Tornadoes · United States · Iowa · 2003

F1 tornado, Columbia to Leighton, Iowa, May 10, 2003

Name: F1 tornado, Columbia to Leighton, Iowa, May 10, 2003
Start: 2003-05-10T22:26:00.000Z
Location: Columbia to Leighton, Iowa

From Columbia to Leighton, this F1 tornado ran 18.5 miles across Marion and Mahaska counties on May 10, 2003, touching down at 5:26 PM CDT and reaching 50 yards wide. It killed nobody, and did $320,000 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: May 10, 2003
Touchdown: 5:26 PM CDT (22:26 UTC)
Path length: 18.5 miles (29.8 km)
Path width: 50 yards (46 m)
Deaths: 0
Injuries: 0
Property damage: $320,000
Counties: Marion and Mahaska counties
Touchdown point: 41.180, -93.120
Lift-off point: 41.350, -92.830
Record number: 825

What the Weather Service recorded

A very intense spring storm system developed over the central Plains and moved east, then northeast across Kansas into eastern Iowa. The low deepened to 986 mb by 06z of the 11th as it passed over La Crosse, WI. A southerly low level jet of 40 to 55 kts developed ahead of the storm system. A warm front extended east from the low and served as a focusing point for thunderstorm development early on, while a dry line extended south from the low lead to the development of a line of severe thunderstorms. Dew point temperatures in the warm sector soared into the upper 60s to mid 70s with temperature readings in the 80s. Dew point values at the 850 mb level were in the 14 to 17 degree C. range. By mid day, CAPE values over eastern KS into western MO were around 5000 J/kg with lifted indices around -11 C. Thunderstorms developed explosively by the mid afternoon hours. For the most part, severe weather from the storms in Iowa was in the form of Hail as most of the activity was north of the warm front. Parts of central into northeast Iowa received golf ball to larger than baseball size hail. The hardest hit area was in Poweshiek County in the Grinnell area, where 3 inch diameter hail caused considerable damage. There were scattered reports of nickel to ping pong ball size hail from Interstate 35 east. A few tornadoes occurred close to the triple point of the storm system. One tornado touched down in Marion County southwest of Attica and moved into Mahaska County northwest of Leighton. The track was generally through open countryside with little damage reported. One trailer was overturned east of Columbia near the beginning of the intermittent track of the tornado. Another brief touchdown was reported in Tama County near Clutier. No damage was reported with this tornado.

Moved in rural area northeast into Mahaska County. Tornado had intermittent track.

Moved from Marion County into rural Mahaska County.

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

The warnings

9 minutes of warning. NWS DMX issued a tornado warning for this county at 22:17 UTC, 9 minutes before the tornado touched down, in force until 22:45 UTC.

Issued (UTC)	Expired	Product	Office
22:11 UTC	22:45 UTC	Severe Thunderstorm Warning	DMX
22:17 UTC	22:45 UTC	Tornado Warning	DMX

Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.

The forecast that day

The Storm Prediction Center had this point in a Slight Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 12:05 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 Des Moines, IA wrote its last area forecast discussion before the tornado touched down at May 10, 3:59 PM CDT, 1 hour 27 minutes earlier.

Area forecast discussion, May 10, 3:59 PM CDT, 1 hour 27 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
2578PM CDT SAT MAY 10 2003

SVRL SGFNT THINGS TO CONSIDER TDA FM SVR WX TO HIGH WND POTENTIAL.
STLT IMAGERY SHOWS LG WV TROF THRU HIGH PLAINS WITH SHRT WV/SHEAR
AXIS FM KS/NE INTO MO VLY.  20Z SFC ANLYS PLACES LOW/TRIPLE POINT
JUST N KMKC METRO AREA WITH OLD OUTFLOW BNDRY TO JUST S KSTL METRO
AND ASSOCD WRMFNT INTO IA ALG KLWD-KCWI LN.  ELEVATED INSTABLITY
AXIS INTO S CNTRL IA WITH MLCAPES AOA 1000 J/KG HEADING INTO SERN IA
AS WRM SECTOR SURGES NWD.  DEEP LAYER SHEAR STG WITH VARIOUS
SUPERCELL/TORNADO SCREAMING...BUT MAINLY S ACRS MO AT THIS
POINT.  PRIMARY WARM SECTOR LOOKS TO BE ASSOCD WITH OUTFLOW BNDRY
WITH EXTRAPOLATION OF CURRENT FEATURES GOING ACRS SERN IA AND OUT OF
FA ARND 23Z.  FAVORED AREA FOR TORNADIC SUPERCELLS WOULD APPR TO BE
ALG AND SE OF KLWD-KPEA-JUST S KALO LN.  MAY SEE HAIL POTENTIAL IN
ELEVATED CONVECTION IN DEFORMATION ZN TOO.  HGT FALL CNTR AND STG
KINEMATIC FORCING CROSSES SRN 2/3RD OF FA THIS EVE.  SYS SHOULD BE
FAST MOVG ENOUGH THAT RAINS MAY BE LCLLY HVY BUT BRIEF ENOUGH TO NOT
AGGREVATE FLOODING SITUATION MUCH.  WL GO WITH CATEGORICAL WORDING
NWRN THIRD...CHCS SW...AND LIKELY CNTRL TO SE.  PCPN SHOULD DMSH
OVNGT TO CHC CATEGORY NERN PTNS.

