Tornadoes · United States · Iowa · 2006

F1 tornado, Pittsburg to Stockport, Iowa, April 2, 2006

Name: F1 tornado, Pittsburg to Stockport, Iowa, April 2, 2006
Start: 2006-04-02T21:19:00.000Z
Location: Pittsburg to Stockport, Iowa

From Pittsburg to Stockport, this F1 tornado ran 3.0 miles across Van Buren County on April 2, 2006, touching down at 4:19 PM CDT and reaching 50 yards wide. It killed nobody, and did $10,000 of property damage.

The rating scale

Tracks are drawn in the color of the rating. The Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

F040 to 72 mph
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
F173 to 112 mphthis tornado
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
F2113 to 157 mph
Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.
F3158 to 206 mph
Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.
F4207 to 260 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
F5261 to 318 mph
Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.
Unrated
The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.

The record

Rating: F1
Date: April 2, 2006
Touchdown: 4:19 PM CDT (21:19 UTC)
Path length: 3.0 miles (4.8 km)
Path width: 50 yards (46 m)
Deaths: 0
Injuries: 0
Property damage: $10,000
County: Van Buren County
Touchdown point: 40.870, -91.820
Lift-off point: 40.900, -91.780
Record number: 216

What the Weather Service recorded

Tornado touched down about 0.5 miles west of Pittsburg near a cemetery and continued northeast for 3 miles just along the west edge of the Des Moines River. Along this path, 2 homes were unroofed and 4 outbuildings were destroyed. Many trees were snapped or uprooted and power poles were blown down.

The second tornado of a cyclic supercell developed 0.7 miles north of Mt Zion and moved northeast for 2 miles and dissipated shortly after crossing highway 16 2.2 miles south of Winchester or 2.6 miles northeast of Mt Zion. A roof was blown off a barn with minor roof damage to a house. Several outbuildings were destroyed with tree damage noted.

The third tornado of a cyclic supercell produced an F1 tornado in Stockport and moved northeast for 3 miles before dissipating. Several outbuildings and trees were either destroyed or damaged.

Rated F2.

Rated F1

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

The forecast that day

The Storm Prediction Center had this point in a Moderate Risk, with a 0.10 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 19:55 UTC.

SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.

What forecasters said that day

The local office's own words before the tornado touched down, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Quad Cities, IA wrote its last area forecast discussion before the tornado touched down at Apr 2, 2:54 PM CDT, 1 hour 25 minutes earlier.

Area forecast discussion, Apr 2, 2:54 PM CDT, 1 hour 25 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
254 PM CDT SUN APR 2 2006

.SYNOPSIS...
ALL EYES ON SEVERE POTENTIAL LATE THIS AFTERNOON AND EVENING WITH
TORNADO WATCH ALREADY IN PLACE FOR AREA OF IMMEDIATE CONCERN OVER
SOUTHERN 2-3 COUNTIES TIL 01Z. SURFACE LOW WAS OVER FAR SW IA AT 19Z
WITH OCCLUDING FRONT EXTENDING SE INTO N CENTRAL MO WITH DRYLINE
SOUTH INTO EASTERN OK. MAIN WARM FRONT WAS E-SE JUST NORTH OF IRK TO
NEAR UIN. EXTENSIVE CLOUD COVER NORTH OF THE WARM FRONT IS HOLDING
TEMPS IN 40S WITH BRISK SE WINDS OVER MUCH OF CWFA. CLOUD COVER HAS
BEEN THINNING OVER W CENTRAL IL...NE MO AND SE IA OVER PAST SEVERAL
HOURS AND CONTINUES TO DESTABILIZE. ALOFT...STRONG SHORTWAVE
ANALYZED OVER S CENTRAL NE WAS CHURNING EAST OVER FAR SE NEB. WATER
VAPOR INDICATED SIGNIFICANT DRY SLOT AHEAD OF THIS VORT MAX FROM
WESTERN MO INTO SW IA. SITUATION BECOMING MORE FAVORABLE FOR SEVERE
TORMS AND A FEW SUPERCELLS AS DEVELOPING SEVERE LINEAR CONVECTION IN
N CENTRAL MO EVOLVES NE INTO SE IA AND NE MO OVER NEXT FEW HOURS.

