Alert archive / Nebraska / Flash Flood Warnings in 2012

Flash Flood Warning 3, NWS Cheyenne, WY

April 26, 2012Box Butte County, Nebraska

NWS Cheyenne, WY issued this flash flood warning at Apr 26, 2012, 9:59 PM MDT for Box Butte 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
Apr 26, 2012, 9:59 PM MDT (03:59 UTC)
Expired
Apr 27, 2012, 2:00 AM MDT
In force
4 hr
Issued by
NWS Cheyenne, WY
Area
Storm-based polygon
Flood severity
None

County Box Butte County, NE

The radar

The North Platte radar (KLNX), 195 km from the middle of the area, began a volume at 04:02 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.

What was reported inside it

TimeReportWhereRemark
Apr 26, 11:00 PM MDTFLASH FLOOD7 N Alliance, NEHIGHWAY 87 NORTH OF ALLIANCE BETWEEN MM 6 AND MM 16 FLLODED AND CLOSED.

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

The nearest sounding before it

Rapid City, SD (KUNR), launched 00:00Z, 4.0 hours before the alert went out and 206 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 00:00Z on 2012-04-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 35 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 00:00Z on 2012-04-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 184 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
35 J/kg
Mixed-layer CIN
-110 J/kg
Mixed-layer LCL
1002 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
184 m²/s²
0-3 km storm-relative helicity
516 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.7

Open this sounding in Storm Lab

The text

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

482 
WGUS55 KCYS 270359
FFWCYS
NEC013-270800-
/O.NEW.KCYS.FF.W.0003.120427T0359Z-120427T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
959 PM MDT THU APR 26 2012

THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CENTRAL BOX BUTTE COUNTY IN THE PANHANDLE OF NEBRASKA...

* UNTIL 200 AM MDT

* AT 940 PM MDT...LAW ENFORCEMENT REPORTED CONTINUED FLOODING ALONG  
  HIGHWAY 87 NORTH OF ALLIANCE...WITH THE HIGHWAY CLOSED BETWEEN     
  MILE MARKER 6 AND MILE MARKER 16. 4 TO 6 INCHES OF WATER REMAINS   
  OVER THE ROAD. AN ADDITIONAL ONE QUARTER OF AN INCH OF RAIN IS     
  POSSIBLE THROUGH 200 AM MDT. 

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...BEREA AND
  WILD HORSE BUTTE.

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.

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

&&

LAT...LON 4230 10282 4215 10278 4211 10303 4225 10309

$$

HAMMER/MAZUR

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 26, 6:05 PM MDTSpecial Weather StatementCYSBox Butte55 min
Apr 26, 7:04 PM MDTSpecial Weather StatementCYSBox Butte56 min
Apr 26, 7:59 PM MDTSpecial Weather StatementCYSBox Butte31 min
Apr 26, 10:58 PM MDTAreal Flood AdvisoryCYSScotts Bluff6 hr
Apr 27, 2:00 AM MDTAreal Flood AdvisoryCYSBox Butte7 hr
Apr 27, 5:02 AM MDTAreal Flood AdvisoryCYSScotts Bluff103 min

Nearby

Flash Flood Warnings in Nebraska, 2012Every flash flood warning in 2012

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.