250 PM     Tstm Wnd Gst     2 SSW Lower Latham Rese 40.32N 104.66W
07/28/2026  M57 MPH          Weld               CO   Public

            Personal weather station.

0216 PM     Hail             3 NW Castle Rock        39.41N 104.89W
07/28/2026  E1.00 Inch       Douglas            CO   Public

            Report from mPING: Quarter (1.00 in.).

0214 PM     Hail             3 NW Castle Rock        39.41N 104.89W
07/28/2026  M0.75 Inch       Douglas            CO   Public

            Report from mPING: Dime (0.75 in.).

0206 PM     Tstm Wnd Gst     4 SW Carter Lake        40.30N 105.28W
07/28/2026  M58 MPH          Larimer            CO   Public

            Personal weather station.

0205 PM     Tstm Wnd Gst     6 NE Elizabeth          39.43N 104.53W
07/28/2026  M60 MPH          Elbert             CO   Public

            Personal weather station.

0158 PM     Tstm Wnd Gst     3 SSE Pinewood Springs  40.23N 105.33W
07/28/2026  M55 MPH          Boulder            CO   Public

            Personal weather station.

0138 PM     Hail             4 W Pinewood Springs    40.27N 105.43W
07/28/2026  E0.75 Inch       Larimer            CO   Public

            Report from mPING: Dime (0.75 in.).

&&

Special Weather Statement
National Weather Service Denver CO
353 PM MDT Tue Jul 28 2026

COZ044-045-282230-
Morgan County CO-Central and East Adams and Arapahoe Counties CO-
353 PM MDT Tue Jul 28 2026

...A LINE OF STRONG THUNDERSTORMS WILL IMPACT CENTRAL MORGAN...
ARAPAHOE AND EASTERN ADAMS COUNTIES UNTIL 430 PM MDT...

At 353 PM MDT, Doppler radar was tracking a line of strong
thunderstorms extending from 6 miles south of Antelope Springs to 6
miles southwest of Leader, or extending from 7 miles north of Fort
Morgan to 35 miles southwest of Fort Morgan, moving southeast at 15
mph.

HAZARD...Wind gusts of 50 to 55 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...
  Fort Morgan, Brush, Log Lane Village, Twelve-Mile Corner, Adena
  School, Adena, Shamrock, Hoyt, Leader, Snyder, Antelope Springs,
  Hoyt Beet Dump and Fort Morgan Airport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the weather situation closely and be alert for threatening
weather conditions.

&&

LAT...LON 3976 10424 4012 10403 4046 10381 4044 10347
      4000 10369 4000 10371 3997 10371 3974 10383
TIME...MOT...LOC 2153Z 298DEG 12KT 4036 10375 4009 10396 3983 10413

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...50 TO 55 MPH

63

Preliminary Local Storm Report...Summary
National Weather Service Denver CO
419 PM MDT Tue Jul 28 2026

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

0330 PM     Tstm Wnd Gst     3 NW Strasburg          39.77N 104.33W
07/28/2026  M67 MPH          Adams              CO   Public

            Personal weather station.

0325 PM     Tstm Wnd Gst     1 SSW Bennett           39.74N 104.43W
07/28/2026  M70 MPH          Adams              CO   Mesonet

            Mesonet station CO072 Bennett.

0310 PM     Tstm Wnd Gst     6 S Manila Village      39.67N 104.53W
07/28/2026  M61 MPH          Arapahoe           CO   Public

            Personal weather station.

0310 PM     Tstm Wnd Gst     10 E Arapahoe Park      39.61N 104.51W
07/28/2026  M58 MPH          Arapahoe           CO   Mesonet

            Mesonet station AV686 Bennett.

0310 PM     Tstm Wnd Gst     5 S Manila Village      39.69N 104.50W
07/28/2026  M58 MPH          Arapahoe           CO   Mesonet

            Mesonet station AX443 BENNETT.

0302 PM     Tstm Wnd Gst     5 SSE Watkins           39.69N 104.58W
07/28/2026  M66 MPH          Arapahoe           CO   Public

0250 PM     Tstm Wnd Gst     2 SSW Lower Latham Rese 40.32N 104.66W
07/28/2026  M57 MPH          Weld               CO   Public

            Personal weather station.

0206 PM     Tstm Wnd Gst     4 SW Carter Lake        40.30N 105.28W
07/28/2026  M58 MPH          Larimer            CO   Public

            Personal weather station.

0205 PM     Tstm Wnd Gst     6 NE Elizabeth          39.43N 104.53W
07/28/2026  M60 MPH          Elbert             CO   Public

            Personal weather station.

0158 PM     Tstm Wnd Gst     3 SSE Pinewood Springs  40.23N 105.33W
07/28/2026  M55 MPH          Boulder            CO   Public

            Personal weather station.

