Tornadoes · United States · Minnesota · 2006

F1 tornado, Donaldson, Minnesota, July 27, 2006

This F1 tornado ran 4.5 miles across Kittson and Marshall counties on July 27, 2006, touching down at 5:02 PM CDT and reaching 50 yards wide. It killed nobody, and did $50,000 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.

  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
July 27, 2006
Touchdown
5:02 PM CDT (22:02 UTC)
Path length
4.5 miles (7.2 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
Property damage
$50,000
Counties
Kittson and Marshall counties
Touchdown point
48.600, -96.830
Lift-off point
48.520, -96.820
Record number
770

What the Weather Service recorded

The tornado touched down in a field just north of highway 11 and travelled for about 3.5 miles before it crossed into Marshall county. Tornadic winds snapped several cottonwood trees at a homestead and swirled tree branches around the yard. Smaller tree branches were lofted over a mile to the south by the tornado and crops were swirled by the winds. Peak winds were estimated at 80 mph.

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

The warnings

13 minutes of warning. NWS FGF issued a tornado warning for this county at 21:49 UTC, 13 minutes before the tornado touched down, in force until 22:45 UTC.

Issued (UTC)ExpiredProductOffice
21:23 UTC22:30 UTCSevere Thunderstorm WarningFGF
21:49 UTC22:45 UTCTornado WarningFGF
22:25 UTC01:32 UTCSevere Thunderstorm WatchFGF

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 General Thunderstorms Risk. The outlook in force was issued at 20:01 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 Grand Forks, ND wrote its last area forecast discussion before the tornado touched down at Jul 27, 2:30 PM CDT, 2 hours 32 minutes earlier.

Area forecast discussion, Jul 27, 2:30 PM CDT, 2 hours 32 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
230 PM CDT THU JUL 27 2006

FORECAST CHALLENGE CONCERNS TEMPERATURES AND PCPN CHANCES.

SIGNIFICANT DIFFERENCES IN MODEL SOLUTIONS MAINLY CONCERNING
SOUTHWARD PUSH OF COLDER AIR AND RESULTING BOUNDARY ORIENTATION.
ALTHOUGH MODELS INITIALIZED CLOSE ON THERMAL FIELDS GFS INITIALIZED
BETTER WITH WEAKER STRENGTH OF SURFACE FEATURES AND NAM
WAY-OVERDOING NEAR TERM QPF. IN ADDITION BASED ON CURRENT NEAR ZONAL
PATTERN AND RISING HEIGHTS FEEL COLD PUSH ON NAM OVERDONE AS WELL.
WITH ABOVE THINKING WILL UTILIZE GFS FOR FORECAST.

SHORTWAVE CONTINUES TO TRACK EAST ACROSS CENTRAL MB INTO ONTARIO
OVERNIGHT. ANOTHER WAVE OVER CENTRAL MT WHICH WILL DROP SE AND RIGHT
NOW TOUGH TO PICKOUT ANY MINOR FEATURE ON WATER VAPOR IMAGERY
BETWEEN THE TWO THAT WOULD AFFECT FA. MAIN ENERGY REMAINS NORTH OF
BORDER TONIGHT. WEAK SURFACE BOUNDARY REMAINS ON WESTERN FA DOORSTEP
AND WILL CROSS FA THIS EVENING. NOT CONFIDENT ON T POTENTIAL WITH
BOUNDARY PASSAGE HOWEVER RUC NOT AS BEEFY WITH CAPPING VS GFS SO
WILL MAINLY SLIGHT POPS TO BE SAFE. COLD ADVECTION IN WAKE OF
BOUNDARY REACHES INTERNATIONAL BORDER LATE TONIGHT SO NOT EXPECTING
BIG DROP IN TEMPERATURES OVERNIGHT AND MIN TEMPERATURES SHOULD
RESEMBLE LAST FEW NIGHTS.

BIG DIFFERENCES IN MODELS STARTING TOMORROW WITH SOUTHWARD PUSH OF
COLDER AIR AS STATED ABOVE. NAM DRIVES COLDER AIR SOUTH THROUGH
WHILE GFS HOLDS COLDEST AIR ALONG CANADIAN BORDER THAN SHIFTS
COLDER AIR EAST. BASED ON CONTINUED ZONAL FLOW AND BUILDING MID
LEVEL HEIGHTS AM HAVING A HARD TIME BELIEVING NAM SOLUTION AND WILL
HOLD WITH WARMER GFS SOLUTION. WILL STILL SEE THERMAL GRADIENT
ACROSS FA WITH LOWEST MAX TEMPERATURES ALONG INTERNATIONAL BORDER.

AS A RESULT OF MODEL DIFFERENCES E-W ORIENTED BOUNDARY LOCATION
DIFFERS WITH GFS ALONG ND/SD BORDER AND NAM ALONG SD/NE BORDER.
850MB LOW LEVEL JET INCREASES TO 30KT ALONG WITH FAVORABLE BULK
SHEAR AND MODEST ELEVATED INSTABILITY. 700 MB TEMPERATURES GET QUITE
WARM OVER SW 1/3 OF FA SO CONVECTION MAY BECOME ORIENTED ALONG
FRINGE OF CAP. WITH BOUNDARY ORIENTATION UNCERTAIN WILL MAINTAIN LOW
POP THREAT ACROSS WHOLE FA.

