Flash Flood Warning 32, NWS Denver/Boulder, CO

908 
WGUS75 KBOU 160213
FFSBOU

Flash Flood Statement
National Weather Service Denver CO
813 PM MDT Sat Aug 15 2026

COC073-160415-
/O.CON.KBOU.FF.W.0032.000000T0000Z-260816T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lincoln CO-
813 PM MDT Sat Aug 15 2026

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1015 PM MDT THIS
EVENING FOR SOUTHEASTERN LINCOLN COUNTY...

At 813 PM MDT, Doppler radar indicated thunderstorms producing heavy
rain were moving out of the warned area. Between 2 and 4 inches of
rain have fallen. Additional rainfall amounts up to 0.2 inches are
possible in the warned area. 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...
  Mainly rural areas of Southeastern Lincoln County.

This includes the following streams and drainages...
  Rush Creek, South Rush Creek and Adobe Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you encounter flooded roads, turn around, don't drown.

Excessive runoff from this storm will cause flash flooding of small
creeks and streams, country roads, farmland along creeks, and other
low lying areas.

&&

LAT...LON 3879 10351 3880 10321 3865 10318 3868 10344
      3871 10347

FLASH FLOOD...RADAR INDICATED

$$

20

030 
WGUS75 KBOU 160407
FFSBOU

Flash Flood Statement
National Weather Service Denver CO
1007 PM MDT Sat Aug 15 2026

COC073-160417-
/O.EXP.KBOU.FF.W.0032.000000T0000Z-260816T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lincoln CO-
1007 PM MDT Sat Aug 15 2026

...FLASH FLOOD WARNING WILL EXPIRE AT 1015 PM MDT THIS EVENING FOR
SOUTHEASTERN LINCOLN COUNTY...

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

&&

LAT...LON 3879 10351 3880 10321 3865 10318 3868 10344
      3871 10347

$$

AP

Area Forecast Discussion
National Weather Service Denver/Boulder CO
612 PM MDT Sat Aug 15 2026

.KEY MESSAGES...

- Another round of showers and thunderstorms this afternoon and
  evening. Heavy rainfall and flash flooding are the main threats
  today. A few thunderstorms could become severe, with strong
  winds and hail possible.

- Monsoon moisture lasts through Sunday, bringing scattered
  showers and thunderstorms again tomorrow.

- Warming and drying trend for Monday and Tuesday.

- Another active day possible middle of next week.

&&

.DISCUSSION /Through Saturday/...
Issued at 103 PM MDT Sat Aug 15 2026

The wetter weather pattern will continue on through this weekend.
For today, there is a risk for severe weather and flash flooding.
The eastern plains should be located near the right entrance region
of a jet over the central US with a small disturbance expected in
the flow aloft. GOES-19 satellite imagery shows a cirrus shield
currently over the mountains that could initially inhibit convective
development. Nevertheless, convective development is starting to
occur across the foothills and in Larimer county. We expect showers
and thunderstorms to develop across the foothills early this
afternoon and move into the I-25 corridor by mid-to-late afternoon.
These storms will then move off to the east in the late afternoon
and early evening.

The previously mentioned cirrus shield could hinder rain coverage
and/or push this timing a bit later. The biggest threat for today
will be heavy rainfall with some episodes of flash flooding possible
across the area. The Weather Prediction Center highlights the
foothills, I-25 corridor, and the eastern plains in a slight (2/4)
risk for excessive rainfall for today. Several ingredients are in
place for this threat. Thus, a Flood Watch is in effect from 2pm to
10pm this afternoon and evening. See the hydro discussion for more
details.

The Storm Prediction Center highlights the plains in a
slight (2/5) risk. MLCAPE values are forecast to be around 1000-1200
J/kg and 0-6 km shear will be around 30-40 kts. Large hail and
damaging winds are possible from storms today, with the highest
chances along the Palmer Divide.

Tomorrow will bring similar threats as today, though we expect less
coverage of thunderstorms. Thus, the threats will be more localized
in nature. MLCAPE and bulk shear values are forecast to be lower
than today. The highest chances for showers and thunderstorms
tomorrow should stay along/near the Palmer Divide, but there will
still be scattered storms possible for most of our plains.