NEXT QUESTION WL BE WNDS LATE TNGT AND SUN.  SFC LOW SHOULD QUICKLY
LIFT INTO KLSE VCNTY TWRD 06Z.  STG HGT FALL CNTR SHOULD DEEPING SFC
LOW WITH PRODUCE SGFNT ISALLOBARIC COUPLET AS DEPICTED BY MDLS.
THIS AND FOLLOWING PRES RISE CNTR SHOULD EXIT FA BY 12Z...WITH
SCNDRY ISALLOBARIC MAX INTO NERN SXNS TMRW.  PRES GRADIENT QUITE
IMPRESSIVE SO HAVE ISSUED WND ADVY LATE TNGT AND SUN FOR NRN 2 TO 3
TIERS OF COUNTIES.  TEMP WISE GENERALLY FOLLOWED COMPROMISE OF
GUIDANCE WHICH IS FAIRLY CLOSE.

PRIMARY QUESTIONS FOR NEXT WEEK WL BE POPS WITH MIDWEEK SYS...AND
WHETHER TO ADD MENTION AGN LATE IN WEEK.  RECENT GFS RUNS STRONGEST
WITH SYS ARND WED...EURO MDLS WEAKEST AND CANADIAN A COMPROMISE.
GFS SLOWEST WITH EURO/CANADIAN SOLUTIONS A BIT FASTER.  HWVR 12Z GFS
AND GFS ENSEMBLES ARE LEANING IN DIRECTION OF CANADIAN/EURO MDLS.
SEE NO REASON TO ALTER NCEP THINKING OF FOLLOWING ECMWF...SPCLLY
ARND MIDWEEK...WITH INFLUENCE OF 12Z GFS AND ENSEMBLES IN LATER PDS
TOO.  THUS WL KEEP CHCS GOING TUE NGT WRN PTNS...AND FA WIDE WED.
TWRD FRI AND SAT...ECMWF MUCH STGR AND FARTHER N WITH SRN PLAINS
SYS.  HWVR WL SIDE WITH SUGGESTIONS FM GFS/CANADIAN ENSEMBLES AND
SURROUNDING OFFICES KEEPING FCST DRY ATTM.  DO NOT HAVE THE BEST
CONFIDENCE IN 00Z MOS EITHER SO HAVE NOT CHGD GOING TEMPS MUCH.

.DSM...WND ADVY OVNGT AND SUN NRN PTNS
       IAZ004>007-015>017-024>028

SMALL

Hazardous weather outlook, May 10, 11:50 AM CDT, 5 hours 36 minutes before

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-111100-

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE DES MOINES IA
1150 AM CDT SAT MAY 10 2003

...MORE SEVERE WEATHER POSSIBLE THIS AFTERNOON AND EARLY EVENING...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL IOWA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

