Alert archive / Utah / Flash Flood Warnings in 2007

Flash Flood Warning 13, NWS Salt Lake City, UT

July 30, 2007Washington County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 30, 2007, 5:19 PM MDT for Washington County, Utah. It was in force for 4 hr. 2 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Jul 30, 2007, 5:19 PM MDT (23:19 UTC)
Expired
Jul 30, 2007, 9:15 PM MDT
In force
4 hr
Issued by
NWS Salt Lake City, UT
Area
Whole counties

County Washington County, UT

The radar

The Cedar City radar (KICX), 66 km from the middle of the area, began a volume at 23:19 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

TimeReportWhereRemark
Jul 30, 7:00 PM MDTFLASH FLOOD2 Se St. George, UTFORT PIERCE DRY WASH WENT FROM 0 TO 1357 CFS
Jul 30, 9:00 PM MDTHEAVY RAIN 1.6613 Sw Gunlock, UTBAGDER SPRINGS RAWS IN SOUTHWEST UTAH. DRY WASHES RUNNING IN IVINS.

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

The nearest sounding before it

Mercury/Desert R, NV (KDRA), launched 12:00Z, 11.3 hours before the alert went out and 234 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, Mercury/Desert R, NV at 12:00Z on 2007-07-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Mercury/Desert R, NV at 12:00Z on 2007-07-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -28 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3436 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
-28 m²/s²
0-3 km storm-relative helicity
24 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.

000 
WGUS55 KSLC 302323
FFWSLC
UTC053-310315-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
519 PM MDT MON JUL 30 2007

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTH CENTRAL WASHINGTON COUNTY IN UTAH...

* UNTIL 915 PM MDT

* AT 512 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
FLASH FLOODING FROM A THUNDERSTORM OVER FORT PIERCE WASH LOCATED 
ALONG THE UTAH/ARIZONA BORDER SOUTHEAST OF ST. GEORGE.

* RAINFALL ESTIMATES FROM THIS STORM INDICATE UP TO 2 INCHES OF 
RAINFALL HAS FALLEN OVER THE FORT PIERCE WASH DRAINAGE.  THIS FLASH 
FLOOD IS EXPECTED TO REACH THE ST. GEORGE AREA AROUND 7 PM THIS 
EVENING.

PERSONS LIVING OR VENTURING NEAR THE FORT PIERCE WASH AS IT ENTERS 
THE ST. GEORGE AREA AND DESERT AREAS UPSTREAM SHOULD TAKE 
PRECAUTIONS TO ENSURE THEIR SAFETY.  

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 3701 11353 3700 11336 3701 11328 3705 11326
      3703 11349 3708 11355 3708 11359

$$

MCINERNEY
1 follow-up statement
000 
WGUS75 KSLC 310140
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
737 PM MDT MON JUL 30 2007

UTC053-310315-
WASHINGTON UT-
737 PM MDT MON JUL 30 2007

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 915 PM MDT FOR SOUTH
CENTRAL WASHINGTON COUNTY...

AT 730 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE THUNDERSTORM ACTIVITY OVER THE FORT PIERCE WASH AREA.  UP 
TO 1.5 INCHES OF RAINFALL HAS FALLEN OVER THE DRAINAGE. 

THE FORT PIERCE WASH IS HISTORICALLY A VERY FLASH FLOOD PRONE BASIN. 
FLOOD WATERS ARE EXPECTED IN THE ST. GEORGE AREA THIS EVENING. AS OF 
THIS WRITING...AN ABSENCE OF FLASH FLOODING HAS BEEN REPORTED.

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 3701 11353 3700 11336 3701 11328 3705 11326
      3703 11349 3708 11355 3708 11359

$$

MCINERNEY

The office that day

Everything else NWS Salt Lake City, UT issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 30, 5:37 PM MDTFlash Flood WarningSLCWashington3 hr

Nearby

Flash Flood Warnings in Utah, 2007Every flash flood warning in 2007

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.