Map of severe weather risk areas and severe storm reports through 7 AM CDT on July 18, 2020.
Courtesy: NOAA Storm Prediction Center
Two waves of severe thunderstorms pounded parts of Minnesota, first from the evening of Friday July 17th into the following morning, and then again in the evening of Saturday July 18th.
The thunderstorms erupted amid a potent combination of summertime heating and strong upper-level winds. For the first wave of storms, forecasters at NOAA's Storm Prediction Center had suspected the storms could be unusually severe, and placed much of central and northern Minnesota in a rare, "Moderate Risk" for severe weather. They followed this dire outlook with an even more unusual "Particularly Dangerous Situation" (PDS) Severe Thunderstorm Watch, indicating the potential for a long path of destructive winds.
The storms formed in North Dakota during Friday afternoon, and marched into Minnesota during evening and overnight. Widespread damaging winds were reported in northwestern, northern, and parts of central Minnesota, though mercifully, the outbreak was slightly less destructive than had been feared. The storms did produce two short-lived, late-night tornadoes in east-central Minnesota.
On Saturday, as dew points surged into the upper 70s F with temperatures in the mid-80s to low-90s, the atmosphere destabilized and new storms formed over the eastern half of the state. These storms produced large hail and wind damage throughout the Arrowhead, and storms developing near sunset went on to produce tornadoes in Washington County.
Following are damage reports and tornado damage surveys from the Grand Forks and Chanhassen National Weather Service offices.
PRELIMINARY LOCAL STORM REPORT...SUMMARY NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND 510 PM CDT SAT JUL 18 2020 ..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON... ..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE.... ..REMARKS.. PEAK WIND MEASURED AT AN RWIS STATION ALONG HIGHWAY 2. 0449 PM TSTM WND GST 8 W ARGYLE 48.34N 96.99W 07/17/2020 M58.00 MPH Marshall MN MESONET PEAK WINDS MEASURED AT A PERSONAL WEATHER STATION. 0505 PM TSTM WND DMG EAST GRAND FORKS 47.93N 97.02W 07/17/2020 POLK MN BROADCAST MEDIA NUMEROUS LARGE BRANCHES AND LIMBS BROKEN DOWN AROUND TOWN. A LARGE OLD TREE SNAPPED. PHOTOS AND REPORTS POSTED VIA SOCIAL MEDIA 0506 PM TSTM WND GST ARGYLE 48.34N 96.82W 07/17/2020 E90.00 MPH Marshall MN PUBLIC BLEACHERS AT THE FOOTBALL FIELD WERE ROLLED AND DESTROYED. A ROOF WAS PEELED OFF A SHOP. GRAIN ELEVATOR COMPLEX HAD TOP AUGER TORN OFF AND LARGE BIN CAVED IN. PHOTO AND REPORT POSTED VIA SOCIAL MEDIA. TIME ESTIMATED BASED ON RADAR. PEAK WINDS ESTIMATED TO 90 MPH. 0515 PM TSTM WND GST 2 NNW CROOKSTON 47.80N 96.62W 07/17/2020 M56.00 MPH Polk MN AWOS PEAK WINDS MEASURED AT THE CROOKSTON AIRPORT /KCKN/. 