Tornadoes · United States · Minnesota · 2002

F0 tornado, Wood Lake, Minnesota, August 16, 2002

This F0 tornado ran 0.2 miles across Yellow Medicine County on August 16, 2002, touching down at 8:43 PM CDT and reaching 25 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 mphthis tornado

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

  2. F173 to 112 mph

    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
F0
Date
August 16, 2002
Touchdown
8:43 PM CDT (01:43 UTC)
Path length
0.2 miles (0.3 km)
Path width
25 yards (23 m)
Deaths
0
Injuries
0
County
Yellow Medicine County
Touchdown point
44.650, -95.450
Lift-off point
44.650, -95.450
Record number
248

What the Weather Service recorded

Brief touchdown in open field. Debris cloud noted.

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

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 Twin Cities, MN wrote its last area forecast discussion before the tornado touched down at Aug 16, 3:30 PM CDT, 5 hours 13 minutes earlier.

Area forecast discussion, Aug 16, 3:30 PM CDT, 5 hours 13 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
330 PM CDT FRI AUG 16 2002

EMPHASIS ON SEVERE WEATHER THREAT TONIGHT AND STRONG WINDS ON SAT.
SIGNIFICANT S/W TRACKING EWD ACRS NRN MT...JUST SLIGHTLY NORTH OF
MODEL GUIDANCE.  SFC DEWPTS IN THE 60S TO NR 70 SURGING NWD TWD
CNTRL SODAK...JUST AHEAD OF SFC 999MB LOW PRES...WHICH IS CLOSER TO
ETA FORECAST.  EXPC SFC LOW PRES TO CONT DEEPENING AS IT TRACKS
NEWD.  SFC WRMFNT HELD BACK OVR ERN NE INTO SRN SODAK DUE TO AFTN
CONVECTION ACRS ERN SODAK.  SODAK CONVECTION FORMED ON STRENGTHENING
LOW LEVEL JET AND IMPRESSIVE MOISTURE RETURN.  CONVECTION HAS BEEN
WEAKENING AS IT PUSHES TWD SWRN MN...HOWEVER LATEST WDL PROFILE
SHOWING INCREASING SLY WNDS TO 20 TO 25KTS IN LOWEST GATES.  SCT
CONVECTION HAS BEGUN TO FIRE OVR FAR WEST CENTRAL MN AS WELL.  STG
ISENTROPIC OMEGA WITH RAPID INCREASE IN LOW TO MID LVL MOISTURE.
RUC 85H THETA E ADVECTION BULLSEYES ONGOING CONVECTION TO THE
SOUTH...AND ADVECTION INCREASES AND PUSHES ACRS MN CWA THRU EVE.
STRONG UPR LEVEL DIVERGENCE ASSOCD WITH RIGHT ENTRANCE RGN SPREADS
INTO AREA LATER TONIGHT WHEN ONGOING SQUALL LN AND POSSIBLE DERECHO
THREAT PUSHES IN FM DAKOTAS.

6 TO 10MB PRES RISES FOLLOWS ON HEELS OF STG COLD FNT INTO WRN CWA
LTR TNGT.  ETA BUFKIT SHOWS 39 KTS JUST OFF THE SFC LATE TNGT AT
KAXN SO WL ISSUE WIND ADVY FOR LATE TNGT INTO SAT MRNG FOR WRN
AREAS.  WL LET MIDNIGHT SHIFT CONSIDER EXPANDING ADVY FARTHER EAST
WITH MIDNIGHT ZONE ISSUANCE.  SFC GRADIENT LOOSENS AND CORE OF COLD
AIR ADVECTION SLIDES RAPIDLY EWD WITH STRONGEST PRES RISES ACRS NRN
MN. DRY AIR ENGULF RGN DURING WEEKEND AND LINGERS INTO MON.
MOISTURE RETURN TUE INTO TUE NGT AS EMBEDDED WAVE IN ZONAL FLOW
MOVES ACRS UPR MIDWEST.  ENSEMBLE PRECIP PROBS SHOW HIGH VALUES FOR
TUE INTO EARLY WED.
.MSP...WIND ADVISORY WEST LATE TNGT INTO SAT MRNG.
MBK

In the hours before

Special weather statement, Aug 16, 5:00 PM CDT, 3 hours 43 minutes before
MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028-170200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
500 PM CDT FRI AUG 16 2002

...RISK OF SEVERE THUNDERSTORMS TONIGHT...

LATE THIS AFTERNOON THE ATMOSPHERE LOOKED RIPE FOR A SEVERE WEATHER
OUTBREAK TO DEVELOP MINNESOTA. IT APPEARS THAT THE GREATEST
POTENTIAL OF SEVERE THUNDERSTORMS...INCLUDING TORNADOES...WILL BE
INITIALLY OVER WEST CENTRAL AND SOUTHWEST MINNESOTA.  PERSONS LIVING
NEAR MORRIS...BENSON...GRANITE FALLS...REDWOOD FALLS...AND FAIRMONT
WILL WANT TO LISTEN FOR SEVERE WEATHER WARNINGS AND MOVE TO SHELTER
QUICKLY.

THE STORMS TONIGHT WILL LIKELY CONTAIN DAMAGING WINDS. DUE TO THE
STRENGTH OF THE APPROACHING LOW PRESSURE SYSTEMS...WIND GUSTS
TONIGHT WITH THE SEVERE STORMS COULD APPROACH 80 MPH.  AN AREA OR
LINE OF STRONG TO SEVERE STORMS...WILL TRACK ACROSS CENTRAL AND
SOUTHERN MINNESOTA...INTO WEST CENTRAL WISCONSIN LATER TONIGHT.

SPOTTERS AND THE PUBLIC ALIKE SHOULD KEEP UP ON THE LATEST
STATEMENTS...WATCHES OR WARNINGS.

IN ADDITION TO THE SEVERE WEATHER POTENTIAL TONIGHT...VERY WINDY
CONDITIONS ARE EXPECTED ACROSS THE REGION ON SATURDAY IN THE WAKE OF
THE LOW PRESSURE STORM SYSTEM.

EDWARDS
Local storm report, Aug 16, 6:45 PM CDT, 1 hour 58 minutes before
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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.

Minneapolis, MN (KMPX), 00:00Z

1.7 hours before the tornado, 148 km from the path. August 17, 2002.

Skew-T log-pSkew-T log-p diagram, Minneapolis, MN at 00:00Z on 2002-08-17Temperature 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 -71223, lifted condensation level 1774 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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, Minneapolis, MN at 00:00Z on 2002-08-17The 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 244 square meters per square second, 0 to 6 km bulk shear 64 knots.1939587897Sfc1 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
-71223 J/kg
Surface CAPE
177 J/kg
Mixed-layer LCL
1774 m above ground
0-6 km bulk shear
64 kt
0-1 km bulk shear
28 kt
0-1 km storm-relative helicity
244 m²/s²
0-3 km storm-relative helicity
375 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1
0-3 km lapse rate
5.8 K/km

Open this sounding in Storm Lab

The surface observations

Redwood Fall (RWF), 31 km from the path, in the two hours either side.

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

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

The radar

The Minneapolis radar (KMPX), 150 km away, was scanning. The volume nearest the touchdown began at 01:43 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 trackEvery 2002 tornado in MinnesotaEvery tornado in Minnesota since 1950Warnings in force in Minnesota nowThe forecast where you are

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.