Flash Flood Warning 37, NWS Denver/Boulder, CO

713 
WGUS75 KBOU 290001
FFSBOU

Flash Flood Statement
National Weather Service Denver CO
601 PM MDT Thu Jul 28 2022

COC049-290045-
/O.CON.KBOU.FF.W.0037.000000T0000Z-220729T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Grand CO-
601 PM MDT Thu Jul 28 2022

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 645 PM MDT THIS 
EVENING FOR NORTH CENTRAL GRAND COUNTY...

At 601 PM MDT, Thunderstorms had produced 0.5 to 1 inch of rain over 
the warned area. These have since moved out of the area, but 
localized flash flooding will still be possible as runoff continues 
over the East Troublesome burn scar.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar.

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...
  Hot Sulphur Springs.

This includes the following additional locations...
Stillwater Pass, Upper Willow Creek Valley, Middle Willow Creek 
Valley, Lower Willow Creek Valley, Drowsy Water Ranch, Elk Mountain, 
Remote East Troublesome Headwaters, East Troublesome Valley and 
Upper Corral Creek Valley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Heavy Rainfall may cause flash flooding of small creeks, streams, 
and ditches in the East Troublesome burn area. Rock slides or debris 
flows can also be expected across rural roads.

&&

LAT...LON 4036 10600 4012 10590 4008 10611 4020 10632
      4033 10621 4033 10619 4034 10617 4033 10614
      4035 10610 4035 10608 4037 10601

FLASH FLOOD...RADAR INDICATED

$$

Rodriguez

411 
WGUS75 KBOU 290037
FFSBOU

Flash Flood Statement
National Weather Service Denver CO
637 PM MDT Thu Jul 28 2022

COC049-290047-
/O.EXP.KBOU.FF.W.0037.000000T0000Z-220729T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Grand CO-
637 PM MDT Thu Jul 28 2022

...FLASH FLOOD WARNING WILL EXPIRE AT 645 PM MDT THIS EVENING FOR 
NORTH CENTRAL GRAND COUNTY...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat, although minor runoff may still be impacting some roadways 
in the area, including CO-125. Please continue to heed any remaining 
road closures.

A Flash Flood Watch remains in effect until 1000 PM MDT for portions 
of central and north central Colorado.

LAT...LON 4036 10600 4012 10590 4008 10611 4020 10632
      4033 10621 4033 10619 4034 10617 4033 10614
      4035 10610 4035 10608 4037 10601

$$

Rodriguez

Area Forecast Discussion
National Weather Service Denver/Boulder CO
231 PM MDT Thu Jul 28 2022

.SHORT TERM...(This evening through Friday)
Issued at 152 PM MDT Thu Jul 28 2022

Moisture levels continue to be elevated with PW values well above
average for this time of year at over an inch on this mornings GJT
sounding. This is aided by the continued high pressure system over
TX helping to pull that moisture into the state. The morning MCS
brought rainfall and cloud cover that kept conditions fairly stable
over the I-25 corridor into the afternoon. Convection has been able
to initiate over the higher terrain, especially over Jackson and
Grand counties where clouds scattered out early on. These storms
will continue to form and push ESE into the evening hours.
Temperatures overall have rebounded slightly with mainly 70s across
the plains and 60s south of I-70 and the Palmer Divide area where
cloud cover has lingered longer. There is higher confidence that
storms will be able to move off the higher terrain and across the
northern plains along and west of I-25 where a Flood Watch is in
place. These areas have seen higher precipitation amounts and
therefore have more saturated soils where some heavy rain could
cause flooding. The latest Denver ACARS soundings show decent lower
level lapse rates with weak shear where a storm could produce heavy
rain and small hail along with strong gusty winds if it is able to
survive off the higher terrain. Overall, CAMs show storms coming to
an end after 10 pm with a mid-level cloud deck sticking around
overnight bringing more mild overnight low temperatures.

For Friday there will be continued ample moisture over the eastern
plains with over an inch along and east of I-25 with a slight drop
over the mountains with 0.5 to 0.8 inches. With the additional hours
of heating there will be MLCAPE values of 1000 to 1200 j/kg by the
afternoon and decent lapse rates. Latest CAMs show storms forming
over the higher terrain and pushing ESE over the I-25 corridor.
Coverage is expected to be less than today but with slower storm
motions will go with a limited threat of burn scar flash flooding.
More information can be found in the hydro section. Temperatures
will rebound slightly with upper 70s to lower 80s expected.

.LONG TERM...(Friday night through Thursday)
Issued at 152 PM MDT Thu Jul 28 2022

Airmass dries out some this weekend with precipitable water
values falling to 0.75 to 1.00 (in) across northeast Colorado. For
the higher terrain precipitable water values drop to 0.5 to 0.75
(in). These values are very near to slightly above normal. Expect
late day showers and storms to form over the higher terrain and
spread eastward. Threat for heavy rain rain will be lower, but the
burn areas will still see a low threat for flash flooding. Upper
level high that has been parked over the western states will
slowly shift eastward through the weekend. This will bring a
warming trend with temperatures topping 90 degrees across
northeast Colorado by Sunday.

