Alert archive / Utah / Flash Flood Warnings in 2010

Flash Flood Warning 21, NWS Salt Lake City, UT

August 1, 2010Kane County, Washington County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Aug 1, 2010, 3:36 PM MDT for Kane County, Washington County, Utah. It was in force for 4 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: Aug 1, 2010, 3:36 PM MDT (21:36 UTC)
Expired: Aug 1, 2010, 7:30 PM MDT
In force: 4 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), 27 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.

The nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 9.6 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: 29 J/kg
Mixed-layer CIN: -19 J/kg
Mixed-layer LCL: 598 m above ground
0-6 km bulk shear: 3 kt
0-1 km storm-relative helicity: -15 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, in the capitals the NWS used until 2016.

323 
WGUS55 KSLC 012136
FFWSLC
UTC025-053-020130-
/O.NEW.KSLC.FF.W.0021.100801T2136Z-100802T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
336 PM MDT SUN AUG 1 2010

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A

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

* UNTIL 730 PM MDT

* AT 319 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
HEAVY RAINFALL OVER THE HEADWATERS OF THE NORTH FORK OF THE VIRGIN 
RIVER...JUST NORTHEAST OF ZION NATIONAL PARK. THE MAIN AREA OF 
CONCERN FOR FLASH FLOODING IS THE UPPER SECTION OF THE 
NARROWS...WITH THE THREAT DECREASING AS THE NORTH FORK APPROACHES 
THE PARK ENTRANCE. 


PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

&&

LAT...LON 3720 11300 3743 11298 3751 11282 3751 11272
      3741 11276 3718 11297

$$

HOSENFELD/CONGER

2 follow-up statements

137 
WGUS75 KSLC 012358
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
558 PM MDT SUN AUG 1 2010

UTC025-053-020130-
/O.CON.KSLC.FF.W.0021.000000T0000Z-100802T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHINGTON UT-KANE UT-
558 PM MDT SUN AUG 1 2010

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 730 PM MDT FOR
NORTHWESTERN KANE AND EAST CENTRAL WASHINGTON COUNTIES...

THUNDERSTORMS TO THE NORTHEAST OF ZION NATIONAL PARK HAVE 
DISSIPATED...BUT THE THREAT FOR FLASH FLOODING ALONG THE NORTH FORK 
OF THE VIRGIN RIVER STILL EXISTS. THE GREATEST POTENTIAL FOR 
FLOODING IS ALONG THE UPPER SECTION OF THE NARROWS...WITH THE THREAT 
DECREASING AS THE NORTH FORK APPROACHES THE PARK ENTRANCE.

LAT...LON 3720 11300 3743 11298 3751 11282 3751 11272
      3741 11276 3718 11297

$$

HOSENFELD

135 
WGUS75 KSLC 020128
FFSSLC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
728 PM MDT SUN AUG 1 2010

UTC025-053-020137-
/O.EXP.KSLC.FF.W.0021.000000T0000Z-100802T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHINGTON UT-KANE UT-
728 PM MDT SUN AUG 1 2010

...THE FLASH FLOOD WARNING WILL EXPIRE AT 730 PM MDT FOR NORTHWESTERN
KANE AND EAST CENTRAL WASHINGTON COUNTIES...

PRECIPITATION OVER THE HEADWATERS OF THE NORTH FORK OF THE VIRGIN 
RIVER HAS DISSIPATED...AND THE POTENTIAL FOR FLASH FLOODING HAS 
DIMINISHED. THEREFORE... THE FLASH FLOOD WARNING HAS BEEN ALLOWED TO 
EXPIRE. MONITOR NOAA WEATHER RADIO OR LOCAL TELEVISION OR RADIO FOR 
THE LATEST WEATHER INFORMATION.

LAT...LON 3720 11300 3743 11298 3751 11282 3751 11272
      3741 11276 3718 11297

$$

HOSENFELD

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 1, 3:44 AM MDT	Flash Flood Watch	SLC		18 hr
Aug 1, 6:42 AM MDT	Areal Flood Advisory	SLC	Emery, Wayne	3 hr
Aug 1, 2:25 PM MDT	Severe Thunderstorm Warning	SLC	Rich	20 min
Aug 1, 2:50 PM MDT	Flash Flood Warning	SLC	Kane	4 hr
Aug 1, 4:07 PM MDT	Severe Thunderstorm Warning	SLC	Duchesne	38 min
Aug 1, 4:48 PM MDT	Areal Flood Advisory	SLC	Duchesne	3 hr
Aug 1, 4:53 PM MDT	Special Weather Statement	SLC	Duchesne	37 min
Aug 1, 5:29 PM MDT	Areal Flood Advisory	SLC	Sanpete	3 hr

Nearby

Flash Flood Warnings in Utah, 2010 Every flash flood warning in 2010

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.