Tornadoes · United States · Missouri · 2004

F1 tornado, Ironton, Missouri, October 18, 2004

This F1 tornado ran 2.0 miles across Iron County on October 18, 2004, touching down at 4:26 PM CDT and reaching 400 yards wide. It killed nobody.

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.

  1. F040 to 72 mph

    Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

  2. F173 to 112 mphthis tornado

    Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

  3. 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.

  4. 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.

  5. F4207 to 260 mph

    Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

  6. 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.

  7. 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
October 18, 2004
Touchdown
4:26 PM CDT (21:26 UTC)
Path length
2.0 miles (3.2 km)
Path width
400 yards (366 m)
Deaths
0
Injuries
0
County
Iron County
Touchdown point
37.600, -90.630
Lift-off point
37.600, -90.630
Record number
587

What the Weather Service recorded

A tornado first caused damage on the west side of Ironton at Shepherd Mountain Lake. Trees were downed and damaged on both sides of the north end of the lake as the tornado moved east at about 40 miles an hour. The tornado moved into west Ironton downing and snapping off trees on West Boulder Drive. On Lake Drive part of the roof of the County Health Department was blown off and landed about 75 yards away. A storage shed in this same area was also destroyed with part of it landing in power lines. The majority of the damage was due to downed and snapped off trees. Power lines and poles were down primarily because of the trees and limbs. About one dozen homes suffered minor damage involving downed trees or roof shingles blown off. One car was severely damaged by a downed tree.

The second Iron County tornado hit east of Ironton in the Killarney Shores neighborhood. Several trees were downed or snapped off.

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

The warnings

12 minutes of warning. NWS LSX issued a tornado warning for this county at 21:14 UTC, 12 minutes before the tornado touched down, in force until 22:00 UTC.

Issued (UTC)ExpiredProductOffice
20:28 UTC21:15 UTCTornado WarningLSX
21:14 UTC22:00 UTCTornado WarningLSX

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 0.05 chance of a tornado within 25 miles. 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.

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.

Springfield, MO (KSGF), 12:00Z

9.4 hours before the tornado, 291 km from the path. October 18, 2004.

Skew-T log-pSkew-T log-p diagram, Springfield, MO at 12:00Z on 2004-10-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 2097 joules per kilogram, CIN -105, lifted condensation level 619 meters above ground. Wind barbs in knots down the right edge.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. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Springfield, MO at 12:00Z on 2004-10-18The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 333 square meters per square second, 0 to 6 km bulk shear 42 knots.19395878Sfc1 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. 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
2097 J/kg
Mixed-layer CIN
-105 J/kg
Surface CAPE
896 J/kg
Mixed-layer LCL
619 m above ground
0-6 km bulk shear
42 kt
0-1 km bulk shear
36 kt
0-1 km storm-relative helicity
333 m²/s²
0-3 km storm-relative helicity
320 m²/s²
Significant tornado parameter
0.0
Supercell composite
7.0
0-3 km lapse rate
4.8 K/km

Open this sounding in Storm Lab

Springfield, MO (KSGF), 00:00Z

2.6 hours after it, 291 km from the path. October 19, 2004.

Skew-T log-pSkew-T log-p diagram, Springfield, MO at 00:00Z on 2004-10-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -71774, lifted condensation level 2578 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 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. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Springfield, MO at 00:00Z on 2004-10-19The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 91 square meters per square second, 0 to 6 km bulk shear 39 knots.19395878Sfc1 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. 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
-71774 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
2578 m above ground
0-6 km bulk shear
39 kt
0-1 km bulk shear
23 kt
0-1 km storm-relative helicity
91 m²/s²
0-3 km storm-relative helicity
123 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
7.7 K/km

Open this sounding in Storm Lab

The surface observations

Farmington (FAM), 25 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
19:35 UTC80.664.4210° 16 kt201001.7
19:55 UTC78.864.4220° 11 kt191001.4
20:15 UTC80.664.4210° 12 kt191001.4
20:35 UTC78.864.4190° 10 kt181001
20:55 UTC78.864.4180° 12 kt171000.3VCTS
21:15 UTC7764.4160° 9 kt1000.3VCTS
21:35 UTC73.466.2190° 4 kt1001TS
21:55 UTC71.669.8230° 10 kt1002.4TS
22:15 UTC69.864.40° 0 kt1002VCTS
22:35 UTC66.262.660° 4 kt1001.7
22:55 UTC66.264.420° 5 kt1003VCTS
23:15 UTC66.262.670° 9 kt171003VCTS

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

The radar

The St Louis radar (KLSX), 122 km away, was scanning. The volume nearest the touchdown began at 21:25 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.

What was reported nearby

Local storm reports within 60 km of the path, in the three hours either side.

