Alert archive / Wyoming / Flash Flood Warnings in 2011

Flash Flood Warning 9, NWS Riverton, WY

July 12, 2011Johnson County, Wyoming

NWS Riverton, WY issued this flash flood warning at Jul 12, 2011, 2:26 PM MDT for Johnson County, Wyoming. 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
Jul 12, 2011, 2:26 PM MDT (20:26 UTC)
Expired
Jul 12, 2011, 5:14 PM MDT
In force
3 hr
Issued by
NWS Riverton, WY
Area
Storm-based polygon
Flood severity
None

County Johnson County, WY

The radar

The Riverton/Lander radar (KRIW), 163 km from the middle of the area, began a volume at 20:25 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

Riverton, WY (KRIW), launched 12:00Z, 8.4 hours before the alert went out and 159 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, Riverton, WY at 12:00Z on 2011-07-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 24 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, Riverton, WY at 12:00Z on 2011-07-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -15 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
24 J/kg
Mixed-layer CIN
-231 J/kg
Mixed-layer LCL
1192 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
-15 m²/s²
0-3 km storm-relative helicity
104 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

009 
WGUS55 KRIW 122026
FFWRIW
WYC019-122330-
/O.NEW.KRIW.FF.W.0009.110712T2026Z-110712T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE RIVERTON WY
226 PM MDT TUE JUL 12 2011

THE NATIONAL WEATHER SERVICE IN RIVERTON HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  WEST CENTRAL JOHNSON COUNTY IN NORTH CENTRAL WYOMING...

* UNTIL 530 PM MDT

* AT 224 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE      
  WARNED AREA. THE RADAR ESTIMATES THAT OVER 2 INCHES OF RAIN HAS    
  FALLEN OVER A SMALL AREA IN A SHORT AMOUNT OF TIME. 

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR.

THIS INCLUDES THE FOLLOWING STREAMS AND DRAINAGES...NORTH FORK 
POWDER RIVER...BILLY CREEK...POISON CREEK...MIDDLE FORK CRAZY WOMAN 
CREEK...DRY POISON CREEK...MATTOX CREEK...TWIN CREEK...BULL 
CREEK...SEVENTYSIX CREEK...BEAVER CREEK...CORPE CREEK...GARDNER 
CREEK...JOHNSON CREEK...SIMMONS CREEK...DOYLE CREEK AND TAYLOR CREEK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

ADDITIONAL RAINFALL AMOUNTS OF ONE HALF TO TWO AND A HALF INCHES ARE 
POSSIBLE IN THE WARNED AREA.

&&

REPORT FLOODING TO THE NATIONAL WEATHER SERVICE OFFICE IN RIVERTON AT
1-800-211-1448.

LAT...LON 4398 10694 4400 10706 4408 10709 4411 10705
      4412 10682 4401 10681

$$

ALLEN
2 follow-up statements
879 
WGUS75 KRIW 122120
FFSRIW

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RIVERTON WY
320 PM MDT TUE JUL 12 2011

WYC019-122330-
/O.CON.KRIW.FF.W.0009.000000T0000Z-110712T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
JOHNSON WY-
320 PM MDT TUE JUL 12 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR WEST CENTRAL JOHNSON
COUNTY UNTIL 530 PM MDT...

AT 315 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. THE 
STORMS HAVE WEAKENED SLIGHTLY...HOWEVER RADAR ESTIMATES EXCEED 4 
INCHES OF RAINFALL DURING THE LIFE OF THIS STORM. 

RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
OCCUR.

THE HAZELTON GAGE HAS RECORDED OVER ONE AND A HALF INCHES OF 
RAINFALL IN A LITTLE LESS THAN ONE HOUR. 

THIS INCLUDES THE FOLLOWING STREAMS AND DRAINAGES...
NORTH FORK POWDER RIVER...BILLY CREEK...POISON CREEK...MIDDLE FORK
CRAZY WOMAN CREEK...DRY POISON CREEK...MATTOX CREEK...TWIN CREEK...
BULL CREEK...SEVENTYSIX CREEK...BEAVER CREEK...CORPE CREEK...GARDNER
CREEK...JOHNSON CREEK...SIMMONS CREEK...DOYLE CREEK AND TAYLOR CREEK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

ADDITIONAL RAINFALL AMOUNTS OF ONE QUARTER TO ONE INCH ARE POSSIBLE 
IN THE WARNED AREA THROUGH 530 PM MDT.

