Alert archive / Wyoming / Flash Flood Warnings in 2007

Flash Flood Warning 2, NWS Cheyenne, WY

June 21, 2007Goshen County, Wyoming; Banner County, Nebraska

NWS Cheyenne, WY issued this flash flood warning at Jun 21, 2007, 5:13 PM MDT for Goshen County, Wyoming; Banner County, Nebraska. It took effect at Jun 21, 2007, 5:18 PM MDT. 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 counties it named.

The facts

Issued
Jun 21, 2007, 5:13 PM MDT (23:13 UTC)
In effect from
Jun 21, 2007, 5:18 PM MDT
Expired
Jun 21, 2007, 8:15 PM MDT
In force
3 hr
Issued by
NWS Cheyenne, WY
Area
Whole counties

Counties Banner County, NE, Goshen County, WY

The radar

The Cheyenne radar (KCYS), 98 km from the middle of the area, began a volume at 23:16 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, 11.2 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, Denver, CO at 12:00Z on 2007-06-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 16 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 2007-06-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 68 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
16 J/kg
Mixed-layer CIN
-340 J/kg
Mixed-layer LCL
3742 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
68 m²/s²
0-3 km storm-relative helicity
69 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 212318
FFWCYS
NEC007-WYC015-220215-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
513 PM MDT THU JUN 21 2007

THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHWESTERN BANNER COUNTY IN THE PANHANDLE OF NEBRASKA...
  SOUTHEASTERN GOSHEN COUNTY IN SOUTHEAST WYOMING...

* UNTIL 815 PM MDT

* AT 512 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  EXCESSIVE RAINFALL IN EXCESS OF 2 INCHES WITH THE POTENTIAL TO 
  CAUSE FLASH FLOODING FROM A SERIES OF THUNDERSTORMS WHICH OCCURRED 
  6 MILES WEST OF BULL CANYON...OR ABOUT 23 MILES SOUTHWEST OF       
  SCOTTSBLUFF.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF
STREAMS...COUNTRY ROADS...NORMALLY DRY WASHES...AS WELL AS LOW LYING
AREAS ALONG THE BANKS OF STREAMS.

REPORT FLOODING TO THE NATIONAL WEATHER SERVICE OFFICE IN CHEYENNE AT
1-800-269-6220.

LAT...LON 4159 10417 4158 10404 4156 10394 4170 10382
      4169 10404

$$

CARPENTER
1 follow-up statement
000
WGUS75 KCYS 220050
FFSCYS

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
646 PM MDT THU JUN 21 2007

NEC007-WYC015-220056-
BANNER NE-GOSHEN WY-
646 PM MDT THU JUN 21 2007

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR SOUTHEASTERN GOSHEN
AND NORTHWESTERN BANNER COUNTIES...

SEVERAL SPOTTERS HAVE REPORTED THAT NO FLOODING IS OCCURRING ACROSS
SOUTHEASTERN GOSHEN AND NORTHWESTERN BANNER COUNTIES ASSOCIATED WITH 
THE PERIOD OF HEAVY RAINFALL EARLIER THIS AFTERNOON. THEREFORE THE 
FLASH FLOOD WARNING HAS BEEN CANCELLED.

LAT...LON 4159 10417 4158 10404 4156 10394 4170 10382
      4169 10404

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 21, 4:06 PM MDTSevere Thunderstorm WarningCYSGoshen, Laramie24 min
Jun 21, 4:50 PM MDTSevere Thunderstorm WarningCYSGoshen, Platte28 min
Jun 21, 4:46 PM MDTSevere Thunderstorm WarningCYSKimball44 min
Jun 21, 5:26 PM MDTSevere Thunderstorm WarningCYSKimball29 min
Jun 21, 5:44 PM MDTSevere Thunderstorm WarningCYSSioux30 min

Nearby

Flash Flood Warnings in Wyoming, 2007Flash Flood Warnings in Nebraska, 2007Every flash flood warning in 2007

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.