F0 tornado, LaPorte County, Indiana, August 25, 2001

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.

Rating

F0

Date

August 25, 2001

Touchdown

6:45 PM CDT (23:45 UTC)

Path length

0.1 miles (0.2 km)

Path width

20 yards (18 m)

Deaths

0

Injuries

0

County

LaPorte County

Touchdown point

41.570, -86.750

Lift-off point

41.570, -86.750

Record number

362

33 minutes of warning. NWS IWX issued a tornado warning for this county at 23:12 UTC, 33 minutes before the tornado touched down, in force until 00:00 UTC.

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 Storm Prediction Center had this point in a Slight Risk. The outlook in force was issued at 22:03 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.

NWS Northern Indiana wrote its last area forecast discussion before the tornado touched down at Aug 25, 2:54 PM CDT, 3 hours 51 minutes earlier.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
254 PM EST SAT AUG 25 2001

PRIMARY FCST CHALLENGE IS TSRA POTENTIAL FOR TONIGHT AND SUN AM.

LATEST MSAS ANALYSIS INDICATED CDFNT FM NRN LWR MI TO S CNTRL IA.
WRMFNT EXTD FM E CNTRL IA ACRS SRN IN TO ERN KY.  MOISTURE
CONVERGENCE AND INSTABILITY AXIS WERE ALIGNED ALONG FRONTAL
BOUNDARIES.  88D AND LIGHTNING DATA LOOPS INDICATED JUST SCT SHRA OVR
CWFA...WITH TSRA OVR CNTRL IN.

MODELS IN EXCELLENT AGREEMENT WITH BRINGING SHORTWAVE ACRS RGN
TONIGHT AND SUN AM. AT THE SFC...MODELS MOV CDFNT ACRS CWFA TONIGHT
AND SUN AM...WITH ETA OFFERING SLOWEST MOVEMENT.  MODELS HAVE
TRENDED SLOWER WITH THIS FEATURE PAST COUPLE OF RUNS...SO WL LEAN
TOWARD SLOWER ETA SOLUTION...WHICH ALSO VERIFIED BEST COUPLE OF
DAYS AGO WITH FRONTAL POSITION.  DESPITE LACK OF ONGOING
PRECIPITATION AND ONLY WK FORCING FM CDFNT AND DPVA...WL OPT FOR
CATEGORICAL POPS TONIGHT DUE TO SATURATED AIRMASS...PW VALUES NEAR 2
INCHES.  WET BULB ZERO HEIGHTS AROUND 12 TO 13K FT...SO HAIL NOT
MUCH OF A THREAT IN TERMS OF SVR WEATHER.  WOLCOTT PROFILER
INDICATED 30 KT WNDS IN MID LVLS...BUT WITH SATURATED AIRMASS...
SHOULD BE DIFFICULT TO GET MUCH MORE THAN THAT TO SFC.  BASED ON
SLOWER ETA SOLUTION...WL HOLD ON TO POPS FOR SERN HALF OF CWFA FOR
SUN AM...THEN SHOULD GET PARTIAL CLEARING DUE TO DRIER AIR ADVECTING
IN AND MIXING.  UNDER INFLUENCE OF HI PRES...SKIES WL CLR EARLY SUN
NIGHT. MODELS HAVE TRENDED A BIT MORE VIGOROUS WITH 5H SHORTWAVE
AND CDFNT FOR MON NIGHT.  MOISTURE STILL LOOKS LIMITED AND TIMING
DOES NOT FAVOR CONVECTIVE DEVELOPMENT.  GIVEN LOW CONFIDENCE
FACTOR AND FOR SAKE OF CONTINUITY...WL KEEP DRY FOR NOW.

AS FOR TEMPS...FAVOR COOLER FWC HIGHS NEXT COUPLE OF DAYS BASED ON
RECENT PERFORMANCE AND TEMP SCHEMES.  FWC AND MAV LOWS IN GOOD
AGREEMENT AND LOOK REASONABLE.

FOR THE EXTD...ECMWF CONTINUES TO OFFER SLIGHTLY SLOWER SOLUTION
WITH SYS FOR THU NIGHT AND FRI THAN AVN/MRF.  THUS...WK KEEP MENTION
OF STORMS ONLY IN FRI PD.  RMNDR OF EXTD LOOKS DRY.

.IWX...NONE.

BARJENBRUCH

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.

The Northern Indiana radar (KIWX), 91 km away, was scanning. The volume nearest the touchdown began at 23:43 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.

The live radar over the trackEvery 2001 tornado in IndianaEvery tornado in Indiana since 1950Warnings in force in Indiana nowThe forecast where you are

4 more were confirmed in the United States that day.

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.

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