Alert archive / Utah / Flash Flood Warnings in 2017

Flash Flood Warning 20, NWS Salt Lake City, UT

July 25, 2017Kane County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 25, 2017, 1:34 PM MDT for Kane 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 25, 2017, 1:34 PM MDT (19:34 UTC)
Expired
Jul 25, 2017, 5:30 PM MDT
In force
4 hr
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Flood severity
None

County Kane County, UT

The radar

The Cedar City radar (KICX), 116 km from the middle of the area, began a volume at 19:37 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 25, 3:30 PM MDTFLASH FLOODBig Water, UTMINOR FLASH FLOOD IN WAHWEAP CREEK.

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, 7.6 hours before the alert went out and 213 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 2017-07-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 11 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 2017-07-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 7 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
11 J/kg
Mixed-layer CIN
-72 J/kg
Mixed-layer LCL
675 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
7 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.

790 
WGUS55 KSLC 251934
FFWSLC
UTC025-252330-
/O.NEW.KSLC.FF.W.0020.170725T1934Z-170725T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
134 PM MDT TUE JUL 25 2017

The National Weather Service in Salt Lake City has issued a

* Flash Flood Warning for...
  South central Kane County in southern Utah...

* Until 530 PM MDT
    
* At 131 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain over Wahweap Creek. Close to one inch of rain has 
  already fallen. Flash flooding is expected to begin shortly along 
  Wahweap Creek.

* Some locations that will experience flooding include...
  Big Water. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, farmland, and other low lying
spots.

Flooding is occurring or is imminent. It is important to know where
you are relative to streams, rivers, or creeks which can become
killers in heavy rains. Campers and hikers should avoid streams or
creeks.

&&

LAT...LON 3727 11172 3711 11157 3700 11139 3700 11161
      3710 11184 3725 11189

$$

LC
2 follow-up statements
664 
WGUS75 KSLC 252141
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
341 PM MDT TUE JUL 25 2017

UTC025-252330-
/O.CON.KSLC.FF.W.0020.000000T0000Z-170725T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kane UT-
341 PM MDT TUE JUL 25 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 530 PM MDT FOR
SOUTH CENTRAL KANE COUNTY...

At 339 PM MDT, Doppler radar indicated up to one inch of rain has 
already fallen along the Wahweap Creek drainage. This is likely 
resulting in flash flooding along Wahweap Creek.

Some locations that will experience flooding include...
Big Water. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, and other low lying spots.

Flooding is occurring or is imminent. It is important to know where
you are relative to streams, rivers, or creeks which can become
killers in heavy rains. Campers and hikers should avoid streams or
creeks.

&&

LAT...LON 3727 11172 3711 11157 3700 11139 3700 11161
      3710 11184 3725 11189

$$

LC
673 
WGUS75 KSLC 252325
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
525 PM MDT TUE JUL 25 2017

UTC025-252333-
/O.EXP.KSLC.FF.W.0020.000000T0000Z-170725T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kane UT-
525 PM MDT TUE JUL 25 2017

...THE FLASH FLOOD WARNING FOR SOUTH CENTRAL KANE COUNTY WILL EXPIRE
AT 530 PM MDT...

The heavy rain has ended over Wahweap Creek. Flooding is no longer 
expected to pose a threat. However, high flows may remain in place 
along Wahweap Creek as flood waters gradually recede. Please 
remain vigilant if you are traveling through this area this evening.

LAT...LON 3727 11172 3711 11157 3700 11139 3700 11161
      3710 11184 3725 11189

$$

LC

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 24, 9:35 PM MDTFlash Flood WarningSLCWashington3 hr
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, 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.