Alert archive / Nebraska / Flash Flood Warnings in 2011

Flash Flood Warning 17, NWS North Platte, NE

August 21, 2011Cherry County, Nebraska

NWS North Platte, NE issued this flash flood warning at Aug 21, 2011, 11:27 PM MDT for Cherry County, Nebraska. It was in force for 6 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: Aug 21, 2011, 11:27 PM MDT (05:27 UTC)
Expired: Aug 22, 2011, 5:30 AM MDT
In force: 6 hr
Issued by: NWS North Platte, NE
Area: Storm-based polygon
Flood severity: None

County Cherry County, NE

The radar

The North Platte radar (KLNX), 107 km from the middle of the area, began a volume at 05:29 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

N. Platte/Lee Bi, NE (KLBF), launched 00:00Z, 5.5 hours before the alert went out and 198 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: 248 J/kg
Mixed-layer CIN: -137 J/kg
Mixed-layer LCL: 2663 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 54 m²/s²
0-3 km storm-relative helicity: 194 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.1

Open this sounding in Storm Lab

The text

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

663 
WGUS53 KLBF 220527
FFWLBF
NEC031-221130-
/O.NEW.KLBF.FF.W.0017.110822T0527Z-110822T1130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE NORTH PLATTE NE
1227 AM CDT MON AUG 22 2011

THE NATIONAL WEATHER SERVICE IN NORTH PLATTE HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHEASTERN CHERRY COUNTY IN NORTH CENTRAL NEBRASKA...

* UNTIL 630 AM CDT

* AT 1222 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE      
  WARNED AREA. THERE ARE RADAR ESTIMATIONS OF 5 TO 6 INCHES OF
  RAINFALL BETWEEN VALENTINE AND SPARKS.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...SMITH
  FALLS STATE PARK AND SPARKS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. DO
NOT ENTER THE WATER. TURN AROUND AND MOVE UP TO HIGHER GROUND TO
ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS SUBJECT TO FLOODING WHEN
WATER BEGINS RISING.

&&

LAT...LON 4300 10020 4267 10020 4284 10057 4300 10045

$$

POWER

2 follow-up statements

774 
WGUS73 KLBF 220805
FFSLBF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE NORTH PLATTE NE
305 AM CDT MON AUG 22 2011

NEC031-221130-
/O.CON.KLBF.FF.W.0017.000000T0000Z-110822T1130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CHERRY NE-
305 AM CDT MON AUG 22 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR NORTHEASTERN CHERRY
COUNTY UNTIL 630 AM CDT...

AT 302 AM CDT...RAIN HAD ENDED OVER THE AREA BUT THERE WERE RADAR 
ESTIMATES OF 7 TO 8 INCHES OF RAIN BETWEEN VALENTINE AND SPARKS. AS 
THIS WATER DRAINS FLASH FLOODING IS POSSIBLE.

SOME LOCATIONS THAT WILL EXPERIENCE FLASH FLOODING INCLUDE...SMITH
FALLS STATE PARK AND SPARKS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FLOODING IS OCCURRING OR IS IMMINENT. IT IS IMPORTANT TO KNOW WHERE
YOU ARE RELATIVE TO STREAMS...RIVERS...OR CREEKS WHICH CAN BECOME
KILLERS IN HEAVY RAINS. CAMPERS AND HIKERS SHOULD AVOID STREAMS OR
CREEKS.

&&

LAT...LON 4300 10020 4267 10020 4284 10057 4300 10045

$$

POWER

339 
WGUS73 KLBF 221126
FFSLBF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE NORTH PLATTE NE
626 AM CDT MON AUG 22 2011

NEC031-221141-
/O.EXP.KLBF.FF.W.0017.000000T0000Z-110822T1130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CHERRY NE-
626 AM CDT MON AUG 22 2011

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR NORTHEASTERN CHERRY
COUNTY WILL BE ALLOWED TO EXPIRE AT 630 AM CDT...

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 4300 10020 4267 10020 4284 10057 4300 10045

$$

POWER

The office that day

Everything else NWS North Platte, NE issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 21, 8:00 PM MDT	Severe Thunderstorm Warning	LBF	Grant, Hooker	45 min
Aug 21, 9:42 PM MDT	Severe Thunderstorm Warning	LBF	Arthur	48 min
Aug 21, 9:59 PM MDT	Severe Thunderstorm Warning	LBF	Brown, Cherry, Keya Paha	46 min
Aug 21, 10:15 PM MDT	Severe Thunderstorm Warning	LBF	Arthur, McPherson	45 min
Aug 21, 10:52 PM MDT	Areal Flood Advisory	LBF	Cherry	3 hr

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.