Alert archive / Utah / Flash Flood Warnings in 2018

Flash Flood Warning 64, NWS Salt Lake City, UT

August 22, 2018Summit County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Aug 22, 2018, 6:02 PM MDT for Summit 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 22, 2018, 6:02 PM MDT (00:02 UTC)
Expired
Aug 22, 2018, 9:00 PM MDT
In force
3 hr
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Flood severity
None

County Summit County, UT

The radar

The Salt Lake City radar (KMTX), 98 km from the middle of the area, began a volume at 00:04 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, 0.0 hours before the alert went out and 36 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 2018-08-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 21 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 2018-08-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 19 square meters per square second.19395878Sfc1 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
21 J/kg
Mixed-layer CIN
-276 J/kg
Mixed-layer LCL
2003 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
19 m²/s²
0-3 km storm-relative helicity
131 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

615 
WGUS55 KSLC 230002
FFWSLC
UTC043-230300-
/O.NEW.KSLC.FF.W.0064.180823T0002Z-180823T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
602 PM MDT WED AUG 22 2018

The National Weather Service in Salt Lake City has issued a

* Flash Flood Warning for...
  Western Summit County in northern Utah...

* Until 900 PM MDT
    
* At 553 PM MDT, Doppler radar indicated a thunderstorm producing 
  heavy rain over the Tollgate Burn Scar.  Debris from this scar has 
  the potential to flow onto I-80 between the junction of I- 80 and 
  Wanship.
  
* Radar rainfall estimates of a half inch in about 20 minutes are 
  expected over the scar.

* If you plan on driving through I-80 from Park City to Wanship 
  please be aware of the potential for debris on the west bound 
  lanes.

LAT...LON 4080 11146 4077 11145 4077 11148 4078 11149

$$

McInerney
1 follow-up statement
840 
WGUS75 KSLC 230251
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
851 PM MDT WED AUG 22 2018

UTC043-230300-
/O.EXP.KSLC.FF.W.0064.000000T0000Z-180823T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Summit UT-
851 PM MDT WED AUG 22 2018

...THE FLASH FLOOD WARNING FOR WESTERN SUMMIT COUNTY WILL EXPIRE AT
900 PM MDT...

Rainfall over the Tollgate Burn Scar has ceased.  As such, the 
threat of a debris flow has passed.

LAT...LON 4080 11146 4077 11145 4077 11148 4078 11149

$$

McInerney

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 22, 6:00 PM MDTSpecial Weather StatementSLCSummit45 min
Aug 22, 6:27 PM MDTSpecial Weather StatementSLCSalt Lake33 min
Aug 22, 6:39 PM MDTSevere Thunderstorm WarningSLCUtah36 min
Aug 22, 6:41 PM MDTSpecial Weather StatementSLCSalt Lake34 min
Aug 22, 7:06 PM MDTSpecial Weather StatementSLCUtah24 min
Aug 22, 7:14 PM MDTSpecial Weather StatementSLCWasatch31 min
Aug 22, 7:30 PM MDTSpecial Weather StatementSLCUtah30 min
Aug 22, 8:11 PM MDTFlash Flood WarningSLCDuchesne, Wasatch3 hr
Aug 22, 9:09 PM MDTFlash Flood WarningSLCUtah, Wasatch3 hr
Aug 22, 11:02 PM MDTFlash Flood WarningSLCDuchesne, Wasatch4 hr
Aug 22, 11:38 PM MDTSpecial Weather StatementSLCCarbon52 min
Aug 23, 12:00 AM MDTSpecial Weather StatementSLCSanpete45 min
Aug 23, 12:08 AM MDTSevere Thunderstorm WarningSLCJuab, Sanpete, Utah45 min
Aug 23, 1:00 PM MDTSpecial Weather StatementSLCKane30 min
Aug 23, 1:13 PM MDTFlash Flood WarningSLCGarfield, Kane3 hr

Nearby

Flash Flood Warnings in Utah, 2018Every flash flood warning in 2018

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.