Friday, July 24th, was one of the hottest and most humid days of 2020. Afternoon high temperatures ranged from the upper 80s to middle 90s, with dew points in the middle 70s to lower 80s.
Every event with a place to put it. Tap one for its entry below.
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.
The episode as NWS FGF wrote it up.
Friday, July 24th, was one of the hottest and most humid days of 2020. Afternoon high temperatures ranged from the upper 80s to middle 90s, with dew points in the middle 70s to lower 80s. During the early evening, thunderstorms broke out along two lines, one from Bismarck to northwest of Grand Forks, and the other from Bismarck to west of Fargo. By the late evening, the strongest storms along both lines were converging toward Grand Forks. This brought a period of very strong winds to eastern Grand Forks and eastern Walsh counties, continuing up toward the Lake of the Woods region. Meanwhile, another cluster of storms over south central North Dakota moved east-northeast, tracking through the Fargo-Moorhead area and into west central Minnesota during the overnight hours. These storms also produced some strong wind gusts.
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 24, 9:13 PM CST, 17 minutes earlier.
Area Forecast Discussion National Weather Service Grand Forks ND 1013 PM CDT Fri Jul 24 2020 .UPDATE... Issued at 952 PM CDT Fri Jul 24 2020 Line of storms has moved into the central and northern valley with highly efficient rainfall producers and some severe wind potential. Threat will increase over the next couple hours if the cold pool develops and shear from the low level jet helps intensify convection. CAMs continue to move this round convection into NW MN in the next couple hours with another round moving across the southern valley overnight. The unidirectional shear values and weak mid level lapse rates suggest storms will be unorganized and with the severe risks highly dependent on the aforementioned low level jet and its ability to increase the shear. UPDATE Issued at 644 PM CDT Fri Jul 24 2020 Convective thunderstorm evolution the main concern in the evening and overnight time frame. Will see thunderstorms expand in coverage as forcing from short wave moves closer to the FA. Upper forcing already responsible for convection upstream and the main question is if there is enough shear to allow storms to organize into a cluster or complex and if it will be producing severe winds. SFC based CAPE peaking out around 6500j/kg per mesoanalysis with 4500j/kg of MLCAPE shows plenty of instability and with PWATS above 1.5 inches heavy rainfall a big concern with any storms even sub severe ones. After the initial storm development expected in the next one to 2 hours along a New Rockford to Grafton line where and when there is a hail threat, the primary concern will be wind gusts to 70mph and heavy rainfall as storms cluster and merge moving eastward into the valley after 10pm per CAM guidance. && .SHORT TERM...(This evening through Saturday night) Issued at 316 PM CDT Fri Jul 24 2020 Convective strength and timing will be the main challenges for the period. Southwesterly flow aloft and south winds continue to bring hot and humid conditions to the region this afternoon. Dew points were already in the 70s this morning, with a few localized spots hitting the low 80s. Will expand the excessive heat warning into the northern Red River Valley as several of the higher dew point pools have been up there and their heat index values are above the portions of the southern RRV currently. With all the heat and humidity, CAPE values have been huge, over 4000 J/kg, although there has been some capping that is starting to erode over the RRV. Cap is still pretty stout further west, but the shortwave is starting to set off some convection off in western SD. There have been towers over central ND that have been struggling to get going and move into our western counties. The good deep layer bulk shear is still well to the west with the forcing, so think these initial updrafts will struggle for a while longer. CAMs continue to show storms developing along the surface trough just to our west close to 00Z, then moving it into our western counties later this evening. Plenty of instability to work