Alert archive / Iowa / Tornado Warnings in 2007

Tornado Warning 40, NWS Sioux Falls, SD

August 4, 2007Buena Vista County, Cherokee County, Iowa

NWS Sioux Falls, SD issued this tornado warning at Aug 4, 2007, 7:14 PM CDT for Buena Vista County, Cherokee County, Iowa. It was in force for 46 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 4, 2007, 7:14 PM CDT (00:14 UTC)
Expired
Aug 4, 2007, 8:00 PM CDT
In force
46 min
Issued by
NWS Sioux Falls, SD
Area
Counties, with a storm outline in the text

Counties Buena Vista County, IA, Cherokee County, IA

The radar

The Sioux Falls radar (KFSD), 130 km from the middle of the area, began a volume at 00:16 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 4, 3:55 PM CDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 0.2 hours before the alert went out and 182 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, Omaha, NE at 00:00Z on 2007-08-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1034 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, Omaha, NE at 00:00Z on 2007-08-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 12 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
1034 J/kg
Mixed-layer CIN
-47 J/kg
Mixed-layer LCL
1889 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
12 m²/s²
0-3 km storm-relative helicity
73 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.8

Open this sounding in Storm Lab

The text

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

000 
WFUS53 KFSD 050015
TORFSD
IAC021-035-050100-
/O.NEW.KFSD.TO.W.0040.070805T0014Z-070805T0100Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
714 PM CDT SAT AUG 4 2007

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHWESTERN BUENA VISTA COUNTY IN NORTHWEST IOWA
  NORTHEASTERN CHEROKEE COUNTY IN NORTHWEST IOWA

* UNTIL 800 PM CDT

* AT 714 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 5 MILES
  SOUTHWEST OF LARRABEE...OR ABOUT 24 MILES NORTHWEST OF STORM
  LAKE...MOVING EAST AT 20 MPH.

* THE TORNADO WILL BE NEAR...
   LARRABEE...CHEROKEE AROUND 720 PM CDT...
   LINN GROVE AROUND 755 PM CDT...

A ROTATING WALL CLOUD HAS BEEN REPORTED BY SPOTTERS WITH THIS STORM.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1100 PM CDT
SATURDAY EVENING FOR NORTHWEST IOWA.

LAT...LON 4290 9572 4275 9571 4269 9521 4291 9520

$$

JM
2 follow-up statements
000 
WWUS53 KFSD 050041
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
739 PM CDT SAT AUG 4 2007

IAC021-035-050100-
/O.CON.KFSD.TO.W.0040.000000T0000Z-070805T0100Z/
CHEROKEE IA-BUENA VISTA IA-
739 PM CDT SAT AUG 4 2007

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 800 PM CDT FOR
NORTHWESTERN BUENA VISTA AND NORTHEASTERN CHEROKEE COUNTIES...

AT 739 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE A STORM CAPABLE OF PRODUCING A TORNADO.  THIS STORM WAS 
LOCATED 4 MILES SOUTHEAST OF LARRABEE...OR ABOUT 19 MILES NORTHWEST 
OF STORM LAKE...MOVING EAST AT 20 MPH.

THE STORM WILL BE NEAR...
  RURAL CHEROKEE COUNTY THROUGH 750 PM CDT
  RURAL BUENA VISTA COUNTY THROUGH 750 PM CDT

A ROATATING WALL CLOUD HAS BEEN REPORTED BY TRAINED SPOTTERS WITH 
THIS STORM.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 1100 PM CDT SATURDAY EVENING
FOR NORTHWEST IOWA.

A SEVERE THUNDERSTORM WATCH ALSO REMAINS IN EFFECT UNTIL 1100 PM CDT
SATURDAY EVENING FOR NORTHWEST IOWA.

LAT...LON 4289 9567 4275 9567 4268 9522 4289 9520

$$

JM
000 
WWUS53 KFSD 050059
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
759 PM CDT SAT AUG 4 2007

IAC021-035-050109-
/O.EXP.KFSD.TO.W.0040.000000T0000Z-070805T0100Z/
CHEROKEE IA-BUENA VISTA IA-
759 PM CDT SAT AUG 4 2007

...THE TORNADO WARNING FOR NORTHWESTERN BUENA VISTA AND NORTHEASTERN
CHEROKEE COUNTIES EXPIRES AT 800 PM CDT...

THE STORM IS NO LONGER SEVERE.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 1100 PM CDT SATURDAY EVENING
FOR NORTHWEST IOWA.

A SEVERE THUNDERSTORM WATCH ALSO REMAINS IN EFFECT UNTIL 1100 PM CDT
SATURDAY EVENING FOR NORTHWEST IOWA.

LAT...LON 4289 9567 4275 9567 4268 9522 4289 9520

$$

JM

Nearby

Tornado Warnings in Iowa, 2007Every tornado warning in 2007Tornadoes 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.