Alert archive / Colorado / Flash Flood Warnings in 2021

Flash Flood Warning 67, NWS Grand Junction, CO

July 31, 2021Garfield County, Mesa County, Colorado

NWS Grand Junction, CO issued this flash flood warning at Jul 31, 2021, 4:16 PM MDT for Garfield County, Mesa County, Colorado. It was in force for 104 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Jul 31, 2021, 4:16 PM MDT (22:16 UTC)
Expired: Jul 31, 2021, 6:00 PM MDT
In force: 104 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 22:16 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.

What was reported inside it

Time	Report	Where	Remark
Jul 31, 5:45 PM MDT	FLASH FLOOD	14 Sse Douglas Pass, CO	10 FEET OF WATER REPORTED ON COUNTY ROAD 205.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Grand Junction, CO (KGJT), launched 12:00Z, 10.3 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1449 m above ground
0-6 km bulk shear: 4 kt
0-1 km storm-relative helicity: 66 m²/s²
0-3 km storm-relative helicity: 112 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

143 
WGUS55 KGJT 312216
FFWGJT
COC045-077-010000-
/O.NEW.KGJT.FF.W.0067.210731T2216Z-210801T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Grand Junction CO
416 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 600 PM MDT.

* At 416 PM MDT, Doppler radar indicated ta slow moving thunderstorm 
  producing heavy rain over the west Pine Gulch Fire Burn Area. 
  Between 0.8 and 1.3 inches of rain have fallen. Additional 
  rainfall amounts of 0.5 to 1 inch are possible in the warned area. 
  Flash flooding is ongoing or expected to begin shortly.

Excessive rainfall over the west side of 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 west Pine Gulch Fire Burn Area.

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

This includes the following streams and drainages...
  East Salt Creek, Little Salt Wash, Kimball Creek, Big Salt Wash 
  and Coal Gulch.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a life threatening situation. Heavy rainfall will cause 
severe flash flooding of creeks...streams...and ditches in the west 
side of the Pine Gulch Fire Burn Area. 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

$$

ERW

1 follow-up statement

376 
WGUS75 KGJT 312354
FFSGJT

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

COC045-077-010004-
/O.EXP.KGJT.FF.W.0067.000000T0000Z-210801T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield CO-Mesa CO-
554 PM MDT Sat Jul 31 2021

...FLASH FLOOD WARNING FOR THE PINE GULCH FIRE BURN AREA WILL EXPIRE 
AT 6 PM MDT THIS EVENING FOR SOUTHWESTERN GARFIELD AND NORTH CENTRAL 
MESA COUNTIES...

The heavy rain has ended and will allow the Flash Flood Warning to 
expire. However, light precipitation will continue over the area for 
the next 1 to 2 hours. 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

$$

ERW

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 30, 6:23 PM MDT	Flash Flood Warning	GJT	Pitkin	112 min
Jul 30, 6:29 PM MDT	Special Weather Statement	GJT	Pitkin	31 min
Jul 30, 7:26 PM MDT	Special Weather Statement	GJT		34 min
Jul 30, 7:37 PM MDT	Severe Thunderstorm Warning	GJT	Mesa	23 min
Jul 30, 7:46 PM MDT	Areal Flood Advisory	GJT	Garfield	119 min
Jul 30, 7:52 PM MDT	Areal Flood Advisory	GJT	Garfield	113 min
Jul 30, 7:55 PM MDT	Areal Flood Advisory	GJT	Mesa, Montrose	3 hr
Jul 30, 8:00 PM MDT	Severe Thunderstorm Warning	GJT	Mesa	30 min
Jul 30, 9:04 PM MDT	Special Weather Statement	GJT	Mesa	26 min
Jul 30, 9:28 PM MDT	Special Weather Statement	GJT	Mesa	32 min
Jul 30, 10:44 PM MDT	Areal Flood Advisory	GJT	Mesa	2 hr
Jul 30, 11:14 PM MDT	Areal Flood Advisory	GJT	Mesa	3 hr
Jul 31, 12:13 AM MDT	Areal Flood Advisory	GJT	Mesa	3 hr
Jul 31, 12:30 AM MDT	Areal Flood Advisory	GJT	Moffat, Rio Blanco	3 hr
Jul 31, 1:08 PM MDT	Special Weather Statement	GJT		22 min
Jul 31, 2:45 PM MDT	Flash Flood Warning	GJT	San Miguel	2 hr
Jul 31, 3:00 PM MDT	Special Weather Statement	GJT	San Miguel	30 min
Jul 31, 3:50 PM MDT	Flash Flood Warning Considerable damage threat	GJT	Eagle, Garfield	115 min
Jul 31, 4:32 PM MDT	Areal Flood Advisory	GJT	Dolores, Montezuma	118 min
Jul 31, 5:48 PM MDT	Flash Flood Warning	GJT	Pitkin	117 min
Jul 31, 5:52 PM MDT	Areal Flood Advisory	GJT	Rio Blanco	3 hr

Nearby

Flash Flood Warnings in Colorado, 2021 Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.