Alert archive / Utah / Flash Flood Watches in 2021

Flash Flood Watch 9, NWS Salt Lake City, UT

July 29, 20217 counties in Utah

NWS Salt Lake City, UT issued this flash flood watch at Jul 29, 2021, 2:38 AM MDT for 7 counties in Utah. It took effect at Jul 29, 2021, 3:00 PM MDT. It was in force for 9 hr.

The area

The counties it named.

The facts

Issued
Jul 29, 2021, 2:38 AM MDT (08:38 UTC)
In effect from
Jul 29, 2021, 3:00 PM MDT
Expired
Jul 29, 2021, 11:53 PM MDT
In force
9 hr
Issued by
NWS Salt Lake City, UT
Flood severity
None

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

The radar

The Cedar City radar (KICX), 134 km from the middle of the area, began a volume at 08:42 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

Grand Junction, CO (KGJT), launched 00:00Z, 8.6 hours before the alert went out and 284 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, Grand Junction, CO at 00:00Z on 2021-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 405 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, Grand Junction, CO at 00:00Z on 2021-07-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -5 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
405 J/kg
Mixed-layer CIN
-60 J/kg
Mixed-layer LCL
3067 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
-5 m²/s²
0-3 km storm-relative helicity
36 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

419 
WGUS65 KSLC 290838
FFASLC

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Salt Lake City UT
238 AM MDT Thu Jul 29 2021

UTZ128>131-292315-
/O.NEW.KSLC.FF.A.0009.210729T2100Z-210730T0900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
South Central Utah-Capitol Reef National Park and Vicinity-Western
Canyonlands-Glen Canyon Recreation Area/Lake Powell-
Including the cities of Loa, Kanab, Bullfrog, Torrey, Escalante, Big 
Water, and Hanksville
238 AM MDT Thu Jul 29 2021

...FLASH FLOOD WATCH IN EFFECT FROM THIS AFTERNOON THROUGH LATE 
TONIGHT...

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, Glen Canyon 
  Recreation Area/Lake Powell, South Central Utah and Western 
  Canyonlands.

* From this afternoon through late tonight.

* Thunderstorms capable of producing heavy rainfall will develop 
  late this afternoon and continue into late tonight. The storms are 
  expected to move from southeast to northwest.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

MS
3 follow-up statements
356 
WGUS65 KSLC 292107
FFASLC

Flood Watch
National Weather Service Salt Lake City UT
307 PM MDT Thu Jul 29 2021

UTZ128>131-300515-
/O.CON.KSLC.FF.A.0009.000000T0000Z-210730T0900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
South Central Utah-Capitol Reef National Park and Vicinity-Western
Canyonlands-Glen Canyon Recreation Area/Lake Powell-
Including the cities of Loa, Kanab, Bullfrog, Torrey, Escalante, Big 
Water, and Hanksville
307 PM MDT Thu Jul 29 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 3 AM MDT FRIDAY...

The Flash Flood Watch continues for

* A portion of Utah, including the following areas, Capitol Reef 
  National Park and Vicinity, Glen Canyon Recreation Area/Lake 
  Powell, South Central Utah and Western Canyonlands.

* Until 3 AM MDT Friday.

* Thunderstorms capable of producing heavy rainfall will develop 
  late this afternoon and continue into late tonight. The storms are 
  expected to move from southeast to northwest.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

GM
978 
WGUS65 KSLC 300346
FFASLC

Flood Watch
National Weather Service Salt Lake City UT
946 PM MDT Thu Jul 29 2021

UTZ128>131-300900-
/O.CON.KSLC.FF.A.0009.000000T0000Z-210730T0900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
South Central Utah-Capitol Reef National Park and Vicinity-Western
Canyonlands-Glen Canyon Recreation Area/Lake Powell-
Including the cities of Loa, Kanab, Bullfrog, Torrey, Escalante, Big 
Water, and Hanksville
946 PM MDT Thu Jul 29 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 3 AM MDT FRIDAY...

The Flash Flood Watch continues for

* A portion of Utah, including the following areas, Capitol Reef 
  National Park and Vicinity, Glen Canyon Recreation Area/Lake 
  Powell, South Central Utah and Western Canyonlands.

* Until 3 AM MDT Friday.

* Thunderstorms capable of producing heavy rainfall will continue 
  until late tonight. The storms are expected to move from southeast 
  to northwest.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

WFO SLC
844 
WGUS65 KSLC 300553
FFASLC

Flood Watch
National Weather Service Salt Lake City UT
1153 PM MDT Thu Jul 29 2021

UTZ128>131-300700-
/O.CAN.KSLC.FF.A.0009.000000T0000Z-210730T0900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
South Central Utah-Capitol Reef National Park and Vicinity-Western
Canyonlands-Glen Canyon Recreation Area/Lake Powell-
Including the cities of Loa, Kanab, Bullfrog, Torrey, Escalante, Big 
Water, and Hanksville
1153 PM MDT Thu Jul 29 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, Glen Canyon Recreation Area/Lake Powell, South Central 
Utah and Western Canyonlands.

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

$$

Church

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 28, 7:56 PM MDTSpecial Weather StatementSLCTooele49 min
Jul 28, 9:52 PM MDTSpecial Weather StatementSLCDavis83 min
Jul 29, 1:40 PM MDTSpecial Weather StatementSLCIron20 min
Jul 29, 2:00 PM MDTSevere Thunderstorm WarningSLCIron, Washington30 min
Jul 29, 2:17 PM MDTSpecial Weather StatementSLCPiute28 min
Jul 29, 2:26 PM MDTSpecial Weather StatementSLCBeaver34 min
Jul 29, 2:39 PM MDTSevere Thunderstorm WarningSLCBeaver, Iron36 min
Jul 29, 2:50 PM MDTAreal Flood AdvisorySLCBeaver115 min
Jul 29, 3:13 PM MDTSpecial Weather StatementSLCBeaver32 min
Jul 29, 3:33 PM MDTSpecial Weather StatementSLCIron27 min
Jul 29, 3:54 PM MDTSpecial Weather StatementSLCMillard36 min
Jul 29, 4:11 PM MDTSpecial Weather StatementSLC34 min
Jul 29, 4:22 PM MDTSpecial Weather StatementSLCJuab23 min
Jul 29, 4:37 PM MDTSpecial Weather StatementSLCGarfield23 min
Jul 29, 4:48 PM MDTSevere Thunderstorm WarningSLCGarfield, Iron27 min
Jul 29, 4:54 PM MDTSevere Thunderstorm WarningSLCPiute, Sevier36 min
Jul 29, 5:18 PM MDTSpecial Weather StatementSLCGarfield27 min
Jul 29, 5:42 PM MDTSevere Thunderstorm WarningSLCGarfield33 min

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.