Alert archive / Colorado / Flash Flood Warnings in 2021

Flash Flood Warning 35, NWS Grand Junction, CO

July 25, 2021Garfield County, Mesa County, Colorado

NWS Grand Junction, CO issued this flash flood warning at Jul 25, 2021, 6:51 PM MDT for Garfield County, Mesa County, Colorado. It was in force for 114 min. 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 25, 2021, 6:51 PM MDT (00:51 UTC)
Expired
Jul 25, 2021, 8:45 PM MDT
In force
114 min
Issued by
NWS Grand Junction, CO
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

Counties Garfield County, CO, Mesa County, CO

The radar

The Grand Junction radar (KGJX), 48 km from the middle of the area, began a volume at 00:52 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 00:00Z, 0.9 hours before the alert went out and 31 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 00:00Z on 2021-07-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 126 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 00:00Z on 2021-07-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 4 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
126 J/kg
Mixed-layer CIN
-77 J/kg
Mixed-layer LCL
2890 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
4 m²/s²
0-3 km storm-relative helicity
11 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

884 
WGUS55 KGJT 260051
FFWGJT
COC045-077-260245-
/O.NEW.KGJT.FF.W.0035.210726T0051Z-210726T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Grand Junction CO
651 PM MDT Sun Jul 25 2021

The National Weather Service in Grand Junction has issued a

* Flash Flood Warning for...
  The Pine Gulch Fire Burn Area in...
  Southwestern Garfield County in west central Colorado...
  North Central Mesa County in west central Colorado...

* Until 845 PM MDT.

* At 651 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain over the Pine Gulch Fire Burn Area. The expected 
  rainfall rate is 0.5 to 1 inch in 1 hour. Flash flooding is 
  ongoing or expected to begin shortly.

Excessive rainfall over the burn scar will result in debris flow 
moving through the Pine Gulch Burn area. The debris flow can consist 
of rock, mud, vegetation and other loose materials.

  HAZARD...Life threatening flash flooding. Thunderstorms
           producing flash flooding in and around the Pine Gulch
           Fire Burn Area.

  SOURCE...Radar.

  IMPACT...Life threatening flash flooding of areas in and around
           the Pine Gulch Fire Burn Area.

* Some locations that will experience flash flooding include...
  mainly rural areas of Southwestern Garfield and North Central Mesa 
  Counties

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a life threatening situation. Heavy rainfall will cause 
extensive and severe flash flooding of creeks...streams...and 
ditches in the Pine Gulch Fire Burn Area. Severe debris flows can 
also be anticipated across roads. Roads and driveways may be washed 
away in places. If you encounter flood waters...climb to safety.

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

&&

LAT...LON 3936 10866 3937 10866 3939 10865 3940 10870
      3944 10876 3943 10878 3946 10879 3951 10875
      3953 10861 3951 10838 3949 10832 3942 10827
      3939 10837 3937 10840 3937 10841 3936 10842
      3932 10851 3929 10853 3929 10858

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...0.5-1 INCH IN 1 HOUR

$$

MDM/NL
1 follow-up statement
207 
WGUS75 KGJT 260243
FFSGJT

Flash Flood Statement
National Weather Service Grand Junction CO
843 PM MDT Sun Jul 25 2021

COC045-077-260253-
/O.EXP.KGJT.FF.W.0035.000000T0000Z-210726T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield CO-Mesa CO-
843 PM MDT Sun Jul 25 2021

...FLASH FLOOD WARNING FOR THE PINE GULCH FIRE BURN AREA WILL EXPIRE 
AT 845 PM MDT THIS EVENING FOR SOUTHWESTERN GARFIELD AND NORTH 
CENTRAL MESA COUNTIES...

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

LAT...LON 3936 10866 3937 10866 3939 10865 3940 10870
      3944 10876 3943 10878 3946 10879 3951 10875
      3953 10861 3951 10838 3949 10832 3942 10827
      3939 10837 3937 10840 3937 10841 3936 10842
      3932 10851 3929 10853 3929 10858

$$

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, 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, 12:03 PM MDTFlash Flood WatchGJTDelta, Dolores, Eagle, Garfield, Mesa, Moffat and 6 more10 hr
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 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.