Alert archive / Wyoming / Flash Flood Warnings in 2003

Flash Flood Warning 1, NWS Cheyenne, WY

July 18, 2003Goshen County, Wyoming

NWS Cheyenne, WY issued this flash flood warning at Jul 18, 2003, 4:02 PM MDT for Goshen 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 18, 2003, 4:02 PM MDT (22:02 UTC)
Expired
Jul 18, 2003, 7:00 PM MDT
In force
3 hr
Issued by
NWS Cheyenne, WY
Area
Counties, with a storm outline in the text

County Goshen County, WY

The radar

The Cheyenne radar (KCYS), 141 km from the middle of the area, began a volume at 22:02 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

Rapid City, SD (KUNR), launched 12:00Z, 10.0 hours before the alert went out and 227 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, Rapid City, SD at 12:00Z on 2003-07-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1538 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, Rapid City, SD at 12:00Z on 2003-07-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -1 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
1538 J/kg
Mixed-layer CIN
-274 J/kg
Mixed-layer LCL
1339 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
-1 m²/s²
0-3 km storm-relative helicity
19 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.

000 
WGUS55 KCYS 182205
FFWCYS
WYC015-190100-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
402 PM MDT FRI JUL 18 2003

THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHWESTERN GOSHEN COUNTY IN SOUTHEAST WYOMING

* UNTIL 700 PM MDT

* AT 352 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  THUNDERSTORMS WITH VERY HEAVY RAINFALL WERE 11 MILES SOUTHWEST OF
  JAY EM...OR ABOUT 25 MILES NORTHWEST OF TORRINGTON...MOVING        
  NORTHEAST AT 5 MPH OR LESS.

DOPPLAR RADAR INDICATED AT LEAST FOUR INCHES OF THUNDERSTORM
RAINFALL MAY HAVE BEEN DROPPED BY THE STORM OVER THE PAST HOUR.  THE 
STORM IS NORTH OF HIGHWAY 26 AND EAST OF WYOMING HIGHWAY 270 IN 
NORTHWEST GOSHEN COUNTY.

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLASH FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...AND NORMALLY DRY WASHES...AS
WELL AS FARMLAND ALONG THE BANKS OF CREEKS AND STREAMS.

A FLASH FLOOD WARNING MEANS THAT 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. IF YOUR VEHICLE STALLS, ABANDON IT IMMEDIATELY AND SEEK
HIGHER GROUND.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM.

TO REPORT SEVERE WEATHER HAVE THE NEAREST LAW ENFORCEMENT AGENCY
RELAY YOUR REPORT TO THE NEAREST NATIONAL WEATHER SERVICE.

LAT...LON 4252 10466 4222 10464 4220 10424 4255 10426

$$

COX
3 follow-up statements
175 
RWUS32 KCYS 182249
FFSCYS
WYC015-182345-

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
450 PM MDT FRI JUL 18 2003

...A FLASH FLOOD WARNING CONTINUES UNTIL 700 PM MDT FOR
NORTHWEST GOSHEN COUNTY...

AT 445 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM ABOUT 20 MILES NORTHWEST OF TORRINGTON 
MOVING SOUTHEAST AT 5 MPH.

BETWEEN 300 AND 400 PM THE STORM DROPPED IN EXCESS OF FOUR INCHES
OF RAIN ABOUT 27 MILES NORTHWEST OF TORRINGTON.  THIS AREA IS
NORTH OF HIGHWAY 26 AND JUST EAST OF THE PLATTE-GOSHEN COUNTY LINE.  
AT 430 PM MDT THE PUBLIC REPORTED LOW LAND FLOODING ABOUT 15 MILES 
NORTHWEST OF FT. LARAMIE.  QUARTER SIZE HAIL ALSO OCCURRED WITH THE 
STORM.

MOST DEATHS IN FLASH FLOODING OCCUR IN AUTOMOBILES. DO NOT DRIVE YOUR
VEHICLE INTO AREAS WHERE WATER COVERS THE ROADWAY. THE WATER DEPTH
MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS SAFELY. VEHICLES CAUGHT
IN RISING WATER SHOULD BE ABANDONED QUICKLY. MOVE TO HIGHER GROUND.

