Tornado and Flash Flooding in Minnesota, July 16 to 17, 2011

Name: Tornado and Flash Flooding in Minnesota, July 16 to 17, 2011
Start: 2011-07-16T19:10
End: 2011-07-17T04:00
Location: Minnesota

July 16 to 17, 2011 · NWS FGF · 14 events in 4 counties and zones

The 16th was hot and humid with late afternoon temperatures topping out in the 80s to around 90 and dew point temperatures well into the 70s. This created a large amount of instability.

Where it happened

Every event with a place to put it. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: $7,000
Crop damage: $10,000
Events: 14

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS FGF wrote it up.

The 16th was hot and humid with late afternoon temperatures topping out in the 80s to around 90 and dew point temperatures well into the 70s. This created a large amount of instability. By early in the evening, thunderstorms began to flare up again aided by a weak low level jet.

What forecasters said that day

The local office's own words before the first event, 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 first event at Jul 16, 6:41 PM CST, 29 minutes earlier.

Area forecast discussion, Jul 16, 6:41 PM CST, 29 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
741 PM CDT SAT JUL 16 2011

.DISCUSSION...

WITH ONGOING SEVERE WEATHER WILL BE FAIRLY BRIEF THIS EVENING.
THUNDERSTORMS HAVE DEVELOPED ALONG A TROUGH LINE FROM CENTRAL ND
INTO EASTERN ND...WITH EXTREME INSTABILITY AND STRONG DEEP LAYERED
SHEAR. A TORNADO WATCH IS IN EFFECT UNTIL MIDNIGHT FOR MUCH OF THE
AREA...AND EXPECT STORMS TO MOVE AND SLOWLY DEVELOP TO THE EAST.
THE RUC/NAM SUPPORT THIS OVERALL SCENARIO. CURRENT GRIDS REFLECT
THIS THINKING AND NO CHANGE EXPECTED THIS EVENING.

&&

.AVIATION...

FOG COULD BECOME A CONCERN OVERNIGHT AFTER CONVECTION DISSIPATES
LATER THIS EVENING AND OVERNIGHT. HAVE MENTIONED FOG AND VSBYS
COULD BE EVEN LOWER IN SPOTS...WITH WINDS BECOME LIGHT AND VARIABLE.

&&

.PREV DISCUSSION... /ISSUED 300 PM CDT SAT JUL 16 2011/

SHORT TERM...
MAIN CHALLENGES CONTINUE TO BE HEAT/HUMIDITY AND CONVECTIVE
CHANCES. NOT A STRONG SIGNAL IN THE MODELS AS TO THESE CHANCES SO
WILL LEAN MORE TOWARD A BLEND OF CONTINUITY/HPC.