0529 PM TSTM WND DMG 1 NW NEWFOLDEN 48.37N 96.35W 07/17/2020 Marshall MN BROADCAST MEDIA BALL FIELD DUGOUT BLOWN OVER. REPORT AND PHOTO POSTED VIA SOCIAL MEDIA. 0540 PM TSTM WND DMG 7 N CLIMAX 47.71N 96.81W 07/17/2020 Polk MN PUBLIC TREE BLOWN DOWN OVER POWER LINES. 0545 PM TSTM WND DMG MENTOR 47.70N 96.14W 07/17/2020 POLK MN PUBLIC TREE DAMAGE IN TOWN FROM 545 THROUGH 550 PM CDT. 0545 PM TSTM WND GST 2 N HOLT 48.32N 96.19W 07/17/2020 M73.00 MPH Marshall MN FIRE DEPT/RESCUE PEAK WIND MEASURED WITH A PERSONAL WEATHER STATION. 0546 PM TSTM WND DMG 1 NW THIEF RIVER FALLS 48.12N 96.19W 07/17/2020 Pennington MN PUBLIC TREES UPROOTED ON NORTHWEST SIDE OF TOWN. REPORTS AND PHOTOS POSTED VIA SOCIAL MEDIA. 0549 PM TSTM WND GST 2 SSW THIEF RIVER FALLS 48.09N 96.19W 07/17/2020 M61.00 MPH Pennington MN AWOS PEAK WIND MEASURED AT THE THIEF RIVER FALLS AIRPORT /KTVF/. 0550 PM TSTM WND GST 2 S BROOKS 47.79N 96.00W 07/17/2020 M54.00 MPH Red Lake MN MESONET PEAK WINDS MEASURED AT AN RWIS STATION. 0555 PM TSTM WND DMG 2 NE MAPLE BAY 47.66N 96.19W 07/17/2020 Polk MN PUBLIC AT LEAST ONE TREE WAS DOWN ON A CAMPER/TRAILER AT THE POLK COUNTY PARK. LARGE TREES WERE BLOWN DOWN AT VARIOUS LOCATIONS AROUND MAPLE LAKE. PHOTOS AND REPORTS POSTED VIA SOCIAL MEDIA. TIMES VARIED BETWEEN 550 AND 6 PM CDT. 0620 PM TSTM WND DMG 4 SE HENDRUM 47.22N 96.75W 07/17/2020 Norman MN PUBLIC TREES BLWON DOWN IN A SHELTERBELT. PHOTO AND REPORT POSTED VIA SOCIAL MEDIA. 0630 PM TSTM WND DMG 4 SE GEORGETOWN 47.04N 96.73W 07/17/2020 Clay MN PUBLIC TREE BLOWN DOWN IN YARD. 0637 PM TSTM WND DMG CLEARBROOK 47.69N 95.43W 07/17/2020 CLEARWATER MN PUBLIC SMALL TREE BLOWN DOWN IN TOWN. PHOTO AND REPORT POSTED VIA SOCIAL MEDIA. TIME ESTIMATED BASED ON RADAR. 0641 PM TSTM WND GST 5 SSE MAHNOMEN 47.25N 95.93W 07/17/2020 M55.00 MPH Mahnomen MN MESONET PEAK WIND MEASURED AT AN RWIS STATION. 0655 PM TSTM WND DMG GLYNDON 46.87N 96.58W 07/17/2020 CLAY MN BROADCAST MEDIA ROOFING WAS TORN OFF A TRAILER HOME. REPORT AND PHOTO POSTED VIA SOCIAL MEDIA. 0703 PM TSTM WND DMG ALIDA 47.38N 95.23W 07/17/2020 CLEARWATER MN PUBLIC NUMEROUS LARGE BRANCHES AND LIMBS BROKEN DOWN. REPORT POSTED VIA SOCIAL MEDIA. TIME ESTIMATED BASED ON RADAR. 0710 PM TSTM WND DMG 5 W BEMIDJI 47.48N 94.99W 07/17/2020 Beltrami MN PUBLIC SEVERAL TREES BLOWN DOWN. 0715 PM TSTM WND DMG 3 SE SOLWAY 47.49N 95.08W 07/17/2020 Beltrami MN EMERGENCY MNGR LARGE MATURE TREES SNAPPED AND BLOCKING ROAD. TIME ESTIMATED BASED ON RADAR. 