Dunkerton Tornado of 2000

In Historical by Jeff Wilcox

This tornado would be remembered more for being similar to the Parkersburg-New Hartford Tornado 8 years later. Some of the same areas were hit by this tornado and again in 2008. Here is the watch that was issued just after 6pm that Thursday Evening.

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URGENT – IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 264
STORM PREDICTION CENTER NORMAN OK
606 PM CDT THU MAY 11 2000

THE STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF

EASTERN IOWA
NORTHWEST ILLINOIS
SOUTHWEST WISCONSIN

EFFECTIVE THIS THURSDAY NIGHT AND FRIDAY MORNING FROM 645 PM UNTIL
MIDNIGHT CDT.

TORNADOES…HAIL TO 3 INCHES IN DIAMETER…THUNDERSTORM WIND GUSTS
TO 80 MPH…AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 90 STATUTE MILES EAST AND WEST
OF A LINE FROM 75 MILES NORTH NORTHEAST OF WATERLOO IOWA TO 20
MILES SOUTHWEST OF MOLINE ILLINOIS.

REMEMBER…A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA.
PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE
WARNINGS.

DISCUSSION…VERY UNSTABLE AIRMASS WITH CAPES TO 5000 J/KG JUST
AHEAD OF SFC LOW CENTRAL IA. STORMS RAPIDLY DEVELOPING N AND E OF
LOW IN AREA OF BEST LOW LEVEL CONVERGENCE. WITH FAVORABLE VEERING
SHEAR PROFILES…TORNADIC SUPERCELLS LIKELY ALONG WITH VERY LARGE
HAIL.

AVIATION…TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 600.
MEAN STORM MOTION VECTOR 24035.

…HALES

Storms began to fire west of Waterloo shortly thereafter similarly to how the storm that went on the produce the Parkersburg Tornado did as well. A few minutes after the watch was issued, a Severe Thunderstorm warning was issued.

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BULLETIN – IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
625 PM CDT THU MAY 11 2000

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR…
SOUTHEASTERN BUTLER COUNTY IN NORTH CENTRAL IOWA

* UNTIL 655 PM CDT

* AT 625 PM CDT DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 3 MILES
EAST OF PARKERSBURG…OR ABOUT 19 MILES WEST OF WATERLOO…MOVING
NORTHEAST AT 20 MPH.

* THE SEVERE THUNDERSTORM WILL BE…
NEAR SHELL ROCK AROUND 650 PM CDT

SEEK A STURDY SHELTER SUCH AS A BASEMENT OR INTERIOR ROOM.
LAT…LON 4257 9286 4255 9268 4259 9256 4287 9256
JOHNSON

It didn’t take long for a tornado to drop out of the storm however,

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BULLETIN – EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
648 PM CDT THU MAY 11 2000

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* TORNADO WARNING FOR…
SOUTHEASTERN BUTLER COUNTY IN NORTH CENTRAL IOWA

* UNTIL 705 PM CDT

* AT 648 PM CDT WEATHER SPOTTERS REPORTED A TORNADO 2 MILES NORTHWEST
OF NEW HARTFORD…OR ABOUT 16 MILES NORTHWEST OF WATERLOO…MOVING
NORTHEAST AT 20 MPH.

* SOME LOCATIONS THREATENED THROUGH 705 PM CDT…
SHELL ROCK

THIS TORNADO WARNING REPLACES THE SEVERE THUNDERSTORM WARNING FOR
SOUTHEAST BUTLER COUNTY.

TO PROTECT YOURSELF FROM FLYING DEBRIS…COVER YOURSELF WITH A
MATTRESS…CUSHIONS…BLANKETS OR PILLOWS.

JOHNSON

Note where the tornado was spotted and compare it to the 2008 tornado.

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IAC023-075-252230-
/O.CON.KDMX.TO.W.0013.000000T0000Z-080525T2230Z/
BUTLER IA-GRUNDY IA-
511 PM CDT SUN MAY 25 2008

…A TORNADO WARNING REMAINS IN EFFECT UNTIL 530 PM CDT FOR NORTHERN
GRUNDY AND SOUTHERN BUTLER COUNTIES…

AT 508 PM CDT…TRAINED WEATHER SPOTTERS REPORTED A TORNADO. THIS
TORNADO WAS LOCATED NEAR NEW HARTFORD…OR 17 MILES WEST OF
WATERLOO…MOVING EAST AT 35 MPH.

THE TORNADO WILL BE NEAR…
7 MILES SOUTH OF SHELL ROCK BY 520 PM CDT…

THIS IS AN EXTREMELY DANGEROUS AND LIFE THREATENING SITUATION. THIS
STORM IS CAPABLE OF PRODUCING STRONG TO VIOLENT TORNADOES. IF YOU ARE IN THE PATH OF THIS TORNADO…TAKE COVER IMMEDIATELY!

A TORNADO WATCH REMAINS IN EFFECT UNTIL 1000 PM CDT SUNDAY EVENING
FOR IOWA.

The storm continued into Black Hawk County skirting the far north side of Cedar Falls (the 2008 tornado was a little further north)

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BULLETIN – EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
656 PM CDT THU MAY 11 2000

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* TORNADO WARNING FOR…
BLACK HAWK COUNTY IN NORTHEAST IOWA

* UNTIL 725 PM CDT

* AT 656 PM CDT DOPPLER RADAR INDICATED A TORNADO 5 MILES NORTH OF
CEDAR FALLS…OR ABOUT 9 MILES NORTHWEST OF WATERLOO…MOVING EAST
AT 35 MPH.

* SOME LOCATIONS THREATENED THROUGH 725 PM CDT…
WATERLOO
ELK RUN HEIGHTS
DUNKERTON

THIS WARNING REPLACES THE SEVERE THUNDERSTORM WARNING FOR NORTHERN
BLACK HAWK COUNTY.

THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A
WORKBENCH OR OTHER PIECE OF STURDY FURNITURE.

JOHNSON

It was around this time that Roger Hill and the Silver Lining Tours captured the tornado as it moved just north of Cedar Falls, crossed US 63 and continued ENE toward Dunkerton.

As evidenced in the video, strong RFD (Rear Flank Downdraft) winds on the south side of the tornado easily did some damage even away from the actual tornado. This storm went on to produce numerous tornadoes across Black Hawk County, at one point several small tornadoes were on the ground at once. A good write up on this storm from current KIMT Chief Meteorologist Adam Frederick and KCWI’s Jason Parkin is included here with pictures.

Above are two radar images from two different dates, (The date has been blacked out on the images.) One of these is the Parkersburg EF5 Tornadic supercell, the other is the supercell that produced the Dunkerton Tornado and numerous others on May 11th 2000. Can you tell the difference? Which radar image is what? Time for your guesses.