A SURFACE LOW WILL TRACK THROUGH SOUTHEAST IOWA...AND DRAW VERY
MOIST...UNSTABLE AIR INTO THE SOUTHERN PART OF THE STATE THIS
AFTERNOON INTO THE EARLY EVENING HOURS. SUPERCELL THUNDERSTORMS WITH
SEVERE WEATHER ARE POSSIBLE FROM AROUND 3 PM TO 9 PM.  THE AREA IN
HIGH RISK FOR SEEING SEVERE WEATHER LIES SOUTHEAST OF A LINE FROM
EDDYVILLE TO CLIO.  LARGE HAIL...DAMAGING WIND AND TORNADOES ARE
POSSIBLE IN THIS AREA.  THERE IS A MODERATE RISK OF SEVERE STORMS
SOUTHEAST OF A LINE FROM BROOKLYN TO LAMONI. LARGE HAIL...DAMAGING
WIND AND ISOLATED TORNADOES ARE POSSIBLE IN THIS AREA. IN
ADDITION...RAINFALL AMOUNTS OF A QUARTER TO ONE HALF INCH ARE
POSSIBLE OVER CENTRAL IOWA THROUGH TONIGHT...WITH ISOLATED TOTALS
BETWEEN 1 AND 2 INCHES. LOCALLY HEAVY RAIN WILL HAVE AN AFFECT ON
AREA RIVERS DURING THE COMING WEEK...BUT THE RISK FOR FLASH FLOODING
IS LOW FOR TODAY AND TONIGHT.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

EXPECT VERY WINDY CONDITIONS ON SUNDAY...WITH A SUSTAINED NORTHWEST
WIND AT 20 TO 30 MPH...AND GUSTS TO 45 MPH. PERIODS OF SHOWERS AND A
FEW THUNDERSTORMS ARE EXPECTED ACROSS PARTS OF CENTRAL IOWA TUESDAY
NIGHT INTO WEDNESDAY...AND AGAIN THURSDAY. NO SEVERE WEATHER IS
ANTICIPATED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS LIKELY THIS AFTERNOON INTO EARLY
EVENING...MAINLY ALONG AND SOUTHEAST OF A LINE FROM BROOKLYN TO
LAMONI.
&&

MORE INFORMATION CAN BE OBTAINED AT WWW.CRH.NOAA.GOV/DMX (ALL LOWER
CASE).

FAB

In the hours before

Local storm report, May 10, 5:10 PM CDT, 16 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
0510 PM CDT SAT MAY 10 2003

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0444 PM    GREENE                    IA   0.75 IN HAIL
05/10/03   BUTLER                         TRAINED SPOTTER

0420 PM    1 NE THORNTON             IA   1.75 IN HAIL
05/10/03   CERRO GORDO                    TRAINED SPOTTER

BF

Local storm report, May 10, 5:25 PM CDT, 1 minute before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
0525 PM CDT SAT MAY 10 2003

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0506 PM    4 NE CHELSEA              IA   1.00 IN HAIL
05/10/03   TAMA                           INTERSECTION OF HWY 21 &
                                          HWY 30. MOBILE SPOTTER.

0354 PM    THORNTON                  IA   1.75 IN HAIL
05/10/03   CERRO GORDO                    BROADCAST MEDIA...KIMT TV.

0411 PM    4 NW THORNTON             IA   1.00 IN HAIL
05/10/03   CERRO GORDO                    TRAINED SPOTTER.

0520 PM    10 N KNOXVILLE            IA   DOWNBURST
05/10/03   MARION                         1/4 MILE NORTH OF RED ROCK
                                          LAKE.

BF

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

10.4 hours before the tornado, 210 km from the path. May 10, 2003.

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: -82973 J/kg
Surface CAPE: 0 J/kg
Mixed-layer LCL: 1102 m above ground
0-6 km bulk shear: 51 kt
0-1 km bulk shear: 14 kt
0-1 km storm-relative helicity: 139 m²/s²
0-3 km storm-relative helicity: 225 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.5
0-3 km lapse rate: 2.8 K/km

Open this sounding in Storm Lab

Davenport, (KDVN), 00:00Z

1.6 hours after it, 210 km from the path. May 11, 2003.

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

Mixed-layer CAPE: 1566 J/kg
Mixed-layer CIN: -80 J/kg
Surface CAPE: 1430 J/kg
Mixed-layer LCL: 910 m above ground
0-6 km bulk shear: 57 kt
0-1 km bulk shear: 27 kt
0-1 km storm-relative helicity: 234 m²/s²
0-3 km storm-relative helicity: 259 m²/s²
Significant tornado parameter: 2.8
Supercell composite: 12.7
0-3 km lapse rate: 6.5 K/km

Open this sounding in Storm Lab

The radar

The Des Moines radar (KDMX), 81 km away, was scanning. The volume nearest the touchdown began at 22:28 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 2003 tornado in Iowa Every tornado in Iowa since 1950 Warnings in force in Iowa now The forecast where you are

The other tornadoes of May 10, 2003

50 more were confirmed in the United States that day.