0735 PM TSTM WND DMG BEMIDJI 47.48N 94.88W 07/17/2020 BELTRAMI MN EMERGENCY MNGR BRANCHES AND POWER LINES DOWN NEAR THE UNIVERSITY. 0737 PM TSTM WND DMG MANY POINT LAKE 47.08N 95.53W 07/17/2020 Becker MN TRAINED SPOTTER TREES BLOWN DOWN ON MANY POINT SCOUT CAMP ROAD. 0750 PM TSTM WND DMG LAKE PARK 46.88N 96.10W 07/17/2020 BECKER MN BROADCAST MEDIA LARGE TREE SNAPPED. TIME ESTIMATED BASED ON RADAR. 0820 PM TSTM WND DMG 3 WSW OSAGE 46.90N 95.32W 07/17/2020 Becker MN PUBLIC TREES DOWN ON HIGHWAY 34. 0824 PM HAIL OSAGE 46.92N 95.26W 07/17/2020 E0.75 INCH BECKER MN PUBLIC 0830 PM TSTM WND DMG MENAHGA 46.75N 95.10W 07/17/2020 WADENA MN PUBLIC WIND DAMAGE TO PORCH. ESTIMATED WINDS OF 70 TO 80 MPH. 0839 PM TSTM WND GST 2 SSW PARK RAPIDS 46.89N 95.08W 07/17/2020 M58.00 MPH Hubbard MN ASOS PEAK WIND MEASURED AT THE PARK RAPIDS AIRPORT /KPKD/. A FEW TREES BLOWN DOWN IN TOWN. 0840 PM HAIL 7 N PARK RAPIDS 47.02N 95.06W 07/17/2020 E1.00 INCH Hubbard MN PUBLIC 0845 PM TSTM WND GST SEBEKA 46.63N 95.09W 07/17/2020 E60.00 MPH WADENA MN PUBLIC 0850 PM TSTM WND DMG AKELEY 47.00N 94.73W 07/17/2020 HUBBARD MN BROADCAST MEDIA TREES BLOWN DOWN. REPORT AND PHOTO POSTED VIA SOCIAL MEDIA. TIME ESTIMATE BASED ON RADAR. 0930 PM TSTM WND GST SEBEKA 46.63N 95.09W 07/17/2020 E60.00 MPH WADENA MN TRAINED SPOTTER SECOND BLAST OF WIND GUSTING TO 60 MPH. SEVERAL LARGE BRANCHES BROKEN DOWN IN A YARD. 0931 PM HAIL 2 W WADENA 46.44N 95.18W 07/17/2020 E1.25 INCH Otter Tail MN TRAINED SPOTTER 0944 PM HAIL VERNDALE 46.40N 95.01W 07/17/2020 E1.00 INCH WADENA MN PUBLIC REPORT FROM SOCIAL MEDIA. 1050 PM TSTM WND GST 2 W TENNEY 46.04N 96.50W 07/17/2020 M54.00 MPH Wilkin MN MESONET PEAK WIND MEASURED AT RWIS STATION 1050 PM TSTM WND DMG 4 W HOFFMAN 45.83N 95.87W 07/17/2020 Grant MN TRAINED SPOTTER SEVERAL LARGE TREE BRANCHES AND LIMBS BROKEN DOWN. WINDS ESTIMATED AT 60 TO 65 MPH. PUBLIC INFORMATION STATEMENT NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 829 PM CDT SUN JUL 19 2020 ...NWS DAMAGE SURVEY FOR EARLY MORNING JULY 18 AND LATE EVENING JULY 18, 2020 TORNADO EVENTS - INITIAL ISSUANCE... .NORTHWEST ISANTI COUNTY, MN TORNADO... RATING: EF-1 ESTIMATED PEAK WIND: 90 MPH PATH LENGTH /STATUTE/: 3.0 MILES PATH WIDTH /MAXIMUM/: 100 YARDS FATALITIES: 0 INJURIES: 0 START DATE: JUL 18 2020 START TIME: 1259 AM CDT START LOCATION: 9 SSE OGILVIE, MN START LAT/LON: 45.7092 / -93.3803 END DATE: JUL 18 2020 END TIME: 105 AM CDT END LOCATION: 7 W BRAHAM, MN END LAT/LON: 45.7092 / -93.3185 THIS TORNADO WAS EMBEDDED WITHIN A LINE OF SEVERE THUNDERSTORMS PRODUCING STRAIGHT LINE WIND