Tornadoes · United States · Michigan · 2004
F0 tornado, Buchanon, Michigan, July 21, 2004
This F0 tornado ran 0.1 miles across Berrien County on July 21, 2004, touching down at 7:20 PM EDT and reaching 15 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.
F040 to 72 mphthis tornado
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
F173 to 112 mph
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
- F0
- Date
- July 21, 2004
- Touchdown
- 7:20 PM EDT (23:20 UTC)
- Path length
- 0.1 miles (0.2 km)
- Path width
- 15 yards (14 m)
- Deaths
- 0
- Injuries
- 0
- County
- Berrien County
- Touchdown point
- 41.870, -86.330
- Lift-off point
- 41.870, -86.330
- Record number
- 1418
What the Weather Service recorded
Evidence of a brief touchdown was found in a corn field near the intersection of Walton and Smith Roads, northeast of Buchanan. The tornado traveled approximately 50 yards and then lifted. Only damage to the corn field was noted as a result of the tornado.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
No tornado warning for this county appears in the archive as in force at the moment the tornado touched down.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 22:46 UTC | 23:45 UTC | Severe Thunderstorm Warning | IWX |
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 Moderate Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 19:39 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 Northern Indiana wrote its last area forecast discussion before the tornado touched down at Jul 21, 3:10 PM EDT, 4 hours 10 minutes earlier.
Area forecast discussion, Jul 21, 3:10 PM EDT, 4 hours 10 minutes before
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 210 PM EST WED JUL 21 2004 .SHORT TERM... TONIGHT AND THURSDAY. MAIN CHALLENGE LIES WITH CONVECTION CHANCES TONIGHT. INITIAL BOUNDARY FROM OVERNIGHT CONVECTION IS MOVING ACROSS THE FORECAST AREA WITH LITTLE MORE THAN A FEW SHOWERS ACROSS MICHIGAN. PLENTY OF INSTABILITY IN PLACE JUST TO THE WEST WITH LIS -9 TO -11 AND CAPES 3K TO 4K J/KG. VIS SAT SHOWS ANOTHER OUTFLOW BOUNDARY FROM EASTERN WISCONSIN TO CENTRAL ILLINOIS...JUST TO THE WEST OF THE INSTABILITY AXIS. THIS MAY END UP BEING THE FOCUS FOR THE EXPECTED LINE OF THUNDERSTORMS TONIGHT. MAIN LIMITING FACTOR HAS BEEN STRONG CAP ACROSS MUCH OF THE AREA (SEE 18Z KILX AND KDVN SOUNDINGS). MODELS SHOW THIS CAP BEING ELIMINATED AS SLIGHTLY COOLER 850 MB TEMPS AND APPROACHING SHORTWAVE/MCV MOVE IN. AREA UNDER A MDT RISK FOR THIS AFTERNOON AND EVENING WITH WIND PROFILES TO THE WEST STARTING TO LOOK MORE FAVORABLE FOR DAMAGING WINDS. EXPECTING NEW WATCH FOR THE AREA OVER THE NEXT COUPLE OF HOURS. HAVE ADJUSTED TIMING OF PRECIP SOMEWHAT WITH LIKELY POPS WEST TO START SPREADING ACROSS THE AREA BY MIDNIGHT THEN BACK TO CHC POPS BEHIND THE MAIN LINE FOR ANYTHING LINGERING. WITH PWATS NEAR 2 TO THE WEST EXPECTED TO MOVE IN...HEAVY RAINFALL ALSO A GOOD BET. LOWS WILL FALL BACK INTO THE LOWER 70S AS DRIER AIR