A FLASH FLOOD WARNING MEANS THAT 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. IF YOUR VEHICLE STALLS...ABANDON IT IMMEDIATELY AND SEEK
HIGHER GROUND.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM.

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

$$

COX
626 
RWUS32 KCYS 182324
FFSCYS
WYC015-190020-

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
520 PM MDT FRI JUL 18 2003

...A FLASH FLOOD WARNING CONTINUES UNTIL 700 PM MDT FOR
NORTHWEST GOSHEN COUNTY...

AT 515 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM ABOUT 8 MILES NORTHWEST OF TORRINGTON MOVING 
SOUTHEAST AT 5 MPH.  BRIEF HEAVY RAIN...SMALL HAIL AND GUSTY
WINDS SHOULD BE EXPECTED WITH THIS STORM.

IN THE HOUR AND A HALF BEFORE 420 PM A RELIABLE MEASUREMENT OF FIVE 
AND A HALF INCHES OF RAIN OCCURRED 11 MILES NORTHWEST OF FT. 
LARAMIE.  UP TO THREE QUARTER INCH HAIL ALSO OCCURRED EARLIER.  A 
COUPLE CULVERTS WERE WASHED OUT AS WELL AS SOME FENCE.   

IN THE HOUR BEFORE 400 PM CHEYENNE DOPPLER RADAR INDICATED FIVE
TO SIX INCHES OF RAINFALL ABOUT 27 MILES NORTHWEST OF TORRINGTON.  
THIS AREA IS NORTH OF HIGHWAY 26 AND JUST EAST OF THE PLATTE-GOSHEN 
COUNTY LINE.

AT 430 PM MDT THE PUBLIC REPORTED LOW LAND FLOODING ABOUT 15 MILES 
NORTHWEST OF FT. LARAMIE.  QUARTER SIZE HAIL ALSO OCCURRED WITH THE 
STORM.

MOST DEATHS IN FLASH FLOODING OCCUR IN AUTOMOBILES. DO NOT DRIVE YOUR
VEHICLE INTO AREAS WHERE WATER COVERS THE ROADWAY. THE WATER DEPTH
MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS SAFELY. VEHICLES CAUGHT
IN RISING WATER SHOULD BE ABANDONED QUICKLY. MOVE TO HIGHER GROUND.

A FLASH FLOOD WARNING MEANS THAT 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. IF YOUR VEHICLE STALLS...ABANDON IT IMMEDIATELY AND SEEK
HIGHER GROUND.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM.

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

$$

COX
834 
RWUS32 KCYS 190100
FFSCYS
WYC015-190200-

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
701 PM MDT FRI JUL 18 2003

...THE FLASH FLOOD WARNING FOR NORTHWEST GOSHEN COUNTY WAS ALLOWED 
TO EXPIRE...

THE FLASH FLOOD WARNING FOR NORTHWEST GOSHEN COUNTY WAS ALLOWED
TO EXPIRE AT 700 PM.  THUNDERSTORMS HAVE MOVED WELL TO THE EAST
AND SOUTH OF THE AREA.  NO HEAVY RAINFALL IS EXPECTED IN THE
FLOODED AREA IN THE NEXT FEW HOURS.   

COTTONWOOD CREEK IN NORTHWEST GOSHEN COUNTY WAS REPORTED RUNNING 
FULL BUT WITHIN ITS BANKS.

IN THE HOUR AND A HALF BEFORE 420 PM FIVE AND A HALF INCHES OF 
THUNDERSTORM RAINFALL OCCURRED 11 MILES NORTHWEST OF FT. LARAMIE.
A COUPLE CULVERTS WERE WASHED OUT AS WELL AS SOME FENCE.   

AT 430 PM MDT THE PUBLIC REPORTED LOW LAND FLOODING ABOUT 15 MILES 
NORTHWEST OF FT. LARAMIE.  QUARTER SIZE HAIL ALSO OCCURRED WITH THE 
STORM.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM.

$$

COX

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 18, 3:17 PM MDTSevere Thunderstorm WarningCYSGoshen43 min
Jul 18, 3:40 PM MDTSevere Thunderstorm WarningCYSAlbany35 min

Nearby

Flash Flood Warnings in Wyoming, 2003Every flash flood warning in 2003

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.