Date	Time	Rating	Where	Path (mi)	Width (yd)	Injuries	Damage
May 10	3:00 AM CDT	F0	Butler, KS	4.0	110		$10,000
May 10	3:05 AM CDT	F0	Marion, KS	6.0	110		$50,000
May 10	7:53 AM CDT	F0	Sangamon, IL	0.1	10
May 10	7:55 AM CDT	F0	Sangamon, IL	0.2	20
May 10	7:58 AM CDT	F0	Sangamon, IL	1.0	30		$40,000
May 10	8:08 AM CDT	F0	Christian, IL	0.3	20
May 10	9:45 AM CDT	F0	Cumberland, IL	0.1	10
May 10	10:40 AM CDT	F0	Edgar, IL	0.1	10
May 10	10:51 AM EST	F0	Putnam, IN	0.5	50		$10,000
May 10	11:00 AM CDT	F1	Jasper, IL	1.5	100		$10,000
May 10	4:45 PM EDT	F3	Mason, KY	25.0	200	17	$5.5 million
May 10	4:02 PM CDT	F0	Linn, MO	0.5	25
May 10	4:38 PM CDT	F0	Mercer, MO	0.1	25		$1,000
May 10	4:56 PM CDT	F1	Putnam, MO	7.0	100		$20,000
May 10	5:23 PM CDT	F0	Macon, MO	5.5	50		$1,000
May 10	5:33 PM CDT	F2	Knox, MO	22.1	200		$500,000
May 10	5:35 PM CDT	F0	Putnam, MO	0.5	50		$1,000
May 10	5:50 PM CDT	F0	Shelby, MO	5.0	50
May 10	6:08 PM CDT	F2	Lewis, MO	20.0	200	6	$5.0 million
May 10	6:10 PM CDT	F0	Lewis, MO	4.0	50
May 10	6:19 PM CDT	F0	Monroe, MO	0.2	40
May 10	6:27 PM CDT	F0	Tama, IA	0.1	25
May 10	6:28 PM CDT	F2	Lee, IA	11.5	200		$1.0 million
May 10	6:30 PM CDT	F0	Marion, MO	2.5	50
May 10	6:36 PM CDT	F2	Adams, IL	69.2	300	4	$1.1 million
May 10	6:37 PM CDT	F3	Marion, MO	12.0	200
May 10	7:10 PM CDT	F0	Van Buren, IA	4.0	100		$100,000
May 10	7:20 PM CDT	F2	Adams, IL	30.8	300
May 10	7:23 PM CDT	F0	Jefferson, IA	5.0	100		$100,000
May 10	7:33 PM CDT	F0	Jefferson, IA	2.4	100		$100,000
May 10	7:44 PM CDT	F1	Henry, IA	27.9	200		$2.0 million
May 10	8:14 PM CDT	F2	Schuyler, IL	6.0	150
May 10	8:15 PM CDT	F1	Lafayette, WI	7.8	200	1	$200,000
May 10	8:30 PM CDT	F0	Mercer, IL	8.3	100		$100,000
May 10	8:32 PM CDT	F1	Fulton, IL	3.0	400
May 10	8:39 PM CDT	F1	Iowa, WI	8.6	200		$300,000
May 10	9:42 PM EDT	F0	Beaufort, NC	0.1	50
May 10	8:45 PM CDT	F0	Mercer, IL	2.1	50		$100,000
May 10	8:47 PM CDT	F1	Fulton, IL	2.7	100
May 10	8:55 PM CDT	F0	Mercer, IL	3.8	50		$50,000
May 10	8:55 PM CDT	F0	Henry, IL	25.5	100		$650,000
May 10	9:12 PM CDT	F1	Mason, IL	8.0	150
May 10	9:33 PM CDT	F2	Mason, IL	2.5	100	1
May 10	9:38 PM CDT	F1	Mason, IL	2.0	100
May 10	9:45 PM CDT	F3	Tazewell, IL	17.5	440	32	$10 million
May 10	9:58 PM CDT	F0	Bureau, IL	4.1	50		$50,000
May 10	10:16 PM CDT	F1	Tazewell, IL	1.5	100
May 10	10:18 PM CDT	F2	Woodford, IL	12.5	300	4
May 10	10:25 PM CDT	F1	Woodford, IL	8.0	200
May 10	10:35 PM CDT	F1	Jackson, AR	0.6	30

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.