Alert archive / Utah / Flash Flood Warnings in 2017

Flash Flood Warning 18, NWS Salt Lake City, UT

July 24, 2017Washington County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 24, 2017, 9:35 PM MDT for Washington 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 24, 2017, 9:35 PM MDT (03:35 UTC)
Expired
Jul 25, 2017, 12:30 AM MDT
In force
3 hr
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Flood severity
None

County Washington County, UT

The radar

The Cedar City radar (KICX), 60 km from the middle of the area, began a volume at 03:36 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.

The nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 00:00Z, 3.6 hours before the alert went out and 228 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 00:00Z on 2017-07-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 85 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Flgstf/Belemont, AZ at 00:00Z on 2017-07-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 51 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
85 J/kg
Mixed-layer CIN
-30 J/kg
Mixed-layer LCL
1138 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
51 m²/s²
0-3 km storm-relative helicity
108 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

As transmitted.

648 
WGUS55 KSLC 250335
FFWSLC
UTC053-250500-
/O.NEW.KSLC.FF.W.0018.170725T0335Z-170725T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
935 PM MDT MON JUL 24 2017

The National Weather Service in Salt Lake City has issued a

* Flash Flood Warning for...
  Southeastern Washington County in northern Utah...

* Until 1100 PM MDT

* At 933 PM MDT, Doppler radar indicated a thunderstorm with
  torrential rain over Hildale and the drainages above Hildale. 
  Radar estimates indicate that over one-half inch of rain has 
  fallen over the past 30 minutes, with very high rainfall rates. 
 
* Some locations that will experience flooding include Hildale and
  Colorado City, including along Short Creek and the washes that feed
  into Short Creek.

LAT...LON 3710 11290 3700 11290 3700 11303 3710 11302

$$

mconger
2 follow-up statements
258 
WGUS55 KSLC 250457
FFWSLC
UTC053-250630-
/O.EXT.KSLC.FF.W.0018.000000T0000Z-170725T0630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
1057 PM MDT MON JUL 24 2017

The National Weather Service in Salt Lake City has extended the

* Flash Flood Warning for...
  Southeastern Washington County in northern Utah...

* Until 1230 AM MDT

* At 1053 PM MDT, Doppler radar indicates showers and thunderstorms, 
  some with torrential rain, continue in Hildale and through the 
  surrounding drainages above Hildale. Radar estimates indicate that 
  over one inch of rain has fallen north of Hildale during the past 
  90 minutes.

* Some locations that will experience flooding include Hildale and
  Colorado City, including along Short Creek and the washes that feed
  into Short Creek.

LAT...LON 3710 11290 3700 11290 3700 11303 3710 11302

$$

mconger
010 
WGUS75 KSLC 250633
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
1233 AM MDT TUE JUL 25 2017

UTC053-250642-
/O.EXP.KSLC.FF.W.0018.000000T0000Z-170725T0630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Washington UT-
1233 AM MDT TUE JUL 25 2017

...THE FLASH FLOOD WARNING FOR SOUTHEASTERN WASHINGTON COUNTY HAS
EXPIRED...

The heavy rain has ended across the area, however periods of light 
to moderate rain will likely persist into the overnight hours. 

LAT...LON 3710 11290 3700 11290 3700 11303 3710 11302

$$

MPS

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 25, 6:36 AM MDTAreal Flood AdvisorySLCWashington3 hr
Jul 25, 9:43 AM MDTAreal Flood AdvisorySLCWashington2 hr
Jul 25, 12:51 PM MDTFlash Flood WarningSLCKane4 hr
Jul 25, 1:34 PM MDTFlash Flood WarningSLCKane4 hr
Jul 25, 2:54 PM MDTFlash Flood WarningSLCGarfield4 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.