Alert archive / Utah / Flash Flood Warnings in 2011

Flash Flood Warning 56, NWS Salt Lake City, UT

September 16, 2011Kane County, Washington County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Sep 16, 2011, 3:33 PM MDT for Kane County, Washington County, Utah. It was in force for 3 hr. 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
Sep 16, 2011, 3:33 PM MDT (21:33 UTC)
Expired
Sep 16, 2011, 6:30 PM MDT
In force
3 hr
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Flood severity
None

Counties Kane County, UT, Washington County, UT

The radar

The Cedar City radar (KICX), 41 km from the middle of the area, began a volume at 21:36 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
Sep 16, 4:43 PM MDTFLASH FLOOD2 N Springdale, UTWIDESPREAD FLASH FLOODING ACROSS MULTIPLE DRAINAGES IN ZION NP. PINE CREEK FLASHED TO 6-7 FT. SPRY CANYON FLASHED IN ADDITION TO ROCKFALL ACROSS MANY ROADS...AND FLASH FLOODING ACROSS ALL NORTHERN ASPECTS OF ZION NP.

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

The nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 9.6 hours before the alert went out and 246 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, Flgstf/Belemont, AZ at 12:00Z on 2011-09-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 459 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Flgstf/Belemont, AZ at 12:00Z on 2011-09-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 37 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
459 J/kg
Mixed-layer CIN
-10 J/kg
Mixed-layer LCL
763 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
37 m²/s²
0-3 km storm-relative helicity
101 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.

043 
WGUS55 KSLC 162133
FFWSLC
UTC025-053-170030-
/O.NEW.KSLC.FF.W.0056.110916T2133Z-110917T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
333 PM MDT FRI SEP 16 2011

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  WEST CENTRAL KANE COUNTY IN UTAH
  EAST CENTRAL WASHINGTON COUNTY IN UTAH

* UNTIL 630 PM MDT

* AT 324 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
HEAVY RAIN FROM A THUNDERSTORM OVER THE EAST AND NORTH FORKS OF THE 
VIRGIN RIVER IN ZION NATIONAL PARK. ADDITIONAL SMALL SLOT CANYONS IN 
THE SOUTHERN END OF THE PARK WILL ALSO BE IMPACTED.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO ZION
  NATIONAL PARK

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 3729 11301 3730 11287 3721 11287 3720 11296
      3716 11299 3716 11301

$$

MCINERNEY
2 follow-up statements
627 
WGUS75 KSLC 162224
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
424 PM MDT FRI SEP 16 2011

UTC025-053-170030-
/O.CON.KSLC.FF.W.0056.000000T0000Z-110917T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHINGTON UT-KANE UT-
424 PM MDT FRI SEP 16 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 630 PM MDT FOR WEST
CENTRAL KANE AND EAST CENTRAL WASHINGTON COUNTIES...

AT 414 PM MDT...AREAS IN THE SOUTHERN AND SOUTHEASTERN PARTS OF ZION 
NATIONAL PARK ARE EXPERIENCING WIDESPREAD FLASH FLOODING.  MANY SLOT 
CANYONS AND SMALL TRIBUTARIES INCLUDING THE EAST FORK OF THE VIRGIN 
RIVER ARE EXPERIENCING FLASH FLOODING.  

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU ARE TRAVELING ALONG SR9 MOVING WEST INTO ZION NATIONAL 
PARK...PLEASE USE CAUTION WHEN VENTURING INTO THIS AREA.

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 3729 11301 3730 11287 3721 11287 3720 11296
      3716 11299 3716 11301

$$

MCINERNEY
345 
WGUS75 KSLC 170025
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
625 PM MDT FRI SEP 16 2011

UTC025-053-170034-
/O.EXP.KSLC.FF.W.0056.000000T0000Z-110917T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHINGTON UT-KANE UT-
625 PM MDT FRI SEP 16 2011

...THE FLASH FLOOD WARNING WILL EXPIRE AT 630 PM MDT FOR WEST CENTRAL
KANE AND EAST CENTRAL WASHINGTON COUNTIES...

THUNDERSTORMS THAT RESULTED IN HEAVY RAIN OVER ZION NATIONAL PARK 
HAVE MOVED EAST OF THE AREA.  THE RUNOFF FROM THESE THUNDERSTORMS 
RESULTED IN SIGNIFICANT FLASH FLOODING IN SOUTHERN PORTIONS OF THE 
PARK THIS AFTERNOON.  FLOODING HAS DIMINISHED ACROSS THE 
AREA...THEREFORE THE WARNING HAS BEEN ALLOWED TO EXPIRE.  
HOWEVER...FLOWS WILL REMAIN HIGH ON AREA STREAMS AND RUNOFF WILL 
CONTINUE THROUGH AFFECTED SLOT CANYONS THROUGH THE EVENING. 

LAT...LON 3729 11301 3730 11287 3721 11287 3720 11296
      3716 11299 3716 11301

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 16, 3:08 PM MDTFlash Flood WarningSLCWashington3 hr
Sep 16, 3:13 PM MDTSevere Thunderstorm WarningSLCGarfield, Wayne62 min
Sep 16, 3:44 PM MDTSevere Thunderstorm WarningSLCEmery, Wayne33 min
Sep 16, 3:53 PM MDTFlash Flood WarningSLCKane4 hr
Sep 16, 3:54 PM MDTFlash Flood WarningSLCEmery3 hr
Sep 16, 4:21 PM MDTSevere Thunderstorm WarningSLCWayne38 min
Sep 16, 4:39 PM MDTSevere Thunderstorm WarningSLCGarfield50 min

Nearby

Flash Flood Warnings in Utah, 2011Every flash flood warning in 2011

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.