&&

.SHORT TERM...TONIGHT THROUGH MONDAY
STRONG LOW TO TRACK E-NE ACROSS CENTRAL PORTION OF FORECAST AREA
THIS EVENING WITH POTENTIAL SEVERE OUTBREAK FOLLOWED BY STRONG
GRADIENT WINDS OVERNIGHT INTO MONDAY. SECONDARY UPPER LEVEL
SHORTWAVE MOVING OUT OF EASTERN WY PROGGED TO GET ABSORBED INTO
CURRENT TROUGH OVER NEB AND SWEEP ACROSS AREA STRENGTHEN AS
DEEPENING UPPER LOW TONIGHT INTO EARLY MON. THIS WILL STRENGTHEN THE
SURFACE LOW AS IT SWEEPS E-NE ACROSS THE CWFA THIS EVENING. CURRENT
PRESSURE FALLS AXIS SUGGESTS THIS PATH WILL BE FROM ABOUT
WILLIAMSBURG TO FREEPORT FROM LATE AFTERNOON THROUGH MIDNIGHT. WILL
KEEP CATEGORICAL THUNDERSTORMS GOING THROUGH THIS PERIOD WITH SEVERE
MENTION OVER ENTIRE AREA...ALTHOUGH GREATEST CONCERN WILL BE SOUTH
OF I-80.

THE DEEPENING SURFACE LOW...AND ASSOCIATED STRONG PRESSURE GRADIENT
WILL RESULT IN WINDY CONDITIONS. CURRENT TIMING SUGGESTS GRADIENT
WINDS WILL NOT CRANK UP TO ADVISORY CRITERIA UNTIL MIDNIGHT. AXIS OF
STRONGEST 850 MB WINDS AND PRESSURE RISES POINT TOWARD STRONGEST
WINDS FROM JUST BEFORE SUNRISE TO MID MORNING MONDAY. ISSUED WIND
ADVISORY FOR ENTIRE AREA FOR MIDNIGHT TONIGHT THROUGH MIDDAY
MONDAY...WHEN WINDS SHOULD DROP BELOW ADVISORY CRITERIA. WIND GUSTS
COULD POTENTIALLY PUSH INTO WARNING CRITERIA...WHICH WILL HAVE TO BE
WATCHED.

.LONG TERM...TUESDAY THROUGH SUNDAY
ACTIVE PATTERN CONTINUES WITH ANOTHER VIGOROUS UPPER LEVEL LOW
APPROACHING LATE IN THE WEEK. ELEVATED CONVECTION TO DEVELOP WITH
NOCTURNAL RETURN FLOW WED NIGHT. WITH ANOTHER STRONG LOW MOVING
THROUGH REGION...SHOWERS AND THUNDERSTORMS LIKELY THU WITH RAIN
CHANCES LINGERING AS NEARLY STACKED SYSTEM SLOWLY DEPARTS TO EAST
FRI. WEEKEND LOOKS DRY WITH TEMPERATURES NEAR EARLY APRIL NORMS.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WIND ADVISORY MIDNIGHT TONIGHT UNTIL NOON MONDAY.
IL...WIND ADVISORY MIDNIGHT TONIGHT UNTIL NOON MONDAY.
MO...WIND ADVISORY MIDNIGHT TONIGHT UNTIL NOON MONDAY.

&&

SHEETS

Hazardous weather outlook, Apr 2, 4:42 AM CDT, 11 hours 37 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
442 AM CDT SUN APR 2 2006

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-030945-
BUCHANAN-DELAWARE-DUBUQUE-BENTON-LINN-JONES-JACKSON-IOWA-JOHNSON-
CEDAR-CLINTON-MUSCATINE-SCOTT-KEOKUK-WASHINGTON-LOUISA-JEFFERSON-
HENRY IA-DES MOINES-VAN BUREN-LEE-JO DAVIESS-STEPHENSON-CARROLL-
WHITESIDE-ROCK ISLAND-HENRY IL-BUREAU-PUTNAM-MERCER-HENDERSON-
WARREN-HANCOCK-MCDONOUGH-SCOTLAND-CLARK-
442 AM CDT SUN APR 2 2006

...POTENTIALLY SIGNIFICANT SEVERE WEATHER TODAY FOLLOWED BY STRONG
WINDS TONIGHT...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL
ILLINOIS...NORTHWEST ILLINOIS...WEST CENTRAL ILLINOIS...EAST
CENTRAL IOWA...NORTHEAST IOWA...SOUTHEAST IOWA AND NORTHEAST
MISSOURI.

.DAY ONE...TODAY AND TONIGHT
A POTENT LOW PRESSURE SYSTEM WILL MOVE THROUGH THE MIDWEST TODAY
BRINGING TWO ROUNDS OF THUNDERSTORMS DURING THE DAY FOLLOWED BY VERY
STRONG WINDS LATER IN THE EVENING.

THE FIRST ROUND OF THUNDERSTORMS WILL MOVE THROUGH THE AREA THIS
MORNING. OTHER THAN ISOLATED HAIL...SEVERE WEATHER IS NOT EXPECTED
WITH THESE STORMS.

