Alert archive / Colorado / Flash Flood Warnings in 2021

Flash Flood Warning 21, NWS Grand Junction, CO

July 23, 2021Dolores County, Montezuma County, Colorado

NWS Grand Junction, CO issued this flash flood warning at Jul 23, 2021, 1:58 PM MDT for Dolores County, Montezuma County, Colorado. It was in force for 4 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 23, 2021, 1:58 PM MDT (19:58 UTC)
Expired
Jul 23, 2021, 6:00 PM MDT
In force
4 hr
Issued by
NWS Grand Junction, CO
Area
Storm-based polygon
Flood severity
None

Counties Dolores County, CO, Montezuma County, CO

The radar

The Grand Junction radar (KGJX), 169 km from the middle of the area, began a volume at 20:01 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Grand Junction, CO (KGJT), launched 12:00Z, 8.0 hours before the alert went out and 177 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Grand Junction, CO at 12:00Z on 2021-07-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 21 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Grand Junction, CO at 12:00Z on 2021-07-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -41 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
21 J/kg
Mixed-layer CIN
-153 J/kg
Mixed-layer LCL
1904 m above ground
0-6 km bulk shear
5 kt
0-1 km storm-relative helicity
-41 m²/s²
0-3 km storm-relative helicity
-27 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

537 
WGUS55 KGJT 231958
FFWGJT
COC033-083-240000-
/O.NEW.KGJT.FF.W.0021.210723T1958Z-210724T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Grand Junction CO
158 PM MDT Fri Jul 23 2021

The National Weather Service in Grand Junction has issued a

* Flash Flood Warning for...
  Central Dolores County in southwestern Colorado...
  North Central Montezuma County in southwestern Colorado...

* Until 600 PM MDT.

* At 158 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 0.6 and 1.3 inches of 
  rain have fallen. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Stoner.

This includes the following streams and drainages...
  Dolores River, Taylor Creek, House Creek, Lost Canyon Creek, 
  Hartman Draw, Pipe Creek, Spring Creek, Fish Creek, Little Taylor 
  Creek, Turkey Creek, West Dolores River, Stoner Creek and Beaver 
  Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Move to higher ground now. Act quickly to protect your life.

&&

LAT...LON 3759 10846 3760 10842 3765 10842 3765 10833
      3761 10827 3762 10821 3759 10821 3759 10819
      3755 10824 3752 10822 3743 10831 3745 10834
      3743 10846 3746 10853 3748 10842 3751 10842
      3751 10850 3753 10851 3755 10845

FLASH FLOOD...RADAR INDICATED

$$

as
2 follow-up statements
491 
WGUS75 KGJT 232157
FFSGJT

Flash Flood Statement
National Weather Service Grand Junction CO
357 PM MDT Fri Jul 23 2021

COC033-083-240000-
/O.CON.KGJT.FF.W.0021.000000T0000Z-210724T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Dolores CO-Montezuma CO-
357 PM MDT Fri Jul 23 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 6 PM MDT THIS EVENING 
FOR CENTRAL DOLORES AND NORTH CENTRAL MONTEZUMA COUNTIES...

At 357 PM MDT, Doppler radar indicated thunderstorms have decrease 
and only light rain is falling over the warned area. Other storms 
are forming in the region. Between 0.6 and 1.5 inches of rain have 
fallen. Flash flooding is ongoing. Flood waters can take hours to 
travel downstream.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar.

IMPACT...Flash flooding of small creeks and streams, urban areas,
         highways, streets and underpasses as well as other poor
         drainage and low-lying areas.

Some locations that will experience flash flooding include...
  Stoner.

This includes the following streams and drainages...
  Dolores River, Taylor Creek, House Creek, Lost Canyon Creek, 
  Hartman Draw, Pipe Creek, Spring Creek, Fish Creek, Little Taylor 
  Creek, Turkey Creek, West Dolores River, Stoner Creek and Beaver 
  Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Move to higher ground now. Act quickly to protect your life.

