Alert archive / Wyoming / Flash Flood Warnings in 2012

Flash Flood Warning 4, NWS Cheyenne, WY

June 6, 2012Goshen County, Laramie County, Platte County, Wyoming

NWS Cheyenne, WY issued this flash flood warning at Jun 6, 2012, 4:48 PM MDT for Goshen County, Laramie County, Platte County, Wyoming. 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
Jun 6, 2012, 4:48 PM MDT (22:48 UTC)
Expired
Jun 6, 2012, 8:30 PM MDT
In force
4 hr
Issued by
NWS Cheyenne, WY
Area
Storm-based polygon
Flood severity
None

Counties Goshen County, WY, Laramie County, WY, Platte County, WY

The radar

The Cheyenne radar (KCYS), 54 km from the middle of the area, began a volume at 22:49 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

Denver, CO (KDNR), launched 12:00Z, 10.8 hours before the alert went out and 222 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, Denver, CO at 12:00Z on 2012-06-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 72 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, Denver, CO at 12:00Z on 2012-06-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 87 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
72 J/kg
Mixed-layer CIN
-389 J/kg
Mixed-layer LCL
2428 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
87 m²/s²
0-3 km storm-relative helicity
82 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.

243 
WGUS55 KCYS 062248
FFWCYS
WYC015-021-031-070300-
/O.NEW.KCYS.FF.W.0004.120606T2248Z-120607T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
448 PM MDT WED JUN 6 2012

THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTH CENTRAL LARAMIE COUNTY IN SOUTHEAST WYOMING...
  SOUTHEASTERN PLATTE COUNTY IN SOUTHEAST WYOMING...
  SOUTHWESTERN GOSHEN COUNTY IN SOUTHEAST WYOMING...

* UNTIL 900 PM MDT

* AT 446 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE      
  WARNED AREA. RADAR ESTIMATES THAT 2 TO 4 INCHES OF RAIN HAS FALLEN 
  ACROSS AREAS EAST OF INTERSTATE 25 NORTH OF WHITAKER IN NORTH      
  CENTRAL LARAMIE COUNTY. THESE THUNDERSTORMS WILL CONTINUE TO MOVE  
  SLOWLY NORTHEAST INTO SOUTHEAST PLATTE AND SOUTHWEST GOSHEN        
  COUNTIES THROUGH 700 PM MDT...AND WILL PRODUCE SIMILAR             
  RAINFALL ACCUMULATIONS. 

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO   
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...GUN  
  BARREL...HAWK SPRINGS AND MERIDEN REST AREA. THIS ALSO INCLUDES    
  LITTLE BEAR CREEK AND LEWIS DRAW IN NORTH CENTRAL LARAMIE COUNTY. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY.

&&

LAT...LON 4180 10424 4129 10426 4142 10486 4148 10488
      4180 10477

$$

HAMMER/WEILAND
2 follow-up statements
062 
WGUS75 KCYS 070107
FFSCYS

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
707 PM MDT WED JUN 6 2012

WYC015-021-031-070300-
/O.CON.KCYS.FF.W.0004.000000T0000Z-120607T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
GOSHEN WY-LARAMIE WY-PLATTE WY-
707 PM MDT WED JUN 6 2012

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR SOUTHEASTERN PLATTE...
NORTH CENTRAL LARAMIE AND SOUTHWESTERN GOSHEN COUNTIES UNTIL 900 PM
MDT...

AT 657 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THAT THE THUNDERSTORMS WHICH PRODUCED THE HEAVY RAINFALL HAVE MOVED
OFF TO THE NORTHEAST. RAINFALL AMOUNTS FROM THE RADAR WERE ESTIMATED
BETWEEN 2 AND 4 INCHES IN THE MID TO LATE AFTERNOON HOURS.  

ADDITIONAL SHOWERS AND THUNDERSTORMS THROUGH 9 PM MAY PRODUCE UP TO
ONE HALF INCH OF RAINFALL OVER THE WARNED AREA. AS OF 7 PM...NO REPORTS
OF FLOODING HAVE BEEN RECEIVED FROM SOUTHEAST PLATTE...NORTH CENTRAL 
LARAMIE AND SOUTHWEST GOSHEN COUNTIES.      

RUNOFF FROM THE RECENT EXCESSIVE RAINFALL WILL CAUSE WATER LEVELS TO
REMAIN HIGH IN AREA SMALL STREAMS...DITCHES AND LOW LYING AREAS.  THE
WATER LEVELS WILL SLOWLY DIMINISH THROUGH THE LATE EVENING SINCE THE 
HEAVIER RAIN HAS ENDED.  

SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...GUN BARREL...
HAWK SPRINGS AND THE MERIDEN REST AREA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY.

&&

LAT...LON 4180 10424 4129 10426 4142 10486 4148 10488
      4180 10477

$$

MSW
898 
WGUS75 KCYS 070230
FFSCYS

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
830 PM MDT WED JUN 6 2012

WYC015-021-031-070244-
/O.CAN.KCYS.FF.W.0004.000000T0000Z-120607T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
GOSHEN WY-LARAMIE WY-PLATTE WY-
830 PM MDT WED JUN 6 2012

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR SOUTHEASTERN
PLATTE...NORTH CENTRAL LARAMIE AND SOUTHWESTERN GOSHEN COUNTIES IS
CANCELLED...

EXCESS RUNOFF FROM HEAVY RAIN HAS ENDED OVER THE WARNED AREA. STREAMS
AND CREEKS IN THE WARNED AREA HAVE RECEDED OR WERE BEGINNING TO
RECEDE...ENDING THE FLOOD THREAT. IF FLOODING HAS BEEN OBSERVED...
PLEASE REPORT IT TO YOUR LOCAL LAW ENFORCEMENT AGENCY. AS OF 830 PM...
NO REPORTS OF FLOODING HAVE BEEN RECEIVED.  

LAT...LON 4180 10424 4129 10426 4142 10486 4148 10488
      4180 10477

$$

MSW

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 6, 3:26 PM MDTSevere Thunderstorm WarningCYSLaramie64 min
Jun 6, 3:39 PM MDTSevere Thunderstorm WarningCYSGoshen, Laramie, Platte51 min
Jun 6, 3:57 PM MDTSpecial Weather StatementCYSLaramie48 min
Jun 6, 4:02 PM MDTSevere Thunderstorm WarningCYSLaramie58 min
Jun 6, 4:27 PM MDTSevere Thunderstorm WarningCYSGoshen, Laramie, Platte35 min
Jun 6, 4:41 PM MDTSevere Thunderstorm WarningCYSGoshen64 min
Jun 6, 4:52 PM MDTSevere Thunderstorm WarningCYSGoshen, Laramie53 min
Jun 6, 5:08 PM MDTSpecial Weather StatementCYSAlbany37 min
Jun 6, 5:13 PM MDTFlash Flood WarningCYSGoshen3 hr
Jun 6, 5:33 PM MDTFlash Flood WarningCYSLaramie3 hr
Jun 6, 5:43 PM MDTSevere Thunderstorm WarningCYSGoshen62 min
Jun 6, 5:47 PM MDTSevere Thunderstorm WarningCYSGoshen, Laramie58 min

Nearby

Flash Flood Warnings in Wyoming, 2012Every flash flood warning in 2012

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.