HEAT THEN BECOMES MAIN ISSUE REMAINDER OF WEEKEND. 700MB
TEMPERATURES CLIMB TO 12-16C WHICH SHOULD EFFECTIVELY CAP ATMOSPHERE
AS WARM FRONT LIFTS NORTH THROUGH FA. PNS ISSUED ADDRESSING HEAT
THREAT.

MON THRU THURS...THE COMBINATION OF SOUTHWEST FLOW ALOFT AND A LOW
PRESSURE SYSTEM DRAPED ACROSS THE UPPER MIDWEST WILL SET THE STAGE
FOR THUNDERSTORM DEVELOPMENT. JUST WHERE THE LOW SETS UP AND ITS
RESULTANT MOVEMENT WILL GREATLY AFFECT AMOUNTS AND TIMING OF PRECIP.
BOTH THE GFS AND DGEX SHOW THE LOW AND ASSOCIATED FRONTS MOVING FROM
CENTRAL SD INTO SOUTHERN MN THRU TUESDAY. HIGH PRESSURE BUILDS IN
FROM THE WEST BY THE MIDDLE OF THE WEEK AS THE FLOW ALOFT BECOMES
MORE ZONAL. TEMPS WILL HINGE ON FRONTAL POSITIONS...BUT OVERALL THE
TREND OF ABOVE AVERAGE VALUES WILL HOLD TRUE.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&

VOELKER/ANDERSON
Hazardous weather outlook, Jul 27, 4:30 PM CDT, 32 minutes before
HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE GRAND FORKS ND
430 PM CDT THU JUL 27 2006

MNZ001>009-013>017-022>024-027>032-040-NDZ006>008-014>016-024-
026>030-038-039-049-052>054-281115-
WEST POLK-NORMAN-CLAY-KITTSON-ROSEAU-LAKE OF THE WOODS-
WEST MARSHALL-EAST MARSHALL-NORTH BELTRAMI-PENNINGTON-RED LAKE-
EAST POLK-NORTH CLEARWATER-SOUTH BELTRAMI-MAHNOMEN-
SOUTH CLEARWATER-HUBBARD-WEST BECKER-EAST BECKER-WILKIN-
WEST OTTER TAIL-EAST OTTER TAIL-WADENA-GRANT-TOWNER-CAVALIER-
PEMBINA-BENSON-RAMSEY-EASTERN WALSH COUNTY-EDDY-NELSON-
GRAND FORKS-GRIGGS-STEELE-TRAILL-BARNES-CASS-RANSOM-SARGENT-
RICHLAND-WESTERN WALSH COUNTY-
430 PM CDT THU JUL 27 2006

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EASTERN NORTH
DAKOTA...WEST CENTRAL AND NORTHWEST MINNESOTA.

.DAY ONE...LATE THIS AFTERNOON AND TONIGHT

ISOLATED SEVERE THUNDERSTORMS PRODUCING LARGE HAIL WILL OCCUR OVER
EXTREME NORTHWEST MINNESOTA UNTIL 9 PM.  THE AREA OF CONCERN IS
NORTH OF HIGHWAY TWO.  AN UPPER LEVEL DISTURBANCE WILL MOVE ALONG
THE MANITOBA AND MINNESOTA BORDER THIS EVENING CAUSING THESE STORMS
TO DEVELOP.  THE ACTIVITY WILL WEAKEN WITH SUNSET AND DIMINISH.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

HOT CONDITIONS ARE EXPECTED TO OVERSPREAD THE REGION SUNDAY INTO
MONDAY. TEMPERATURES IN THE 90S COUPLED WITH INCREASING HUMIDITY
WILL RESULT IN HEAT INDICES APPROACHING 100 DEGREES FOR AREAS
GENERALLY ALONG AND SOUTH OF THE I-94 CORRIDOR.

ADDITIONAL THUNDERSTORM CHANCES ARE POSSIBLE ACROSS THE REGION FRIDAY
NIGHT INTO SATURDAY AND THEN AGAIN ON MONDAY NIGHT.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS POSSIBLE FROM HALLOCK TO BEMIDJI TO ROSEAU.

RIDDLE

In the hours before

Local storm report, Jul 27, 4:57 PM CDT, 5 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS
457 PM CDT THU JUL 27 2006

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0440 PM     HAIL             4 SE HALLOCK            48.73N 96.88W
07/27/2006  E0.88 INCH       KITTSON            MN   PUBLIC

&&

BRAMER
Local storm report, Jul 27, 4:59 PM CDT, 3 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS
459 PM CDT THU JUL 27 2006

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0440 PM     TSTM WND DMG     4 SE HALLOCK            48.73N 96.88W
07/27/2006                   KITTSON            MN   PUBLIC

            SIGNIFICANT TREE DAMAGE DUE TO STRAIGHT LINE WINDS.

&&

BRAMER

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.

