Alert archive / Nebraska / Flash Flood Warnings in 2011

Flash Flood Warning 9, NWS Cheyenne, WY

July 2, 2011Goshen County, Wyoming; Banner County, Scotts Bluff County, Nebraska

NWS Cheyenne, WY issued this flash flood warning at Jul 2, 2011, 8:25 PM MDT for Goshen County, Wyoming; Banner County, Scotts Bluff County, Nebraska. It was in force for 6 hr. 5 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 2, 2011, 8:25 PM MDT (02:25 UTC)
Expired
Jul 3, 2011, 1:56 AM MDT
In force
6 hr
Issued by
NWS Cheyenne, WY
Area
Storm-based polygon
Flood severity
None

Counties Banner County, NE, Scotts Bluff County, NE, Goshen County, WY

The radar

The Cheyenne radar (KCYS), 115 km from the middle of the area, began a volume at 02:27 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 2, 8:25 PM MDTFLASH FLOOD4 W Lyman, WYWATER OVER HIGHWAY 92 EAST OF HUNTLEY
Jul 2, 8:40 PM MDTFLASH FLOOD9 Se Torrington, WYINTERSECTION OF HIGHWAY 61 AND 92 FLOODED AND CLOSED
Jul 2, 8:58 PM MDTFLASH FLOOD3 Ssw Lyman, WYHIGHWAY 158...MILE MARKER 1 FLOODED WITH DEBRIS OVER ROAD
Jul 2, 10:58 PM MDTFLASH FLOODLyman, NEHIGHWAY 92 BETWEEN LYMAN AND GERING FLOODED IN MANY AREAS
Jul 2, 11:00 PM MDTFLASH FLOOD9 Nw Harrisburg, NESEVERAL COUNTY ROADS ACROSS NORTHWESTERN BANNER COUNTY FLOODED AND CLOSED

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, 2.4 hours before the alert went out and 224 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 2011-07-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 920 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 2011-07-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -51 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
920 J/kg
Mixed-layer CIN
-98 J/kg
Mixed-layer LCL
2294 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
-51 m²/s²
0-3 km storm-relative helicity
-12 m²/s²
Significant tornado parameter
0.0
Supercell composite
-1.0

Open this sounding in Storm Lab

The text

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

315 
WGUS55 KCYS 030225
FFWCYS
NEC007-157-WYC015-030830-
/O.NEW.KCYS.FF.W.0009.110703T0225Z-110703T0830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
825 PM MDT SAT JUL 2 2011

THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A

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

* UNTIL 230 AM MDT SUNDAY

* AT 824 PM MDT...EMERGENCY MANAGEMENT REPORTED SLOW MOVING          
  THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA.     
  WATER WAS REPORTED OVER HIGHWAY 92 SOUTH OF HUNTLEY BY THE         
  SCOTTSBLUFF EMERGENCY MANAGER.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  SCOTTSBLUFF...GERING...LAKE ALICE...LYMAN...MITCHELL...MORRILL...
  SCOTTS BLUFF NATIONAL MONUMENT...SCOTTSBLUFF AIRPORT...STEGALL...
  TERRYTOWN AND WILDCAT HILLS STATE RECREATION AREA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4201 10354 4162 10350 4158 10410 4199 10424

$$

CLAYCOMB
1 follow-up statement
576 
WGUS75 KCYS 030756
FFSCYS

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
156 AM MDT SUN JUL 3 2011

NEC007-157-WYC015-030811-
/O.CAN.KCYS.FF.W.0009.000000T0000Z-110703T0830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BANNER NE-SCOTTS BLUFF NE-GOSHEN WY-
156 AM MDT SUN JUL 3 2011

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR SOUTHEASTERN 
GOSHEN...SCOTTS BLUFF AND NORTHERN BANNER COUNTIES IS CANCELLED AND 
HAS BEEN REPLACED WITH AN AREAL FLOOD WARNING THROUGH 10 AM TODAY...

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.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF FLOODING WAS OBSERVED PLEASE RELAY YOUR REPORT TO LOCAL LAW
ENFORCEMENT OR TO THE NATIONAL WEATHER SERVICE IN CHEYENNE.

&&

LAT...LON 4201 10354 4162 10350 4158 10410 4199 10424

$$

CLAYCOMB

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 2, 6:04 PM MDTSevere Thunderstorm WarningCYSGoshen, Platte41 min
Jul 2, 6:22 PM MDTTornado WarningCYSGoshen37 min
Jul 2, 6:44 PM MDTSevere Thunderstorm WarningCYSGoshen61 min
Jul 2, 6:56 PM MDTTornado WarningCYSGoshen49 min
Jul 2, 7:23 PM MDTTornado WarningCYSGoshen37 min
Jul 2, 7:54 PM MDTTornado WarningCYSGoshen40 min
Jul 2, 8:30 PM MDTTornado WarningCYSGoshen45 min
Jul 3, 1:55 AM MDTAreal Flood WarningCYSGoshen7 hr
Jul 2, 7:41 PM MDTSevere Thunderstorm WarningCYSBox Butte, Morrill, Scotts Bluff, Sioux49 min
Jul 2, 9:11 PM MDTSevere Thunderstorm WarningCYSBanner, Cheyenne, Kimball, Morrill, Scotts Bluff49 min

Nearby

Flash Flood Warnings in Nebraska, 2011Flash 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.