Alert archive / Utah / Flash Flood Watches in 2021

Flash Flood Watch 5, NWS Salt Lake City, UT

July 22, 20216 counties in Utah

NWS Salt Lake City, UT issued this flash flood watch at Jul 22, 2021, 2:43 AM MDT for 6 counties in Utah. It took effect at Jul 22, 2021, 11:00 AM MDT. It was in force for 12 hr.

The area

The counties it named.

The facts

Issued
Jul 22, 2021, 2:43 AM MDT (08:43 UTC)
In effect from
Jul 22, 2021, 11:00 AM MDT
Expired
Jul 22, 2021, 10:44 PM MDT
In force
12 hr
Issued by
NWS Salt Lake City, UT
Flood severity
None

Counties Emery County, UT, Garfield County, UT, Kane County, UT, Sevier County, UT, Washington County, UT, Wayne County, UT

The radar

The Cedar City radar (KICX), 115 km from the middle of the area, began a volume at 08:45 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

Salt Lake City I, UT (KSLC), launched 00:00Z, 8.7 hours before the alert went out and 301 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, Salt Lake City I, UT at 00:00Z on 2021-07-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 175 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Salt Lake City I, UT at 00:00Z on 2021-07-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 9 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
175 J/kg
Mixed-layer CIN
-17 J/kg
Mixed-layer LCL
3232 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
9 m²/s²
0-3 km storm-relative helicity
45 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

861 
WGUS65 KSLC 220843
FFASLC

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Salt Lake City UT
243 AM MDT Thu Jul 22 2021

UTZ128-129-221645-
/O.NEW.KSLC.FF.A.0005.210722T1700Z-210723T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
South Central Utah-Capitol Reef National Park and Vicinity-
Including the cities of Torrey, Loa, Escalante, and Kanab
243 AM MDT Thu Jul 22 2021

...FLASH FLOOD WATCH IN EFFECT FROM 11 AM MDT THIS MORNING THROUGH 
THIS EVENING...

The National Weather Service in Salt Lake City has issued a

* Flash Flood Watch for a portion of Utah, including the following 
  areas, Capitol Reef National Park and Vicinity and South Central 
  Utah.

* From 11 AM MDT this morning through this evening.

* Thunderstorms capable of heavy rainfall are expected to develop 
  and train off of Boulder Mountain today, and may move down 
  sensitive drainages and slot canyons in Capitol Reef National Park 
  as well as in the Escalante River basin.

* Heavy rainfall may result in flash flooding, especially in area 
  slot canyons, and normally dry washes and streams.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the latest forecasts and be prepared to take action should 
Flash Flood Warnings be issued. Consider avoiding slot canyons and 
normally dry washes.

&&

$$

Church
3 follow-up statements
688 
WGUS65 KSLC 221343
FFASLC

Flood Watch
National Weather Service Salt Lake City UT
743 AM MDT Thu Jul 22 2021

UTZ128-129-230600-
/O.CON.KSLC.FF.A.0005.210722T1700Z-210723T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
South Central Utah-Capitol Reef National Park and Vicinity-
Including the cities of Torrey, Loa, Escalante, and Kanab
743 AM MDT Thu Jul 22 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT FROM 11 AM MDT THIS MORNING 
THROUGH THIS EVENING...

The Flash Flood Watch continues for

* A portion of Utah, including the following areas, Capitol Reef 
  National Park and Vicinity and South Central Utah.

* From 11 AM MDT this morning through this evening.

* Thunderstorms capable of heavy rainfall are expected to develop 
  and train off of Boulder Mountain today, and may move down 
  sensitive drainages and slot canyons in Capitol Reef National Park 
  as well as in the Escalante River basin.

* Heavy rainfall may result in flash flooding, especially in area 
  slot canyons, and normally dry washes and streams.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the latest forecasts and be prepared to take action should 
Flash Flood Warnings be issued. Consider avoiding slot canyons and 
normally dry washes.

&&

$$

MS
745 
WGUS65 KSLC 221754
FFASLC

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Salt Lake City UT
1154 AM MDT Thu Jul 22 2021

UTZ124-125-230600-
/O.NEW.KSLC.FA.A.0001.210722T1754Z-210723T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Zion National Park-Southern Mountains-
Including the cities of Brian Head, Springdale, and Alton
1154 AM MDT Thu Jul 22 2021

...FLOOD WATCH IN EFFECT THROUGH THIS EVENING...

The National Weather Service in Salt Lake City has issued a

* Flood Watch for a portion of Utah, including the following areas, 
  Southern Mountains and Zion National Park.

* Through this evening.

* Thunderstorms capable of heavy rainfall are expected to develop 
  and train off of Boulder Mountain today, and may move down 
  sensitive drainages and slot canyons in Capitol Reef National Park 
  as well as in the Escalante River basin.