&&

Special Weather Statement
National Weather Service Denver CO
550 PM MDT Tue Jul 28 2026

COZ049-290030-
Washington County CO-
550 PM MDT Tue Jul 28 2026

...A LINE OF STRONG THUNDERSTORMS WILL IMPACT SOUTHEASTERN WASHINGTON
COUNTY UNTIL 630 PM MDT...

At 550 PM MDT, Doppler radar was tracking a line of strong
thunderstorms extending from 6 miles northeast of Otis to near
Arickaree School, or extending from 19 miles east of Akron to 32
miles southeast of Akron, moving east at 15 mph.

HAZARD...Wind gusts of 50 to 55 mph and half inch 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...
  Cope and Hyde.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the weather situation closely and be alert for threatening
weather conditions.

&&

LAT...LON 3968 10302 3999 10293 4019 10287 4019 10279
      4000 10279 4000 10280 3966 10280
TIME...MOT...LOC 2350Z 280DEG 12KT 4019 10286 4000 10291 3974 10297

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...50 TO 55 MPH

63

Special Weather Statement
National Weather Service Denver CO
604 PM MDT Tue Jul 28 2026

COZ050-290045-
Sedgwick County CO-
604 PM MDT Tue Jul 28 2026

...A LINE OF STRONG THUNDERSTORMS WILL IMPACT SEDGWICK COUNTY UNTIL
645 PM MDT...

At 604 PM MDT, Doppler radar was tracking a line of strong
thunderstorms extending from near Barton to 7 miles northwest of
Sedgwick, or extending from near Julesburg to 12 miles southwest of
Chappell, moving south at 20 mph.

HAZARD...Wind gusts of 50 to 55 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...
  Julesburg, Ovid, Sedgwick and Marks Butte.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the weather situation closely and be alert for threatening
weather conditions.

&&

LAT...LON 4100 10206 4092 10205 4082 10205 4078 10233
      4078 10265 4100 10265
TIME...MOT...LOC 0003Z 350DEG 19KT 4104 10223 4102 10241 4099 10264

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...50 TO 55 MPH

63

Preliminary Local Storm Report
National Weather Service Denver CO
724 PM MDT Tue Jul 28 2026

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

0513 PM     Tstm Wnd Gst     1 NNW Akron             40.17N 103.22W
07/28/2026  M59 MPH          Washington         CO   AWOS

            AWOS station KAKO Akron.

0459 PM     Tstm Wnd Gst     5 W Akron               40.16N 103.31W
07/28/2026  M66 MPH          Washington         CO   Trained Spotter

0330 PM     Tstm Wnd Gst     3 NW Strasburg          39.77N 104.33W
07/28/2026  M67 MPH          Adams              CO   Public

            Personal weather station.

0330 PM     Tstm Wnd Gst     3 NW Strasburg          39.77N 104.34W
07/28/2026  M65 MPH          Adams              CO   Public

            Personal weather station.

0325 PM     Tstm Wnd Gst     1 SSW Bennett           39.74N 104.43W
07/28/2026  M70 MPH          Adams              CO   Mesonet

            Mesonet station CO072 Bennett.

0310 PM     Tstm Wnd Gst     6 S Manila Village      39.67N 104.53W
07/28/2026  M61 MPH          Arapahoe           CO   Public

            Personal weather station.

0310 PM     Tstm Wnd Gst     5 S Manila Village      39.69N 104.50W
07/28/2026  M58 MPH          Arapahoe           CO   Mesonet

            Mesonet station AX443 BENNETT.

0310 PM     Tstm Wnd Gst     10 E Arapahoe Park      39.61N 104.51W
07/28/2026  M58 MPH          Arapahoe           CO   Mesonet

            Mesonet station AV686 Bennett.

0302 PM     Tstm Wnd Gst     5 SSE Watkins           39.69N 104.58W
07/28/2026  M66 MPH          Arapahoe           CO   Public

0250 PM     Tstm Wnd Gst     2 SSW Lower Latham Rese 40.32N 104.66W
07/28/2026  M57 MPH          Weld               CO   Public

            Personal weather station.

0206 PM     Tstm Wnd Gst     4 SW Carter Lake        40.30N 105.28W
07/28/2026  M58 MPH          Larimer            CO   Public

            Personal weather station.

0205 PM     Tstm Wnd Gst     6 NE Elizabeth          39.43N 104.53W
07/28/2026  M60 MPH          Elbert             CO   Public

            Personal weather station.

0158 PM     Tstm Wnd Gst     3 SSE Pinewood Springs  40.23N 105.33W
07/28/2026  M55 MPH          Boulder            CO   Public

            Personal weather station.

&&