DOESNT START MOVING IN TILL EARLY THURSDAY. MUCH OF THURSDAY COULD BE DRY IN SUBSIDENCE BEHIND TONIGHTS SYSTEM. MODELS HINT AT NEXT WAVE TO MOVE IN TOWARDS EVE FOR ANOTHER CHANCE OF PRECIP. WILL GO WITH 30 POPS ALL AREAS FOR THURS FOR NOW AND LET OVERNIGHT CREW MAKE CHANGES BASED ON FRONTAL POSITION. WITH 850 MB TEMPS STILL EXPECTED +19 TO +20...HIGHS SHOULD MAKE IT INTO THE UPR 80S. && .LONG TERM... SOME CHANGES TO EXTENDED BASED ON LATEST MODEL RUNS. TEMPERATURES LOOK GOOD AND FEW CHANGES MADE THERE. FORECAST CHALLENGE IS WITH POPS FRIDAY THEN AGAIN MONDAY NIGHT THROUGH TUESDAY NIGHT. FRONT TO PUSH THROUGH THURSDAY BUT MODELS HINTING AS AN MCS DEVELOPING ON NORTH SIDE OF FRONT THURSDAY NIGHT AND MOVING ALONG FRONT FRIDAY. LATEST ETA40 SHOWS ALL ACTIVITY SOUTH OF OUR AREA BY 12Z FRIDAY WITH DRY NORTHEAST FLOW BEHIND. LEANING TOWARD THIS SOLUTION AS IT MATCHES CURRENT GRIDS AND SEEMS PLAUSIBLE AT THIS POINT. THUS NO ADDITIONAL POPS FOR FRI. GFS AND ECMWF AS WELL AS UKMO AGREE ON INVERTED TROUGH OVER OUR AREA MONDAY NIGHT INTO TUESDAY NIGHT WITH A COUPLE OF POSSIBLE WAVES RIDING NORTH ALONG FRONT. SURFACE TROUGH IS NEAR OUR EASTERN AREAS BUT UPPER TROUGH STILL TO OUR WEST AND SLIGHTLY DIGGING. THUS SURFACE TROUGH COULD END UP FARTHER WEST AND ANY PCPN MOVING NORTH OUT OF OPEN GULF AND ATLANTIC COULD BE DRAWN FARTHER WEST. THUS WILL NOT TRY AND DIFFERENTIATE ACROSS THE AREA AND ADD POPS TO ENTIRE FORECAST AREA AT THIS TIME WITH PRETTY GOOD MEDIUM RANGE MODEL AGREEMENT. && .AVIATION... TOUGH FORECAST FOR THE NEXT 6 TO 12 HOURS AS INITIAL LINE OF CONVECTION HAS WEAKENED...BUT OUTFLOW BOUNDARY FROM IT IS NOW INTERACTING WITH VERY UNSTABLE ATMOSPHERE NEAR KSBN. STILL A CHANCE THAT SOMETHING COULD FIRE ALONG THIS AND HEAD EAST. CONFIDENCE LOW AT THIS TIME SO NO MENTION OF PRECIP THIS AFTERNOON. ANOTHER SHOT AT PRECIP LOOKS TO MOVE IN THIS EVENING WITH MCV IN MN/IA AT THIS TIME. LOTS OF UNCERTANTITY WITH THIS AS WELL DEPENDING ON ANY AFTERNOON CONVECTION ACROSS THE AREA. AT THIS TIME...HAVE OPTED TO GO WITH MENTION OF VCTS FOR SEVERAL HOURS AS BETTER DYNAMICS MOVE IN. LATER FORECASTS CAN HOPEFULLY FINE TUNE THINGS BETTER. WILL KEEP VFR SKIES/VSBYS BUT LOCAL MVFR/IFR WILL BE POSSIBLE WITH ANY CONVECTION THAT CAN FORM. STRONG WINDS EXCEEDING 50 KTS WILL ALSO BE POSSIBLE...BUT AGAIN CONFIDENCE TOO LOW TO PLACE IN TAFS. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. && FISHER/LASHLEY
Hazardous weather outlook, Jul 21, 12:28 PM EDT, 6 hours 52 minutes before
HAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE NORTHERN INDIANA 1128 AM EST WED JUL 21 2004 INZ003>009-012>018-020-022>027-032>034-MIZ077>081-OHZ001-002-004-005- 015-016-024-025-221100- ADAMS IN-ALLEN OH-ALLEN IN-BERRIEN MI-BLACKFORD IN-BRANCH MI-CASS MI- CASS IN-DE KALB IN-DEFIANCE OH-ELKHART IN-FULTON OH-FULTON IN- GRANT IN-HENRY OH-HILLSDALE MI-HUNTINGTON IN-JAY IN-KOSCIUSKO IN- LA PORTE IN-LAGRANGE IN-MARSHALL IN-MIAMI IN-NOBLE IN-PAULDING OH- PULASKI IN-PUTNAM