Alert archive / South Dakota / Tornado Warnings in 2017

Tornado Warning 21, NWS Aberdeen, SD

September 19, 2017Clark County, Codington County, Day County, South Dakota

NWS Aberdeen, SD issued this tornado warning at Sep 19, 2017, 9:24 PM CDT for Clark County, Codington County, Day County, South Dakota. It was in force for 36 min. 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
Sep 19, 2017, 9:24 PM CDT (02:24 UTC)
Expired
Sep 19, 2017, 10:00 PM CDT
In force
36 min
Issued by
NWS Aberdeen, SD
Area
Storm-based polygon
Tornado
Radar indicated
Hail
1.0 in

Counties Clark County, SD, Codington County, SD, Day County, SD

The radar

The Aberdeen radar (KABR), 85 km from the middle of the area, began a volume at 02:22 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
Sep 19, 9:26 PM CDTTORNADOBradley, SDBRIEF TOUCHDOWN REPORTED BY WXNATION TV METEOROLOGIST.

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.

IssuedProductOfficeLasted
Sep 19, 3:37 PM CDTTornado WatchSPC8 hr

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 2.4 hours before the alert went out and 70 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, Aberdeen, SD at 00:00Z on 2017-09-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2563 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, Aberdeen, SD at 00:00Z on 2017-09-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 229 square meters per square second.1939587897Sfc1 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
2563 J/kg
Mixed-layer CIN
-16 J/kg
Mixed-layer LCL
1127 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
229 m²/s²
0-3 km storm-relative helicity
239 m²/s²
Significant tornado parameter
2.6
Supercell composite
16.8

Open this sounding in Storm Lab

The text

As transmitted.

521 
WFUS53 KABR 200224
TORABR
SDC025-029-037-200300-
/O.NEW.KABR.TO.W.0021.170920T0224Z-170920T0300Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Aberdeen SD
924 PM CDT TUE SEP 19 2017

The National Weather Service in Aberdeen has issued a

* Tornado Warning for...
  Southeastern Day County in northeastern South Dakota...
  Northeastern Clark County in northeastern South Dakota...
  Northwestern Codington County in northeastern South Dakota...

* Until 1000 PM CDT

* At 923 PM CDT, a severe thunderstorm capable of producing a tornado
  was located near Bradley, or 12 miles northeast of Clark, moving
  northeast at 30 mph.

  HAZARD...Tornado and quarter size hail. 

  SOURCE...Weather spotters reported funnel cloud. 

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely. 

* This dangerous storm will be near...
  Swan Lake around 930 PM CDT. 
  Wallace around 935 PM CDT. 
  Florence and Grass Lake around 945 PM CDT. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

Tornadoes are extremely difficult to see and confirm at night. Do not
wait to see or hear the tornado. TAKE COVER NOW!

&&

LAT...LON 4482 9764 4507 9783 4529 9744 4506 9710
TIME...MOT...LOC 0223Z 237DEG 27KT 4504 9758 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

Connelly
2 follow-up statements
953 
WWUS53 KABR 200248
SVSABR

Severe Weather Statement
National Weather Service Aberdeen SD
948 PM CDT TUE SEP 19 2017

SDC025-200257-
/O.CAN.KABR.TO.W.0021.000000T0000Z-170920T0300Z/
Clark SD-
948 PM CDT TUE SEP 19 2017

...THE TORNADO WARNING FOR NORTHEASTERN CLARK COUNTY IS CANCELLED...
    
The tornadic thunderstorm which prompted the warning has weakened. 
Therefore, the warning has been cancelled.

A tornado watch remains in effect until midnight CDT for northeastern
South Dakota.

LAT...LON 4507 9712 4496 9732 4512 9750 4515 9749
      4515 9750 4525 9738
TIME...MOT...LOC 0247Z 237DEG 27KT 4514 9736 

$$

SDC029-037-200300-
/O.CON.KABR.TO.W.0021.000000T0000Z-170920T0300Z/
Day SD-Codington SD-
948 PM CDT TUE SEP 19 2017

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1000 PM CDT FOR
SOUTHEASTERN DAY AND NORTHWESTERN CODINGTON COUNTIES...
    
At 947 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Grass Lake, or 15 miles southeast of Webster, moving
northeast at 30 mph.

HAZARD...Tornado. 

SOURCE...Radar indicated rotation. 

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely. 

This tornadic thunderstorm will remain over mainly rural areas of
southeastern Day and northwestern Codington Counties.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. TAKE COVER NOW!

Tornadoes are extremely difficult to see and confirm at night. Do not
wait to see or hear the tornado. TAKE COVER NOW!

&&

LAT...LON 4507 9712 4496 9732 4512 9750 4515 9749
      4515 9750 4525 9738
TIME...MOT...LOC 0247Z 237DEG 27KT 4514 9736 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

Connelly
942 
WWUS53 KABR 200258
SVSABR

Severe Weather Statement
National Weather Service Aberdeen SD
958 PM CDT TUE SEP 19 2017

SDC029-037-200306-
/O.EXP.KABR.TO.W.0021.000000T0000Z-170920T0300Z/
Day SD-Codington SD-
958 PM CDT TUE SEP 19 2017

...THE TORNADO WARNING FOR SOUTHEASTERN DAY AND NORTHWESTERN
CODINGTON COUNTIES WILL EXPIRE AT 1000 PM CDT...
        
The storm which prompted the warning has moved out of the area.
Therefore the warning will be allowed to expire.

A tornado watch remains in effect until midnight CDT for northeastern
South Dakota.

Remember, a Tornado Warning still remains in effect for parts of 
southeast Day and north central Codington counties until 1030 PM CDT.

LAT...LON 4507 9712 4496 9732 4512 9750 4515 9749
      4515 9750 4525 9738
TIME...MOT...LOC 0256Z 237DEG 27KT 4517 9729 

$$

Connelly

The office that day

Everything else NWS Aberdeen, SD issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 19, 7:01 PM CDTTornado WarningABRCampbell, Edmunds, McPherson, Walworth29 min
Sep 19, 7:23 PM CDTTornado WarningABRMcPherson20 min
Sep 19, 7:29 PM CDTSevere Thunderstorm WarningABRBrown, Marshall46 min
Sep 19, 7:40 PM CDTTornado Warning Tornado observedABRSpink35 min
Sep 19, 7:46 PM CDTSevere Thunderstorm WarningABRBrown, Spink44 min
Sep 19, 7:52 PM CDTTornado WarningABRMcPherson24 min
Sep 19, 8:12 PM CDTSevere Thunderstorm WarningABRBrown, Marshall33 min
Sep 19, 8:13 PM CDTTornado WarningABRClark, Spink32 min
Sep 19, 8:23 PM CDTSevere Thunderstorm WarningABRBrown, Day, Marshall, Spink37 min
Sep 19, 8:28 PM CDTTornado WarningABRClark, Spink32 min
Sep 19, 8:41 PM CDTSevere Thunderstorm WarningABRBrown, Marshall34 min
Sep 19, 8:53 PM CDTTornado WarningABRClark, Codington, Day, Spink37 min
Sep 19, 9:54 PM CDTTornado WarningABRCodington, Day, Grant, Roberts15 min
Sep 19, 10:43 PM CDTAreal Flood WarningABRCodington3 hr
Sep 19, 10:49 PM CDTSevere Thunderstorm WarningABRGrant, Roberts41 min
Sep 19, 11:26 PM CDTSevere Thunderstorm WarningABRGrant, Roberts19 min

Nearby

Tornado Warnings in South Dakota, 2017Every tornado warning in 2017Tornadoes in 2017

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.