Alert archive / Utah / Flash Flood Warnings in 2020

Flash Flood Warning 2, NWS Salt Lake City, UT

March 13, 2020Washington County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Mar 13, 2020, 1:01 PM MDT for Washington 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
Mar 13, 2020, 1:01 PM MDT (19:01 UTC)
Expired
Mar 13, 2020, 4:00 PM MDT
In force
3 hr
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

County Washington County, UT

The radar

The Cedar City radar (KICX), 38 km from the middle of the area, began a volume at 19:03 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, 7.0 hours before the alert went out and 248 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, Flgstf/Belemont, AZ at 12:00Z on 2020-03-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 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, Flgstf/Belemont, AZ at 12:00Z on 2020-03-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -17 square meters per square second.1939587897117Sfc1 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
1 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
671 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
-17 m²/s²
0-3 km storm-relative helicity
-202 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

560 
WGUS55 KSLC 131901
FFWSLC
UTC053-132200-
/O.NEW.KSLC.FF.W.0002.200313T1901Z-200313T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
101 PM MDT Fri Mar 13 2020

The National Weather Service in Salt Lake City has issued a

* Flash Flood Warning for...
  East central Washington County in northern Utah...Specifically for 
  Zion National Park

* Until 400 PM MDT

* At 1255 PM MDT, Park rangers in Zion National Park continue to 
  report residual flash flooding in the following slot canyons above 
  the scenic drive...Echo...Hidden...Telephone...and Refrigerator 
  canyons. Up to 1.5 inches of rainfall has fallen since midnight 
  last night, and additional rainfall up to .25 inches is expected 
  through 4pm.

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

  SOURCE...Law enforcement. 

  IMPACT...Life threatening flash flooding of slot canyons above the 
           scenic drive.
           

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3734 11291 3714 11291 3714 11301 3734 11299

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

$$

GM
1 follow-up statement
813 
WGUS75 KSLC 132202
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
402 PM MDT Fri Mar 13 2020

UTC053-132208-
/O.EXP.KSLC.FF.W.0002.000000T0000Z-200313T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Washington UT-
402 PM MDT Fri Mar 13 2020

...THE FLASH FLOOD WARNING FOR EAST CENTRAL WASHINGTON COUNTY WILL
EXPIRE AT 400 PM MDT...

The heavy rain has ended and only periodic light rain showers are 
expected into this evening. Elevated flows continue in slot canyons 
above the scenic drive including Echo...Hidden...Telephone...and 
Refrigerator canyons, but flows are receding. Continue to heed any 
remaining park closures.

LAT...LON 3734 11291 3714 11291 3714 11301 3734 11299

$$

GM

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 13, 3:19 AM MDTWinter Weather AdvisorySLC19 hr
Mar 13, 9:44 AM MDTFlash Flood WarningSLCWashington3 hr

Nearby

Flash Flood Warnings in Utah, 2020Every flash flood warning in 2020

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.