Alert archive / Utah / Flash Flood Warnings in 2021

Flash Flood Warning 2, NWS Salt Lake City, UT

June 29, 2021Kane County, Washington County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jun 29, 2021, 2:11 PM MDT for Kane County, Washington County, Utah. It was in force for 3 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: Jun 29, 2021, 2:11 PM MDT (20:11 UTC)
Expired: Jun 29, 2021, 5:15 PM MDT
In force: 3 hr
Issued by: NWS Salt Lake City, UT
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

Counties Kane County, UT, Washington County, UT

The radar

The Cedar City radar (KICX), 43 km from the middle of the area, began a volume at 20:11 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

Time	Report	Where	Remark
Jun 29, 3:47 PM MDT	FLASH FLOOD	Zion Np, UT	SIGNIFICANT FLASH FLOODING FROM THE ENTRANCE OF ZION NP ACROSS THE EASTERN PORTIONS OF THE PARK. STATE ROUTE 9 WITHIN THE PARK CLOSED DUE TO FLOODING AND DEBRIS ON THE ROADWAY.

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, 8.2 hours before the alert went out and 241 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: 225 J/kg
Mixed-layer CIN: -162 J/kg
Mixed-layer LCL: 1570 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: -75 m²/s²
0-3 km storm-relative helicity: -28 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

Open this sounding in Storm Lab

The text

As transmitted.

286 
WGUS55 KSLC 292011
FFWSLC
UTC025-053-292315-
/O.NEW.KSLC.FF.W.0002.210629T2011Z-210629T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
211 PM MDT Tue Jun 29 2021

The National Weather Service in Salt Lake City has issued a

* Flash Flood Warning for...
  West Central Kane County in southern Utah...
  Eastern Washington County in southwestern Utah...

* Until 515 PM MDT.

* At 211 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain in For eastern Zion National Park, specifically for 
  Echo, Keyhole, and Pine Creek Canyons. Between 0.25 and 0.75 
  inches of rain have fallen. Flash flooding is ongoing or expected 
  to begin shortly.

  HAZARD...Life threatening flash flooding. Thunderstorms
           producing flash flooding.

  SOURCE...Radar.

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

* Some locations that will experience flash flooding include...
  Zion National Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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 3714 11290 3714 11297 3731 11298 3732 11290
      3725 11285 3714 11284

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

GM

2 follow-up statements

473 
WGUS75 KSLC 292148
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
348 PM MDT Tue Jun 29 2021

UTC025-053-292315-
/O.CON.KSLC.FF.W.0002.000000T0000Z-210629T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kane UT-Washington UT-
348 PM MDT Tue Jun 29 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 515 PM MDT THIS 
AFTERNOON FOR WEST CENTRAL KANE AND EASTERN WASHINGTON COUNTIES...
SPECIFICALLY FOR ZION NATIONAL PARK.

At 348 PM MDT, Zion National Park officials have reported 
significant flash flooding extending from the south entrance across 
eastern portions of Zion National Park. SR 9 within the park is 
currently closed due to flooding and debris on the roadway. Between 
0.75 and 1.25 inches of rain have fallen.

HAZARD...Life threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...Zion National Park Officials.

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

Some locations that will experience flash flooding include...
  Zion National Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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 3714 11297 3731 11298 3732 11290 3725 11285
      3714 11284

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

$$

GM

334 
WGUS75 KSLC 292321
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
521 PM MDT Tue Jun 29 2021

UTC025-292331-
/O.EXP.KSLC.FF.W.0002.000000T0000Z-210629T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kane UT-
521 PM MDT Tue Jun 29 2021

...FLASH FLOOD WARNING HAS EXPIRED FOR WEST CENTRAL KANE AND EASTERN 
WASHINGTON COUNTIES...SPECIFICALLY FOR ZION NATIONAL PARK...

Flood waters have receded. The heavy rain has ended. National Park 
officials report that SR 9 remains closed and will remain closed for 
the foreseeable future as damage is assessed, and cleanup continues. 
Please continue to heed remaining road closures.

LAT...LON 3714 11297 3731 11298 3732 11290 3725 11285
      3714 11284

$$

GM

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 29, 1:53 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Garfield	3 hr
Jun 29, 2:14 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Washington	3 hr
Jun 29, 3:09 PM MDT	Special Weather Statement	SLC		36 min
Jun 29, 4:03 PM MDT	Severe Thunderstorm Warning	SLC	Kane, San Juan	27 min
Jun 29, 4:40 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Kane	3 hr

Nearby

Flash Flood Warnings in Utah, 2021 Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.