Alert archive / Colorado / Flash Flood Warnings in 2012

Flash Flood Warning 2, NWS Grand Junction, CO

July 7, 2012Garfield County, Colorado

NWS Grand Junction, CO issued this flash flood warning at Jul 7, 2012, 4:45 PM MDT for Garfield County, Colorado. It was in force for 3 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 7, 2012, 4:45 PM MDT (22:45 UTC)
Expired
Jul 7, 2012, 7:29 PM MDT
In force
3 hr
Issued by
NWS Grand Junction, CO
Area
Storm-based polygon
Flood severity
None

County Garfield County, CO

The radar

The Grand Junction radar (KGJX), 58 km from the middle of the area, began a volume at 22:48 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, 10.8 hours before the alert went out and 72 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 2012-07-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 107 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 2012-07-07The 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
107 J/kg
Mixed-layer CIN
-174 J/kg
Mixed-layer LCL
1835 m above ground
0-6 km bulk shear
4 kt
0-1 km storm-relative helicity
-7 m²/s²
0-3 km storm-relative helicity
-29 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

815 
WGUS55 KGJT 072245
FFWGJT
COC045-080130-
/O.NEW.KGJT.FF.W.0002.120707T2245Z-120708T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
445 PM MDT SAT JUL 7 2012

THE NATIONAL WEATHER SERVICE IN GRAND JUNCTION HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTH CENTRAL GARFIELD COUNTY IN WEST CENTRAL COLORADO...

* UNTIL 730 PM MDT

* AT 440 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL SOUTH OF 
INTERSTATE 70 BETWEEN RIFLE AND NEW CASTLE. NATIONAL WEATHER SERVICE 
DOPPLER RADAR ESTIMATES NEARLY 2 INCHES OF RAINFALL HAS OCCURRED IN 
CACHE...BEAVER AND MAMM CREEKS.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO   
OCCUR WITH MUD AND DEBRIS FLOWS THE PRIMARY THREAT.   

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY.

FLOODING IS OCCURRING OR IS IMMINENT. MOST FLOOD RELATED DEATHS OCCUR
IN VEHICLES. DO NOT ATTEMPT TO CROSS WATER COVERED BRIDGES...DIPS...
OR LOW WATER CROSSINGS. NEVER TRY TO CROSS A FLOWING STREAM... EVEN A
SMALL ONE...ON FOOT OR IN A VEHICLE.

&&

LAT...LON 3937 10767 3936 10793 3955 10794 3953 10781
      3955 10765

$$

JOE
2 follow-up statements
702 
WGUS75 KGJT 080044
FFSGJT

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
644 PM MDT SAT JUL 7 2012

COC045-080130-
/O.CON.KGJT.FF.W.0002.000000T0000Z-120708T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
GARFIELD CO-
644 PM MDT SAT JUL 7 2012

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR SOUTH CENTRAL GARFIELD
COUNTY UNTIL 730 PM MDT...

EARLIER THIS EVENING...WEATHER SPOTTERS REPORTED THUNDERSTORMS WITH 
VERY HEAVY RAINFALL ACROSS THE WARNED AREA. NATIONAL WEATHER SERVICE 
DOPPLER RADAR ESTIMATED OVER 2 INCHES OF RAINFALL OCCURRED TO THE 
WEST OF DEBEQUE BETWEEN 2:30 AND 3:30 PM THIS AFTERNOON. THERE IS 
SOME INDICATION THAT JERRY CREEK TO THE SOUTH OF THE WARNED AREA BUT 
NORTH OF CAMEO RECEIVED THE HEAVIEST RAINFALL. AT 6:40 PM MDT...A 
LINE OF HEAVY SHOWERS WAS APPROACHING THE WARNED AREA FROM THE 
NORTHWEST. 

RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
OCCUR.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN HILLY TERRAIN...LOW WATER CROSSINGS CAN BE DANGEROUS IN HEAVY 
RAIN. DO NOT ATTEMPT TO TRAVEL ACROSS FLOODED ROADS. FIND ALTERNATE 
ROUTES. IT ONLY TAKES A FEW INCHES OF SWIFTLY FLOWING WATER TO CARRY 
VEHICLES AWAY.

&&

LAT...LON 3937 10767 3936 10793 3955 10794 3953 10781
      3955 10765

$$
JOE
169 
WGUS75 KGJT 080129
FFSGJT

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
729 PM MDT SAT JUL 7 2012

COC045-080144-
/O.CAN.KGJT.FF.W.0002.000000T0000Z-120708T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
GARFIELD CO-
729 PM MDT SAT JUL 7 2012

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR SOUTH CENTRAL
GARFIELD COUNTY IS CANCELLED...

EXCESS RUNOFF FROM HEAVY RAIN HAS ENDED OVER THE WARNED AREA. STREAMS
AND CREEKS IN THE WARNED AREA HAVE RECEDED OR WERE BEGINNING TO
RECEDE...ENDING THE FLOOD THREAT. IF FLOODING HAS BEEN OBSERVED...
PLEASE REPORT IT TO YOUR LOCAL LAW ENFORCEMENT AGENCY.

LAT...LON 3937 10767 3936 10793 3955 10794 3953 10781
      3955 10765

$$
JOE

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 7, 3:56 AM MDTFlash Flood WatchGJTArchuleta, Delta, Dolores, Eagle, Garfield, Gunnison and 11 more17 hr
Jul 7, 4:21 PM MDTFlash Flood WarningGJTGunnison, Pitkin3 hr
Jul 7, 5:07 PM MDTFlash Flood WarningGJTGarfield, Mesa3 hr
Jul 7, 5:50 PM MDTFlash Flood WarningGJTMoffat, Routt3 hr

Nearby

Flash Flood Warnings in Colorado, 2012Every flash flood warning in 2012

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.