OH-ST. JOSEPH MI-ST. JOSEPH IN-STARKE IN- STEUBEN IN-VAN WERT OH-WABASH IN-WELLS IN-WHITE IN-WHITLEY IN- WILLIAMS OH- INCLUDING THE CITIES OF...ANGOLA...ARCHBOLD...AUBURN... BENTON HARBOR...BENTON HEIGHTS...BERNE...BLUFFTON...BREMEN...BRYAN... BUCHANAN...BUTLER...COLDWATER...COLUMBIA CITY...DECATUR...DEFIANCE... DELPHOS...DOWAGIAC...DUNKIRK...DUNLAP...ELKHART...FAIR PLAIN... FAIRMOUNT...FORT SHAWNEE...FORT WAYNE...GARRETT...GAS CITY... GEORGETOWN...GOSHEN...GRANGER...GRISSOM AFB...GULIVOIRE PARK... HARTFORD CITY...HICKSVILLE...HILLSDALE...HUNTINGTON...KENDALLVILLE... KNOX...LA PORTE...LAGRANGE...LIGONIER...LIMA...LOGANSPORT...MARION... MICHIGAN CITY...MISHAWAKA...MONTICELLO...MONTPELIER...NAPOLEON... NAPPANEE...NEW HAVEN...NILES...NORTH MANCHESTER...OSSIAN...OTTAWA... PERU...PLYMOUTH...PORTLAND...ROCHESTER...SIMONTON LAKE... SOUTH BEND...ST. JOSEPH...STURGIS...SWANTON...SYRACUSE... THREE RIVERS...TRAIL CREEK...TRI-LAKES...UPLAND...VAN WERT... WABASH...WARSAW...WAUSEON...WESTVILLE...WINAMAC AND WINONA LAKE 1128 AM EST WED JUL 21 2004 THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHERN INDIANA...NORTHWEST OHIO AND SOUTHWEST LOWER MICHIGAN. .DAY ONE...THIS AFTERNOON AND TONIGHT THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING. THE GREATEST THREAT WITH THESE STORMS WILL BE DAMAGING WINDS...WHICH COULD EXCEED 70 MPH IN SOME AREAS. RAINFALL RATES OF 1 TO 2 INCHES PER HOUR WILL ALSO BE POSSIBLE WITH THE STRONGER STORMS...CAUSING PONDING OF WATER IN LOW AREAS. THUNDERSTORMS ARE EXPECTED TO MOVE ACROSS THE REGION THIS AFTERNOON...WITH ADDITIONAL THUNDERSTORMS POSSIBLE TONIGHT. IN ADVANCE OF THE THUNDERSTORMS...THE COMBINATION OF HEAT AND HUMIDITY WILL CREATE HEAT INDEX VALUES APPROACHING 100 DEGREES IN SOME AREAS. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY THERE IS A CHANCE FOR SEVERE STORMS THURSDAY AND THURSDAY EVENING. LARGE HAIL AND DAMAGING WINDS ARE POSSIBLE. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS LIKELY THIS AFTERNOON AND EVENING. STAY TUNED TO NOAA WEATHER RADIO FOR FURTHER DETAILS OR UPDATES, OR CHECK OUR WEB SITE AT WWW.CRH.NOAA.GOV/IWX
In the hours before
Local storm report, Jul 21, 7:09 PM EDT, 11 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTHERN INDIANA
609 PM EST WED JUL 21 2004
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION...ST.. ...SOURCE....
..REMARKS..
0555 PM TSTM WND DMG MICHIGAN CITY 41.71N 86.88W
07/21/2004 LA PORTE IN LAW ENFORCEMENT
NUMEROUS TREES AND POWERLINES KNOCKED DOWN OVER NORTHERN
HALF OF THE COUNTY.
0545 PM TSTM WND DMG MICHIGAN CITY 41.71N 86.88W
07/21/2004 LA PORTE IN COAST GUARD
MICHIGAN CITY LIGHTHOUSE RECORDED A WIND GUST OF 59 MPH.
0602 PM TSTM WND DMG MICHIGAN CITY 41.71N 86.88W
07/21/2004 LA PORTE IN AMATEUR RADIO
TREES AND POWERLINES REPORTED KNOCKED OVER.
&&
WAMSLEYThe 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.
Detroit, MI (KDTX), 12:00Z
11.3 hours before the tornado, 257 km from the path. July 21, 2004.