International Fa, MN (KINL), 12:00Z

10.0 hours before the tornado, 259 km from the path. July 27, 2006.

Skew-T log-pSkew-T log-p diagram, International Fa, MN at 12:00Z on 2006-07-27Temperature 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 -88206, lifted condensation level 1526 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, International Fa, MN at 12:00Z on 2006-07-27The 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 10 square meters per square second, 0 to 6 km bulk shear 27 knots.1939Sfc1 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
-88206 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1526 m above ground
0-6 km bulk shear
27 kt
0-1 km bulk shear
2 kt
0-1 km storm-relative helicity
10 m²/s²
0-3 km storm-relative helicity
43 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.0 K/km

Open this sounding in Storm Lab

International Fa, MN (KINL), 00:00Z

2.0 hours after it, 259 km from the path. July 28, 2006.

Skew-T log-pSkew-T log-p diagram, International Fa, MN at 00:00Z on 2006-07-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 411 joules per kilogram, CIN -6, lifted condensation level 2111 meters above ground. Wind barbs in knots down the right edge.LCLEL10008507005003002001001 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, International Fa, MN at 00:00Z on 2006-07-28The 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 12 square meters per square second, 0 to 6 km bulk shear 27 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
411 J/kg
Mixed-layer CIN
-6 J/kg
Surface CAPE
862 J/kg
Mixed-layer LCL
2111 m above ground
0-6 km bulk shear
27 kt
0-1 km bulk shear
9 kt
0-1 km storm-relative helicity
12 m²/s²
0-3 km storm-relative helicity
82 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5
0-3 km lapse rate
8.7 K/km

Open this sounding in Storm Lab

The surface observations

Hallock (HCO), 23 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
20:15 UTC91.466.2210° 6 kt1006.1
20:35 UTC93.266.2200° 9 kt1005.8
20:55 UTC89.664.4200° 7 kt1005.4TS
21:37 UTC66.264.4140° 25 kt361006.1+TSRA
21:55 UTC6868130° 16 kt231006.1VCTS
21:57 UTC6868130° 13 kt1006.1VCTS
22:15 UTC69.869.8130° 17 kt231006.1
22:35 UTC73.473.4130° 10 kt161006.1
22:55 UTC7777140° 7 kt1005.8
23:15 UTC75.275.2140° 5 kt1005.8
23:35 UTC80.680.6100° 5 kt1005.8
23:55 UTC80.680.6360° 11 kt1006.1

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

The radar

The Fargo/Grand Forks radar (KMVX), 121 km away, was scanning. The volume nearest the touchdown began at 22:02 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
21:40 UTCTSTM WND DMG4 Se HallockKittson, MNSIGNIFICANT TREE DAMAGE DUE TO STRAIGHT LINE WINDS.
21:40 UTCHAIL 0.884 Se HallockKittson, MN
21:50 UTCFUNNEL CLOUD3 Ese KennedyKittson, MNA FUNNEL CLOUD BEGAN TO DEVELOP UNDER A PERSISTENT WALL CLOUD FORMATION AND WAS VIEWED BY A FARMER IN HIS FIELD SOUTHEAST OF KENNEDY. THE WALL CLOUD APPEARED TO TURN TO THE RIGHT OF ITS ORIGINAL SOUTHEAST PATH AND TOWARD
21:58 UTCHAIL 2.755 Ene DonaldsonKittson, MNSEVERAL SQUARE MILES OF CROPS WERE SHATTERED OR FLATTENED BY LARGE HAIL IN EASTERN DAVIS AND WESTERN SPRINGBROOK TOWNSHIPS.
22:01 UTCHAIL 1.753 E DonaldsonKittson, MN
22:01 UTCHAIL 1.754 E DonaldsonKittson, MN
22:02 UTCTORNADO 13 Ene DonaldsonKittson, MNA TORNADO TOUCHED DOWN IN A FIELD JUST NORTH OF HIGHWAY 11 AND TRAVELED FOR ABOUT 3.5 MILES BEFORE IT ENDED IN MARSHALL COUNTY. TORNADIC WINDS SNAPPED SEVERAL COTTONWOOD TREES AT A HOMESTEAD AND SWIRLED TREE BRANCHES ARO
22:04 UTCHAIL 1.759 Ne StephenMarshall, MN
22:09 UTCTORNADO 16 Nne StephenMarshall, MNA TORNADO CONTINUED FROM KITTSON COUNTY INTO MARSHALL COUNTY AND TRACKED FOR ABOUT 1 MORE MILE TO THE SOUTH UNTIL 512 PM. THE TORNADO BLEW OVER A ROAD SIGN AND CAUSED ADDITIONAL EXTREME WIND STRESS AS CROPS WERE SWIRLED

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

This ground now

The live radar over the trackEvery 2006 tornado in MinnesotaEvery tornado in Minnesota since 1950Warnings in force in Minnesota nowThe forecast where you are

The other tornadoes of July 27, 2006

3 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
July 276:46 PM CDTF0Polk, MN2.525$30,000
July 276:57 PM CDTF0Red Lake, MN2.525$2,000
July 277:26 PM CDTF0Lac qui Parle, MN0.533

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.