with in the 00Z to 03Z time frame before sun sets, and although the shear is still around 30 kts, it should be enough to maintain some sort of thunderstorm complex with hail over an inch early on as well as damaging winds up to 70 mph throughout the night. With the low level jet ramping up, some winds continuing as the system moves into western MN remains possible. Much of tomorrow will depend on how tonight plays out and if there is lingering convective debris. It does look like there should be at least some clearing, and heat and humidity will continue to hang around before the front comes through Saturday. After a bit of a break at least in the western counties think there is the potential for another round of thunderstorms, and with shear even better than today (35 to 40 kts), some severe hail and winds are not out of the question. A shortwave moving through southern Canada will help push a cold front down Saturday night, with the complex moving east with it. .LONG TERM...(Sunday through Friday) Issued at 316 PM CDT Fri Jul 24 2020 The weather pattern is expected to quiet down a bit heading into next week. H5 flow becomes northwesterly on Sunday with ridging taking shape across the northern US Rockies and into British Columbia and Alberta. Heading into mid-week, the ridge axis progresses into Saskatchewan, with H5 flow responding and becoming more northerly over the CWA late Wednesday. Overall, a much drier and slightly cooler pattern is expected Sunday through Friday. Remnant showers and thunderstorms work eastward Sunday morning, with quiet weather expected through the remainder of the day. Highs are expected to be in the 70s to near 80 degrees. Monday brings very similar conditions with dry weather expected across much of the CWA. Heading into Tuesday, most of the area remains dry, with slight precipitation chances working back into the Lake of the Woods region, in association with a shortwave passage. Look for warmer temperatures Wednesday through Friday slight chances for afternoon thunderstorms each day. Ensemble members diverge significantly starting Wednesday, with a divide regarding moisture values and timing. This will determine our risk for severe weather heading into the end of next week. At this time, there is low confidence in specifics, but a weak signal for a return to hotter and more humid conditions. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 644 PM CDT Fri Jul 24 2020 Will be monitoring convective evolution this evening into the overnight with the risk of impacting all TAF sites by 08Z. Some MVFR CIGs are possible in the wake of the convection into the mid morning hours. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. UPDATE...JK SHORT TERM...JR LONG TERM...Lynch AVIATION...JK
Hazardous Weather Outlook National Weather Service Grand Forks ND 355 PM CDT Fri Jul 24 2020 MNZ001>004-007-029-NDZ008-016-026>030-038-039-049-052-053-252100- West Polk-Norman-Clay-Kittson-West Marshall-Wilkin-Pembina- Eastern Walsh-Nelson-Grand Forks-Griggs-Steele-Traill-Barnes-Cass- Ransom-Sargent-Richland- 355 PM CDT Fri Jul 24 2020 This hazardous weather outlook is for portions of eastern North Dakota, west central and northwest Minnesota. .DAY ONE...This Afternoon and Tonight Dangerous heat index values around 105 are expected this afternoon and early evening. Scattered severe thunderstorms may develop into eastern North Dakota late this afternoon and spread into parts of west central and northwest Minnesota this evening. Large hail, damaging winds, and localized flooding will be the main threats. The severe threat ends during the evening, however clusters of showers and thunderstorms will continue through the overnight period. Localized flooding will continue to be a threat. .DAYS TWO THROUGH SEVEN...Saturday through Thursday Clusters of showers and thunderstorms will continue to move across parts of the region Saturday and Saturday night. A few strong to severe thunderstorms can't be ruled out during the afternoon and evening. Large hail, damaging winds, and localized flooding would be the main threats. .SPOTTER INFORMATION STATEMENT... Spotter activation may be required. MNZ005-006-008-009-013>017-022>024-027-028-030>032-040-252100- Roseau-Lake Of The Woods-East Marshall-North Beltrami-Pennington- Red