Alert archive / Nebraska / Flash Flood Warnings in 2011

Flash Flood Warning 10, NWS Cheyenne, WY

July 4, 2011Scotts Bluff County, Sioux County, Nebraska

NWS Cheyenne, WY issued this flash flood warning at Jul 4, 2011, 5:41 PM MDT for Scotts Bluff County, Sioux County, Nebraska. It was in force for 2 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 4, 2011, 5:41 PM MDT (23:41 UTC)
Expired: Jul 4, 2011, 7:56 PM MDT
In force: 2 hr
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Flood severity: None

Counties Scotts Bluff County, NE, Sioux County, NE

The radar

The Cheyenne radar (KCYS), 126 km from the middle of the area, began a volume at 23:42 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, 11.7 hours before the alert went out and 241 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 3650 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 11 m²/s²
0-3 km storm-relative helicity: 55 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.

407 
WGUS55 KCYS 042341
FFWCYS
NEC157-165-050300-
/O.NEW.KCYS.FF.W.0010.110704T2341Z-110705T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
541 PM MDT MON JUL 4 2011

THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTH CENTRAL SCOTTS BLUFF COUNTY IN THE PANHANDLE OF NEBRASKA...
  SOUTHWESTERN SIOUX COUNTY IN THE PANHANDLE OF NEBRASKA...

* UNTIL 900 PM MDT

* AT 540 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE   
  WARNED AREA. RAINFALL ESTIMATES OF 1 TO 2 INCHES CAN BE EXPECTED. 
* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  SCOTTSBLUFF...LAKE ALICE...MITCHELL...MORRILL AND SCOTTS BLUFF
  NATIONAL MONUMENT.


LAT...LON 4181 10370 4202 10406 4205 10405 4225 10382
      4204 10350

$$
APFEL

1 follow-up statement

192 
WGUS75 KCYS 050156
FFSCYS

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
756 PM MDT MON JUL 4 2011

NEC157-165-050211-
/O.CAN.KCYS.FF.W.0010.000000T0000Z-110705T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SCOTTS BLUFF NE-SIOUX NE-
756 PM MDT MON JUL 4 2011

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR SOUTHERN SIOUX AND
NORTH CENTRAL SCOTTS BLUFF 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.

LAT...LON 4181 10370 4202 10406 4205 10405 4225 10382
      4204 10350

$$
APFEL

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 4, 4:27 PM MDT	Severe Thunderstorm Warning	CYS	Kimball	29 min
Jul 4, 4:35 PM MDT	Severe Thunderstorm Warning	CYS	Sioux	12 min
Jul 4, 4:45 PM MDT	Tornado Warning	CYS	Sioux	27 min
Jul 4, 5:08 PM MDT	Tornado Warning	CYS	Scotts Bluff, Sioux	37 min
Jul 4, 5:37 PM MDT	Tornado Warning	CYS	Banner, Scotts Bluff	26 min

Nearby

Flash Flood Warnings in Nebraska, 2011 Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.