Alert archive / Utah / Flash Flood Warnings in 2013

Flash Flood Warning 21, NWS Grand Junction, CO

August 26, 2013San Juan County, Utah

NWS Grand Junction, CO issued this flash flood warning at Aug 26, 2013, 4:47 PM MDT for San Juan County, Utah. 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
Aug 26, 2013, 4:47 PM MDT (22:47 UTC)
Expired
Aug 26, 2013, 7:30 PM MDT
In force
3 hr
Issued by
NWS Grand Junction, CO
Area
Storm-based polygon
Flood severity
None

County San Juan County, UT

The radar

The Grand Junction radar (KGJX), 226 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 222 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 2013-08-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 80 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 2013-08-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 165 square meters per square second.193958Sfc1 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
80 J/kg
Mixed-layer CIN
-64 J/kg
Mixed-layer LCL
731 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
165 m²/s²
0-3 km storm-relative helicity
163 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

406 
WGUS55 KGJT 262247
FFWGJT
UTC037-270130-
/O.NEW.KGJT.FF.W.0021.130826T2247Z-130827T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
447 PM MDT MON AUG 26 2013

THE NATIONAL WEATHER SERVICE IN GRAND JUNCTION HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTH CENTRAL SAN JUAN COUNTY IN SOUTHEAST UTAH...

* UNTIL 730 PM MDT

* AT 444 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A SLOW MOVING THUNDERSTORM 8 MILES SOUTH OF BLUFF WITH VERY HEAVY 
  RAINFALL ACROSS THE WARNED AREA. RAINFALL RATES OF ONE INCH PER 
  HOUR ARE EXPECTED.
 
* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO   
OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...BLUFF.

THIS INCLUDES THE FOLLOWING STREAMS AND DRAINAGES...CROSS 
CANYON...ALKALI CREEK...MONTEZUMA CREEK...NAVAJO CANYON...MC ELMO 
CREEK...SAHGZIE CREEK...DESERT CREEK...LONE MOUNTAIN CREEK AND EAST 
MC ELMO CREEK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL 
CREEKS AND STREAMS...AND HIGHWAYS. ADDITIONALLY...COUNTRY ROADS AND 
ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW LYING 
AREAS ARE SUBJECT TO FLOODING.

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.

&&

LAT...LON 3746 10934 3705 10943 3705 10965 3745 10972

$$
JD
2 follow-up statements
234 
WGUS75 KGJT 262350
FFSGJT

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
550 PM MDT MON AUG 26 2013

UTC037-270130-
/O.CON.KGJT.FF.W.0021.000000T0000Z-130827T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN JUAN UT-
550 PM MDT MON AUG 26 2013

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

AT 547 PM MDT...DOPPLER RADAR INDICATED THAT THE HEAVY RAIN HAD 
ENDED ACROSS THE WARNED AREA. A LOCAL SPOTTER REPORTED THAT THE 
HEAVIEST RAINFALL OCCURRED EAST OF BLUFF.

WHILE THE HEAVY RAIN HAS ENDED...WATER MAY STILL BE FLOWING IN 
STREAMS AND NORMALLY DRY WASHES DUE TO EXCESSIVE RUNOFF.

THIS INCLUDES THE FOLLOWING STREAMS AND DRAINAGES...CROSS 
CANYON...ALKALI CREEK...MONTEZUMA CREEK...NAVAJO CANYON...MC ELMO 
CREEK...SAHGZIE CREEK...DESERT CREEK...LONE MOUNTAIN CREEK AND EAST 
MC ELMO CREEK.

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.

&&

LAT...LON 3746 10934 3705 10943 3705 10965 3745 10972

$$
JD
267 
WGUS75 KGJT 270039
FFSGJT

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
639 PM MDT MON AUG 26 2013

UTC037-270053-
/O.CAN.KGJT.FF.W.0021.000000T0000Z-130827T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN JUAN UT-
639 PM MDT MON AUG 26 2013

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR SOUTH CENTRAL SAN
JUAN 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. 

THUNDERSTORMS WILL REMAIN A THREAT THROUGH THIS EVENING ACROSS 
SOUTHERN SAN JUAN COUNTY. IF FLOODING IS OBSERVED...PLEASE REPORT IT 
TO YOUR LOCAL LAW ENFORCEMENT AGENCY.

LAT...LON 3746 10934 3705 10943 3705 10965 3745 10972

$$

JD

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 26, 10:58 AM MDTRiver Flood AdvisoryGJTSan Juan22 hr
Aug 26, 5:18 PM MDTFlash Flood WarningGJTSan Juan3 hr

Nearby

Flash Flood Warnings in Utah, 2013Every flash flood warning in 2013

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.