Alert archive / Nebraska / Flash Flood Warnings in 2017

Flash Flood Warning 15, NWS North Platte, NE

August 19, 2017Custer County, Loup County, Nebraska

NWS North Platte, NE issued this flash flood warning at Aug 19, 2017, 9:20 PM CDT for Custer County, Loup County, Nebraska. It was in force for 6 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, 2017, 9:20 PM CDT (02:20 UTC)
Expired
Aug 20, 2017, 3:15 AM CDT
In force
6 hr
Issued by
NWS North Platte, NE
Area
Storm-based polygon
Flood severity
None

Counties Custer County, NE, Loup County, NE

The radar

The North Platte radar (KLNX), 88 km from the middle of the area, began a volume at 02:18 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, 10:05 PM CDTFLASH FLOODSargent, NEWATER ABOUT TO RUN OVER ROADS IN SARGENT. DITCHES ARE FULL AND CITY PUMPS ARE RUNNING.

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, 2.3 hours before the alert went out and 110 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 2017-08-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2449 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 2017-08-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 62 square meters per square second.1939Sfc1 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
2449 J/kg
Mixed-layer CIN
-45 J/kg
Mixed-layer LCL
2367 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
62 m²/s²
0-3 km storm-relative helicity
144 m²/s²
Significant tornado parameter
0.0
Supercell composite
6.1

Open this sounding in Storm Lab

The text

As transmitted.

405 
WGUS53 KLBF 200220
FFWLBF
NEC041-115-200815-
/O.NEW.KLBF.FF.W.0015.170820T0220Z-170820T0815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service North Platte NE
920 PM CDT SAT AUG 19 2017

The National Weather Service in North Platte has issued a

* Flash Flood Warning for...
  Southern Loup County in north central Nebraska...
  Northeastern Custer County in central Nebraska...

* Until 315 AM CDT

* At 919 PM CDT, Doppler radar indicated heavy rain across the warned
  area. Up to two inches of rain have already fallen. Flash flooding
  is expected to begin shortly.

* Some locations that will experience flooding include...
  Taylor, Sargent, Victoria Springs State Recreation Area, Calamus
  Reservoir State Recreation Area, Lillian, Walworth, Almeria, Nunda
  Shoal Campground, Divide Hill, Valley View Flat Campground, Gates
  and Kent Diversion Dam State Wildlife Management Area.

Additional rainfall amounts of up to 2 inches are possible in the 
warned area.

This includes Highway 183 between mile markers 110 and 132.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

&&

LAT...LON 4156 9928 4158 9978 4170 9975 4174 9972
      4174 9968 4180 9968 4185 9965 4186 9947
      4193 9925

$$

Taylor
2 follow-up statements
099 
WGUS73 KLBF 200330
FFSLBF

Flash Flood Statement
National Weather Service North Platte NE
1030 PM CDT SAT AUG 19 2017

NEC041-115-200815-
/O.CON.KLBF.FF.W.0015.000000T0000Z-170820T0815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Loup NE-Custer NE-
1030 PM CDT SAT AUG 19 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 315 AM CDT FOR
SOUTHERN LOUP AND NORTHEASTERN CUSTER COUNTIES...

At 1027 PM CDT, Doppler radar indicated thunderstorms producing 
heavy rain are exiting eastern portions of the warned area. 
Additional thunderstorms could still redevelop. Doppler radar 
estimates 1 to 4 inches of rain have fallen. Flash flooding is 
expected.

Some locations that will experience flooding include...
Taylor, Sargent, Victoria Springs State Recreation Area, Calamus
Reservoir State Recreation Area, Lillian, Walworth, Almeria, Nunda
Shoal Campground, Divide Hill, Valley View Flat Campground, Gates and
Kent Diversion Dam State Wildlife Management Area.

Additional rainfall amounts of a half inch are possible in the 
warned area.

This includes Highway 183 between mile markers 110 and 132.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

&&

LAT...LON 4156 9928 4158 9978 4170 9975 4174 9972
      4174 9968 4180 9968 4185 9965 4186 9947
      4193 9925

$$

Roberg
753 
WGUS73 KLBF 200811
FFSLBF

Flash Flood Statement
National Weather Service North Platte NE
311 AM CDT SUN AUG 20 2017

NEC041-115-200820-
/O.EXP.KLBF.FF.W.0015.000000T0000Z-170820T0815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Loup NE-Custer NE-
311 AM CDT SUN AUG 20 2017

...THE FLASH FLOOD WARNING FOR SOUTHERN LOUP AND NORTHEASTERN CUSTER
COUNTIES WILL EXPIRE AT 315 AM CDT...

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

LAT...LON 4156 9928 4158 9978 4170 9975 4174 9972
      4174 9968 4180 9968 4185 9965 4186 9947
      4193 9925

$$

Snively

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 19, 7:14 PM CDTSevere Thunderstorm WarningLBFBlaine, Loup, Rock46 min
Aug 19, 7:39 PM CDTTornado WarningLBFLoup51 min
Aug 19, 7:54 PM CDTFlash Flood WarningLBFBlaine, Loup, Rock6 hr
Aug 19, 8:02 PM CDTTornado WarningLBFLoup43 min
Aug 19, 8:44 PM CDTSevere Thunderstorm WarningLBFCuster61 min
Aug 19, 8:48 PM CDTSevere Thunderstorm WarningLBFLoup27 min
Aug 19, 9:01 PM CDTTornado Warning Tornado observedLBFCuster29 min
Aug 19, 9:45 PM CDTSevere Thunderstorm WarningLBFCuster45 min
Aug 19, 10:20 PM CDTSpecial Weather StatementLBFLoup40 min
Aug 19, 10:40 PM CDTSpecial Weather StatementLBFCuster50 min

Nearby

Flash Flood Warnings in Nebraska, 2017Every flash flood warning in 2017

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.