Alert archive / Kansas / Flash Flood Warnings in 2012

Flash Flood Warning 5, NWS Kansas City, MO

May 6, 2012Johnson County, Kansas

NWS Kansas City, MO issued this flash flood warning at May 6, 2012, 7:04 PM CDT for Johnson County, Kansas. It was in force for 7 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 6, 2012, 7:04 PM CDT (00:04 UTC)
Expired
May 7, 2012, 2:00 AM CDT
In force
7 hr
Issued by
NWS Kansas City, MO
Area
Storm-based polygon
Flood severity
None

County Johnson County, KS

The radar

The Pleasant Hill radar (KEAX), 44 km from the middle of the area, began a volume at 00:05 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
May 6, 7:40 PM CDTFLASH FLOODOlathe, KSNUMEROUS STREETS FLOODED

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 00:00Z, 0.1 hours before the alert went out and 78 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, Topeka, KS at 00:00Z on 2012-05-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2839 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, Topeka, KS at 00:00Z on 2012-05-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 62 square meters per square second.193958Sfc1 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
2839 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
698 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
62 m²/s²
0-3 km storm-relative helicity
169 m²/s²
Significant tornado parameter
0.9
Supercell composite
5.0

Open this sounding in Storm Lab

The text

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

808 
WGUS53 KEAX 070004
FFWEAX
KSC091-070700-
/O.NEW.KEAX.FF.W.0005.120507T0004Z-120507T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
704 PM CDT SUN MAY 6 2012

THE NATIONAL WEATHER SERVICE IN PLEASANT HILL HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CENTRAL JOHNSON COUNTY IN EAST CENTRAL KANSAS...

* UNTIL 200 AM CDT MONDAY

* AT 701 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE   
  WARNED AREA. DOPPLER RADAR ESTIMATES RAINFALL RATES UP TO 2 INCHES 
  PER HOUR WITH THESE STORMS. 

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  LENEXA AND OLATHE.

THIS WILL IMPACT THE FOLLOWING INTERSTATES...

  I-35 BETWEEN MILE MARKERS 214 AND 226.
  I-435 LOOP FROM MILE MARKERS 0 TO 1...78 TO 83.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

ADDITIONAL RAINFALL AMOUNTS OF 1 TO 2 INCHES ARE POSSIBLE THIS 
EVENING IN THE WARNED AREA. EARLIER THUNDERSTORMS THIS MORNING 
PRODUCED BETWEEN 1 AND 2 INCHES OF RAINFALL OVER PARTS OF THE WARNED 
AREA. ALL OF THIS RAINFALL WILL LIKELY RESULT IN FLASH FLOODING 
CONDITIONS THIS EVENING.  

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES
AS WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

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 3900 9469 3890 9464 3882 9483 3889 9489

$$

MJ
2 follow-up statements
927 
WGUS73 KEAX 070226
FFSEAX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
926 PM CDT SUN MAY 6 2012

KSC091-070700-
/O.CON.KEAX.FF.W.0005.000000T0000Z-120507T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
JOHNSON KS-
926 PM CDT SUN MAY 6 2012

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR CENTRAL JOHNSON COUNTY
IN EAST CENTRAL KANSAS UNTIL 200 AM CDT...

AT 920 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
THUNDERSTORMS HAD PUSHED SOUTH OF THE WARNED AREA.  RAINFALL AMOUNTS
RANGING FROM 3...TO NEARLY 5 INCHES WERE COMMON FROM THE EARLIER
THUNDERSTORMS.  ADDITIONAL SCATTERED THUNDERSTORMS ARE LIKELY DURING
THE OVERNIGHT HOURS. RAINFALL AMOUNTS FROM THESE STORMS IS
EXPECTED TO BE AROUND A QUARTER OF AN INCH.

RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO 
OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING 
INCLUDE...LENEXA...OVERLAND PARK AND OLATHE. IN ADDITION...FLOODING
IS EXPECTED WITHIN THE INDIAN CREEK BASIN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLASH FLOODING OF SMALL
CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES
AS WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLOODING IS OBSERVED...ACT QUICKLY. DO NOT
ENTER THE WATER. TURN AROUND AND MOVE UP TO HIGHER GROUND. DO NOT
STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

&&

LAT...LON 3900 9469 3890 9464 3882 9483 3889 9489

$$

SAW
823 
WGUS73 KEAX 070655
FFSEAX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
155 AM CDT MON MAY 7 2012

KSC091-070709-
/O.EXP.KEAX.FF.W.0005.000000T0000Z-120507T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
JOHNSON KS-
155 AM CDT MON MAY 7 2012

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR CENTRAL JOHNSON
COUNTY IN EAST CENTRAL KANSAS WILL BE ALLOWED TO EXPIRE AT 200 AM
CDT...

EXCESS RUNOFF FROM HEAVY RAIN HAS ENDED OVER THE WARNED AREA. 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 3900 9469 3890 9464 3882 9483 3889 9489

$$

ACH

The office that day

Everything else NWS Kansas City, MO issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 6, 7:08 PM CDTSevere Thunderstorm WarningEAXJohnson37 min
May 6, 7:23 PM CDTSevere Thunderstorm WarningEAXJohnson, Miami24 min
May 6, 8:06 PM CDTSpecial Weather StatementEAXJohnson9 min
May 6, 8:08 PM CDTSpecial Weather StatementEAXMiami37 min
May 6, 8:18 PM CDTFlash Flood WarningEAXJohnson6 hr
May 6, 8:39 PM CDTSpecial Weather StatementEAXMiami21 min
May 6, 8:44 PM CDTRiver Flood WarningEAXJohnson3 hr
May 6, 9:07 PM CDTSevere Thunderstorm WarningEAXMiami23 min

Nearby

Flash Flood Warnings in Kansas, 2012Every flash flood warning in 2012

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.