TONIGHT...ONE ROGUE AREA OF TSTMS RODE THROUGH THE CENTER OF THE
FA TODAY. MAIN THREAT FROM THESE TSTMS WAS WIND. THE MORNING FOG
MAY HAVE AFFECTED THE WIND POTENTIAL AS THIS AREA OF TSTMS MOVED
ACROSS. THERE WAS FOG JUST ABOUT EVERYWHERE TODAY WHICH HAS HELD
THE TEMP DOWN/KEPT AN INVERSION LAYER NEAR THE SFC. THE ONE WIND
REPORT RECEIVED AT NORTHWOOD MAY HAVE BEEN THE EXCEPTION AS THIS
AREA DID NOT GET AS MUCH FOG AND ACTUALLY HAD SOME SUN EARLY ON.
CURRENTLY THIS AREA OF TSTMS IS MOVING OUT OF THE FA WITH ONLY A
FEW SCATTERED ECHOES BEHIND IT. COULD HAVE SOME SUBSIDENCE IN THE
WAKE OF THIS FIRST ROUND OF CONVECTION ALTHOUGH THERE IS STILL A
LOT OF ACCAS OUT THERE. LOTS OF HEAT AND HUMIDITY GENERATING A LOT
OF CAPE. QUESTION FOR ADDITIONAL CONVECTION MAY AGAIN BE THE
SOURCE OF THE KICKER. SFC FLOW PRETTY WEAK BUT SOME LOW LEVEL
CONVERGENCE ACROSS WESTERN AND CENTRAL ND. SOME 850MB WIND
CONVERGENCE INTO CENTRAL ND INTO THE SAME AREA TOO. HOWEVER 700MB
TEMPS ARE INCREASING...ESPECIALLY ACROSS THE SOUTHWEST/SOUTH.
HARD TO PICK OUT MUCH ON WATER VAPOR IMAGERY SO IF ANYTHING HELPS
INITIATE CONVECTION IN THE MID/UPPER LEVELS IT WILL BE SUBTLE. IF
NOTHING CAN RE-FIRE LATE THIS AFTERNOON INTO THE EARLY EVENING MAY
HAVE TO WAIT FOR SOME LOW LEVEL JET ACTIVITY...WHICH LOOKS BETTER
SOUTH OF THE REGION. ALL SAID IT WILL BE ANOTHER NIGHT WHERE WILL
JUST HAVE TO WATCH WAIT AND SEE. THEREFORE KEPT JUST CHANCES FOR
TSTMS ACROSS MAINLY THE NORTHERN HALF OF THE FA AND LEFT ANY
MENTION OF SEVERE OUT FOR NOW. ALTHOUGH SOME AREAS HAVE BEEN
COOLER SO FAR EXPECT THE LATE DAY HEATING TO BRING MOST AREAS BACK
INTO HEAT/HUMIDITY RELATED HEADLINES. WENT AHEAD AND ADDED FOG TO
THE FORECAST TONIGHT AS CONDITIONS SHOULD BE SIMILAR TO LAST
NIGHT...WHERE FOG GOT DENSE IN MANY PLACES.

SUN-TUE...THE HEAT AND HUMIDITY CONTINUES AND MADE NO CHANGES TO
THE HEAT RELATED HEADLINES WHICH ARE IN EFFECT AT THIS POINT UNTIL
EARLY WED. SEEMS LIKE BEST CHANCES FOR WARNING CRITERIA WILL STILL
BE ALONG AND SOUTH OF HIGHWAY 2 AND JUST A BIT COOLER TO THE
NORTH. SO CURRENT HEADLINES FINE. QUESTIONS ARE STILL CONVECTIVE
CHANCES. STILL LOOKS LIKE THERE COULD BE LOW CHANCES FOR TSTMS
THROUGHOUT THE ENTIRE SHORT TERM PERIOD. CURRENTLY HAVE TUE DRY
BUT MODELS TODAY ARE COMING IN A LITTLE WETTER. NOT A GOOD SIGNAL
BETWEEN ANY OF THE MODELS SO ELECTED TO KEEP TUE DRY FOR NOW. LOW
PCPN CHANCES PRIOR TO TUE BASICALLY LEFT AS IS.

LONG TERM (WED-SAT)...
LOW CONFIDENCE ON EXTENDED PORTION OF FORECAST. MODELS ALL DIFFER ON
DEGREE OF FLATTENING CURRENT MID LEVEL RIDGE AS WELL AS SHORT WAVE
ENERGY CROSSING FRINGE OF RIDGE THROUGH PERIOD. TIMING OF ASSOCIATED
SURFACE FEATURES ALSO NOT IN GOOD AGREEMENT. WILL LEAN WITH
PERSISTENCE/NATIONAL GUIDANCE.

POPS SEEM REASONABLE EARLY IN PERIOD (WEDNESDAY) WITH PASSAGE OF
SURFACE BOUNDARY/SHORTWAVE RIDING OVER CREST OF RIDGE. MODELS IN
REASONABLE AGREEMENT WITH THIS. AFTERWARDS LITTLE AGREEMENT SO WILL
MAINTAIN EXISTING LOW END POPS. THERMAL PROFILES ALSO DIFFER WITH
ANY SIGNIFICANT COOLING NOT COMING TIL LATE OR AFTER END OF PERIOD.

AVIATION...
PESKY MVFR CIGS LIFTING BUT STILL MOST PREVALENT ACROSS SOUTHERN AND
FAR EASTERN FA...FAR/BJI TAF SITES. ONCE CONVECTION EXITS BJI TAF
SITE VERY TOUGH TO PIN POINT WHERE ADDITIONAL CONVECTION POSSIBLE.
WITH WEAK FLOW AND VERY MOIST LOW LEVELS FOG A GOOD BET ACROSS FA
LATE TONIGHT...POSSIBLY DENSE.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...EXCESSIVE HEAT WARNING UNTIL 1 AM CDT WEDNESDAY FOR NDZ024-
     026>030-038-039-049-052-053.

