Alert archive / Wyoming / Flash Flood Warnings in 2011

Flash Flood Warning 2, NWS Riverton, WY

May 22, 2011Johnson County, Wyoming

NWS Riverton, WY issued this flash flood warning at May 22, 2011, 11:34 AM MDT for Johnson County, Wyoming. It was in force for 6 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
May 22, 2011, 11:34 AM MDT (17:34 UTC)
Expired
May 22, 2011, 5:30 PM MDT
In force
6 hr
Issued by
NWS Riverton, WY
Area
Storm-based polygon
Flood severity
None

County Johnson County, WY

The radar

The Riverton/Lander radar (KRIW), 156 km from the middle of the area, began a volume at 17:36 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, 5.6 hours before the alert went out and 150 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 2011-05-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2011-05-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 60 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1594 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
60 m²/s²
0-3 km storm-relative helicity
48 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

155 
WGUS55 KRIW 221734
FFWRIW
WYC019-222330-
/O.NEW.KRIW.FF.W.0002.110522T1734Z-110522T2330Z/
/00000.0.RS.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE RIVERTON WY
1134 AM MDT SUN MAY 22 2011

THE NATIONAL WEATHER SERVICE IN RIVERTON HAS ISSUED A

* FLASH FLOOD WARNING FOR RAINFALL AND MELTING SNOW IN...
  SOUTH CENTRAL JOHNSON COUNTY IN NORTH CENTRAL WYOMING
  ALONG MIDDLE FORK POWDER RIVER ABOVE KAYCEE...

* UNTIL 530 PM MDT SUNDAY

* AT 1126 AM MDT...THE MIDDLE FORK POWDER RIVER WAS RISING RAPIDLY   
  TO ONE HALF FOOT BELOW FLOOD STAGE...10 MILES SOUTHWEST OF         
  KAYCEE.  THE RIVER IS EXPECTED TO RISE THIS AFTERNOON...BEFORE     
  CRESTING AT 8 FEET THIS EVENING...WHICH IS AT FLOOD STAGE.

* SOME LOCATIONS THAT WILL EXPERIENCE SOME FLOODING                  
  INCLUDE...KAYCEE.  THOSE WHO LIVE ALONG HIGHWAY 190 SOUTHWEST      
  OF KAYCEE MAY EXPERIENCE SOME FLOODING THIS AFTERNOON...WITH THE   
  MIDDLE FORK SPILLING OVER ITS BANKS...ESPECIALLY IN LOW AREAS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...AS WELL AS FARMLAND ALONG THE
BANKS OF CREEKS AND STREAMS.

&&

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

LAT...LON 4368 10675 4373 10666 4373 10662 4370 10662
      4364 10677 4363 10683 4366 10685 4366 10680

$$

T. BAKER

The office that day

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

IssuedProductOfficeCountiesLasted
May 22, 9:07 AM MDTAreal Flood AdvisoryRIWJohnson6 hr
May 22, 1:45 PM MDTAreal Flood AdvisoryRIWHot Springs6 hr
May 22, 2:22 PM MDTFlash Flood WatchRIWBig Horn, Fremont, Hot Springs, Johnson, Lincoln, Natrona and 5 more64 hr
May 22, 2:37 PM MDTAreal Flood AdvisoryRIWJohnson18 hr
May 22, 3:13 PM MDTAreal Flood WarningRIWJohnson13 hr
May 22, 3:26 PM MDTSpecial Weather StatementRIW49 min
May 22, 3:35 PM MDTSpecial Weather StatementRIW40 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.