Alert archive / Nebraska / Flash Flood Warnings in 2011

Flash Flood Warning 18, NWS Cheyenne, WY

July 14, 2011Cheyenne County, Morrill County, Nebraska

NWS Cheyenne, WY issued this flash flood warning at Jul 14, 2011, 8:44 PM MDT for Cheyenne County, Morrill County, Nebraska. It was in force for 4 hr. 1 report 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 14, 2011, 8:44 PM MDT (02:44 UTC)
Expired
Jul 15, 2011, 1:12 AM MDT
In force
4 hr
Issued by
NWS Cheyenne, WY
Area
Storm-based polygon
Flood severity
None

Counties Cheyenne County, NE, Morrill County, NE

The radar

The Cheyenne radar (KCYS), 164 km from the middle of the area, began a volume at 02:45 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 14, 9:14 PM MDTHEAVY RAIN 3Dalton, NE

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, 2.7 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 2011-07-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 12 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 2011-07-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 2 square meters per square second.19395878Sfc1 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
12 J/kg
Mixed-layer CIN
-140 J/kg
Mixed-layer LCL
1824 m above ground
0-6 km bulk shear
4 kt
0-1 km storm-relative helicity
2 m²/s²
0-3 km storm-relative helicity
74 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.

207 
WGUS55 KCYS 150244
FFWCYS
NEC033-123-150830-
/O.NEW.KCYS.FF.W.0018.110715T0244Z-110715T0830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
844 PM MDT THU JUL 14 2011

THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTH CENTRAL CHEYENNE COUNTY IN THE PANHANDLE OF NEBRASKA...
  SOUTH CENTRAL MORRILL COUNTY IN THE PANHANDLE OF NEBRASKA...

* UNTIL 230 AM MDT

* AT 842 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE      
  WARNED AREA. DOPPLER RADAR ESTIMATES INDICATED ABOUT 2 INCHES OF   
  RAIN HAD OCCURRED DURING THE LAST COUPLE OF HOURS. ADDITIONAL      
  AMOUNTS UP TO 1 INCH CAN BE EXPECTED DURING THE NEXT HOUR OR SO. 

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  DALTON AND MUD SPRINGS.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...AS WELL AS FARMLAND ALONG THE
BANKS OF CREEKS AND STREAMS.

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 4157 10275 4134 10275 4134 10311 4156 10311

$$

COX
2 follow-up statements
185 
WGUS75 KCYS 150354
FFSCYS

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
954 PM MDT THU JUL 14 2011

NEC033-123-150830-
/O.CON.KCYS.FF.W.0018.000000T0000Z-110715T0830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CHEYENNE NE-MORRILL NE-
954 PM MDT THU JUL 14 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR SOUTH CENTRAL MORRILL
AND NORTH CENTRAL CHEYENNE COUNTIES UNTIL 230 AM MDT...

AT 950 PM MDT...CHEYENNE COUNTY DISPATCH REPORTED THAT A SPOTTER IN 
DALTON REPORTED 3 INCHES OF RAINFALL DURING THE PAST 3 HOURS. THE 
RAINFALL WAS CONTINUING TO DIMINISH ACROSS THIS REGION AND MAY 
PRODUCE ANOTHER ONE HALF INCH OF RAIN. HOWEVER...THE POTENTIAL FOR 
FLOODING WILL CONTINUE ACROSS THIS AREA. 

SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...DALTON AND MUD
SPRINGS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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 4157 10275 4134 10275 4134 10311 4156 10311

$$

COX
131 
WGUS75 KCYS 150712
FFSCYS

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
112 AM MDT FRI JUL 15 2011

NEC033-123-150727-
/O.CAN.KCYS.FF.W.0018.000000T0000Z-110715T0830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CHEYENNE NE-MORRILL NE-
112 AM MDT FRI JUL 15 2011

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR SOUTH CENTRAL
MORRILL AND NORTH CENTRAL CHEYENNE 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 OR 
THE NATIONAL WEATHER SERVICE OFFICE IN CHEYENNE.

&&

LAT...LON 4157 10275 4134 10275 4134 10311 4156 10311

$$

HAHN

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 14, 6:10 PM MDTAreal Flood AdvisoryCYSBanner, Morrill, Scotts Bluff6 hr
Jul 14, 6:28 PM MDTAreal Flood AdvisoryCYSBanner, Kimball4 hr
Jul 14, 7:30 PM MDTAreal Flood AdvisoryCYSCheyenne, Morrill3 hr

Nearby

Flash Flood Warnings in Nebraska, 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.