     HEAT ADVISORY UNTIL 1 AM CDT WEDNESDAY FOR NDZ006>008-014>016-
     054.

MN...EXCESSIVE HEAT WARNING UNTIL 1 AM CDT WEDNESDAY FOR MNZ001>003-
     014-015-022>024-027>032-040.

     HEAT ADVISORY UNTIL 1 AM CDT WEDNESDAY FOR MNZ004>009-013-016-
     017.

&&

DK

Hazardous weather outlook, Jul 16, 4:57 AM CST, 14 hours 13 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GRAND FORKS ND
557 AM CDT SAT JUL 16 2011

MNZ001>009-013>017-022>024-027>032-040-NDZ006>008-014>016-024-
026>030-038-039-049-052>054-171100-
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-EDDY-NELSON-GRAND FORKS-
GRIGGS-STEELE-TRAILL-BARNES-CASS-RANSOM-SARGENT-RICHLAND-
WESTERN WALSH-
557 AM CDT SAT JUL 16 2011

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

.DAY ONE...TODAY AND TONIGHT

THERE IS A SLIGHT CHANCE FOR SEVERE THUNDERSTORMS THIS AFTERNOON
AND EVENING...WITH THE HIGHEST PROBABILITIES NEAR THE
INTERNATIONAL BORDER. MOIST...UNSTABLE AIR WILL CONTINUE TO POUR
INTO THE NORTHERN PLAINS. WHILE HOT TEMPERATURES ALOFT WILL KEEP
THUNDERSTORM DEVELOPMENT FROM BECOMING WIDESPREAD...ANY STORMS
THAT DEVELOP COULD BECOME SEVERE DUE TO STRONG WINDS IN THE UPPER
LEVELS OF THE ATMOSPHERE. HAIL AND DAMAGING WINDS WILL BE THE
PRIMARY THREAT...ALTHOUGH AN ISOLATED TORNADO IS NOT OUT OF THE
QUESTION.

THE HUMID CONDITIONS AND TEMPERATURES REACHING THE 90S WILL ALLOW
HEAT INDEX VALUES TO CLIMB ABOVE 100 OR EVEN 105 DEGREES ACROSS A
LARGE PORTION OF THE FORECAST AREA. EXCESSIVE HEAT WARNINGS AND
HEAT ADVISORIES ARE IN EFFECT.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

THERE WILL BE A CHANCE FOR THUNDERSTORMS ON SUNDAY AFTERNOON AND
EVENING...WITH SOME HAIL AND DAMAGING WINDS POSSIBLE.

THE HUMID CONDITIONS AND TEMPERATURES REACHING THE 90S WILL ALLOW
HEAT INDEX VALUES TO CLIMB ABOVE 100 OR EVEN DEGREES ACROSS A
LARGE PORTION OF THE FORECAST AREA. EXCESSIVE HEAT WARNINGS AND
HEAT ADVISORIES ARE IN EFFECT THROUGH TUESDAY EVENING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED NORTH OF THE HIGHWAY 200
CORRIDOR.

JR

In the hours before

Local storm report, Jul 16, 4:32 PM CST, 2 hours 38 minutes before

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
532 PM CDT SAT JUL 16 2011

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

1130 AM     TSTM WND DMG     NORTHWOOD               47.74N 97.57W
07/16/2011                   GRAND FORKS        ND   LAW ENFORCEMENT

            TREES BLOWN DOWN.

1200 PM     TSTM WND DMG     2 S THOMPSON            47.75N 97.11W
07/16/2011                   GRAND FORKS        ND   NWS STORM SURVEY

            SEVERAL LARGE 3 TO 5 INCH DIAMETER TREE BRANCHES WERE
            BROKEN DOWN. LARGE PORTIONS OF SMALL GRAIN AND CORN CROPS
            WERE LODGED BY THE WINDS ACROSS NORTHEAST MICHIGAN AND
            NORTHERN AMERICUS TOWNSHIPS.

