Alert archive / South Dakota / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 12, NWS Sioux Falls, SD

May 1, 2012Lake County, McCook County, South Dakota

NWS Sioux Falls, SD issued this severe thunderstorm warning at May 1, 2012, 4:03 PM CDT for Lake County, McCook County, South Dakota. It was in force for 27 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 1, 2012, 4:03 PM CDT (21:03 UTC)
Expired: May 1, 2012, 4:30 PM CDT
In force: 27 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Hail: 1.0 in
Wind: 58.0 mph

Counties Lake County, SD, McCook County, SD

The radar

The Sioux Falls radar (KFSD), 54 km from the middle of the area, began a volume at 21:03 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
May 1, 4:05 PM CDT	HAIL 1	2 W Salem, SD
May 1, 4:15 PM CDT	HAIL 1.75	1 Nw Salem, SD	HAIL COVERED GROUND AND DRIFTED. STILL PILES LEFT THE NEXT MORNING. ALSO HEAVY RAIN WHICH MEASURED 2.04 INCHES. NO HAIL 1 MILE NORTH OF THIS LOCATION.
May 1, 4:20 PM CDT	HAIL 1.25	1 Nw Salem, SD	GROUND IS COVERED IN HAIL DRIFTS

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 1, 2:59 PM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Aberdeen, SD (KABR), launched 12:00Z, 9.1 hours before the alert went out and 147 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: 364 J/kg
Mixed-layer CIN: -252 J/kg
Mixed-layer LCL: 607 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 217 m²/s²
0-3 km storm-relative helicity: 233 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

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

426 
WUUS53 KFSD 012103
SVRFSD
SDC079-087-012130-
/O.NEW.KFSD.SV.W.0012.120501T2103Z-120501T2130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
403 PM CDT TUE MAY 1 2012

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHWESTERN LAKE COUNTY IN EAST CENTRAL SOUTH DAKOTA...
  NORTHERN MCCOOK COUNTY IN SOUTHEAST SOUTH DAKOTA...

* UNTIL 430 PM CDT

* AT 403 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE
  TRACKING A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE
  HAIL.  THIS STORM WAS LOCATED NEAR SALEM...OR 27 MILES SOUTHWEST OF
  MADISON...AND MOVING NORTHEAST AT 30 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  ORLAND AROUND 430 PM CDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MILES PER
HOUR...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. FOR
YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR
HOME OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE
INTO AREAS WHERE WATER COVERS THE ROAD.

&&

A TORNADO WATCH REMAINS IN EFFECT UNTIL 1000 PM CDT TUESDAY EVENING
FOR NORTHWEST IOWA AND SOUTHWEST MINNESOTA AND SOUTHEASTERN SOUTH
DAKOTA.

LAT...LON 4394 9724 4386 9713 4374 9713 4366 9744
      4376 9754 4385 9739 4385 9737 4386 9737
TIME...MOT...LOC 2103Z 235DEG 26KT 4373 9741
WIND...HAIL <58MPH 1.00IN

$$

CJ

2 follow-up statements

491 
WWUS53 KFSD 012109
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
409 PM CDT TUE MAY 1 2012

SDC079-087-012130-
/O.CON.KFSD.SV.W.0012.000000T0000Z-120501T2130Z/
MCCOOK SD-LAKE SD-
409 PM CDT TUE MAY 1 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR SOUTHWESTERN
LAKE AND NORTHERN MCCOOK COUNTIES UNTIL 430 PM CDT...

AT 409 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE TRACKING
A SEVERE THUNDERSTORM CAPABLE OF PRODUCING HALF DOLLAR SIZE HAIL. 
THIS STORM WAS LOCATED NEAR SALEM...OR 26 MILES NORTHWEST OF
PARKER...MOVING NORTHEAST AT 30 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  SALEM AROUND 415 PM CDT...
  ORLAND AROUND 430 PM CDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. TORNADOES CAN
DEVELOP QUICKLY FROM SEVERE THUNDERSTORMS. ALTHOUGH NOT IMMEDIATELY
LIKELY...IF A TORNADO IS SPOTTED ACT QUICKLY AND MOVE TO A PLACE OF
SAFETY INSIDE A STURDY STRUCTURE...SUCH AS A BASEMENT OR SMALL
INTERIOR ROOM.

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MILES PER
HOUR...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. FOR
YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR
HOME OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE
INTO AREAS WHERE WATER COVERS THE ROAD.

&&

LAT...LON 4394 9724 4386 9713 4374 9713 4366 9744
      4376 9754 4385 9739 4385 9737 4386 9737
TIME...MOT...LOC 2109Z 235DEG 26KT 4370 9745
WIND...HAIL <58MPH 1.25IN

$$

CJ

816 
WWUS53 KFSD 012129
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
429 PM CDT TUE MAY 1 2012

SDC079-087-012139-
/O.EXP.KFSD.SV.W.0012.000000T0000Z-120501T2130Z/
MCCOOK SD-LAKE SD-
429 PM CDT TUE MAY 1 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN LAKE AND NORTHERN
MCCOOK COUNTIES WILL EXPIRE AT 430 PM CDT...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR
PROPERTY...HOWEVER SMALL HAIL AND GUSTY WINDS ARE STILL POSSIBLE WITH
THIS THUNDERSTORM.

LAT...LON 4394 9724 4386 9713 4374 9713 4366 9744
      4376 9754 4385 9739 4385 9737 4386 9737
TIME...MOT...LOC 2129Z 235DEG 26KT 4378 9729

$$

CJ

The office that day

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

Issued	Product	Office	Counties	Lasted
May 1, 3:35 PM CDT	Severe Thunderstorm Warning	FSD	Gregory	40 min
May 1, 4:02 PM CDT	Severe Thunderstorm Warning	FSD	Charles Mix, Douglas	28 min
May 1, 5:16 PM CDT	Severe Thunderstorm Warning	FSD	Moody	29 min
May 1, 6:18 PM CDT	Severe Thunderstorm Warning	FSD	Lake, Minnehaha	27 min
May 1, 6:29 PM CDT	Severe Thunderstorm Warning	FSD	Hutchinson, Lincoln, McCook, Minnehaha, Turner	46 min

Nearby

Severe Thunderstorm Warnings in South Dakota, 2012 Every severe thunderstorm warning in 2012

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.