&&

LAT...LON 3759 10846 3760 10842 3765 10842 3765 10833
      3761 10827 3762 10821 3759 10821 3759 10819
      3755 10824 3752 10822 3743 10831 3745 10834
      3743 10846 3746 10853 3748 10842 3751 10842
      3751 10850 3753 10851 3755 10845

FLASH FLOOD...RADAR INDICATED

$$

as
228 
WGUS75 KGJT 232352
FFSGJT

Flash Flood Statement
National Weather Service Grand Junction CO
552 PM MDT Fri Jul 23 2021

COC033-083-240002-
/O.EXP.KGJT.FF.W.0021.000000T0000Z-210724T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Dolores CO-Montezuma CO-
552 PM MDT Fri Jul 23 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 6 PM MDT THIS EVENING FOR 
CENTRAL DOLORES AND NORTH CENTRAL MONTEZUMA COUNTIES...

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

A Flash Flood Watch remains in effect until 300 AM MDT Saturday for 
a portion of southwest Colorado.

LAT...LON 3759 10846 3760 10842 3765 10842 3765 10833
      3761 10827 3762 10821 3759 10821 3759 10819
      3755 10824 3752 10822 3743 10831 3745 10834
      3743 10846 3746 10853 3748 10842 3751 10842
      3751 10850 3753 10851 3755 10845

$$

as

The office that day

Everything else NWS Grand Junction, CO issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 23, 12:18 PM MDTSpecial Weather StatementGJTDelta27 min
Jul 23, 12:21 PM MDTSpecial Weather StatementGJT39 min
Jul 23, 12:46 PM MDTAreal Flood AdvisoryGJTMontezuma3 hr
Jul 23, 12:48 PM MDTSpecial Weather StatementGJTMontezuma42 min
Jul 23, 1:22 PM MDTAreal Flood AdvisoryGJTDolores, Montezuma3 hr
Jul 23, 2:17 PM MDTAreal Flood AdvisoryGJTDolores, Montezuma, San Juan, San Miguel3 hr
Jul 23, 3:07 PM MDTSpecial Weather StatementGJTChaffee38 min
Jul 23, 3:26 PM MDTAreal Flood AdvisoryGJTOuray3 hr
Jul 23, 3:42 PM MDTSpecial Weather StatementGJTChaffee33 min
Jul 23, 3:50 PM MDTSpecial Weather StatementGJTArchuleta40 min
Jul 23, 3:50 PM MDTSpecial Weather StatementGJTLa Plata25 min
Jul 23, 4:16 PM MDTSpecial Weather StatementGJTDelta29 min
Jul 23, 4:28 PM MDTAreal Flood AdvisoryGJTGunnison3 hr
Jul 23, 4:57 PM MDTAreal Flood AdvisoryGJTHinsdale, Ouray, San Juan3 hr
Jul 23, 5:11 PM MDTSpecial Weather StatementGJTMesa49 min
Jul 23, 5:12 PM MDTAreal Flood AdvisoryGJTMesa3 hr
Jul 23, 5:19 PM MDTAreal Flood AdvisoryGJTGarfield3 hr
Jul 23, 5:25 PM MDTAreal Flood AdvisoryGJTGarfield, Mesa3 hr
Jul 23, 5:29 PM MDTAreal Flood AdvisoryGJTGarfield3 hr
Jul 23, 5:34 PM MDTFlash Flood Warning Considerable damage threatGJTEagle, Garfield3 hr
Jul 23, 5:36 PM MDTAreal Flood AdvisoryGJTGunnison, Hinsdale3 hr
Jul 23, 5:39 PM MDTSpecial Weather StatementGJTHinsdale51 min
Jul 23, 5:47 PM MDTSpecial Weather StatementGJTDelta43 min
Jul 23, 5:51 PM MDTAreal Flood AdvisoryGJTMontrose3 hr

Nearby

Flash Flood Warnings in Colorado, 2021Every flash flood warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.