Alert archive / Utah / Flash Flood Warnings in 2021

Flash Flood Warning 83, NWS Salt Lake City, UT

August 1, 2021Davis County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Aug 1, 2021, 7:58 PM MDT for Davis 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
Aug 1, 2021, 7:58 PM MDT (01:58 UTC)
Expired
Aug 1, 2021, 11:00 PM MDT
In force
3 hr
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

County Davis County, UT

The radar

The Salt Lake City radar (KMTX), 63 km from the middle of the area, began a volume at 01:59 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, 2.0 hours before the alert went out and 15 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 2021-08-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 336 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 2021-08-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -3 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
336 J/kg
Mixed-layer CIN
-64 J/kg
Mixed-layer LCL
2282 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
-3 m²/s²
0-3 km storm-relative helicity
33 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

585 
WGUS55 KSLC 020158
FFWSLC
UTC011-020500-
/O.NEW.KSLC.FF.W.0083.210802T0158Z-210802T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
758 PM MDT Sun Aug 1 2021

The National Weather Service in Salt Lake City has issued a

* Flash Flood Warning for...
  East Central Davis County in northern Utah...

* Until 1100 PM MDT.

* At 758 PM MDT, trained weather spotters reported flash flooding on 
  the Bountiful Bench. Between 1 and 2 inches of rain have fallen. 
  Flash flooding is already occurring.

  HAZARD...Life threatening flash flooding. Heavy rain producing
           flash flooding.

  SOURCE...Trained spotters reported.

  IMPACT...Life threatening flash flooding of creeks and streams,
           urban areas, highways, streets and underpasses.

* Some locations that will experience flash flooding include...
  Bountiful and Centerville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Move away from recently burned areas such as the Gun Range Burn 
Scar. Life-threatening flooding of creeks, roads and normally dry 
washes is likely. The heavy rains will likely trigger rockslides, 
mudslides and debris flows in steep terrain, especially in and 
around these areas.

&&

LAT...LON 4092 11186 4092 11184 4091 11184 4090 11184
      4089 11185 4089 11187 4092 11187

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

LC
2 follow-up statements
763 
WGUS75 KSLC 020338
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
938 PM MDT Sun Aug 1 2021

UTC011-020500-
/O.CON.KSLC.FF.W.0083.000000T0000Z-210802T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Davis UT-
938 PM MDT Sun Aug 1 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 11 PM MDT THIS 
EVENING FOR EAST CENTRAL DAVIS COUNTY...

At 938 PM MDT, trained weather spotters reported flash flooding 
across the warned area. Between 1.5 and 2.25 inches of rain have 
fallen. Flash flooding is already occurring.

HAZARD...Life threatening flash flooding. Heavy rain producing
         flash flooding.

SOURCE...Trained spotters reported.

IMPACT...Life threatening flash flooding of creeks and streams,
         urban areas, highways, streets and underpasses.

Some locations that will experience flash flooding include...
  Bountiful and Centerville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Move away from recently burned areas such as the Gun Range Burn 
Scar. Life-threatening flooding of creeks, roads and normally dry 
washes is likely. The heavy rains will likely trigger rockslides, 
mudslides and debris flows in steep terrain, especially in and 
around these areas.

&&

LAT...LON 4092 11186 4092 11184 4091 11184 4090 11184
      4089 11185 4089 11187 4092 11187

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

LC
518 
WGUS75 KSLC 020452
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
1052 PM MDT Sun Aug 1 2021

UTC011-020502-
/O.EXP.KSLC.FF.W.0083.000000T0000Z-210802T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Davis UT-
1052 PM MDT Sun Aug 1 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 11 PM MDT THIS EVENING FOR 
EAST CENTRAL DAVIS COUNTY...

The heavy rain has ended in the Bountiful area. Flooding is no 
longer expected to pose a threat. Runoff from earlier heavy rain and 
flooding will continue to gradually recede through late this 
evening. Please continue to heed remaining road closures.

LAT...LON 4092 11186 4092 11184 4091 11184 4090 11184
      4089 11185 4089 11187 4092 11187

$$

LC

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 1, 6:01 PM MDTFlash Flood Warning Considerable damage threatSLCEmery, Garfield, Wayne3 hr
Aug 1, 6:09 PM MDTSevere Thunderstorm WarningSLCBox Elder, Tooele51 min
Aug 1, 6:17 PM MDTSpecial Weather StatementSLCBox Elder43 min
Aug 1, 6:27 PM MDTAreal Flood AdvisorySLCTooele3 hr
Aug 1, 6:36 PM MDTSpecial Weather StatementSLCSalt Lake39 min
Aug 1, 6:47 PM MDTSevere Thunderstorm WarningSLCDavis, Salt Lake, Tooele43 min
Aug 1, 7:00 PM MDTAreal Flood AdvisorySLCSalt Lake3 hr
Aug 1, 7:07 PM MDTAreal Flood AdvisorySLCGarfield, Iron113 min
Aug 1, 7:25 PM MDTSevere Thunderstorm WarningSLCDavis, Salt Lake35 min
Aug 1, 7:41 PM MDTAreal Flood AdvisorySLCSalt Lake3 hr
Aug 1, 8:25 PM MDTAreal Flood AdvisorySLCDavis3 hr
Aug 1, 8:51 PM MDTAreal Flood AdvisorySLCUtah114 min
Aug 1, 9:06 PM MDTAreal Flood AdvisorySLCDavis, Weber3 hr
Aug 2, 2:04 AM MDTFlash Flood WatchSLCBeaver, Box Elder, Cache, Carbon, Davis, Duchesne and 19 more18 hr
Aug 2, 1:16 PM MDTFlash Flood Warning Considerable damage threatSLCCarbon3 hr
Aug 2, 1:27 PM MDTFlash Flood Warning Considerable damage threatSLCEmery3 hr
Aug 2, 2:30 PM MDTFlash Flood Warning Considerable damage threatSLCWayne4 hr
Aug 2, 2:56 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield, Wayne3 hr
Aug 2, 3:24 PM MDTSevere Thunderstorm WarningSLCGarfield66 min
Aug 2, 3:32 PM MDTSpecial Weather StatementSLCEmery43 min
Aug 2, 3:52 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield4 hr
Aug 2, 4:00 PM MDTSpecial Weather StatementSLCJuab45 min
Aug 2, 4:14 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield, San Juan3 hr
Aug 2, 4:25 PM MDTSpecial Weather StatementSLC50 min
Aug 2, 4:55 PM MDTSpecial Weather StatementSLC50 min
Aug 2, 5:22 PM MDTSpecial Weather StatementSLCBox Elder38 min

Nearby

Flash Flood Warnings in Utah, 2021Every flash flood warning 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.