* Heavy rainfall may result in flash flooding, especially in area 
  slot canyons, and normally dry washes and streams.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be alert for possible Flood 
Warnings. Those living in areas prone to flooding should be prepared 
to take action should flooding develop.

&&

$$

UTZ128-129-230600-
/O.CON.KSLC.FF.A.0005.000000T0000Z-210723T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
South Central Utah-Capitol Reef National Park and Vicinity-
Including the cities of Torrey, Loa, Escalante, and Kanab
1154 AM MDT Thu Jul 22 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH THIS EVENING...

The Flash Flood Watch continues for

* A portion of Utah, including the following areas, Capitol Reef 
  National Park and Vicinity and South Central Utah.

* Through this evening.

* Thunderstorms capable of heavy rainfall are expected to develop 
  and train off of Boulder Mountain today, and may move down 
  sensitive drainages and slot canyons in Capitol Reef National Park 
  as well as in the Escalante River basin.

* Heavy rainfall may result in flash flooding, especially in area 
  slot canyons, and normally dry washes and streams.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the latest forecasts and be prepared to take action should 
Flash Flood Warnings be issued. Consider avoiding slot canyons and 
normally dry washes.

&&

$$

MS
358 
WGUS65 KSLC 230444
FFASLC

Flood Watch
National Weather Service Salt Lake City UT
1044 PM MDT Thu Jul 22 2021

UTZ128-129-230545-
/O.CAN.KSLC.FF.A.0005.000000T0000Z-210723T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
South Central Utah-Capitol Reef National Park and Vicinity-
Including the cities of Torrey, Loa, Escalante, and Kanab
1044 PM MDT Thu Jul 22 2021

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch has been cancelled for a portion of Utah, 
including the following areas, Capitol Reef National Park and 
Vicinity and South Central Utah.

The Flood Watch is cancelled. Flooding is no longer expected to pose 
a threat tonight. Please continue to heed remaining road closures.

$$

UTZ124-125-230545-
/O.CAN.KSLC.FA.A.0001.000000T0000Z-210723T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Zion National Park-Southern Mountains-
Including the cities of Brian Head, Springdale, and Alton
1044 PM MDT Thu Jul 22 2021

...FLOOD WATCH IS CANCELLED...

The Flood Watch has been cancelled for a portion of Utah, including 
the following areas, Southern Mountains and Zion National Park.

The Flood Watch is cancelled. Flooding is no longer expected to pose 
a threat tonight. Please continue to heed remaining road closures.

$$

WFO SLC

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 21, 8:41 PM MDTFlash Flood Warning Considerable damage threatSLCKane6 hr
Jul 22, 11:16 AM MDTSpecial Weather StatementSLCPiute29 min
Jul 22, 11:41 AM MDTSpecial Weather StatementSLC49 min
Jul 22, 11:54 AM MDTFlood WatchSLCBeaver, Garfield, Iron, Kane, Piute, Washington and 1 more11 hr
Jul 22, 1:02 PM MDTSpecial Weather StatementSLCIron43 min
Jul 22, 1:13 PM MDTSpecial Weather StatementSLCGarfield32 min
Jul 22, 1:18 PM MDTAreal Flood AdvisorySLCIron117 min
Jul 22, 1:20 PM MDTSevere Thunderstorm WarningSLCGarfield25 min
Jul 22, 1:45 PM MDTSpecial Weather StatementSLCKane45 min
Jul 22, 2:00 PM MDTSpecial Weather StatementSLCBeaver30 min
Jul 22, 2:13 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield, Kane3 hr
Jul 22, 2:13 PM MDTSevere Thunderstorm WarningSLCBeaver32 min
Jul 22, 2:34 PM MDTFlash Flood Warning Considerable damage threatSLCKane, Washington3 hr
Jul 22, 2:42 PM MDTAreal Flood AdvisorySLCBeaver2 hr
Jul 22, 2:58 PM MDTSevere Thunderstorm WarningSLCWashington32 min
Jul 22, 3:08 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield, Wayne3 hr
Jul 22, 3:14 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield, Kane5 hr
Jul 22, 3:14 PM MDTSpecial Weather StatementSLCWashington46 min
Jul 22, 3:30 PM MDTSevere Thunderstorm WarningSLCGarfield
Jul 22, 3:46 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield, Kane7 hr
Jul 22, 4:02 PM MDTSevere Thunderstorm WarningSLCIron28 min
Jul 22, 4:15 PM MDTSpecial Weather StatementSLCBox Elder30 min
Jul 22, 4:28 PM MDTSevere Thunderstorm WarningSLCIron32 min
Jul 22, 4:48 PM MDTSpecial Weather StatementSLCWashington27 min
Jul 22, 5:51 PM MDTSpecial Weather StatementSLC39 min
Jul 22, 5:58 PM MDTFlash Flood Warning Considerable damage threatSLCUtah3 hr

Nearby

Flash Flood Watches in Utah, 2021Every flash flood watch in 2021

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.