A SECOND AND MORE SIGNIFICANT ROUND OF THUNDERSTORMS WILL DEVELOP
THIS AFTERNOON IN SOUTHERN IOWA AND MISSOURI AND MOVE EAST INTO
ILLINOIS...BRINGING A THREAT OF SEVERE WEATHER TO THE ENTIRE AREA.
A FACTOR LIMITING THE SEVERE THREAT TODAY WILL BE THE AMOUNT OF
LINGERING CLOUDS FROM THIS MORNINGS STORMS. IF WE GET SUNSHINE
AND RESULTANT INSTABILITY...SHEAR WILL BE SUFFICIENT FOR SUPERCELL
THUNDERSTORMS AND TORNADOES...ESPECIALLY AT LOCATIONS ROUGHLY
ALONG AND SOUTH OF HIGHWAY 34 LATER THIS AFTERNOON AND EARLY
EVENING.

ONCE THE SEVERE THREAT DIMINISHES EARLY THIS EVENING...STRONG
WINDS WILL DEVELOP AS THE INTENSIFYING SURFACE LOW MOVES EAST.
WIND GUSTS IN EXCESS OF 50 MPH ARE POSSIBLE LATE TONIGHT INTO
EARLY MONDAY MORNING.

STAY TUNED FOR LATER INFORMATION.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY
HIGH WINDS WILL CONTINUE INTO MONDAY. ANOTHER ROUND OF THUNDERSTORMS
IS FORECAST FOR THURSDAY...BUT IT IS TOO EARLY TO SPECIFY A SEVERE
OR HEAVY RAIN THREAT AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION SHOULD BE ANTICIPATED LATER TODAY.

In the hours before

Local storm report, Apr 2, 3:44 PM CDT, 35 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
344 PM CDT SUN APR 02 2006

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0340 PM     HAIL             1 W MEMPHIS             40.46N 92.19W
04/02/2006  E1.00 INCH       SCOTLAND           MO   TRAINED SPOTTER

            NICKLE TO QUARTER SIZE HAIL

&&

TS

Local storm report, Apr 2, 3:55 PM CDT, 24 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
355 PM CDT SUN APR 02 2006

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0354 PM     HAIL             MEMPHIS                 40.46N 92.17W
04/02/2006  E0.25 INCH       SCOTLAND           MO   TRAINED SPOTTER

&&

TS

Local storm report, Apr 2, 4:03 PM CDT, 16 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
403 PM CDT SUN APR 02 2006

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0358 PM     HAIL             7 NE MEMPHIS            40.53N 92.08W
04/02/2006  E1.00 INCH       SCOTLAND           MO   TRAINED SPOTTER

            AND WIND GUSTS TO 40 MPH

&&

TS

Local storm report, Apr 2, 4:05 PM CDT, 14 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
405 PM CDT SUN APR 02 2006

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0403 PM     TSTM WND GST     5 E MOUNT STERLING      40.62N 91.84W
04/02/2006  E50 MPH          VAN BUREN          IA   TRAINED SPOTTER

            ALSO PEA SIZED HAIL

&&

DD

Local storm report, Apr 2, 4:10 PM CDT, 9 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
410 PM CDT SUN APR 02 2006

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0410 PM     HAIL             LURAY                   40.45N 91.88W
04/02/2006  E0.25 INCH       CLARK              MO   TRAINED SPOTTER

            WIND GUSTS 40 TO 50 MPH

&&

TS

The air that afternoon

The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.

Davenport, (KDVN), 12:00Z

9.3 hours before the tornado, 136 km from the path. April 2, 2006.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.

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. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.

Mixed-layer CAPE: 0 J/kg
Mixed-layer CIN: -100942 J/kg
Surface CAPE: 0 J/kg
Mixed-layer LCL: 903 m above ground
0-6 km bulk shear: 42 kt
0-1 km bulk shear: 25 kt
0-1 km storm-relative helicity: 246 m²/s²
0-3 km storm-relative helicity: 257 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0
0-3 km lapse rate: 1.3 K/km

Open this sounding in Storm Lab

The surface observations

Fairfield (FFL), 24 km from the path, in the two hours either side.

Time (UTC)	Temp (°F)	Dew point (°F)	Wind	Gust (kt)	Pressure (mb)	Weather
00:00 UTC

From the Iowa Environmental Mesonet's archive of airport observations.

The radar

The Quad Cities radar (KDVN), 130 km away, was scanning. The volume nearest the touchdown began at 21:20 UTC.

Open the radar archive at this moment, over the track

Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.

This ground now

The live radar over the track Every 2006 tornado in Iowa Every tornado in Iowa since 1950 Warnings in force in Iowa now The forecast where you are

The other tornadoes of April 2, 2006

66 more were confirmed in the United States that day.