High pressure will shift closer to our area for Monday and Tuesday
further lowering rain chances and raising temperatures to around
90 degrees for the plains. By Wednesday, high pressure should
shift off to the southwest, opening the door for a disturbance to
move through the flow aloft and bringing back some isolated to
scattered rain chances. This will only be a brief break as high
pressure will start to build over the Four Corners region.
Temperatures are expected to return to the low to mid 90s across
the plains for the end of the week and into next weekend.

&&

.AVIATION /00Z TAFS through 00Z Monday/...
Issued at 610 PM MDT Sat Aug 15 2026

Storms have mostly moved out of the Denver metro area, though some
lingering showers and wind gusts may remain this evening through
02Z. Winds will become light and variable behind today's convection,
with some mild S-SW drainage starting around 09Z. The main concern
overnight and into the early morning hours, around 12-14Z, will be
low ceilings and potential fog (60% chance), particularly over KDEN.
Models are in fairly good agreement on moisture lingering in the low
levels at KDEN, prompting a TEMPO for fog and low visibility. Low
stratus could also be advected into the vicinities of KAPA and KBJC,
though confidence remains lower to the west of KDEN at this time.

Prevailing winds will remain light (<10kts) tomorrow. There will be
another chance for isolated showers and storms, mainly between 22Z
and 02Z. Like today, any thunderstorms may produce brief heavy rain
and strong wind gusts (30kts).

&&

.HYDROLOGY...
Issued at 103 PM MDT Sat Aug 15 2026

Several ingredients are in place for the excessive rainfall
threat today. PWATs values will be around 150% of normal. Warm cloud
layer heights will approach 5000 feet, allowing for rather efficient
warm rain processes. Easterly (upslope) winds are occurring which is
continuing to advect moisture into the area. Dewpoints should be in
the 50s for the I-25 corridor and low to mid 60s across the plains
this afternoon and evening. Significant portions of our area have
received 2 to 5 inches over the last 3 days, lowering flash flood
guidance. Although, storm motions should be a touch faster than
yesterday- around 20-25 kts. Any storms today could produce 1 to 2
inches in 30 minutes. Rainfall totals for today could be in excess
of 2 to 4 inches. Given the nature of these storms, there will be
varying rainfall totals across short distances. A Flood Watch is in
effect from 2pm to 10pm this afternoon and evening.

For tomorrow, moisture is expected to decrease- PWATs will drop to
about 100 to 125% of average. The flooding risk for tomorrow will be
lower than today and more isolated in nature. The Weather Prediction
Center only highlights the Palmer Divide in a slight (2/4) risk for
excessive rainfall for tomorrow, where storm coverage should be
highest.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Flood Watch until 10 PM MDT this evening for COZ036-038>051.

&&

DISCUSSION...MV
AVIATION...Striplin
HYDROLOGY...MV

Special Weather Statement
National Weather Service Denver CO
418 PM MDT Sat Aug 15 2026

COZ042-152245-
Northeast Weld County CO-
418 PM MDT Sat Aug 15 2026

...A STRONG THUNDERSTORM WILL IMPACT EASTERN WELD COUNTY UNTIL 445 PM
MDT...

At 418 PM MDT, Doppler radar was tracking a strong thunderstorm near
New Raymer, or 23 miles north of Fort Morgan, moving northeast at 10
mph.

HAZARD...Landspouts, wind gusts up to 50 mph, and penny size hail.

SOURCE...Radar indicated.

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

Locations impacted include...
  Stoneham and New Raymer.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Heavy rain is occurring with this storm and may lead to flooding. Do
not drive your vehicle through flooded roadways.

&&

LAT...LON 4052 10385 4070 10390 4077 10366 4057 10358
      4052 10358
TIME...MOT...LOC 2218Z 246DEG 9KT 4060 10379

LANDSPOUT...POSSIBLE
MAX HAIL SIZE...0.75 IN
MAX WIND GUST...50 MPH

63

Special Weather Statement
National Weather Service Denver CO
520 PM MDT Sat Aug 15 2026

COZ048-160000-
Logan County CO-
520 PM MDT Sat Aug 15 2026

...A LINE OF STRONG THUNDERSTORMS WILL IMPACT WESTERN LOGAN COUNTY
UNTIL 6 PM MDT...

