Alert archive / Nebraska / Flash Flood Warnings in 2021

Flash Flood Warning 6, NWS North Platte, NE

August 19, 2021Keith County, Nebraska

NWS North Platte, NE issued this flash flood warning at Aug 19, 2021, 6:13 PM MDT for Keith County, Nebraska. It was in force for 3 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
Aug 19, 2021, 6:13 PM MDT (00:13 UTC)
Expired
Aug 19, 2021, 9:15 PM MDT
In force
3 hr
Issued by
NWS North Platte, NE
Area
Storm-based polygon
Flood severity
None

County Keith County, NE

The radar

The North Platte radar (KLNX), 133 km from the middle of the area, began a volume at 00:16 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
Aug 19, 6:35 PM MDTFLASH FLOODOgallala, NENUMEROUS STREETS FLOODED IN OGALLALA.

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

The nearest sounding before it

N. Platte/Lee Bi, NE (KLBF), launched 00:00Z, 0.2 hours before the alert went out and 95 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, N. Platte/Lee Bi, NE at 00:00Z on 2021-08-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1368 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, N. Platte/Lee Bi, NE at 00:00Z on 2021-08-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 145 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
1368 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
1220 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
145 m²/s²
0-3 km storm-relative helicity
208 m²/s²
Significant tornado parameter
1.1
Supercell composite
10.2

Open this sounding in Storm Lab

The text

As transmitted.

444 
WGUS53 KLBF 200013
FFWLBF
NEC101-200315-
/O.NEW.KLBF.FF.W.0006.210820T0013Z-210820T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service North Platte NE
613 PM MDT Thu Aug 19 2021

The National Weather Service in North Platte has issued a

* Flash Flood Warning for...
  Central Keith County in southwestern Nebraska...

* Until 915 PM MDT.

* At 613 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2.5 inches of 
  rain have fallen. Additional rainfall amounts up to 1 inch are 
  possible in the warned area. Flash flooding is ongoing or expected 
  to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Ogallala.

This includes the following highways...
	Highway 61 between mile markers 85 and 93.
	Interstate 80 in Nebraska between mile markers 124 and 128.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

&&

LAT...LON 4107 10176 4123 10182 4120 10166 4110 10168

FLASH FLOOD...RADAR INDICATED

$$

Roberg
2 follow-up statements
913 
WGUS73 KLBF 200105
FFSLBF

Flash Flood Statement
National Weather Service North Platte NE
705 PM MDT Thu Aug 19 2021

NEC101-200315-
/O.CON.KLBF.FF.W.0006.000000T0000Z-210820T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Keith NE-
705 PM MDT Thu Aug 19 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 915 PM MDT THIS 
EVENING FOR CENTRAL KEITH COUNTY...

At 705 PM MDT, local law enforcement reported flooding in Ogallala. 
Between 1 and 3 inches of rain have fallen. The expected rainfall 
rate is 0.25 to 0.5 inches in 1 hour. Additional rainfall amounts up 
to 1 inch are possible in the warned area. Flash flooding is already 
occurring.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Law enforcement reported.

IMPACT...Flash flooding of small creeks and streams, urban areas,
         highways, streets and underpasses as well as other poor
         drainage and low-lying areas.

Some locations that will experience flash flooding include...
  Ogallala.

This includes the following highways...
	Highway 61 between mile markers 85 and 93...and
	near mile marker 95.
	Interstate 80 in Nebraska between mile markers 124 and 128.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

&&

LAT...LON 4107 10176 4123 10182 4120 10166 4110 10168

FLASH FLOOD...OBSERVED
EXPECTED RAINFALL...0.25-0.5 INCHES IN 1 HOUR

$$

Roberg
742 
WGUS73 KLBF 200307
FFSLBF

Flash Flood Statement
National Weather Service North Platte NE
907 PM MDT Thu Aug 19 2021

NEC101-200317-
/O.EXP.KLBF.FF.W.0006.000000T0000Z-210820T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Keith NE-
907 PM MDT Thu Aug 19 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 915 PM MDT THIS EVENING FOR 
CENTRAL KEITH COUNTY...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

LAT...LON 4107 10176 4123 10182 4120 10166 4110 10168

$$

Buttler

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 19, 6:02 PM MDTSevere Thunderstorm Warning Considerable damage threatLBFChase, Perkins43 min
Aug 19, 6:32 PM MDTSevere Thunderstorm WarningLBFChase, Perkins43 min
Aug 19, 6:42 PM MDTSevere Thunderstorm WarningLBFChase, Perkins48 min
Aug 19, 6:50 PM MDTAreal Flood AdvisoryLBFArthur2 hr
Aug 19, 6:59 PM MDTAreal Flood AdvisoryLBFChase, Perkins2 hr
Aug 19, 7:13 PM MDTAreal Flood WarningLBFChase, Perkins24 hr
Aug 19, 7:39 PM MDTAreal Flood AdvisoryLBFKeith, Lincoln, Perkins3 hr
Aug 19, 7:42 PM MDTSpecial Weather StatementLBFPerkins48 min
Aug 19, 8:14 PM MDTSpecial Weather StatementLBFChase46 min
Aug 19, 8:17 PM MDTSevere Thunderstorm Warning Considerable damage threatLBFChase, Hayes, Lincoln, Perkins43 min
Aug 19, 8:28 PM MDTSpecial Weather StatementLBFLincoln47 min
Aug 19, 8:40 PM MDTSevere Thunderstorm Warning Considerable damage threatLBFChase, Frontier, Hayes, Lincoln, Perkins50 min
Aug 19, 8:51 PM MDTAreal Flood AdvisoryLBFCuster, Keith, Lincoln4 hr
Aug 19, 8:56 PM MDTSevere Thunderstorm WarningLBFLincoln49 min
Aug 19, 9:34 PM MDTSpecial Weather StatementLBFFrontier, Hayes41 min
Aug 19, 9:41 PM MDTSpecial Weather StatementLBFDawson49 min
Aug 19, 10:22 PM MDTSpecial Weather StatementLBFCuster38 min
Aug 19, 10:28 PM MDTSpecial Weather StatementLBFFrontier47 min
Aug 19, 10:32 PM MDTSpecial Weather StatementLBFChase43 min
Aug 19, 11:15 PM MDTSpecial Weather StatementLBFChase45 min
Aug 19, 11:58 PM MDTSpecial Weather StatementLBFHayes47 min
Aug 20, 12:39 AM MDTAreal Flood WarningLBFChase, Hayes19 hr
Aug 20, 12:50 AM MDTAreal Flood AdvisoryLBFLincoln2 hr
Aug 20, 12:56 AM MDTSpecial Weather StatementLBFLincoln49 min
Aug 20, 2:12 AM MDTSpecial Weather StatementLBFCuster48 min
Aug 20, 9:35 AM MDTRiver Flood AdvisoryLBFHayes10 hr
Aug 20, 1:40 PM MDTRiver Flood AdvisoryLBFLincoln24 hr

Nearby

Flash Flood Warnings in Nebraska, 2021Every flash flood warning in 2021

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.