Alert archive / Nebraska / Flash Flood Warnings in 2011

Flash Flood Warning 37, NWS Omaha, NE

August 19, 2011Pawnee County, Richardson County, Nebraska

NWS Omaha, NE issued this flash flood warning at Aug 19, 2011, 11:04 PM CDT for Pawnee County, Richardson County, Nebraska. It was in force for 3 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 19, 2011, 11:04 PM CDT (04:04 UTC)
Expired: Aug 20, 2011, 2:00 AM CDT
In force: 3 hr
Issued by: NWS Omaha, NE
Area: Storm-based polygon
Flood severity: None

Counties Pawnee County, NE, Richardson County, NE

The radar

The Topeka radar (KTWX), 131 km from the middle of the area, began a volume at 04:06 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.

The nearest sounding before it

Topeka, KS (KTOP), launched 00:00Z, 4.1 hours before the alert went out and 124 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: 1999 J/kg
Mixed-layer CIN: -345 J/kg
Mixed-layer LCL: 1353 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 92 m²/s²
0-3 km storm-relative helicity: 287 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.5

Open this sounding in Storm Lab

The text

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

847 
WGUS53 KOAX 200404
FFWOAX
NEC133-147-200700-
/O.NEW.KOAX.FF.W.0037.110820T0404Z-110820T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
1104 PM CDT FRI AUG 19 2011

THE NATIONAL WEATHER SERVICE IN OMAHA HAS ISSUED A

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

* UNTIL 200 AM CDT

* AT 1057 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE   
  WARNED AREA. RADAR ESTIMATES OF 2 TO 3 INCHES OF RAIN HAS ALREADY 
  FALLEN IN NORTHERN PAWNEE THROUGH MOST OF RICHARDSON COUNTIES...
  AND MORE SLOW MOVING THUNDERSTORMS COULD DUMP ANOTHER 1 TO 2 
  INCHES OF RAIN BY 1 AM. 

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...FALLS
  CITY...HUMBOLDT...PAWNEE CITY...SHUBERT...STELLA...TABLE ROCK AND
  VERDON.

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 4000 9645 4016 9646 4026 9646 4025 9552
      4022 9547 4018 9547 4012 9539 4008 9539
      4006 9542 4004 9541 4003 9535 4001 9533

$$

EASTLACK

1 follow-up statement

491 
WGUS73 KOAX 200659
FFSOAX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
159 AM CDT SAT AUG 20 2011

NEC133-147-200707-
/O.EXP.KOAX.FF.W.0037.000000T0000Z-110820T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
PAWNEE NE-RICHARDSON NE-
159 AM CDT SAT AUG 20 2011

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR RICHARDSON AND
PAWNEE COUNTIES WILL BE ALLOWED TO EXPIRE AT 200 AM CDT...

EXCESS RUNOFF FROM HEAVY RAIN HAS ENDED OVER THE WARNED AREA. LIGHT 
TO MODERATE RAIN WILL CONTINUE FOR THE NEXT FEW HOURS. HOURLY 
RAINFALL AMOUNTS AROUND A QUARTER INCH AN HOUR CAN BE EXPECTED. 
SINCE THE THREAT FOR HEAVY RAINFALL HAS ENDED...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 4000 9645 4016 9646 4026 9646 4025 9552
      4022 9547 4018 9547 4012 9539 4008 9539
      4006 9542 4004 9541 4003 9535 4001 9533

$$

ROBERG

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 19, 8:23 PM CDT	Severe Thunderstorm Warning	OAX	Gage, Johnson, Lancaster, Nemaha, Otoe	52 min
Aug 19, 8:52 PM CDT	Severe Thunderstorm Warning	OAX	Johnson	23 min
Aug 19, 9:12 PM CDT	Severe Thunderstorm Warning	OAX	Johnson, Nemaha, Pawnee, Richardson	37 min
Aug 19, 9:34 PM CDT	Severe Thunderstorm Warning	OAX	Pawnee, Richardson	26 min
Aug 19, 10:39 PM CDT	Severe Thunderstorm Warning	OAX	Gage, Jefferson, Saline	18 min
Aug 19, 10:42 PM CDT	Severe Thunderstorm Warning	OAX	Gage, Johnson, Lancaster, Otoe	33 min
Aug 19, 10:43 PM CDT	Severe Thunderstorm Warning	OAX	Gage, Johnson	32 min

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.