Alert archive / Nebraska / Flash Flood Warnings in 2011

Flash Flood Warning 9, NWS Omaha, NE

May 25, 2011Richardson County, Nebraska

NWS Omaha, NE issued this flash flood warning at May 25, 2011, 3:57 PM CDT for Richardson County, Nebraska. It was in force for 6 hr. 2 reports 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 25, 2011, 3:57 PM CDT (20:57 UTC)
Expired: May 25, 2011, 10:00 PM CDT
In force: 6 hr
Issued by: NWS Omaha, NE
Area: Storm-based polygon
Flood severity: None

County Richardson County, NE

The radar

The Topeka radar (KTWX), 141 km from the middle of the area, began a volume at 20:57 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 25, 6:10 PM CDT	FLASH FLOOD	1 S Falls City, NE	PONY CREEK COUNTY ROAD CLOSED DUE TO HIGH WATER. CORRECTION TO LOCATION.
May 25, 6:10 PM CDT	FLASH FLOOD	2 N Falls City, NE	COUNTY ROAD CLOSED DUE TO HIGH WATER.

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

The nearest sounding before it

Topeka, KS (KTOP), launched 12:00Z, 9.0 hours before the alert went out and 126 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: 772 J/kg
Mixed-layer CIN: -131 J/kg
Mixed-layer LCL: 580 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 173 m²/s²
0-3 km storm-relative helicity: 208 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

The text

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

901 
WGUS53 KOAX 252057
FFWOAX
NEC147-260300-
/O.NEW.KOAX.FF.W.0009.110525T2057Z-110526T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
357 PM CDT WED MAY 25 2011

THE NATIONAL WEATHER SERVICE IN OMAHA HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHEASTERN RICHARDSON COUNTY IN SOUTHEAST NEBRASKA

* UNTIL 1000 PM CDT

* AT 345 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE      
  WARNED AREA. RADAR ESTIMATES AS MUCH AS 4 INCHES OF RAIN HAS       
  FALLEN IN THE AREA.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...FALLS
  CITY...RULO AND VERDON.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FLOODING IS OCCURRING OR IS IMMINENT. MOST FLOOD RELATED DEATHS OCCUR
IN AUTOMOBILES. DO NOT ATTEMPT TO CROSS WATER COVERED BRIDGES...
DIPS...OR LOW WATER CROSSINGS. NEVER TRY TO CROSS A FLOWING STREAM...
EVEN A SMALL ONE...ON FOOT OR IN A VEHICLE.

IN HILLY TERRAIN THERE ARE HUNDREDS OF LOW WATER CROSSINGS WHICH ARE
POTENTIALLY DANGEROUS IN HEAVY RAIN. DO NOT ATTEMPT TO TRAVEL ACROSS
FLOODED ROADS. FIND ALTERNATE ROUTES. IT ONLY TAKES A FEW INCHES OF
SWIFTLY FLOWING WATER TO CARRY VEHICLES AWAY.

&&

LAT...LON 4026 9559 4026 9555 4024 9547 4023 9546
      4020 9548 4018 9547 4016 9543 4013 9542
      4012 9539 4008 9539 4006 9542 4004 9541
      4003 9539 4003 9535 4000 9530 4000 9548
      4000 9599

$$

PEARSON

2 follow-up statements

449 
WGUS73 KOAX 252312
FFSOAX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
612 PM CDT WED MAY 25 2011

NEC147-260300-
/O.CON.KOAX.FF.W.0009.000000T0000Z-110526T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
RICHARDSON NE-
612 PM CDT WED MAY 25 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR SOUTHEASTERN RICHARDSON
COUNTY UNTIL 1000 PM CDT...

AT 612 PM CDT...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED THAT A 
COUNTY ROAD WAS CLOSED ABOUT 2 MILES NORTH OF FALLS CITY. DOPPLER 
RADAR HAD INDICATED THAT THE HEAVY RAINS HAD MOVED SOUTH OF THE 
AREA. WHILE A FEW SPRINKLES WILL BE POSSIBLE THROUGH THE EVENING...A 
FLASH FLOOD WARNING WILL REMAIN IN EFFECT UNTIL 10 PM TO ALLOW HIGH 
WATERS TO RECEDE.

SOME LOCATIONS THAT MAY EXPERIENCE FLOODING INCLUDE...FALLS CITY AND
VERDON.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY.

&&

LAT...LON 4026 9559 4026 9555 4024 9547 4023 9546
      4020 9548 4018 9547 4016 9543 4013 9542
      4012 9539 4008 9539 4006 9542 4004 9541
      4003 9539 4003 9535 4000 9530 4000 9548
      4000 9599

$$

DEWALD

752 
WGUS73 KOAX 260259
FFSOAX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
959 PM CDT WED MAY 25 2011

NEC147-260314-
/O.EXP.KOAX.FF.W.0009.000000T0000Z-110526T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
RICHARDSON NE-
959 PM CDT WED MAY 25 2011

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR SOUTHEASTERN
RICHARDSON COUNTY WILL BE ALLOWED TO EXPIRE AT 1000 PM CDT...

EXCESS RUNOFF FROM HEAVY RAIN HAS LIKELY ENDED OVER THE WARNED 
AREA...ENDING THE FLOOD THREAT. IF FLOODING HAS BEEN OBSERVED... 
PLEASE REPORT IT TO YOUR LOCAL LAW ENFORCEMENT AGENCY.

LAT...LON 4026 9559 4026 9555 4024 9547 4023 9546
      4020 9548 4018 9547 4016 9543 4013 9542
      4012 9539 4008 9539 4006 9542 4004 9541
      4003 9539 4003 9535 4000 9530 4000 9548
      4000 9599

$$

DEWALD

The office that day

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

Issued	Product	Office	Counties	Lasted
May 24, 8:21 PM CDT	River Flood Warning	OAX	Saunders	12 hr
May 25, 4:01 AM CDT	Wind Advisory	OAX	Antelope, Boone, Cedar, Knox, Madison, Pierce and 3 more	12 hr
May 25, 11:28 AM CDT	Areal Flood Warning	OAX	Dodge	5 hr
May 25, 11:37 AM CDT	Areal Flood Advisory	OAX	Butler, Colfax, Platte	6 hr
May 25, 1:16 PM CDT	Areal Flood Advisory	OAX	Richardson	3 hr
May 25, 5:47 PM CDT	River Flood Advisory	OAX	Washington	3 days

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.