- Mixed-layer CAPE
- 1495 J/kg
- Mixed-layer CIN
- -15 J/kg
- Surface CAPE
- 429 J/kg
- Mixed-layer LCL
- 704 m above ground
- 0-6 km bulk shear
- 19 kt
- 0-1 km bulk shear
- 11 kt
- 0-1 km storm-relative helicity
- 34 m²/s²
- 0-3 km storm-relative helicity
- 37 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 5.3 K/km
Detroit, MI (KDTX), 00:00Z
0.7 hours after it, 257 km from the path. July 22, 2004.
- Mixed-layer CAPE
- 1124 J/kg
- Mixed-layer CIN
- -3 J/kg
- Surface CAPE
- 1622 J/kg
- Mixed-layer LCL
- 1078 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km bulk shear
- 5 kt
- 0-1 km storm-relative helicity
- 36 m²/s²
- 0-3 km storm-relative helicity
- 76 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.8
- 0-3 km lapse rate
- 6.5 K/km
The surface observations
South Bend (SBN), 18 km from the path, in the two hours either side.
| Time (UTC) | Temp (°F) | Dew point (°F) | Wind | Gust (kt) | Pressure (mb) | Weather |
|---|---|---|---|---|---|---|
| 21:54 UTC | 85 | 75 | 170° 14 kt | 1009.5 | HZ | |
| 22:25 UTC | 84.2 | 73.4 | 200° 9 kt | 1010.2 | HZ | |
| 22:54 UTC | 83 | 75 | 210° 7 kt | 1010.5 | HZ | |
| 23:01 UTC | 82.4 | 75.2 | 190° 10 kt | 1009.8 | HZ | |
| 23:19 UTC | 80.6 | 73.4 | 260° 33 kt | 39 | 1011.5 | TSRA SQ |
| 23:22 UTC | 75.2 | 71.6 | 290° 29 kt | 41 | 1012.5 | +TSRA SQ |
| 23:27 UTC | 71.6 | 69.8 | 310° 18 kt | 41 | 1012.5 | +TSRA SQ |
| 23:30 UTC | 69.8 | 69.8 | 330° 18 kt | 36 | 1011.9 | +TSRA |
| 23:33 UTC | 69.8 | 69.8 | 330° 15 kt | 23 | 1011.2 | +TSRA |
| 23:36 UTC | 69.8 | 69.8 | 330° 15 kt | 23 | 1011.2 | TSRA BR |
| 23:40 UTC | 69.8 | 69.8 | 340° 7 kt | 1011.2 | -TSRA BR | |
| 23:54 UTC | 70 | 69 | 150° 6 kt | 1010.8 | TSRA | |
| 00:01 UTC | 71.6 | 69.8 | 130° 7 kt | 1010.8 | -TSRA | |
| 00:54 UTC | 70 | 69 | 200° 11 kt | 1009.8 | -TSRA |
From the Iowa Environmental Mesonet's archive of airport observations.
The radar
The Northern Indiana radar (KIWX), 77 km away, was scanning. The volume nearest the touchdown began at 23:20 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.
What was reported nearby
Local storm reports within 60 km of the path, in the three hours either side.
| Time (UTC) | Report | Where | County | Remark |
|---|---|---|---|---|
| 23:10 UTC | TSTM WND DMG | Berrien Springs | Berrien, MI | NUMEROUS TREES AND POWERLINES KNOCKED DOWN COUNTYWIDE. |
| 23:32 UTC | TSTM WND DMG | 2 E Edwardsburg | Cass, MI | NUMEROUS TREES AND POWERLINES REPORTED KNOCKED DOWN. |
| 23:45 UTC | TSTM WND DMG | 3 Ne Niles | Berrien, MI | REPORTS OF TREES AND POWERLINES DOWN IN MARLIN VILLAGE TRAILER PARK. |
| 23:45 UTC | TSTM WND DMG | Edwardsburg | Cass, MI | REPORTS OF TREES AND POWERLINES DOWN IN EAGLE LAKE ESTATES. |
| 23:58 UTC | TSTM WND DMG | Constantine | St. Joseph, MI | LARGE TREE LIMBS REPORTED KNOCKED DOWN. |
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 MichiganEvery tornado in Michigan since 1950Warnings in force in Michigan nowThe forecast where you are
The other tornadoes of July 21, 2004
1 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| July 21 | 6:35 PM EST | F0 | Cass, MI | 0.5 | 50 |
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.