DAMAGE, BUT A CONCENTRATED AREA OF DAMAGE EXHIBITING TORNADO CHARACTERISTICS TRACKED ACROSS NORTHWEST ISANTI COUNTY. A LOCAL ANEMOMETER MEASURED AN 87 MPH GUST. .RUSH LAKE, MN TORNADO... RATING: EF-0 ESTIMATED PEAK WIND: 80 MPH PATH LENGTH /STATUTE/: 1.5 MILES PATH WIDTH /MAXIMUM/: 100 YARDS FATALITIES: 0 INJURIES: 0 START DATE: JUL 18 2020 START TIME: 124 AM CDT START LOCATION: 5 SE BRAHAM, MN (WEST SIDE OF RUSH LAKE) START LAT/LON: 45.6765 / -93.1032 END DATE: JUL 18 2020 END TIME: 127 AM CDT END LOCATION: 6 SE BRAHAM, MN (SOUTH SIDE OF RUSH LAKE) END LAT/LON: 45.6634 / -93.0886 A BRIEF TORNADO SPIN UP WITHIN A LINE OF SEVERE THUNDERSTORMS OCCURRED ON THE WEST SIDE OF RUSH LAKE AND TRACKED TO THE SOUTH SIDE. BOATS AND DOCKS WERE DAMAGED. SPORADIC STRAIGHT LINE WIND DAMAGE OCCURRED SURROUNDING THIS TRACK. .WOODBURY, MN TO AFTON, MN TORNADO... RATING: EF-0 ESTIMATED PEAK WIND: 65 MPH PATH LENGTH /STATUTE/: 3.1 MILES PATH WIDTH /MAXIMUM/: 50 YARDS FATALITIES: 0 INJURIES: 0 START DATE: JUL 18 2020 START TIME: 942 PM CDT START LOCATION: 2 SE WOODBURY, MN START LAT/LON: 44.8900 / -92.9050 END DATE: JUL 18 2020 END TIME: 951 PM CDT END LOCATION: 3 W AFTON, MN END LAT/LON: 44.9050 / -92.8450 NO DAMAGE WAS FOUND AND NO DAMAGE REPORTS WERE RECEIVED. HOWEVER, KMPX RADAR CONFIRMED A TORNADO BASED ON A BRIEF TORNADIC DEBRIS SIGNATURE AND TMSP RADAR TRACKED A COUPLET NORTHEAST ACROSS SOUTHERN WASHINGTON COUNTY. THEREFORE, THE TORNADO IS RATED EF0. PATH LENGTH, BEGINNING AND ENDING POINTS, AND BEGINNING AND ENDING TIMES ARE APPROXIMATE. .SOUTHERN WASHINGTON COUNTY, MN INTO PIERCE COUNTY, WI TORNADO... RATING: EF-1 ESTIMATED PEAK WIND: 100 MPH PATH LENGTH /STATUTE/: 9.5 MILES PATH WIDTH /MAXIMUM/: 400 YARDS FATALITIES: 0 INJURIES: 0 START DATE: JUL 18 2020 START TIME: 953 PM CDT START LOCATION: 5 N HASTINGS, MN START LAT/LON: 44.8188 / -92.8441 END DATE: JUL 18 2020 END TIME: 1020 PM CDT END LOCATION: 2 SW RIVER FALLS, WI END LAT/LON: 44.8336 / -92.6571 EXTENSIVE TREE DAMAGE ALONG THE PATH, MANY OF WHICH WERE SNAPPED ABOUT HALF WAY UP. THE HEAVIEST DAMAGE OCCURRED ON TOP OF A BLUFF AS THE TORNADO CROSSED THE ST. CROIX RIVER INTO WISCONSIN. A FEW FARM OUTBUILDINGS WERE ALSO DAMAGED. EF SCALE: THE ENHANCED FUJITA SCALE CLASSIFIES TORNADOES INTO THE FOLLOWING CATEGORIES. EF0...WEAK......65 TO 85 MPH EF1...WEAK......86 TO 110 MPH EF2...STRONG....111 TO 135 MPH EF3...STRONG....136 TO 165 MPH EF4...VIOLENT...166 TO 200MPH EF5...VIOLENT...>200MPH NOTE: THE INFORMATION IN THIS STATEMENT IS PRELIMINARY AND SUBJECT TO CHANGE PENDING FINAL REVIEW OF THE EVENTS AND PUBLICATION IN NWS STORM DATA.
Updated July 22, 2020