Alert archive / Colorado / Flash Flood Watches in 2021

Flash Flood Watch 21, NWS Grand Junction, CO

July 26, 202112 counties in Colorado; Grand County, San Juan County, Utah

NWS Grand Junction, CO issued this flash flood watch at Jul 26, 2021, 12:03 PM MDT for 12 counties in Colorado; Grand County, San Juan County, Utah. It was in force for 10 hr.

The area

The counties it named.

The facts

Issued
Jul 26, 2021, 12:03 PM MDT (18:03 UTC)
Expired
Jul 26, 2021, 10:00 PM MDT
In force
10 hr
Issued by
NWS Grand Junction, CO
Flood severity
None

Counties Delta County, CO, Dolores County, CO, Eagle County, CO, Garfield County, CO, Mesa County, CO, Moffat County, CO, Montrose County, CO, Ouray County, CO, Pitkin County, CO, Rio Blanco County, CO, Routt County, CO, San Miguel County, CO, Grand County, UT, San Juan County, UT

The radar

The Grand Junction radar (KGJX), 10 km from the middle of the area, began a volume at 18:05 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, 6.1 hours before the alert went out and 35 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 2021-07-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3 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 2021-07-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -9 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
3 J/kg
Mixed-layer CIN
-335 J/kg
Mixed-layer LCL
1886 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
-9 m²/s²
0-3 km storm-relative helicity
88 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

914 
WGUS65 KGJT 261803
FFAGJT

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Grand Junction CO
1203 PM MDT Mon Jul 26 2021

UTZ028-270400-
/O.NEW.KGJT.FF.A.0021.210726T1803Z-210727T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
La Sal and Abajo Mountains-
Including the cities of Monticello
1203 PM MDT Mon Jul 26 2021

...FLASH FLOOD WATCH IN EFFECT UNTIL 10 PM MDT THIS EVENING...

The National Weather Service in Grand Junction has issued a

* Flash Flood Watch for a portion of southeast Utah, including the 
  following area, La Sal and Abajo Mountains.

* Until 10 PM MDT this evening.

* Monsoonal moisture remains entrenched over portions of western 
  Colorado and southeast Utah. This will lead to another round of 
  afternoon thunderstorms capable of producing heavy rainfall. 
  Several areas have received heavy rainfall the past few days and 
  additional amounts could lead to excess runoff and localized flash 
  flooding. Rainfall amounts of a half to one inch in a short 
  duration will exacerbate flooding concerns in the watch area.

* This includes the Pack Creek Fire Burn Scar.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

COZ020-270400-
/O.NEW.KGJT.FF.A.0021.210726T1803Z-210727T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Paradox Valley/Lower Dolores River-
Including the cities of Gateway and Nucla
1203 PM MDT Mon Jul 26 2021

...FLASH FLOOD WATCH IN EFFECT UNTIL 10 PM MDT THIS EVENING...

The National Weather Service in Grand Junction has issued a

* Flash Flood Watch for a portion of southwest Colorado, including 
  the following area, Paradox Valley/Lower Dolores River.

* Until 10 PM MDT this evening.

* Monsoonal moisture remains entrenched over portions of western 
  Colorado and southeast Utah. This will lead to another round of 
  afternoon thunderstorms capable of producing heavy rainfall. 
  Several areas have received heavy rainfall the past few days and 
  additional amounts could lead to excess runoff and localized flash 
  flooding. Rainfall amounts of a half to one inch in a short 
  duration will exacerbate flooding concerns in the watch area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

COZ017-270400-
/O.NEW.KGJT.FF.A.0021.210726T1803Z-210727T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Uncompahgre Plateau and Dallas Divide-
Including the cities of Ridgway and Glade Park
1203 PM MDT Mon Jul 26 2021

...FLASH FLOOD WATCH IN EFFECT UNTIL 10 PM MDT THIS EVENING...

The National Weather Service in Grand Junction has issued a

* Flash Flood Watch for a portion of west central Colorado, 
  including the following area, Uncompahgre Plateau and Dallas 
  Divide.

* Until 10 PM MDT this evening.

* Monsoonal moisture remains entrenched over portions of western 
  Colorado and southeast Utah. This will lead to another round of 
  afternoon thunderstorms capable of producing heavy rainfall. 
  Several areas have received heavy rainfall the past few days and 
  additional amounts could lead to excess runoff and localized flash 
  flooding. Rainfall amounts of a half to one inch in a short 
  duration will exacerbate flooding concerns in the watch area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

MMS
2 follow-up statements
962 
WGUS65 KGJT 270136
FFAGJT

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Grand Junction CO
736 PM MDT Mon Jul 26 2021

COZ008-010-013-270400-
/O.EXA.KGJT.FF.A.0021.000000T0000Z-210727T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Central Colorado River Basin-Gore and Elk Mountains/Central Mountain
Valleys-Flat Tops-
736 PM MDT Mon Jul 26 2021

...FLASH FLOOD WATCH FOR THE GRIZZLY CREEK FIRE BURN AREA IN EFFECT 
UNTIL 10 PM MDT THIS EVENING...

The National Weather Service in Grand Junction has expanded the

* Flash Flood Watch to include portions of northwest Colorado and 
  west central Colorado, including the following areas, in northwest 
  Colorado, Flat Tops. In west central Colorado, Central Colorado 
  River Basin and Gore and Elk Mountains/Central Mountain Valleys.

* Until 10 PM MDT this evening.