IN HILLY TERRAIN...THERE ARE NUMEROUS LOW WATER CROSSINGS WHICH
ARE POTENTIALLY DANGEROUS IN HEAVY RAIN. DO NOT ATTEMPT TO TRAVEL
ACROSS FLOODED ROADS. FIND ALTERNATE ROUTES. IT ONLY TAKES A FEW
INCHES OF SWIFTLY FLOWING WATER TO CARRY VEHICLES AWAY.

A FLASH FLOOD WARNING MEANS THAT FLASH FLOODING IS IMMINENT OR
OCCURRING. IF YOU ARE IN THE WARNING AREA...MOVE TO HIGHER GROUND
IMMEDIATELY. RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE
IMMEDIATE PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO
CROSS SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

&&

REPORT FLOODING TO THE NATIONAL WEATHER SERVICE OFFICE IN RIVERTON AT
1-800-211-1448.

LAT...LON 4398 10694 4400 10706 4408 10709 4411 10705
      4412 10682 4401 10681

$$
838 
WGUS75 KRIW 122314
FFSRIW

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RIVERTON WY
514 PM MDT TUE JUL 12 2011

WYC019-122329-
/O.CAN.KRIW.FF.W.0009.000000T0000Z-110712T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
JOHNSON WY-
514 PM MDT TUE JUL 12 2011

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR WEST CENTRAL
JOHNSON COUNTY IS CANCELLED...

THIS WARNING HAS BEEN REPLACED BY A NEW WARNING FOR WEST CENTRAL 
JOHNSON COUNTY. 

REPORT FLOODING TO THE NATIONAL WEATHER SERVICE OFFICE IN RIVERTON AT
1-800-211-1448.

LAT...LON 4398 10694 4400 10706 4408 10709 4411 10705
      4412 10682 4401 10681

$$

ALLEN

The office that day

Everything else NWS Riverton, WY issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 11, 6:54 PM MDTSevere Thunderstorm WarningRIWJohnson51 min
Jul 11, 7:29 PM MDTSpecial Weather StatementRIW46 min
Jul 11, 7:31 PM MDTSpecial Weather StatementRIWTeton44 min
Jul 11, 10:12 PM MDTSpecial Weather StatementRIWTeton63 min
Jul 12, 8:34 AM MDTSpecial Weather StatementRIWTeton41 min
Jul 12, 10:31 AM MDTSpecial Weather StatementRIWTeton44 min
Jul 12, 11:18 AM MDTSpecial Weather StatementRIWTeton42 min
Jul 12, 11:56 AM MDTSpecial Weather StatementRIWJohnson49 min
Jul 12, 12:03 PM MDTSpecial Weather StatementRIWTeton42 min
Jul 12, 12:07 PM MDTFlash Flood WatchRIWFremont, Hot Springs, Lincoln, Park, Sublette, Teton6 hr
Jul 12, 12:12 PM MDTSpecial Weather StatementRIWHot Springs48 min
Jul 12, 12:33 PM MDTSpecial Weather StatementRIWTeton42 min
Jul 12, 12:39 PM MDTSpecial Weather StatementRIWTeton36 min
Jul 12, 12:46 PM MDTSpecial Weather StatementRIWSweetwater44 min
Jul 12, 1:24 PM MDTSpecial Weather StatementRIWSweetwater51 min
Jul 12, 1:30 PM MDTAreal Flood AdvisoryRIWPark60 min
Jul 12, 1:40 PM MDTAreal Flood AdvisoryRIWJohnson, Washakie60 min
Jul 12, 1:50 PM MDTSpecial Weather StatementRIWNatrona40 min
Jul 12, 2:06 PM MDTSpecial Weather StatementRIWSublette39 min
Jul 12, 2:09 PM MDTFlash Flood WarningRIWJohnson, Washakie3 hr
Jul 12, 2:32 PM MDTSevere Thunderstorm WarningRIWJohnson, Washakie58 min
Jul 12, 3:59 PM MDTSpecial Weather StatementRIW46 min
Jul 12, 4:26 PM MDTAreal Flood AdvisoryRIWFremont3 hr
Jul 12, 4:29 PM MDTSpecial Weather StatementRIWBig Horn46 min
Jul 12, 4:32 PM MDTSpecial Weather StatementRIWBig Horn43 min
Jul 12, 4:59 PM MDTFlash Flood WarningRIWJohnson, Washakie7 hr
Jul 12, 5:12 PM MDTFlash Flood WarningRIWJohnson6 hr
Jul 12, 5:13 PM MDTSpecial Weather StatementRIWFremont47 min
Jul 12, 5:49 PM MDTSpecial Weather StatementRIWHot Springs41 min

Nearby

Flash Flood Warnings in Wyoming, 2011Every flash flood warning in 2011

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.