At 520 PM MDT, Doppler radar was tracking a line of strong
thunderstorms extending from near Westplains to near Atwood, or
extending from 25 miles northwest of Sterling to 9 miles southwest of
Sterling, moving east at 15 mph.

HAZARD...Wind gusts up to 50 mph and pea 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...
  Sterling, Iliff, Peetz, North Sterling Reservoir, Padroni, Logan
  Corners, Atwood, Westplains and Reiradon Hill.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Heavy rain is occurring with these storms and may lead to flooding.
Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4050 10340 4072 10344 4092 10355 4097 10311
      4073 10302 4050 10303
TIME...MOT...LOC 2320Z 266DEG 12KT 4092 10347 4075 10336 4050 10327

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...50 MPH

63

Preliminary Local Storm Report
National Weather Service Denver CO
524 PM MDT Sat Aug 15 2026

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

0455 PM     Flash Flood      10 W Westplains         40.88N 103.69W
08/15/2026                   Weld               CO   Storm Chaser

            Significant amount of water running across
            CO-71. Report via SpotterNetwork.

&&

Special Weather Statement
National Weather Service Denver CO
549 PM MDT Sat Aug 15 2026

COZ047-160030-
Southeast Elbert County Below 6000 Feet/South Lincoln County CO-
549 PM MDT Sat Aug 15 2026

...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN ELBERT AND
SOUTHWESTERN LINCOLN COUNTIES UNTIL 630 PM MDT...

At 549 PM MDT, Doppler radar was tracking a strong thunderstorm near
Rush, or 39 miles southwest of Limon, moving east at 15 mph.

HAZARD...Wind gusts up to 50 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...
  Mainly rural areas of Southeastern Elbert and Southwestern Lincoln
  Counties.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Heavy rain is occurring with this storm and may lead to flooding. Do
not drive your vehicle through flooded roadways.

&&

LAT...LON 3887 10406 3887 10382 3865 10387 3866 10405
      3878 10405
TIME...MOT...LOC 2349Z 275DEG 11KT 3879 10407

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

63

Special Weather Statement
National Weather Service Denver CO
644 PM MDT Sat Aug 15 2026

COZ047-160115-
Southeast Elbert County Below 6000 Feet/South Lincoln County CO-
644 PM MDT Sat Aug 15 2026

...A STRONG THUNDERSTORM WILL IMPACT SOUTH CENTRAL LINCOLN COUNTY
UNTIL 715 PM MDT...

At 644 PM MDT, Doppler radar was tracking a strong thunderstorm 4
miles east of Forder, or 41 miles south of Limon, moving northeast at
10 mph.

HAZARD...Wind gusts up to 50 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...
  Karval and Forder.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Heavy rain is occurring with this storm and may lead to flooding. Do
not drive your vehicle through flooded roadways.

&&

LAT...LON 3856 10369 3876 10373 3884 10352 3858 10341
TIME...MOT...LOC 0044Z 243DEG 7KT 3867 10363

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

63

Special Weather Statement
National Weather Service Denver CO
646 PM MDT Sat Aug 15 2026

COZ048-050-051-160130-
Phillips County CO-Logan County CO-Sedgwick County CO-
646 PM MDT Sat Aug 15 2026

...A LINE OF STRONG THUNDERSTORMS WILL IMPACT WESTERN PHILLIPS...
SOUTHWESTERN SEDGWICK AND SOUTHEASTERN LOGAN COUNTIES UNTIL 730 PM
MDT...

At 646 PM MDT, Doppler radar was tracking a line of strong
thunderstorms extending from 5 miles west of Sedgwick to near
Highland Center, or extending from 18 miles west of Julesburg to 18
miles west of Holyoke, moving east at 10 mph.

HAZARD...Wind gusts up to 50 mph and pea 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...
  Haxtun, Sedgwick, Paoli, Fairfield, Marks Butte, Highland Center
  and Dailey.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Heavy rain is occurring with these storms and may lead to flooding.
Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4044 10271 4069 10273 4095 10271 4095 10241
      4044 10243
TIME...MOT...LOC 0046Z 270DEG 7KT 4096 10261 4069 10261 4049 10262

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...50 MPH

63