Date	Time	Rating	Where	Path (mi)	Width (yd)	Deaths	Injuries	Damage
April 2	3:47 PM CDT	F0	Davis, IA	0.2	30
April 2	3:57 PM CDT	F0	Davis, IA	0.1	25
April 2	4:03 PM CDT	F2	Van Buren, IA	3.0	100			$30,000
April 2	4:15 PM CDT	F1	Van Buren, IA	2.0	50			$10,000
April 2	4:18 PM CDT	F1	Jefferson, IA	0.3	50			$10,000
April 2	4:25 PM CDT	F2	Ralls, MO	3.5	350
April 2	4:46 PM CDT	F2	Washington, IA	1.0	75			$30,000
April 2	4:59 PM CDT	F1	Sharp, AR	9.5	100			$100,000
April 2	5:00 PM CDT	F0	Saint Francois, MO	0.1	50
April 2	5:00 PM CDT	F1	Washington, IA	0.1	50			$10,000
April 2	5:05 PM CDT	F0	Sainte Genevieve, MO	2.0	40
April 2	5:06 PM CDT	F0	Warren, IA	0.2	30
April 2	5:15 PM CDT	F2	Saint Clair, IL	7.0	100	1	11
April 2	5:15 PM CDT	F0	Macoupin, IL	2.0	30
April 2	5:15 PM CDT	F0	Macoupin, IL	0.5	30
April 2	5:16 PM CDT	F0	Henderson, IL	0.0	25
April 2	5:20 PM CDT	F1	McDonough, IL	12.0	233			$150,000
April 2	5:21 PM CDT	F0	Madison, IL	16.0	50
April 2	5:30 PM CDT	F1	Madison, IL	2.0	100
April 2	5:31 PM CDT	F0	Polk, IA	0.2	30
April 2	5:35 PM CDT	F0	Macoupin, IL	0.1	20
April 2	5:37 PM CDT	F3	Randolph, AR to MO	77.0	880	2	177	$86 million
April 2	5:41 PM CDT	F0	Montgomery, IL	1.0	50
April 2	5:46 PM CDT	F1	Sangamon, IL	0.5	200
April 2	5:49 PM CDT	F1	Sangamon, IL	2.0	100
April 2	5:50 PM CDT	F2	Montgomery, IL	20.0	200
April 2	5:56 PM CDT	F1	Sangamon, IL	1.0	100
April 2	5:56 PM CDT	F1	Montgomery, IL	2.2	100
April 2	5:58 PM CDT	F1	Sangamon, IL	1.0	100
April 2	5:59 PM CDT	F0	Sangamon, IL	1.3	50
April 2	6:00 PM CDT	F2	White, AR	6.3	100
April 2	6:06 PM CDT	F1	Sangamon, IL	0.8	50
April 2	6:08 PM CDT	F1	Christian, IL	6.3	300		1
April 2	6:13 PM CDT	F1	Sangamon, IL	1.5	100		1
April 2	6:14 PM CDT	F1	Christian, IL	6.0	150
April 2	6:17 PM CDT	F0	Christian, IL	0.1	50
April 2	6:20 PM CDT	F1	Christian, IL	1.0	100
April 2	6:22 PM CDT	F0	Menard, IL	0.3	40
April 2	6:29 PM CDT	F3	Woodruff, AR	38.0	500		5	$5.0 million
April 2	6:30 PM CDT	F0	Macon, IL	0.1	30
April 2	6:30 PM CDT	F2	Macon, IL	4.5	300
April 2	6:32 PM CDT	F0	Logan, IL	1.0	80
April 2	6:36 PM CDT	F0	Logan, IL	2.5	50
April 2	6:36 PM CDT	F1	Macon, IL	7.5	150		3
April 2	6:42 PM CDT	F0	Cumberland, IL	0.8	100
April 2	6:43 PM CDT	F0	Scott, MO	1.5	50			$20,000
April 2	7:01 PM CDT	F0	DeWitt, IL	0.1	30
April 2	7:08 PM CDT	F0	McLean, IL	0.1	30
April 2	7:12 PM CDT	F0	McLean, IL	0.5	50
April 2	7:13 PM CDT	F1	McLean, IL	1.0	50
April 2	7:15 PM CDT	F0	Champaign, IL	0.1	30
April 2	7:22 PM CDT	F0	McLean, IL	2.6	50
April 2	7:25 PM CDT	F0	Champaign, IL	0.3	50
April 2	7:31 PM CDT	F0	Ballard, KY	0.1	30
April 2	7:32 PM CDT	F3	Dyer, TN	18.0	880	16	70	$20 million
April 2	9:07 PM EDT	F1	Lawrence, IN	0.5	100			$100,000
April 2	8:09 PM CDT	F3	Gibson, TN	31.0	880	6	44	$27 million
April 2	9:25 PM EDT	F1	Tippecanoe, IN	0.5	100			$50,000
April 2	9:37 PM EDT	F1	Jackson, IN	0.5	100			$200,000
April 2	8:43 PM CDT	F3	Gibson, TN	8.0	880	2	6	$15 million

All 67 of them

What this means

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.

Sources

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.