Lake-East Polk-North Clearwater-South Beltrami-Mahnomen- South Clearwater-Hubbard-West Becker-East Becker-West Otter Tail- East Otter Tail-Wadena-Grant- 355 PM CDT Fri Jul 24 2020 This hazardous weather outlook is for portions of west central and northwest Minnesota. .DAY ONE...This Afternoon and Tonight High heat index values around 100 are expected this afternoon and early evening. Scattered severe thunderstorms may develop into eastern North Dakota late this afternoon and spread into parts of west central and northwest Minnesota this evening. Large hail, damaging winds, and localized flooding will be the main threats. The severe threat ends during the evening, however clusters of showers and thunderstorms will continue through the overnight period. Localized flooding will continue to be a threat. .DAYS TWO THROUGH SEVEN...Saturday through Thursday Clusters of showers and thunderstorms will continue to move across parts of the region Saturday and Saturday night. A few strong to severe thunderstorms can't be ruled out during the afternoon and evening. Large hail, damaging winds, and localized flooding would be the main threats. .SPOTTER INFORMATION STATEMENT... Spotter activation may be required. NDZ006-007-014-015-024-054-252100- Towner-Cavalier-Benson-Ramsey-Eddy-Western Walsh- 355 PM CDT Fri Jul 24 2020 This hazardous weather outlook is for portions of eastern North Dakota. .DAY ONE...This Afternoon and Tonight Scattered severe thunderstorms may develop into eastern North Dakota late this afternoon and spread into parts of west central and northwest Minnesota this evening. Large hail, damaging winds, and localized flooding will be the main threats. The severe threat ends during the evening, however clusters of showers and thunderstorms will continue through the overnight period. Localized flooding will continue to be a threat. .DAYS TWO THROUGH SEVEN...Saturday through Thursday Clusters of showers and thunderstorms will continue to move across parts of the region Saturday and Saturday night. A few strong to severe thunderstorms can't be ruled out during the afternoon and evening. Large hail, damaging winds, and localized flooding would be the main threats. .SPOTTER INFORMATION STATEMENT... Spotter activation may be required.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND FORKS ND
933 PM CDT FRI JUL 24 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0931 PM TSTM WND GST 1 SE COOPERSTOWN 47.43N 98.11W
07/24/2020 M52 MPH Griggs ND ASOS
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PJSPRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE GRAND FORKS ND
941 PM CDT FRI JUL 24 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0926 PM TSTM WND GST 1 SE COOPERSTOWN 47.43N 98.11W
07/24/2020 M52.00 MPH Griggs ND ASOS
&&
PJSSpecial Weather Statement National Weather Service Grand Forks ND 943 PM CDT Fri Jul 24 2020 MNZ001-007-NDZ016-027-250330- West Polk MN-West Marshall MN-Eastern Walsh County ND-Grand Forks ND- 943 PM CDT Fri Jul 24 2020 ...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN MARSHALL... NORTHWESTERN POLK...NORTHERN GRAND FORKS AND SOUTHEASTERN WALSH COUNTIES UNTIL 1030 PM CDT... At 943 PM CDT, Doppler radar was tracking strong thunderstorms along a line extending from near Veseleyville to near Larimore. Movement was east at 35 mph. Wind gusts up to 50 mph will be possible with these storms. Strong thunderstorms will be near... Veseleyville around 945 PM CDT. Voss, Larimore and Forest River around 950 PM CDT. Minto around 955 PM CDT. Arvilla, Ardoch and Turtle River State Park around 1000 PM CDT. Warsaw around 1005 PM CDT. Other locations impacted by these storms include Grand Forks Airport. PRECAUTIONARY/PREPAREDNESS ACTIONS... To report severe weather, contact your nearest law enforcement agency. They will relay your report to the National Weather Service office in Grand Forks. && A Severe Thunderstorm Watch remains in effect until 1100 PM CDT for northeastern North Dakota. LAT...LON 4834 9684 4785 9700 4788 9781 4834 9760 TIME...MOT...LOC 0243Z 273DEG 32KT 4828 9754 4788 9773 VG
