Alert archive / Utah / Flash Flood Warnings in 2021

Flash Flood Warning 46, NWS Grand Junction, CO

July 28, 2021Grand County, San Juan County, Utah

NWS Grand Junction, CO issued this flash flood warning at Jul 28, 2021, 3:17 PM MDT for Grand County, San Juan County, Utah. It was in force for 5 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 28, 2021, 3:17 PM MDT (21:17 UTC)
Expired
Jul 28, 2021, 8:00 PM MDT
In force
5 hr
Issued by
NWS Grand Junction, CO
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

Counties Grand County, UT, San Juan County, UT

The radar

The Grand Junction radar (KGJX), 115 km from the middle of the area, began a volume at 21:17 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, 9.3 hours before the alert went out and 101 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 2021-07-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 68 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 2021-07-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -38 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
68 J/kg
Mixed-layer CIN
-138 J/kg
Mixed-layer LCL
1671 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
-38 m²/s²
0-3 km storm-relative helicity
37 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

044 
WGUS55 KGJT 282117
FFWGJT
UTC019-037-282200-
/O.NEW.KGJT.FF.W.0046.210728T2117Z-210728T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Grand Junction CO
317 PM MDT Wed Jul 28 2021

The National Weather Service in Grand Junction has issued a

* Flash Flood Warning for...
  The Pack Creek Fire Burn Area in...
  Southeastern Grand County in east central Utah...
  Northeastern San Juan County in southeastern Utah...

* Until 400 PM MDT.

* At 317 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain moving over the Pack Creek 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 Pack Creek 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 Pack Creek
           Fire Burn Area.

  SOURCE...Radar.

  IMPACT...Life threatening flash flooding of areas in and around
           the Pack Creek Fire Burn Area.

* Some locations that will experience flash flooding include...
  Spanish Valley.

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 Pack Creek 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 3850 10927 3851 10926 3850 10922 3844 10923
      3844 10926 3845 10928 3842 10932 3843 10939
      3845 10939 3847 10934 3848 10930

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

ERW
4 follow-up statements
313 
WGUS55 KGJT 282147
FFWGJT
UTC019-037-290000-
/O.EXT.KGJT.FF.W.0046.000000T0000Z-210729T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Grand Junction CO
347 PM MDT Wed Jul 28 2021

The National Weather Service in Grand Junction has extended the

* Flash Flood Warning for...
  The Pack Creek Fire Burn Area in...
  Southeastern Grand County in east central Utah...
  Northeastern San Juan County in southeastern Utah...

* Until 600 PM MDT.

* At 347 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain over the Pack Creek Fire Burn Area. Between 0.5 and 1 
  inch of rain has 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 burn scar will result in debris flow 
moving through the Pack Creek 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 Pack Creek
           Fire Burn Area.

  SOURCE...Radar.

  IMPACT...Life threatening flash flooding of areas in and around
           the Pack Creek Fire Burn Area.

* Some locations that will experience flash flooding include...
  Spanish Valley.

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 Pack Creek 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 3850 10927 3851 10926 3850 10922 3844 10923
      3844 10926 3845 10928 3842 10932 3843 10939
      3845 10939 3847 10934 3848 10930

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

ERW
947 
WGUS55 KGJT 282355
FFWGJT
UTC019-037-290100-
/O.EXT.KGJT.FF.W.0046.000000T0000Z-210729T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Grand Junction CO
555 PM MDT Wed Jul 28 2021

The National Weather Service in Grand Junction has extended the

* Flash Flood Warning for...
  The Pack Creek Fire Burn Area in...
  Southeastern Grand County in east central Utah...
  Northeastern San Juan County in southeastern Utah...

* Until 700 PM MDT.

* At 555 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain near the Pack Creek Fire Burn Area. Between 0.5 and 1 
  inch of rain has 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 burn scar will result in debris flow 
moving through the Pack Creek 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 Pack Creek
           Fire Burn Area.

  SOURCE...Radar.

  IMPACT...Life threatening flash flooding of areas in and around
           the Pack Creek Fire Burn Area.

* Some locations that will experience flash flooding include...
  Spanish Valley.

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 Pack Creek 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 3850 10927 3851 10926 3850 10922 3844 10923
      3844 10926 3845 10928 3842 10932 3843 10939
      3845 10939 3847 10934 3848 10930

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

MMS
932 
WGUS55 KGJT 290053
FFWGJT
UTC019-037-290200-
/O.EXT.KGJT.FF.W.0046.000000T0000Z-210729T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Grand Junction CO
653 PM MDT Wed Jul 28 2021

The National Weather Service in Grand Junction has extended the

* Flash Flood Warning for...
  The Pack Creek Fire Burn Area in...
  Southeastern Grand County in east central Utah...
  Northeastern San Juan County in southeastern Utah...

* Until 800 PM MDT.

* At 653 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain over the Pack Creek Fire Burn Area. Flash flooding is 
  ongoing or expected to begin shortly.

Excessive rainfall over the burn scar will result in debris flow 
moving through the Pack Creek 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 Pack Creek
           Fire Burn Area.

  SOURCE...Radar.

  IMPACT...Life threatening flash flooding of areas in and around
           the Pack Creek Fire Burn Area.

* Some locations that will experience flash flooding include...
  Spanish Valley.

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 Pack Creek 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 3850 10927 3851 10926 3850 10922 3844 10923
      3844 10926 3845 10928 3842 10932 3843 10939
      3845 10939 3847 10934 3848 10930

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

MMS
795 
WGUS75 KGJT 290150
FFSGJT

Flash Flood Statement
National Weather Service Grand Junction CO
750 PM MDT Wed Jul 28 2021

UTC019-037-290200-
/O.EXP.KGJT.FF.W.0046.000000T0000Z-210729T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Grand UT-San Juan UT-
750 PM MDT Wed Jul 28 2021

...FLASH FLOOD WARNING FOR THE PACK CREEK FIRE BURN AREA WILL EXPIRE 
AT 8 PM MDT THIS EVENING FOR SOUTHEASTERN GRAND AND NORTHEASTERN SAN 
JUAN COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. However, light rain will continue for the next couple of 
hours. Please continue to heed remaining road closures.

LAT...LON 3850 10927 3851 10926 3850 10922 3844 10923
      3844 10926 3845 10928 3842 10932 3843 10939
      3845 10939 3847 10934 3848 10930

$$

MMS

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 28, 2:28 PM MDTFlash Flood WatchGJTGrand, San Juan34 hr

Nearby

Flash Flood Warnings in Utah, 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.