Alert archive / Kansas / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 155, NWS Topeka, KS

August 20, 2021Jefferson County, Kansas

NWS Topeka, KS issued this severe thunderstorm warning at Aug 20, 2021, 10:08 PM CDT for Jefferson County, Kansas. It was in force for 37 min. 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 20, 2021, 10:08 PM CDT (03:08 UTC)
Expired
Aug 20, 2021, 10:45 PM CDT
In force
37 min
Issued by
NWS Topeka, KS
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

County Jefferson County, KS

The radar

The Topeka radar (KTWX), 77 km from the middle of the area, began a volume at 03:10 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 watch it was issued in

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

IssuedProductOfficeLasted
Aug 20, 7:40 PM CDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Topeka, KS (KTOP), launched 00:00Z, 3.1 hours before the alert went out and 38 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 2021-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3676 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 2021-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 145 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
3676 J/kg
Mixed-layer CIN
-53 J/kg
Mixed-layer LCL
1017 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
145 m²/s²
0-3 km storm-relative helicity
242 m²/s²
Significant tornado parameter
3.1
Supercell composite
18.5

Open this sounding in Storm Lab

The text

As transmitted.

461 
WUUS53 KTOP 210308
SVRTOP
KSC087-210345-
/O.NEW.KTOP.SV.W.0155.210821T0308Z-210821T0345Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Topeka KS
1008 PM CDT Fri Aug 20 2021

The National Weather Service in Topeka has issued a

* Severe Thunderstorm Warning for...
  Northern Jefferson County in northeastern Kansas...

* Until 1045 PM CDT.

* At 1008 PM CDT, a severe thunderstorm was located near Valley
  Falls, moving east at 40 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Locations impacted include...
  Valley Falls, Meriden, Ozawkie, Nortonville and Winchester. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3918 9559 3938 9559 3942 9548 3942 9518
      3926 9518
TIME...MOT...LOC 0308Z 254DEG 44KT 3931 9550 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

BD
2 follow-up statements
621 
WWUS53 KTOP 210333
SVSTOP

Severe Weather Statement
National Weather Service Topeka KS
1033 PM CDT Fri Aug 20 2021

KSC087-210345-
/O.CON.KTOP.SV.W.0155.000000T0000Z-210821T0345Z/
Jefferson-
1033 PM CDT Fri Aug 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1045 PM CDT
FOR NORTHEASTERN JEFFERSON COUNTY...

At 1033 PM CDT, a severe thunderstorm was located near Easton, moving
east at 40 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Valley Falls, Ozawkie, Nortonville and Winchester. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3920 9548 3942 9548 3942 9518 3926 9518
TIME...MOT...LOC 0333Z 254DEG 44KT 3940 9511 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

BD
306 
WWUS53 KTOP 210342
SVSTOP

Severe Weather Statement
National Weather Service Topeka KS
1042 PM CDT Fri Aug 20 2021

KSC087-210352-
/O.EXP.KTOP.SV.W.0155.000000T0000Z-210821T0345Z/
Jefferson-
1042 PM CDT Fri Aug 20 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN JEFFERSON COUNTY
WILL EXPIRE AT 1045 PM CDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.

A Severe Thunderstorm Watch remains in effect until 200 AM CDT for
northeastern Kansas.

LAT...LON 3920 9548 3942 9548 3942 9518 3926 9518
TIME...MOT...LOC 0342Z 254DEG 44KT 3934 9537 

$$

BD

The office that day

Everything else NWS Topeka, KS issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 20, 7:07 PM CDTSevere Thunderstorm WarningTOPClay, Dickinson, Geary, Riley38 min
Aug 20, 7:15 PM CDTSpecial Weather StatementTOPMarshall, Nemaha30 min
Aug 20, 7:23 PM CDTSevere Thunderstorm WarningTOPPottawatomie37 min
Aug 20, 7:27 PM CDTSevere Thunderstorm WarningTOPGeary, Pottawatomie, Riley33 min
Aug 20, 7:45 PM CDTSpecial Weather StatementTOPBrown, Jackson, Nemaha, Pottawatomie30 min
Aug 20, 7:51 PM CDTSevere Thunderstorm WarningTOPBrown, Nemaha39 min
Aug 20, 7:56 PM CDTSevere Thunderstorm WarningTOPJackson, Pottawatomie, Riley, Wabaunsee34 min
Aug 20, 8:01 PM CDTSevere Thunderstorm WarningTOPDickinson, Morris44 min
Aug 20, 8:29 PM CDTSpecial Weather StatementTOPJackson, Wabaunsee31 min
Aug 20, 8:32 PM CDTSevere Thunderstorm WarningTOPGeary, Lyon, Morris, Wabaunsee28 min
Aug 20, 8:33 PM CDTSpecial Weather StatementTOPCloud27 min
Aug 20, 8:58 PM CDTSpecial Weather StatementTOPBrown, Geary, Jackson, Jefferson, Nemaha, Pottawatomie and 2 more47 min
Aug 20, 9:01 PM CDTSpecial Weather StatementTOPLyon29 min
Aug 20, 9:37 PM CDTSpecial Weather StatementTOPLyon, Osage23 min
Aug 20, 9:40 PM CDTSpecial Weather StatementTOPBrown, Jackson, Jefferson, Pottawatomie, Shawnee, Wabaunsee35 min
Aug 20, 9:43 PM CDTSevere Thunderstorm WarningTOPDouglas, Jefferson, Osage, Shawnee32 min
Aug 20, 9:53 PM CDTSevere Thunderstorm WarningTOPJackson, Jefferson, Shawnee37 min
Aug 20, 10:00 PM CDTSevere Thunderstorm WarningTOPDouglas, Jefferson, Osage, Shawnee45 min
Aug 20, 10:32 PM CDTAreal Flood AdvisoryTOPJackson, Jefferson2 hr
Aug 20, 10:40 PM CDTSpecial Weather StatementTOPOsage50 min
Aug 20, 11:06 PM CDTSevere Thunderstorm WarningTOPOsage24 min
Aug 20, 11:30 PM CDTSevere Thunderstorm WarningTOPDouglas, Franklin, Osage25 min
Aug 21, 12:57 AM CDTSpecial Weather StatementTOPAnderson48 min

Nearby

Severe Thunderstorm Warnings in Kansas, 2021Every severe thunderstorm 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.