Alert archive / Missouri / Flash Flood Warnings in 2021

Flash Flood Warning 2, NWS Kansas City, MO

April 28, 2021Platte County, Missouri

NWS Kansas City, MO issued this flash flood warning at Apr 28, 2021, 3:04 PM CDT for Platte County, Missouri. 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, 3:04 PM CDT (20:04 UTC)
Expired: Apr 28, 2021, 6:03 PM CDT
In force: 3 hr
Issued by: NWS Kansas City, MO
Area: Storm-based polygon
Flood severity: None

County Platte County, MO

The radar

The Pleasant Hill radar (KEAX), 66 km from the middle of the area, began a volume at 20:05 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

Time	Report	Where	Remark
Apr 28, 3:45 PM CDT	FLASH FLOOD	2 Nne Waldron, MO	WATER OVER JONES MYER AND HILLSBORO RD. WATER 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, 8.1 hours before the alert went out and 80 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: 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.

836 
WGUS53 KEAX 282004
FFWEAX
MOC165-282315-
/O.NEW.KEAX.FF.W.0002.210428T2004Z-210428T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Pleasant Hill MO has issued a

* Flash Flood Warning for...
  Southeastern Platte County in west central Missouri...

* Until 615 PM CDT.

* At 304 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...
  Kansas City, Lansing, Smithville, Parkville, Weatherby Lake, 
  Ferrelview, Farley, Kansas City Intl Arpt, Hoover and Waldron.

This includes the following highways...
	Interstate 29 between mile markers 8 and 15.
	Interstate 435 between mile markers 20 and 29...and
	between mile markers 33 and 39.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3927 9484 3938 9465 3939 9460 3927 9460
      3918 9476 3921 9478 3921 9479 3921 9480
      3921 9482 3922 9483 3924 9483 3925 9483

FLASH FLOOD...RADAR INDICATED

$$

Atkins

1 follow-up statement

892 
WGUS73 KEAX 282303
FFSEAX

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

MOC165-282313-
/O.CAN.KEAX.FF.W.0002.000000T0000Z-210428T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Platte MO-
603 PM CDT Wed Apr 28 2021

...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHEASTERN PLATTE COUNTY...

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

LAT...LON 3927 9484 3938 9465 3939 9460 3927 9460
      3918 9476 3921 9478 3921 9479 3921 9480
      3921 9482 3922 9483 3924 9483 3925 9483

$$

BT

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 28, 8:26 AM CDT	River Flood Warning	EAX	Cass, Henry, Johnson	67 hr
Apr 28, 4:04 PM CDT	Areal Flood Advisory	EAX	Caldwell, Carroll, Clay, Clinton, Livingston, Ray	3 hr
Apr 28, 4:48 PM CDT	Areal Flood Advisory	EAX	Cass, Johnson	3 hr
Apr 28, 5:00 PM CDT	Flash Flood Warning	EAX	Cass	3 hr

Nearby

Flash Flood Warnings in Missouri, 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.