Alert archive / Kansas / Flash Flood Warnings in 2021

Flash Flood Warning 1, NWS Kansas City, MO

April 28, 2021Leavenworth County, Wyandotte County, Kansas

NWS Kansas City, MO issued this flash flood warning at Apr 28, 2021, 2:55 PM CDT for Leavenworth County, Wyandotte County, Kansas. 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
Apr 28, 2021, 2:55 PM CDT (19:55 UTC)
Expired
Apr 28, 2021, 6:00 PM CDT
In force
3 hr
Issued by
NWS Kansas City, MO
Area
Storm-based polygon
Flood severity
None

Counties Leavenworth County, KS, Wyandotte County, KS

The radar

The Pleasant Hill radar (KEAX), 67 km from the middle of the area, began a volume at 19:56 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
Apr 28, 3:05 PM CDTFLASH FLOOD5 Nne Linwood, KSWATER OVER THE HEMPHILL RD. HAS SINCE RECEDED.

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, 7.9 hours before the alert went out and 57 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 12:00Z on 2021-04-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 986 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 12:00Z on 2021-04-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 168 square meters per square second.1939587897117136Sfc1 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
986 J/kg
Mixed-layer CIN
-48 J/kg
Mixed-layer LCL
592 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
168 m²/s²
0-3 km storm-relative helicity
167 m²/s²
Significant tornado parameter
0.0
Supercell composite
4.1

Open this sounding in Storm Lab

The text

As transmitted.

928 
WGUS53 KEAX 281955
FFWEAX
KSC103-209-282300-
/O.NEW.KEAX.FF.W.0001.210428T1955Z-210428T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Kansas City/Pleasant Hill MO
255 PM CDT Wed Apr 28 2021

The National Weather Service in Pleasant Hill MO has issued a

* Flash Flood Warning for...
  Southern Leavenworth County in northeastern Kansas...
  Northwestern Wyandotte County in northeastern Kansas...

* Until 600 PM CDT.

* At 255 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2 inches of rain 
  have fallen. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Shawnee, Leavenworth, Lansing, Bonner Springs, De Soto, 
  Tonganoxie, Basehor, Edwardsville, Kansas City, Linwood, Reno, 
  Fairmount, Piper, Maywood and Wolcott.

This includes the following highways...
	Kansas Turnpike between mile markers 206 and 226.
	Interstate 435 between mile markers 13 and 19.
	Interstate 70 in Kansas between mile markers 410 and 411.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3908 9519 3927 9484 3922 9483 3920 9478
      3918 9476 3906 9485 3905 9488 3901 9489
      3899 9491 3898 9492 3900 9492 3898 9496
      3900 9501 3898 9503 3899 9507 3898 9509
      3895 9509 3898 9516 3896 9519

FLASH FLOOD...RADAR INDICATED

$$

Atkins
1 follow-up statement
768 
WGUS73 KEAX 282255
FFSEAX

Flash Flood Statement
National Weather Service Kansas City/Pleasant Hill MO
555 PM CDT Wed Apr 28 2021

KSC103-209-282305-
/O.EXP.KEAX.FF.W.0001.000000T0000Z-210428T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Leavenworth KS-Wyandotte KS-
555 PM CDT Wed Apr 28 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 6 PM CDT THIS EVENING FOR 
SOUTHERN LEAVENWORTH AND NORTHWESTERN WYANDOTTE COUNTIES...

Flood waters have receded. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

LAT...LON 3908 9519 3927 9484 3922 9483 3920 9478
      3918 9476 3906 9485 3905 9488 3901 9489
      3899 9491 3898 9492 3900 9492 3898 9496
      3900 9501 3898 9503 3899 9507 3898 9509
      3895 9509 3898 9516 3896 9519

$$

73

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 28, 2:30 PM CDTSpecial Weather StatementEAXLeavenworth, Wyandotte45 min
Apr 28, 4:48 PM CDTAreal Flood AdvisoryEAXMiami3 hr

Nearby

Flash Flood Warnings in Kansas, 2021Every 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.