Alert archive / Utah / Flash Flood Warnings in 2017

Flash Flood Warning 49, NWS Salt Lake City, UT

September 15, 2017Garfield County, Wayne County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Sep 15, 2017, 5:45 PM MDT for Garfield County, Wayne County, Utah. It was in force for 4 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
Sep 15, 2017, 5:45 PM MDT (23:45 UTC)
Expired
Sep 15, 2017, 9:45 PM MDT
In force
4 hr
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Flood severity
None

Counties Garfield County, UT, Wayne County, UT

The radar

The Cedar City radar (KICX), 165 km from the middle of the area, began a volume at 23:48 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 12:00Z, 11.8 hours before the alert went out and 252 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 12:00Z on 2017-09-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 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, Grand Junction, CO at 12:00Z on 2017-09-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 221 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
2 J/kg
Mixed-layer CIN
-96 J/kg
Mixed-layer LCL
1272 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
221 m²/s²
0-3 km storm-relative helicity
306 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

533 
WGUS55 KSLC 152345
FFWSLC
UTC017-055-160345-
/O.NEW.KSLC.FF.W.0049.170915T2345Z-170916T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Salt Lake City UT
545 PM MDT FRI SEP 15 2017

The National Weather Service in Salt Lake City has issued a

* Flash Flood Warning for...
  North central Garfield County in southern Utah...
  South central Wayne County in southern Utah...

* Until 945 PM MDT

* At 538 PM MDT, Park Rangers in Capitol Reef National Park reported 
  flash flooding on Pleasant Creek. Flash flooding is already 
  occurring.

* Flash flooding is only affecting the Pleasant Creek drainage in 
  Capitol Reef National Park. Other primary washes in the park such 
  as Grand wash are not flooding at this time. 

* Additional rainfall is expected in this area and Pleasant Creek 
  is expected to continue to flood into this evening. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain alert for flooding even in locations not receiving rain. Dry
washes, streams, and rivers can become raging killer currents in a
matter of minutes, even from distant rainfall.

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 in the Capitol Reef area.

&&

LAT...LON 3826 11105 3797 11099 3797 11120 3821 11127

$$

PW
2 follow-up statements
543 
WGUS75 KSLC 160144
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
744 PM MDT FRI SEP 15 2017

UTC017-055-160345-
/O.CON.KSLC.FF.W.0049.000000T0000Z-170916T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-Wayne UT-
744 PM MDT FRI SEP 15 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 945 PM MDT FOR
NORTH CENTRAL GARFIELD AND SOUTH CENTRAL WAYNE COUNTIES...

At 737 PM MDT, rain had ended across Capitol Reef National Park and 
the threat of any additional rainfall is small. However, flood 
waters in Pleasant Creek will take a while longer to recede.

Visitors in Capitol Reef National Park are urged to avoid the 
Pleasant Creek area tonight. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain alert for flooding even in locations not receiving rain. Dry
washes, streams, and rivers can become raging killer currents in a
matter of minutes, even from distant rainfall.

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 in the southern portions of Capitol Reef National Park.

&&

LAT...LON 3826 11105 3797 11099 3797 11120 3821 11127

$$

PW
907 
WGUS75 KSLC 160338
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
938 PM MDT FRI SEP 15 2017

UTC017-055-160347-
/O.EXP.KSLC.FF.W.0049.000000T0000Z-170916T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Garfield UT-Wayne UT-
938 PM MDT FRI SEP 15 2017

...THE FLASH FLOOD WARNING FOR NORTH CENTRAL GARFIELD AND SOUTH
CENTRAL WAYNE COUNTIES WILL EXPIRE AT 945 PM MDT...

Flooding is no longer expected to pose a threat. Please continue to
heed any remaining road closures.

LAT...LON 3826 11105 3797 11099 3797 11120 3821 11127

$$

PW

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 14, 6:26 PM MDTSpecial Weather StatementSLC34 min
Sep 15, 7:02 AM MDTAreal Flood AdvisorySLCDavis, Weber3 hr
Sep 15, 9:11 AM MDTAreal Flood AdvisorySLCSalt Lake64 min
Sep 15, 10:16 AM MDTAreal Flood AdvisorySLCSalt Lake, Utah119 min
Sep 15, 3:17 PM MDTSpecial Weather StatementSLC43 min

Nearby

Flash Flood Warnings in Utah, 2017Every flash flood warning in 2017

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.