Alert archive / Utah / Flash Flood Warnings in 2012

Flash Flood Warning 25, NWS Salt Lake City, UT

July 28, 2012Wayne County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 28, 2012, 5:26 PM MDT for Wayne County, Utah. It was in force for 4 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: Jul 28, 2012, 5:26 PM MDT (23:26 UTC)
Expired: Jul 28, 2012, 9:15 PM MDT
In force: 4 hr
Issued by: NWS Salt Lake City, UT
Area: Storm-based polygon
Flood severity: None

County Wayne County, UT

The radar

The Cedar City radar (KICX), 164 km from the middle of the area, began a volume at 23:28 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

Time	Report	Where	Remark
Jul 28, 7:30 PM MDT	FLASH FLOOD	10 Ne Torrey, UT	FLASH FLOOD REPORTED IN CATHEDRAL VALLEY, THE NORTHERN PORTION OF CAPITOL REEF NATIONAL PARK. ROADS IN THE AREA WERE WASHED OUT, STRANDING VISITORS. PARK RANGERS REPORTED THAT THE CATHEDRAL VALLEY ROAD HAD A 2 1/2 FOOT DEEP TRENCH CREATED BY THE WATER.

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

The nearest sounding before it

Grand Junction, CO (KGJT), launched 12:00Z, 11.4 hours before the alert went out and 255 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 19 J/kg
Mixed-layer CIN: -281 J/kg
Mixed-layer LCL: 1377 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 87 m²/s²
0-3 km storm-relative helicity: 78 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.

570 
WGUS55 KSLC 282326
FFWSLC
UTC055-290315-
/O.NEW.KSLC.FF.W.0025.120728T2326Z-120729T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
526 PM MDT SAT JUL 28 2012

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTH CENTRAL WAYNE COUNTY IN UTAH

* UNTIL 915 PM MDT

* AT 515 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  HEAVY RAIN FROM A THUNDERSTORM OVER THE WARNED AREA.

* THE STORM PRODUCING FLASH FLOODING WILL OTHERWISE REMAIN OVER
  MAINLY RURAL AREAS OF THE INDICATED COUNTY.

HEAVY RAIN HAS BEEN FALLING IN THE CATHEDRAL VALLEY PORTION OF 
CAPITOL REEF NATIONAL PARK WITH RADAR ESTIMATES OF 1 TO 2 INCHES OF 
RAINFALL IN THE LAST HOUR. THIS INCLUDES THE POLK CREEK DRAINAGE. 
DIRT ROADS IN THIS AREA WILL BECOME MUDDY AND MAY BE LOCALLY WASHED 
OUT. 

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 3850 11145 3850 11111 3829 11112 3829 11120
      3831 11128 3836 11139

$$

PW

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 28, 5:49 PM MDT	Flash Flood Warning	SLC	Wayne	6 hr

Nearby

Flash Flood Warnings in Utah, 2012 Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.