Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 375, NWS Twin Cities, MN

September 20, 2007Pierce County, Saint Croix County, Wisconsin; Washington County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Sep 20, 2007, 6:07 PM CDT for Pierce County, Saint Croix County, Wisconsin; Washington County, Minnesota. It was in force for 53 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: Sep 20, 2007, 6:07 PM CDT (23:07 UTC)
Expired: Sep 20, 2007, 7:00 PM CDT
In force: 53 min
Issued by: NWS Twin Cities, MN
Area: Counties, with a storm outline in the text

Counties Washington County, MN, Pierce County, WI, Saint Croix County, WI

The radar

The Minneapolis radar (KMPX), 71 km from the middle of the area, began a volume at 23:06 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
Sep 20, 6:30 PM CDT	TORNADO	Woodbury, MN	IT HAS BEEN DETERMINED BY THE NWS STORM SURVEY...THAT AN EF ZERO TORNADO OCCURRED AT APPROXIMATELY 630 PM...IN THE SOUTHWEST CORNER OF THE CITY OF WOODBURY MINNESOTA ALONG BAILEY ROAD...THURSDAY EVENING.
Sep 20, 6:35 PM CDT	TSTM WND DMG	Woodbury, MN	LATE REPORT RECEIVED AT 715 PM. 25 FOOT SPRUCE TREE DOWN. 10 INCH LIMBS DOWN. STREET SIGNS DOWN.
Sep 20, 6:48 PM CDT	FUNNEL CLOUD	River Falls, WI

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
Sep 20, 5:37 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Sep 20, 3:45 PM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 11.1 hours before the alert went out and 73 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1024 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 215 m²/s²
0-3 km storm-relative helicity: 291 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

000 
WUUS53 KMPX 202308
SVRMPX
MNC163-WIC093-109-210000-
/O.NEW.KMPX.SV.W.0375.070920T2307Z-070921T0000Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
607 PM CDT THU SEP 20 2007

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  WASHINGTON COUNTY IN EAST CENTRAL MINNESOTA...
  ST. CROIX COUNTY IN WEST CENTRAL WISCONSIN...
  PIERCE COUNTY IN WEST CENTRAL WISCONSIN...

* UNTIL 700 PM CDT

* AT 602 PM CDT...DOPPLER RADAR INDICATED A LINE OF SEVERE
  THUNDERSTORMS...CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED     
  ALONG A LINE EXTENDING FROM 11 MILES NORTH OF OAKDALE TO 8 MILES   
  SOUTHWEST OF OAKDALE TO 16 MILES WEST OF COTTAGE GROVE...  AND     
  MOVING EAST AT 40 MPH.

* LOCATIONS IMPACTED INCLUDE...
  WOODBURY...
  STILLWATER...
  COTTAGE GROVE...
  HUDSON...
  SOMERSET...
  NEW RICHMOND...
  RIVER FALLS...
  BALDWIN...
  ELLSWORTH...

SEVERE THUNDERSTORMS CAN PRODUCE TORNADOES WITH LITTLE OR NO ADVANCE
WARNING. PREPARE TO MOVE TO A PLACE OF SAFETY IN A STURDY STRUCTURE
SUCH AS A BASEMENT OR SMALL INTERIOR ROOM IF A TORNADO IS SPOTTED.

LAT...LON 4522 9276 4518 9231 4495 9223 4471 9235
      4479 9299 4491 9298 4503 9297 4527 9301
TIME...MOT...LOC 2307Z 268DEG 38KT 4515 9294 4501 9294
          4492 9301 4479 9317