* National Weather Service Meteorologists are forecasting possible 
  heavy rainfall over the Grizzly Creek Fire Burn Area, which may 
  lead to flash flooding and debris flows.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

UTZ028-270400-
/O.CON.KGJT.FF.A.0021.000000T0000Z-210727T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
La Sal and Abajo Mountains-
Including the cities of Monticello
736 PM MDT Mon Jul 26 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 10 PM MDT THIS 
EVENING...

The Flash Flood Watch continues for

* A portion of southeast Utah, including the following area, La Sal 
  and Abajo Mountains.

* Until 10 PM MDT this evening.

* Monsoonal moisture remains entrenched over portions of western 
  Colorado and southeast Utah. This will lead to another round of 
  afternoon thunderstorms capable of producing heavy rainfall. 
  Several areas have received heavy rainfall the past few days and 
  additional amounts could lead to excess runoff and localized flash 
  flooding. Rainfall amounts of a half to one inch in a short 
  duration will exacerbate flooding concerns in the watch area.

* This includes the Pack Creek Fire Burn Scar.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

COZ020-270400-
/O.CON.KGJT.FF.A.0021.000000T0000Z-210727T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Paradox Valley/Lower Dolores River-
Including the cities of Gateway and Nucla
736 PM MDT Mon Jul 26 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 10 PM MDT THIS 
EVENING...

The Flash Flood Watch continues for

* A portion of southwest Colorado, including the following area, 
  Paradox Valley/Lower Dolores River.

* Until 10 PM MDT this evening.

* Monsoonal moisture remains entrenched over portions of western 
  Colorado and southeast Utah. This will lead to another round of 
  afternoon thunderstorms capable of producing heavy rainfall. 
  Several areas have received heavy rainfall the past few days and 
  additional amounts could lead to excess runoff and localized flash 
  flooding. Rainfall amounts of a half to one inch in a short 
  duration will exacerbate flooding concerns in the watch area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

COZ017-270400-
/O.CON.KGJT.FF.A.0021.000000T0000Z-210727T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Uncompahgre Plateau and Dallas Divide-
Including the cities of Ridgway and Glade Park
736 PM MDT Mon Jul 26 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 10 PM MDT THIS 
EVENING...

The Flash Flood Watch continues for

* A portion of west central Colorado, including the following area, 
  Uncompahgre Plateau and Dallas Divide.

* Until 10 PM MDT this evening.

* Monsoonal moisture remains entrenched over portions of western 
  Colorado and southeast Utah. This will lead to another round of 
  afternoon thunderstorms capable of producing heavy rainfall. 
  Several areas have received heavy rainfall the past few days and 
  additional amounts could lead to excess runoff and localized flash 
  flooding. Rainfall amounts of a half to one inch in a short 
  duration will exacerbate flooding concerns in the watch area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

NL
861 
WGUS65 KGJT 270357
FFAGJT

Flood Watch
National Weather Service Grand Junction CO
957 PM MDT Mon Jul 26 2021

COZ008-010-013-017-020-UTZ028-270500-
/O.EXP.KGJT.FF.A.0021.000000T0000Z-210727T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Central Colorado River Basin-Gore and Elk Mountains/Central Mountain
Valleys-Flat Tops-Uncompahgre Plateau and Dallas Divide-Paradox
Valley/Lower Dolores River-La Sal and Abajo Mountains-
Including the cities of Eagle, Edwards, Glenwood Springs, 
Carbondale, Basalt, Aspen, Vail, Snowmass, Buford, Trappers Lake, 
Ridgway, Glade Park, Gateway, Nucla, and Monticello
957 PM MDT Mon Jul 26 2021

...FLASH FLOOD WATCH FOR THE GRIZZLY CREEK FIRE BURN AREA WILL 
EXPIRE AT 10 PM MDT THIS EVENING...

The Flash Flood Watch for portions of Colorado and southeast Utah, 
including the following areas, in Colorado, Central Colorado River 
Basin, Flat Tops, Gore and Elk Mountains/Central Mountain Valleys, 
Paradox Valley/Lower Dolores River and Uncompahgre Plateau and 
Dallas Divide. In southeast Utah, La Sal and Abajo Mountains will 
expire at 10 PM MDT this evening.

Flooding is no longer expected to pose a threat. Please continue to 
heed remaining road closures.

$$

NL

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 25, 6:03 PM MDTSpecial Weather StatementGJT42 min
Jul 25, 6:51 PM MDTFlash Flood Warning Considerable damage threatGJTGarfield, Mesa114 min
Jul 25, 7:19 PM MDTFlash Flood WarningGJTMesa3 hr
Jul 25, 7:39 PM MDTFlash Flood Warning Considerable damage threatGJTEagle, Garfield81 min
Jul 25, 8:03 PM MDTSpecial Weather StatementGJTMesa42 min
Jul 25, 8:42 PM MDTAreal Flood AdvisoryGJTMesa3 hr
Jul 25, 11:03 PM MDTAreal Flood AdvisoryGJTMesa2 hr
Jul 25, 11:35 PM MDTFlash Flood WarningGJTMesa115 min
Jul 26, 4:06 PM MDTAreal Flood AdvisoryGJTLa Plata3 hr
Jul 26, 4:37 PM MDTAreal Flood AdvisoryGJTMontezuma3 hr
Jul 26, 5:14 PM MDTAreal Flood AdvisoryGJTDolores3 hr
Jul 26, 5:50 PM MDTFlash Flood WarningGJTMesa, Montrose114 min
Jul 26, 5:52 PM MDTSpecial Weather StatementGJT38 min

Nearby

Flash Flood Watches in Colorado, 2021Flash Flood Watches in Utah, 2021Every flash flood watch 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.