Alert archive / Kansas / Tornado Warnings in 2011

Tornado Warning 4, NWS Kansas City, MO

May 21, 2011Atchison County, Leavenworth County, Kansas

NWS Kansas City, MO issued this tornado warning at May 21, 2011, 7:34 PM CDT for Atchison County, Leavenworth County, Kansas. It was in force for 41 min. 3 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 21, 2011, 7:34 PM CDT (00:34 UTC)
Expired: May 21, 2011, 8:15 PM CDT
In force: 41 min
Issued by: NWS Kansas City, MO
Area: Storm-based polygon

Counties Atchison County, KS, Leavenworth County, KS

The radar

The Pleasant Hill radar (KEAX), 88 km from the middle of the area, began a volume at 00:37 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
May 21, 7:57 PM CDT	HAIL 1.75	2 W Easton Ks, KS
May 21, 8:07 PM CDT	HAIL 1.75	4 N Easton Ks, KS
May 21, 8:17 PM CDT	HAIL 1	2 W Easton Ks, KS

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

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
May 21, 5:34 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 0.6 hours before the alert went out and 247 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: 1436 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 1205 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 99 m²/s²
0-3 km storm-relative helicity: 145 m²/s²
Significant tornado parameter: 0.6
Supercell composite: 5.0

Open this sounding in Storm Lab

The text

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

385 
WFUS53 KEAX 220034
TOREAX
KSC005-103-220115-
/O.NEW.KEAX.TO.W.0004.110522T0034Z-110522T0115Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
734 PM CDT SAT MAY 21 2011

THE NATIONAL WEATHER SERVICE IN PLEASANT HILL HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHEASTERN ATCHISON COUNTY IN NORTHEAST KANSAS...
  NORTHERN LEAVENWORTH COUNTY IN NORTHEAST KANSAS...

* UNTIL 815 PM CDT

* AT 732 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED NEAR OSKALOOSA...OR 13 MILES SOUTH OF   
  NORTONVILLE...AND MOVING NORTHEAST AT 30 MPH.  THIS STORM HAS HAD A 
  HISTORY OF PRODUCING TORNADOES. SEEK SHELTER NOW. IN ADDITION TO A   
  TORNADO...LARGE DESTRUCTIVE HAIL UP TO TENNIS BALL SIZE IS 
  EXPECTED   WITH THIS STORM.

* LOCATIONS IMPACTED INCLUDE...
  LANSING...LEAVENWORTH...EASTON...JARBALO...POTTER...LOWEMONT AND
  FORT LEAVENWORTH.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 3941 9519 3949 9505 3947 9504 3945 9500
      3942 9497 3941 9495 3938 9494 3939 9491
      3938 9490 3930 9490 3925 9483 3921 9484
      3916 9519
TIME...MOT...LOC 0034Z 240DEG 27KT 3923 9534
HAIL 2.50IN

$$

CDB

1 follow-up statement

951 
WWUS53 KEAX 220050
SVSEAX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
750 PM CDT SAT MAY 21 2011

KSC005-103-220115-
/O.CON.KEAX.TO.W.0004.000000T0000Z-110522T0115Z/
LEAVENWORTH KS-ATCHISON KS-
750 PM CDT SAT MAY 21 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR SOUTHEASTERN ATCHISON AND
NORTHERN LEAVENWORTH COUNTIES UNTIL 815 PM CDT...

AT 747 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS DANGEROUS
STORM WAS LOCATED NEAR WINCHESTER...OR 10 MILES SOUTHEAST OF
NORTONVILLE...MOVING NORTHEAST AT 40 MPH.  THIS STORM HAS HAD A 
HISTORY OF PRODUCING TORNADOES. IN ADDITION TO A TORNADO...LARGE 
DESTRUCTIVE HAIL UP TO TENNIS BALL SIZE IS EXPECTED
WITH THIS STORM.

LOCATIONS IMPACTED INCLUDE...
  LANSING...LEAVENWORTH...EASTON...JARBALO...POTTER...LOWEMONT AND
  FORT LEAVENWORTH.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

HEAVY RAINFALL MAY OBSCURE THIS TORNADO. DO NOT WAIT TO SEE OR HEAR
THE TORNADO. TAKE COVER NOW.

&&

LAT...LON 3941 9519 3949 9505 3947 9504 3945 9500
      3942 9497 3941 9495 3938 9494 3939 9491
      3938 9490 3930 9490 3925 9483 3921 9484
      3916 9519
TIME...MOT...LOC 0049Z 241DEG 33KT 3930 9520
HAIL 2.50IN

$$

CDB

The office that day

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

Issued	Product	Office	Counties	Lasted
May 21, 8:01 PM CDT	Severe Thunderstorm Warning	EAX	Atchison	44 min
May 21, 8:08 PM CDT	Severe Thunderstorm Warning	EAX	Atchison, Leavenworth	22 min
May 21, 8:12 PM CDT	Tornado Warning	EAX	Leavenworth	33 min
May 21, 8:34 PM CDT	Special Weather Statement	EAX	Doniphan	26 min
May 21, 8:38 PM CDT	Severe Thunderstorm Warning	EAX	Atchison, Leavenworth	37 min
May 21, 8:46 PM CDT	Severe Thunderstorm Warning	EAX	Atchison, Leavenworth	29 min
May 21, 9:13 PM CDT	Severe Thunderstorm Warning	EAX	Atchison, Leavenworth	32 min
May 21, 9:23 PM CDT	Severe Thunderstorm Warning	EAX	Atchison, Leavenworth	37 min
May 21, 9:34 PM CDT	Special Weather Statement	EAX	Atchison	26 min
May 21, 9:38 PM CDT	Areal Flood Advisory	EAX	Atchison, Doniphan, Leavenworth	4 hr
May 21, 9:44 PM CDT	Severe Thunderstorm Warning	EAX	Atchison, Leavenworth	35 min
May 21, 9:50 PM CDT	Severe Thunderstorm Warning	EAX	Leavenworth	25 min
May 21, 10:11 PM CDT	Severe Thunderstorm Warning	EAX	Atchison, Leavenworth	21 min
May 21, 10:54 PM CDT	Tornado Warning	EAX	Johnson, Miami	51 min
May 21, 11:17 PM CDT	Severe Thunderstorm Warning	EAX	Johnson, Miami	28 min
May 21, 11:29 PM CDT	Tornado Warning	EAX	Miami	31 min
May 21, 11:41 PM CDT	Severe Thunderstorm Warning	EAX	Johnson	34 min
May 22, 1:27 AM CDT	River Flood Warning	EAX	Atchison, Leavenworth	32 hr
May 22, 4:04 AM CDT	River Flood Warning	EAX	Atchison	126 days
May 22, 3:23 PM CDT	Special Weather Statement	EAX	Linn	37 min

Nearby

Tornado Warnings in Kansas, 2011 Every tornado warning in 2011 Tornadoes 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.