1210 PM     HAIL             8 ESE THOMPSON          47.73N 96.95W
07/16/2011  E0.88 INCH       GRAND FORKS        ND   PUBLIC

            VERY HEAVY RAINS AND STRONG WINDS WERE ACCOMPANIED BY AN
            A FEW DIME TO NICKEL SIZED HAIL.

1215 PM     TSTM WND DMG     2 SSE BYGLAND           47.78N 96.92W
07/16/2011                   POLK               MN   NWS STORM SURVEY

            A FEW LARGE 3 TO 5 INCH TREE BRANCHES WERE BROKEN DOWN
            AND AREA SMALL GRAIN AND CORN CORPS WERE PARTIALLY LODGED
            ACROSS SOUTHERN BYGLAND TOWNSHIP.

&&

GGUST

Local storm report, Jul 16, 6:14 PM CST, 56 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
714 PM CDT SAT JUL 16 2011

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

0712 PM     TORNADO          15 SE SUTTON            47.25N 98.21W
07/10/2011                   GRIGGS             ND   PUBLIC

            PERSON 5 S OF SUTTON ND SEES A TORNADO 10 MILES TO HIS
            EAST ... RELAYED VIA WFO BISMARCK

&&

PJS

Local storm report, Jul 16, 6:20 PM CST, 50 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
720 PM CDT SAT JUL 16 2011

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

0714 PM     FUNNEL CLOUD     6 W COOPERSTOWN         47.44N 98.25W
07/16/2011                   GRIGGS             ND   PUBLIC

            PUBLIC REPORT OF FUNNEL CLOUD REPORTED ON VALLEY NEWS
            LIVE FACEBOOK PAGE

&&

PJS

Local storm report, Jul 16, 6:21 PM CST, 49 minutes before

PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
721 PM CDT SAT JUL 16 2011

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

0710 PM     TORNADO          15 SE SUTTON            47.25N 98.21W
07/16/2011                   GRIGGS             ND   PUBLIC

            PERSON 5 S OF SUTTON ND SEES A TORNADO 10 MILES TO HIS
            EAST ... RELAYED VIA WFO BISMARCK

&&

PJS

Local storm report, Jul 16, 6:54 PM CST, 16 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
754 PM CDT SAT JUL 16 2011

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

0751 PM     TORNADO          1 SW MINNEWAUKAN        48.06N 99.27W
07/16/2011                   BENSON             ND   LAW ENFORCEMENT

            FIRE DEPT AND LAW ENFORCEMENT REPORT TORNADO ON THE
            GROUND 2 SOUTH AND 1 WEST OF MINNEWAUKAN

&&

PJS

Local storm report, Jul 16, 6:58 PM CST, 12 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
758 PM CDT SAT JUL 16 2011

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

0756 PM     TORNADO          3 S MINNEWAUKAN         48.03N 99.25W
07/16/2011                   BENSON             ND   FIRE DEPT/RESCUE

            TORNADO REPORTED OVER LONG LAKE SUCKING UP WATER

&&

PJS

The radar

The Fargo/Grand Forks radar (KMVX), 119 km away, was scanning. The volume nearest the first event began at 01:11 UTC.

Open the radar archive at this moment

Event by event

8 hail, 2 flash flood, 2 thunderstorm wind, 1 tornado, 1 funnel cloud. Local standard time, as filed.

Hail, Kittson

When: July 16, 7:10 PM CST
Where: Kittson County, 1.38 mi S of Donaldson
Measured: 1.25 in hail
Reported by: Public
Coordinates: 48.560, -96.900

Tornado, Marshall

When: July 16, 7:25 PM CST to 7:26 PM CST
Where: Marshall County, 3.72 mi NNE of Stephen Arpt
Rating: EF0
Path length: 0.1 mi
Path width: 10 yd
Reported by: Fire Department/Rescue
Coordinates: 48.520, -96.840

A brief touchdown with dust swirl was noted in a open field. Peak winds were estimated at 70 mph.