Time (UTC)ReportWhereCountyRemark
20:46 UTCHAIL 1.75ViburnumIron, MO
21:00 UTCHAIL 1PotosiWashington, MO
21:05 UTCHAIL 1.75Old MinesWashington, MOGOLFBALL SIZED HAIL FOR THE LAST 10 MINUTES
21:19 UTCTSTM WND DMG1 N PotosiWashington, MOSTRUCTUAL DAMAGE...6 PEOPLE TRAPPED IN THE POTOSI LUMBER CO.
21:21 UTCTORNADO1 N PotosiWashington, MO*** 6 INJ *** POSSIBLE TORNADO--ENTIRE BUILDING AT THE POTOSI LUMBER CO WAS DESTROYED.
21:22 UTCTSTM WND DMGCadetWashington, MOPOWER LINES DOWN
21:25 UTCHAIL 0.8810 W FredericktownMadison, MO
21:25 UTCHAIL 0.884 Se BelleviewIron, MODIME INCREASING TO NICKLE SIZED HAIL
21:25 UTCHAIL 23 N Bonne TerreSt. Francois, MO
21:30 UTCTSTM WND DMGMineral PointWashington, MONUMEROUS TREES DOWN
21:30 UTCHAIL 1.7510 S De SotoSt. Francois, MO
21:35 UTCTSTM WND DMG3 S CentervilleReynolds, MOTREES DOWN AND GOLFBALL SIZED HAIL ON HWY 21
21:35 UTCTORNADOMineral PointWashington, MO2 MOBILE HOMES DESTROYED ON HWY E EAST OF POTOSI...AND MULTIPLE HOMES WITH ROOFS OFF...SAME LOCATION.
21:40 UTCTSTM WND DMGIrontonIron, MOPUBLIC REPORTED TREES AND POWERLINES DOWN. NO STRUCTURAL DAMAGE...
21:50 UTCHAIL 0.75Rocky RidgeSte. Genevieve, MO
21:55 UTCHAIL 0.75BloomsdaleSte. Genevieve, MO
21:55 UTCHAIL 0.75BloomsdaleSte. Genevieve, MO
21:55 UTCTORNADOFredericktownMadison, MOTORNADO SIGHTED ON THE GROUND 1 NORTH OF THE HWY 72/67 INTERSECTION
22:08 UTCHAIL 1LodiWayne, MO
22:10 UTCTORNADOCatherine PlaceMadison, MORADIO STATION IN FREDERICKTOWN REPORTED TORNADO NEAR CATHERINE PLACE...WITNESSES REPORTED SEEING SHEET METAL BEING THROWN INTO THE AIR.
22:10 UTCTORNADON FredericktownMadison, MOTRAILER PARK DAMAGED...NUMEROUS TREES DOWN...HWY-H BLOCKED BY TREES
22:40 UTCHAIL 1Patton JunctionBollinger, MO
22:45 UTCHAIL 2.54 N Patton JunctionBollinger, MO

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

This ground now

The live radar over the trackEvery 2004 tornado in MissouriEvery tornado in Missouri since 1950Warnings in force in Missouri nowThe forecast where you are

The other tornadoes of October 18, 2004

35 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
October 188:59 AM CDTF1Saline, AR2.0300
October 189:20 AM CDTF2Saline, AR24.080011
October 1810:07 AM CDTF0Lonoke, AR3.350
October 1810:42 AM CDTF2Lonoke, AR19.0600$12 million
October 184:08 PM CDTF1Washington, MO0.2807
October 184:10 PM CDTF0Washington, MO0.850
October 184:11 PM CDTF0Washington, MO0.840
October 184:12 PM CDTF0Washington, MO0.840
October 184:13 PM CDTF0Washington, MO0.840
October 184:35 PM CDTF0Iron, MO0.5100
October 184:37 PM CDTF0Reynolds, MO0.540$100,000
October 184:45 PM CDTF1Colbert, AL2.0200$2,000
October 184:48 PM CDTF1Lauderdale, AL5.0200$20,000
October 184:50 PM CDTF0Randolph, AR2.025$10,000
October 184:59 PM CDTF0Madison, MO1.5250
October 185:05 PM CDTF1Randolph, AR13.075$70,000
October 185:10 PM CDTF1Madison, MO5.5100
October 185:10 PM CDTF0Greene, AR8.025$1,000
October 185:10 PM CDTF1Lauderdale, AL2.050$10,000
October 185:16 PM CDTF0Randolph, AR0.525$1,000
October 185:25 PM CDTF0Clay, AR0.525$1,000
October 185:51 PM CDTF0Bollinger, MO0.250
October 186:00 PM CDTF0Clay, AR4.025$1,000
October 186:15 PM CDTF1Lawrence, TN0.7200$10,000
October 186:27 PM CDTF0Limestone, AL2.035
October 186:35 PM CDTF0Lawrence, AR23.0100$150,000
October 187:10 PM CDTF0Greene, AR0.325$1,000
October 187:16 PM CDTF2Johnson, IL8.82503$540,000
October 187:34 PM CDTF0Dallas, AR0.225
October 187:40 PM CDTF0Clay, MS1.075$1,000
October 187:43 PM CDTF2Johnson, IL14.0300$200,000
October 187:55 PM CDTF2Pemiscot, MO0.512537$300,000
October 188:14 PM CDTF0Calloway, KY0.250$10,000
October 188:50 PM CDTF1Dyer, TN0.51001$1.0 million
October 189:12 PM CDTF1Henry, TN8.33001$800,000

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.