$$

DWE

The office that day

Everything else NWS Twin Cities, MN issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 20, 1:04 PM CDT	Flash Flood Watch	MPX	Pierce, Polk, Saint Croix	18 hr
Sep 20, 6:56 PM CDT	Tornado Warning	MPX	Pierce, Saint Croix	34 min
Sep 20, 7:33 AM CDT	Severe Thunderstorm Warning	MPX	Lac qui Parle, Yellow Medicine	42 min
Sep 20, 8:11 AM CDT	Tornado Warning	MPX	Lac qui Parle, Yellow Medicine	34 min
Sep 20, 8:36 AM CDT	Severe Thunderstorm Warning	MPX	Lac qui Parle	39 min
Sep 20, 8:43 AM CDT	Tornado Warning	MPX	Lac qui Parle, Yellow Medicine	47 min
Sep 20, 9:14 AM CDT	Severe Thunderstorm Warning	MPX	Chippewa, Lac qui Parle, Swift	61 min
Sep 20, 10:14 AM CDT	Severe Thunderstorm Warning	MPX	Swift	31 min
Sep 20, 10:28 AM CDT	Severe Thunderstorm Warning	MPX	Chippewa, Swift	47 min
Sep 20, 10:44 AM CDT	Severe Thunderstorm Warning	MPX	Swift	46 min
Sep 20, 10:58 AM CDT	Severe Thunderstorm Warning	MPX	Chippewa, Lac qui Parle, Swift	44 min
Sep 20, 11:31 AM CDT	Severe Thunderstorm Warning	MPX	Kandiyohi, Pope, Stearns, Swift	59 min
Sep 20, 12:16 PM CDT	Severe Thunderstorm Warning	MPX	Chippewa, Kandiyohi	38 min
Sep 20, 12:26 PM CDT	Severe Thunderstorm Warning	MPX	Douglas, Pope	64 min
Sep 20, 1:05 PM CDT	Severe Thunderstorm Warning	MPX	Meeker, Stearns, Wright	27 min
Sep 20, 1:14 PM CDT	Severe Thunderstorm Warning	MPX	Morrison, Stearns, Todd	61 min
Sep 20, 1:51 PM CDT	Severe Thunderstorm Warning	MPX	Benton, Mille Lacs, Morrison	54 min
Sep 20, 2:01 PM CDT	Flash Flood Warning	MPX	Benton, Mille Lacs, Morrison, Pope, Stearns, Todd	6 hr
Sep 20, 2:20 PM CDT	Tornado Warning	MPX	Benton, Sherburne, Stearns	25 min
Sep 20, 2:42 PM CDT	Tornado Warning	MPX	Benton, Sherburne	33 min
Sep 20, 2:44 PM CDT	Tornado Warning	MPX	Chippewa, Kandiyohi, Renville	46 min
Sep 20, 2:47 PM CDT	Severe Thunderstorm Warning	MPX	Benton, Morrison	58 min
Sep 20, 2:57 PM CDT	Tornado Warning	MPX	Benton, Mille Lacs, Sherburne	33 min
Sep 20, 3:13 PM CDT	Severe Thunderstorm Warning	MPX	Isanti	16 min
Sep 20, 3:27 PM CDT	Severe Thunderstorm Warning	MPX	Kanabec, Mille Lacs, Morrison	63 min
Sep 20, 3:28 PM CDT	Tornado Warning	MPX	Kandiyohi, Meeker	47 min
Sep 20, 3:54 PM CDT	Tornado Warning	MPX	Kanabec, Mille Lacs	35 min
Sep 20, 4:11 PM CDT	Tornado Warning	MPX	Kanabec, Mille Lacs	25 min
Sep 20, 4:13 PM CDT	Tornado Warning	MPX	Kandiyohi, Meeker	47 min
Sep 20, 4:42 PM CDT	Severe Thunderstorm Warning	MPX	Wright	63 min
Sep 20, 5:07 PM CDT	Severe Thunderstorm Warning	MPX	Carver, Hennepin	53 min
Sep 20, 5:30 PM CDT	Severe Thunderstorm Warning	MPX	Anoka, Dakota, Ramsey, Scott	60 min
Sep 20, 5:47 PM CDT	Tornado Warning	MPX	Hennepin, Scott	31 min
Sep 20, 6:01 PM CDT	Severe Thunderstorm Warning	MPX	Hennepin	29 min
Sep 20, 6:11 PM CDT	Severe Thunderstorm Warning	MPX	Sherburne, Wright	34 min
Sep 20, 6:14 PM CDT	Tornado Warning	MPX	Dakota, Washington	31 min
Sep 20, 6:30 PM CDT	Severe Thunderstorm Warning	MPX	Anoka, Hennepin	60 min
Sep 20, 6:51 PM CDT	Severe Thunderstorm Warning	MPX	Wright	39 min

Nearby

Severe Thunderstorm Warnings in Wisconsin, 2007 Severe Thunderstorm Warnings in Minnesota, 2007 Every severe thunderstorm warning in 2007

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.