Alert archive / Wyoming / Flash Flood Warnings in 2011

Flash Flood Warning 13, NWS Cheyenne, WY

July 12, 2011Goshen County, Laramie County, Wyoming

NWS Cheyenne, WY issued this flash flood warning at Jul 12, 2011, 7:09 PM MDT for Goshen County, Laramie County, Wyoming. It was in force for 8 hr. 3 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Jul 12, 2011, 7:09 PM MDT (01:09 UTC)
Expired
Jul 13, 2011, 3:05 AM MDT
In force
8 hr
Issued by
NWS Cheyenne, WY
Area
Storm-based polygon
Flood severity
None

Counties Goshen County, WY, Laramie County, WY

The radar

The Cheyenne radar (KCYS), 41 km from the middle of the area, began a volume at 01:09 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.

What was reported inside it

TimeReportWhereRemark
Jul 12, 7:16 PM MDTFLASH FLOOD3 Sw Burns, WYFLOODING OVER ACCESS ROAD BETWEEN MILE MARKER 380 AND 381 ON INTERSTATE 80. FLOODING OF ROAD 142 NEAR MILE MARKER 380 AND 381 FLOODED AS WELL
Jul 12, 8:25 PM MDTFLASH FLOOD20 W Pine Bluffs, WYAT MILE MARKER 380 ON INTERSTATE 80...APPROXIMATELY 2 INCHES OF WATER IS COVERING THE ROAD. WATER IS RECEDING AT TIME OF REPORT.
Jul 12, 9:39 PM MDTFLASH FLOOD10 S Burns, WY4 INCHES OF WATER OVER ROADWAY FLOWING FROM FLOODING IN NEARBY FARM FIELDS.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Denver, CO (KDNR), launched 00:00Z, 1.2 hours before the alert went out and 181 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 00:00Z on 2011-07-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 596 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, Denver, CO at 00:00Z on 2011-07-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -12 square meters per square second.1939Sfc1 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
596 J/kg
Mixed-layer CIN
-61 J/kg
Mixed-layer LCL
1449 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
-12 m²/s²
0-3 km storm-relative helicity
256 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.2

Open this sounding in Storm Lab

The text

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

333 
WGUS55 KCYS 130109
FFWCYS
WYC015-021-130400-
/O.NEW.KCYS.FF.W.0013.110713T0109Z-110713T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EASTERN LARAMIE COUNTY IN SOUTHEAST WYOMING...
  SOUTH CENTRAL GOSHEN COUNTY IN SOUTHEAST WYOMING...

* UNTIL 1000 PM MDT

* AT 708 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE      
  WARNED AREA. RADAR ESTIMATED RAINFALL OF 2 TO 3 INCHES HAS FALLEN  
  IN THE WARNED AREA.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  ALBIN...BURNS...CARPENTER...GUN BARREL...MERIDEN REST AREA AND PINE
  BLUFFS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

ADDITIONAL RAINFALL AMOUNTS OF 1 TO 2 INCHES ARE POSSIBLE IN THE 
WARNED AREA.

TO REPORT FLOODING...HAVE THE NEAREST LAW ENFORCEMENT AGENCY RELAY
YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN
CHEYENNE.

&&

LAT...LON 4102 10451 4170 10456 4155 10405 4102 10405

$$

CLAYCOMB
2 follow-up statements
734 
WGUS55 KCYS 130354
FFWCYS
WYC015-021-131000-
/O.EXT.KCYS.FF.W.0013.000000T0000Z-110713T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS EXTENDED THE

* FLASH FLOOD WARNING FOR...
  EASTERN LARAMIE COUNTY IN SOUTHEAST WYOMING...
  SOUTH CENTRAL GOSHEN COUNTY IN SOUTHEAST WYOMING...

* UNTIL 400 AM MDT WEDNESDAY

* AT 948 PM MDT...SPOTTERS AND DEPARTMENT OF TRANSPORTATION PERSONNEL
  REPORTED SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS 
  THE WARNED AREA...CREATING CONTINUED FLOODING CONDITIONS. RADAR    
  ESTIMATED RAINFALL OF 3.0 TO 3.5 INCHES HAS FALLEN IN THE WARNED   
  AREAS.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  ALBIN...BURNS...CARPENTER...GUN BARREL...MERIDEN REST AREA AND PINE
  BLUFFS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

ADDITIONAL RAINFALL AMOUNTS OF 1 TO 2 INCHES ARE POSSIBLE IN THE 
WARNED AREA.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. DO
NOT ENTER THE WATER. TURN AROUND AND MOVE UP TO HIGHER GROUND TO
ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS SUBJECT TO FLOODING WHEN
WATER BEGINS RISING.

TO REPORT FLOODING...HAVE THE NEAREST LAW ENFORCEMENT AGENCY RELAY
YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN
CHEYENNE.

&&

LAT...LON 4102 10451 4170 10456 4155 10405 4102 10405

$$

CLAYCOMB
730 
WGUS75 KCYS 130905
FFSCYS

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
305 AM MDT WED JUL 13 2011

WYC015-021-130920-
/O.CAN.KCYS.FF.W.0013.000000T0000Z-110713T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
GOSHEN WY-LARAMIE WY-
305 AM MDT WED JUL 13 2011

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR EASTERN LARAMIE AND
SOUTH CENTRAL GOSHEN COUNTIES IS CANCELLED...

EXCESS RUNOFF FROM HEAVY RAIN HAS ENDED OVER THE WARNED AREA. STREAMS
AND CREEKS IN THE WARNED AREA WERE BEGINNING TO RECEDE...BUT WILL 
LIKELY REMAIN BANKFULL THROUGH EARLY THIS MORNING. IF FLOODING HAS 
BEEN OBSERVED...PLEASE REPORT IT TO YOUR LOCAL LAW ENFORCEMENT 
AGENCY.

LAT...LON 4102 10451 4170 10456 4155 10405 4102 10405

$$

TJT

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 12, 6:03 PM MDTTornado WarningCYSGoshen, Laramie, Platte30 min
Jul 12, 6:03 PM MDTTornado WarningCYSLaramie27 min
Jul 12, 6:56 PM MDTSevere Thunderstorm WarningCYSLaramie45 min
Jul 12, 7:46 PM MDTSevere Thunderstorm WarningCYSLaramie32 min
Jul 12, 10:26 PM MDTFlash Flood WarningCYSGoshen, Laramie, Platte4 hr

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.