Upper level high will track east across the Central and Southern
Rockies Monday and end up southeast of Colorado by Tuesday. Dry
and warm air will accompany the ridge. Other than a few weak
showers/storms over the higher terrain, dry conditions are
expected for Monday. Highs will climb well into the 90s across
northeast Colorado. Southwesterly flow around the high will bring
monsoonal moisture back to the area Tuesday. Best moisture should
be across western and central Colorado. Some models showing a
short wave trough for Tuesday as well, so will have scattered PoPs
for areas along and west of I-25. It should be another very warm
day with highs in the 90s across northeast Colorado. The upper
level high remains to the southeast of Colorado for Wednesday and
Thursday. This will keep a southwesterly flow aloft and monsoonal
moisture over Colorado. Expect daily afternoon and evening storms
to continue with temperatures topping out in the lower to mid 90s
across northeast Colorado.

&&

.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
Issued at 142 PM MDT Thu Jul 28 2022

MVFR/ILS conditions will persist with convection expected at area
terminals between 22 and 02z. Current convection temperature has
been reached so confidence is high that a cell or two could push
into DEN and BJC during this time. Winds will be out of the south
with a surface high to the southeast with variable winds possible
with convection. After 02z winds will switch to drainage with
diurnal patterns into Friday morning.

&&

.HYDROLOGY...
Issued at 152 PM MDT Thu Jul 28 2022

A flash flood watch for the burn scars in addition to a flood
watch and flood advisory will continue for the region until 10 pm
this evening for saturated soils, especially over portions of
Larimer, Boulder, Jefferson, and Washington counties. Widespread
storms will bring moderate to heavy rainfall into the evening that
could cause some flash flooding over urban areas and burn scars.

Another round of convection combined with continued high
levels of precipitable water will bring a limited threat of flash
flooding to area burn scars Friday afternoon and evening.
Thunderstorms are expected to form over the higher terrain and
move ESE over the I-25 corridor into the late afternoon and
evening. Although storm coverage is expected to be less than today
storms could still produce up to an inch of rain in less than a
hour.

Airmass dries some for this weekend. However, enough will be
around for scattered afternoon and evening thunderstorms. Flash
flood threat will be confined to the burn areas where the threat
will be limited both Saturday and Sunday. Upper level high will
bring warm and mostly dry conditions for Monday. Other than a few
weak storms, dry conditions will prevail. Moisture begins to
return to the area Tuesday with daily showers and storms expected
Tuesday through the rest of the week.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch until 10 PM MDT this evening for COZ032>035.

Flood Watch until 10 PM MDT this evening for COZ038-039.

&&

SHORT TERM...Bowen
LONG TERM...Meier
AVIATION...Bowen
HYDROLOGY...Bowen/Meier

Hazardous Weather Outlook
National Weather Service Denver/Boulder CO
1102 AM MDT Thu Jul 28 2022

COZ030>051-291715-
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 Thu Jul 28 2022

...Flash Flood Watch late this morning through early this evening
for the burn scars...

...Flood Watch for late this morning through the evening for
portions of the Urban Corridor mainly west of I-25 and north of
I-70...

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

.DAY ONE...Today and Tonight

Showers and thunderstorms will redevelop by late morning through
the afternoon hours with heavy rainfall, hail, and gusty winds
being the main hazards. Rainfall amounts from 1 to 2 inches will
be possible in some areas in 45 minutes or less with the stronger
storms. This will lead to an increased risk for flash flooding in
the burn scars and for areas along the I-25 corridor mainly north
of I-70. An isolated severe storm may also occur with hail to one
inch in diameter along with wind gusts to 60 mph.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday

Friday through this weekend, scattered to numerous thunderstorms
will occur each afternoon through late evening. These storms may
produce heavy rainfall and small hail across the region. Monday,
temperatures will increase and drier weather will occur for all
areas. Another round of thunderstorms arrives Tuesday and
Wednesday mainly for the mountains and valleys.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today or tonight but
rainfall reports would be greatly appreciated.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
1033 AM MDT THU JUL 28 2022

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

0220 AM     TSTM WND DMG     2 SSW LOVELAND          40.37N 105.10W
07/28/2022                   LARIMER            CO   NWS EMPLOYEE

            TREE BRANCH BROKEN OFF. TIME FROM RADAR.

0250 AM     TSTM WND DMG     1 NNE BERTHOUD          40.32N 105.08W
07/28/2022                   LARIMER            CO   EMERGENCY MNGR

            1 MAPLE AND TWO PINE TREES KNOCKED DOWN.
            TIME FROM RADAR.

&&

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
244 PM MDT THU JUL 28 2022

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

0748 PM     HAIL             1 SW WELLINGTON         40.70N 105.01W
07/27/2022  M1.75 INCH       LARIMER            CO   COCORAHS

            COCORAHS CO-LR-1008. DELAYED REPORT. TIME
            ESTIMATED VIA RADAR.

&&