Alert archive / Colorado / Flash Flood Warnings in 2021

Flash Flood Warning 69, NWS Grand Junction, CO

July 31, 2021Garfield County, Mesa County, Colorado

NWS Grand Junction, CO issued this flash flood warning at Jul 31, 2021, 6:11 PM MDT for Garfield County, Mesa County, Colorado. It was in force for 109 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 31, 2021, 6:11 PM MDT (00:11 UTC)
Expired
Jul 31, 2021, 8:00 PM MDT
In force
109 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 00:10 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, 0.2 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 2021-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 59 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 2021-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 7 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
59 J/kg
Mixed-layer CIN
-60 J/kg
Mixed-layer LCL
2545 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
7 m²/s²
0-3 km storm-relative helicity
33 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

003 
WGUS55 KGJT 010011
FFWGJT
COC045-077-010200-
/O.NEW.KGJT.FF.W.0069.210801T0011Z-210801T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Grand Junction CO
611 PM MDT Sat Jul 31 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 800 PM MDT.

* At 611 PM MDT, Emergency management reported flash flooding over 
  roadways and along ditches along the western portions of the Pine 
  Gulch Fire Burn Area. Flash flooding is ongoing.

Recent excessive rainfall over the burn scar will continue to 
produce 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...Emergency management reported.

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

* Some locations that will experience flash flooding include...
  County Road 205 within Coal Creek Drainage, of Southwestern 
  Garfield and North Central Mesa Counties

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a life threatening situation. Heavy rainfall caused 
extensive and severe flash flooding of creeks...streams...and 
ditches on the west side of the Pine Gulch Fire Burn Area. Severe 
debris flows have been observed 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...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

ERW
1 follow-up statement
282 
WGUS75 KGJT 010152
FFSGJT

Flash Flood Statement
National Weather Service Grand Junction CO
752 PM MDT Sat Jul 31 2021

COC045-077-010202-
/O.EXP.KGJT.FF.W.0069.000000T0000Z-210801T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield CO-Mesa CO-
752 PM MDT Sat Jul 31 2021

...FLASH FLOOD WARNING FOR THE PINE GULCH FIRE BURN AREA WILL EXPIRE 
AT 8 PM MDT THIS EVENING FOR SOUTHWESTERN GARFIELD AND NORTH CENTRAL 
MESA COUNTIES...

The heavy rain has ended. However, flooded washes may persist. 
Please heed all road closures and evacuations.

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

$$

ERW

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 31, 7:00 PM MDTFlash Flood Warning Considerable damage threatGJTGarfield, Mesa2 hr
Aug 1, 3:05 AM MDTFlash Flood WatchGJTArchuleta, Delta, Dolores, Eagle, Garfield, Gunnison and 12 more18 hr
Aug 1, 11:34 AM MDTSpecial Weather StatementGJTMesa26 min
Aug 1, 1:25 PM MDTFlash Flood WatchGJTArchuleta, Delta, Dolores, Eagle, Garfield, Gunnison and 12 more35 hr
Aug 1, 2:49 PM MDTAreal Flood AdvisoryGJTGarfield, Mesa3 hr
Aug 1, 3:20 PM MDTSpecial Weather StatementGJTGarfield40 min
Aug 1, 4:34 PM MDTAreal Flood AdvisoryGJTDelta, Mesa116 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.