Special Weather Statement National Weather Service Grand Forks ND 953 PM CDT Fri Jul 24 2020 MNZ001-002-NDZ027-029-030-039-250345- West Polk MN-Norman MN-Steele ND-Traill ND-Cass ND-Grand Forks ND- 953 PM CDT Fri Jul 24 2020 ...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN NORMAN... SOUTHWESTERN POLK...SOUTHEASTERN GRAND FORKS...NORTHERN CASS...TRAILL AND EASTERN STEELE COUNTIES UNTIL 1045 PM CDT... At 953 PM CDT, Doppler radar was tracking strong thunderstorms along a line extending from near Kempton to Hope. Movement was east at 25 mph. Wind gusts up to 50 mph will be possible with these storms. Strong thunderstorms will be near... Northwood around 955 PM CDT. Holmes around 1005 PM CDT. Clifford and Galesburg around 1015 PM CDT. Thompson, Merrifield and Grand Forks around 1020 PM CDT. Blanchard around 1025 PM CDT. Other locations impacted by these storms include American Crystal Sugar. PRECAUTIONARY/PREPAREDNESS ACTIONS... To report severe weather, contact your nearest law enforcement agency. They will relay your report to the National Weather Service office in Grand Forks. && A Severe Thunderstorm Watch remains in effect until 1100 PM CDT for southeastern and northeastern North Dakota. LAT...LON 4787 9758 4784 9662 4716 9688 4725 9787 TIME...MOT...LOC 0253Z 272DEG 38KT 4782 9751 4733 9774 VG
Special Weather Statement National Weather Service Grand Forks ND 1006 PM CDT Fri Jul 24 2020 MNZ007-NDZ016-250330- West Marshall MN-Eastern Walsh County ND- 1006 PM CDT Fri Jul 24 2020 ...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN MARSHALL AND NORTHEASTERN WALSH COUNTIES UNTIL 1030 PM CDT... At 1005 PM CDT, Doppler radar was tracking a strong thunderstorm over Grafton, moving east at 25 mph. Penny size hail and winds in excess of 40 mph will be possible with this storm. This strong thunderstorm will be near... Oakwood and Cashel around 1015 PM CDT. PRECAUTIONARY/PREPAREDNESS ACTIONS... To report severe weather, contact your nearest law enforcement agency. They will relay your report to the National Weather Service office in Grand Forks. && A Severe Thunderstorm Watch remains in effect until 1100 PM CDT for northeastern North Dakota. LAT...LON 4834 9758 4853 9758 4854 9682 4833 9683 TIME...MOT...LOC 0305Z 272DEG 31KT 4840 9741 VG
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND FORKS ND
1028 PM CDT FRI JUL 24 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1022 PM TSTM WND GST 6 WNW GRAND FORKS 47.95N 97.19W
07/24/2020 M62 MPH Grand Forks ND ASOS
PEAK WIND MEASURED AT THE GRAND FORKS INTERNATIONAL
AIRPORT /KGFK/.
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GGUSTThe Fargo/Grand Forks radar (KMVX), 52 km away, was scanning. The volume nearest the first event began at 03:30 UTC.
14 thunderstorm wind, 1 tornado. Local standard time, as filed.
The wind gust was measured by a RWIS mesonet sensor along highway 2, near Mallory.
Tree branches were blown down.
The wind gust was measured by a RAWS mesonet sensor.
A tree was blown down at a rural homestead.
Several 3 to 5 inch diameter branches were blown down.
The wind gust was measured by a personal weather station.
A weak tornado formed in the bookend vortex portion of a squall line. The tornado knocked down sunflowers and left a distinctive swirl pattern. Peak winds were estimated at 65 mph.
An apple tree was blown down on the south side of Big Cormorant Lake. After the storm had passed, 1.58 inches of rain was also measured.
A microburst (downburst wind) likely initiated over the west end of Long Lake and moved rapidly eastward across Long Lake Point Road. A trailer home was blown over and demolished. Several large tree limbs were broken down by the wind, while a pontoon was flipped over by the combination of wave and wind action.
Several 3 to 5 inch diameter tree limbs were blown down.
Several large tree branches were blown down around Island Lake.
Numerous trees were uprooted around Dead Lake, with damage to a boat lift.
Trees were blown down on the south side of Big Pine Lake.
A mobile home was damaged.
A few trees were blown down between Kabekona and Benedict lakes.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Minnesota in 2020Every state in 2020This day in weather historyThe tornado archive for Minnesota, 2020Warnings in Minnesota, July 2020
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: 898170, 898171, 898172, 898173, 898174, 898175, 898177, 898178, 898181, 898182, 898184, 898187, 898188, 898189, 898190.