Hail, Kittson

When: July 16, 8:06 PM CST
Where: Kittson County, Karlstad
Measured: 0.75 in hail
Reported by: Amateur Radio
Coordinates: 48.580, -96.520

Hail, Kittson

When: July 16, 8:10 PM CST
Where: Kittson County, Karlstad
Measured: 1 in hail
Reported by: Trained Spotter
Coordinates: 48.580, -96.520

The hail was mostly pea sized, but there were a few quarters mixed in.

Funnel Cloud, Roseau

When: July 16, 8:30 PM CST
Where: Roseau County, 4.57 mi W of Strathcona
Reported by: Law Enforcement
Coordinates: 48.550, -96.280

Two brief funnels were noted west and southwest from highway 32 along the Roseau and Marshall county line.

Flash Flood, Kittson

When: July 16, 9:15 PM CST to July 17, 4:00 AM CST
Where: Kittson County, 2 mi NW of Karlstad to 2 mi SW of Karlstad
Cause: Heavy Rain
Property damage: $5,000
Crop damage: $5,000
Reported by: Amateur Radio
Coordinates: 48.600, -96.551

Street flooding was reported in Karlstad after 3.95 inches of rain fell.

Hail, Roseau

When: July 16, 9:28 PM CST
Where: Roseau County, 1.37 mi E of Strathcona
Measured: 1 in hail
Reported by: Trained Spotter
Coordinates: 48.550, -96.150

A deck was covered with quarter sized hail. There were a few bigger ones, but not as large as half dollars.

Flash Flood, Roseau

When: July 16, 9:30 PM CST to July 17, 4:00 AM CST
Where: Roseau County, 2 mi NW of Strathcona to 2 mi SW of Strathcona
Cause: Heavy Rain
Property damage: $2,000
Crop damage: $5,000
Reported by: Law Enforcement
Coordinates: 48.571, -96.211

Street flooding was reported in Strathcona. Several farm access roads were also flooded near town.

Thunderstorm Wind, Kittson

When: July 16, 9:57 PM CST
Where: Kittson County, 0.46 mi W of Hallock Arpt
Measured: 53 kt (61 mph) measured gust
Reported by: AWOS
Coordinates: 48.770, -96.940

Hail, Marshall

When: July 16, 10:15 PM CST
Where: Marshall County, 3.72 mi SSE of Big Woods
Measured: 1 in hail
Reported by: Trained Spotter
Coordinates: 48.250, -97.090

Hail, Beltrami

When: July 17, 12:15 AM CST
Where: Beltrami County, 0.69 mi N of Thorhult
Measured: 1 in hail
Reported by: Public
Coordinates: 48.240, -95.250

Hail, Beltrami

When: July 17, 1:20 AM CST
Where: Beltrami County, 2.79 mi W of Blackduck
Measured: 1 in hail
Reported by: Trained Spotter
Coordinates: 47.730, -94.610

Thunderstorm Wind, Beltrami

When: July 17, 1:20 AM CST
Where: Beltrami County, 2.79 mi W of Blackduck
Measured: 61 kt (70 mph) estimated gust
Reported by: Trained Spotter
Coordinates: 47.730, -94.610

A spotter reported 70 mph winds west of Blackduck.

Hail, Beltrami

When: July 17, 1:35 AM CST
Where: Beltrami County, 3.1 mi SSE of Blackduck
Measured: 1 in hail
Reported by: Trained Spotter
Coordinates: 47.690, -94.520

A few dime to quarter sized hailstones fell along with heavy rain and very strong winds.

What these are

Hail: Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
Tornado: A violently rotating column of air in contact with the ground and extending from a thunderstorm, filed with its path, width and Fujita or Enhanced Fujita rating from the damage survey.
Funnel Cloud: A rotating column of cloud extending from a thunderstorm that did not reach the ground.
Flash Flood: Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.
Thunderstorm Wind: Winds from a thunderstorm of 50 knots (58 mph) or more, or lower winds that caused damage or casualties. Measured gusts are marked MG, estimated EG.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Minnesota in 2011 Every state in 2011 This day in weather history The tornado archive for Minnesota, 2011 Warnings in Minnesota, July 2011

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 332409, 332415, 313569, 313571, 332419, 313578, 313572, 332424, 313574, 332426, 313582, 313580, 313581, 313583.