Alert archive / Nebraska / Flash Flood Warnings in 2021

Flash Flood Warning 1, NWS North Platte, NE

May 17, 2021Chase County, Nebraska

NWS North Platte, NE issued this flash flood warning at May 17, 2021, 2:02 AM MDT for Chase 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: May 17, 2021, 2:02 AM MDT (08:02 UTC)
Expired: May 17, 2021, 5:21 AM MDT
In force: 3 hr
Issued by: NWS North Platte, NE
Area: Storm-based polygon
Flood severity: None

County Chase County, NE

The radar

The Goodland radar (KGLD), 133 km from the middle of the area, began a volume at 08:06 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

Time	Report	Where	Remark
May 17, 2:53 AM MDT	HEAVY RAIN 2.55	Imperial, NE

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, 8.0 hours before the alert went out and 109 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: 751 J/kg
Mixed-layer CIN: -13 J/kg
Mixed-layer LCL: 872 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 78 m²/s²
0-3 km storm-relative helicity: 179 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 2.1

Open this sounding in Storm Lab

The text

As transmitted.

106 
WGUS53 KLBF 170802
FFWLBF
NEC029-171230-
/O.NEW.KLBF.FF.W.0001.210517T0802Z-210517T1230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service North Platte NE
202 AM MDT Mon May 17 2021

The National Weather Service in North Platte has issued a

* Flash Flood Warning for...
  Chase County in southwestern Nebraska...

* Until 630 AM MDT.

* At 202 AM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 3 inches of rain 
  have fallen. Flash flooding is already occurring.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Doppler radar.

  IMPACT...Flooding of small creeks and streams, urban areas,
           highways, streets and underpasses as well as other
           drainage and low lying areas.

* Some locations that will experience flash flooding include...
  Imperial, Wauneta, Champion, Enders Reservoir State Recreation 
  Area, Enders, Crete, Chase, Wanamaker State Wildfire Management 
  Area, Church Grove Campground, Center Dam Campground and Area A 
  Campground.

This includes the following highways...
	Highway 61 between mile markers 25 and 52.

Additional rainfall amounts of 1 to 2 inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4069 10164 4046 10203 4035 10201 4036 10136
      4068 10143 4069 10146

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR 

$$

CDC

2 follow-up statements

153 
WGUS73 KLBF 170911
FFSLBF

Flash Flood Statement
National Weather Service North Platte NE
311 AM MDT Mon May 17 2021

NEC029-171230-
/O.CON.KLBF.FF.W.0001.000000T0000Z-210517T1230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chase NE-
311 AM MDT Mon May 17 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 630 AM MDT THIS 
MORNING FOR CHASE COUNTY...

At 311 AM MDT, Doppler radar and automated rain gauges indicated 
thunderstorms producing heavy rain across the warned area have 
decreased. Between 1 and 3 inches of rain have fallen. Flash 
flooding is already occurring. Additional heavy showers and 
thunderstorms may redevelop.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Doppler radar and automated gauges.

IMPACT...Flooding of small creeks and streams, urban areas,
         highways, streets and underpasses as well as other
         drainage and low lying areas.

Some locations that will experience flash flooding include...
  Imperial, Wauneta, Champion, Enders Reservoir State Recreation 
  Area, Enders, Crete, Chase, Wanamaker State Wildfire Management 
  Area, Church Grove Campground, Center Dam Campground and Area A 
  Campground.

This includes the following highways...
	Highway 61 between mile markers 25 and 52.

Additional rainfall amounts up to 1 inch are possible in the warned 
area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4069 10164 4046 10203 4035 10201 4036 10136
      4068 10143 4069 10146

FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL...1 INCH IN 3 HOURS 

$$

CDC

743 
WGUS73 KLBF 171121
FFSLBF

Flash Flood Statement
National Weather Service North Platte NE
521 AM MDT Mon May 17 2021

NEC029-171131-
/O.CAN.KLBF.FF.W.0001.000000T0000Z-210517T1230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chase NE-
521 AM MDT Mon May 17 2021

...FLASH FLOOD WARNING IS CANCELLED FOR CHASE COUNTY...

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

LAT...LON 4069 10164 4046 10203 4035 10201 4036 10136
      4068 10143 4069 10146

$$

CDC

The office that day

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

Issued	Product	Office	Counties	Lasted
May 16, 8:25 PM MDT	Special Weather Statement	LBF	Frontier	65 min
May 16, 8:33 PM MDT	Severe Thunderstorm Warning	LBF	Frontier, Hayes	18 min
May 17, 1:31 AM MDT	Areal Flood Advisory	LBF	Chase	31 min
May 17, 8:37 AM MDT	Areal Flood Warning	LBF	Keith, Lincoln, McPherson	3 hr

Nearby

Flash Flood Warnings in Nebraska, 2021 Every 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.