Alert archive / Utah / Flash Flood Warnings in 2017

Flash Flood Warning 5, NWS Salt Lake City, UT

July 12, 2017Garfield County, Iron County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 12, 2017, 1:19 PM MDT for Garfield County, Iron 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
Jul 12, 2017, 1:19 PM MDT (19:19 UTC)
Expired
Jul 12, 2017, 4:15 PM MDT
In force
3 hr
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Flood severity
None

Counties Garfield County, UT, Iron County, UT

The radar

The Cedar City radar (KICX), 21 km from the middle of the area, began a volume at 19:23 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

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 7.3 hours before the alert went out and 286 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 2017-07-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 62 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 2017-07-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -20 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
62 J/kg
Mixed-layer CIN
-98 J/kg
Mixed-layer LCL
1512 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
-20 m²/s²
0-3 km storm-relative helicity
47 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

013 
WGUS55 KSLC 121919
FFWSLC
UTC017-021-122215-
/O.NEW.KSLC.FF.W.0005.170712T1919Z-170712T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
119 PM MDT WED JUL 12 2017

The National Weather Service in Salt Lake City has issued a

* Flash Flood Warning for...
  Western Garfield County in southern Utah...
  East central Iron County in southern Utah...

* Until 415 PM MDT

* At 116 PM MDT, Doppler radar indicated heavy rain over the Brian 
  Head burn scar.

* Excessive rainfall over the Brian Head burn scar is expected to 
  result in debris flows moving through the Clear Water, Mammoth, 
  and Bunker drainages, and other smaller drainages flowing towards 
  Panguitch Lake. The debris flow can consist of rock, mud, 
  vegetation and other loose materials. These debris flows may also 
  impact State Route 143.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If a debris flow has occurred it is important to realize that the
runout area remains very dangerous. Additional debris flows may occur
within minutes of the original flow. Please remain vigilant and be
prepared to take swift action.

&&

LAT...LON 3776 11264 3765 11259 3763 11274 3772 11277

$$

ES/MS
2 follow-up statements
886 
WGUS75 KSLC 122039
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
239 PM MDT WED JUL 12 2017

UTC017-021-122215-
/O.CON.KSLC.FF.W.0005.000000T0000Z-170712T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-Iron UT-
239 PM MDT WED JUL 12 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 415 PM MDT FOR
WESTERN GARFIELD AND EAST CENTRAL IRON COUNTIES...

At 237 PM MDT, rain over the Brian Head burn scar has decreased 
significantly. The flash flood warning remains in effect until 415 
pm MDT, as earlier heavy rain over the burn scar could be causing 
debris flows in the Clear Water, Mammoth, and Bunker drainages, as 
well as other smaller drainages flowing towards Panguitch Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If a debris flow has occurred it is important to realize that the
runout area remains very dangerous. Additional debris flows may occur
within minutes of the original flow. Please remain vigilant and be
prepared to take swift action.

&&

LAT...LON 3776 11264 3765 11259 3763 11274 3772 11277

$$

ES
123 
WGUS75 KSLC 122214
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
414 PM MDT WED JUL 12 2017

UTC017-021-122223-
/O.EXP.KSLC.FF.W.0005.000000T0000Z-170712T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-Iron UT-
414 PM MDT WED JUL 12 2017

...THE FLASH FLOOD WARNING FOR WESTERN GARFIELD AND EAST CENTRAL IRON
COUNTIES WILL EXPIRE AT 415 PM MDT...

The heavy rain has ended over the Brian Head burn scar as of 415 pm. 
Thunderstorms remain active across the area, so please continue to 
monitor future conditions.

LAT...LON 3776 11264 3765 11259 3763 11274 3772 11277

$$

ES

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 11, 7:23 PM MDTFlash Flood WarningSLCWayne3 hr

Nearby

Flash Flood Warnings in Utah, 2017Every flash flood warning in 2017

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.