A cold front associated with low pressure proceeded through MN on June 12th. Early morning warm advection helped to spawn storms in the morning and midday hours.
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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 MPX wrote it up.
A cold front associated with low pressure proceeded through MN on June 12th. Early morning warm advection helped to spawn storms in the morning and midday hours. Instability increased across western MN during the afternoon to values between 2000 to 3000 J/kg, with shear between 40-50 kts. Scattered thunderstorms began to develop across western MN and move east. Across central MN, storms mainly produced damaging wind gusts, large hail, and heavy rainfall.
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 Twin Cities, MN wrote its last area forecast discussion before the first event at Jun 12, 5:24 AM CST, 3 minutes earlier. Its key messages:
Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 624 AM CDT Wed Jun 12 2024 .KEY MESSAGES... - Warm and muggy today with strong to severe thunderstorms expected. Large hail, damaging winds and a few tornadoes are possible. - Seasonable temperatures and dry weather are expected to end the week with rain returning Saturday through early Sunday. - Chances for precipitation along with warmer temperatures will persist through early next week. && .DISCUSSION... Issued at 235 AM CDT Wed Jun 12 2024 Surface analysis early this morning shows a departed cold front over central WI snaking SW over southern IA, high pressure briefly sitting behind the front over northwest IA and southeast SD, and a second cold front emanating from a low pressure center over southern Saskatchewan province and extending SW over MT/IA. It is this second cold front that will be the focus for anticipated convection across portions of the WFO MPX coverage area today and tonight. Aloft, a rather lengthy zonal pattern, and a fast one at that, is present from the Bacon all the way to the Great Lakes over the northern tier states. While there are some minor buckles in the flow from H85 all the way up to H5, the prevailing west-to-east flow will aid in producing speed shear across a broad area of the Upper Midwest. To be specific, H5 flow is nearly 60kt over MN, while low level flow is generally from the S and SSW, aiding in advecting higher moisture content into the region As the front approaches from the west, lapse rates will become much steeper, ranging 7-8 C/km per model soundings. In addition, a highly unstable airmass will also be present in advance of the front with MLCAPE values likely around 2000 J/kg, potentially as high as 3000 J/kg. Model soundings, particularly for this afternoon, show strong winds veering with height, which is a good indicator of supercell potential. These factors with the steep lapse rates indicate a strong potential for large hail. So, with multiple severe weather indices showing the strong potential for severe weather, the questions now are: when and where. And this is where different CAMs have different ideas for such. The main consensus this morning looks to be a pre-dawn cluster of storms over southeastern ND that will move into west-central MN around 12z then continue spreading SE over southern MN through midday. Models had previously shown a second round of convection not too far behind the initial, but that idea looks to have less support at this time. Once the morning Cc pushes through, residual cloud cover with plenty of convective energy having been used, there may not be enough time for recovery to occur later in the day in southern MN due to sufficient mid-to-late day capping. However, northern MN looks to have less such capping and is also in closer proximity to the low pressure center. Thus, with the better prolonged period of convection expected, the addition of an Enhanced Risk over northern MN makes sense, as is the greater possibility of any tornadic storms. As the storms develop, the hazard mode will transition from one of hail to one of wind gusts, especially the more they can propagate east and maintain themselves. Of course, there are outliers to this which diminish the incoming cluster and instead focus on a cluster near-north of I-94 in MN which drives SE mid to- late afternoon. This complication in timing/location is the main reason of holding back the severe risk to a Slight while points north have been upgraded to Enhanced. The cold front will sweep across MN/WI tonight through sunrise Thursday, followed by a broad area of high pressure from southwest Canada spreading ESE into the Upper Midwest. This will promote cooler, drier and clearing conditions for Thursday- Friday. The focus then turns to the weekend as a conglomerate areas of small low pressure centers over WY/CO undergoes cyclogenesis into a primary low over the Northern Plains. Impressive moisture advection is again expected across the Upper Midwest in advance of this next system, such that PWATs exceed 1.50", possibly near 1.75". The slow progress of the frontal system across the area along with only modest instability will make for plenty of rainfall across the region Saturday into Saturday night. QPF for much of the WFO MPX coverage area will exceed 1", with south- central MN possibly looking at over 2". The warm front of this system is expected to snap northeast, placing central-southern MN and western WI within its warm sector. Thus, another warm/humid day is expected on Sunday but with lower precipitation chances. The weak frontal boundary is expected to stall out over the Northern Plains and Upper Midwest while several weak shortwaves drift across the region, keeping chances for rain in the forecast through early next week. && .AVIATION /12Z TAFS THROUGH 12Z THURSDAY/... Issued at 610 AM CDT Wed Jun 12 2024 Short-term models appear to hone in on two distinct rounds of CB/TS: one in the roughly 14z-18z timeframe, which is of higher confidence, and a second in the roughly 00z-06z timeframe, which is of lesser confidence. Still, these two periods look to have the best chances of convection reaching and impacting all terminals. Have currently advertised MVFR conditions but IFR certainly cannot be ruled out, particularly for visibility. Otherwise, a mixture of mid- and upper-level decks can be expected throughout this duration with occasional ceilings. Winds will be mainly southerly, varying a bit to the west and east at times, with peak speeds near 15G20kts. KMSP...Best timing for the initial swath of convection looks to be 14z-18z. Likely will not last that entire 4hr window but wanted to advertise some wiggle room in there in case the precip lasts a bit longer given the 14z arrival time. Next batch looks to come around 00z, or potentially as late as 03z. That next batch, while of lower confidence, will have the better chance of severe thunderstorms. /OUTLOOK FOR KMSP/ FRI...VFR. Wind VRBL at 5 kts. SAT...RA/TSRA/MVFR likely, IFR possible. Wind SE 10-15 kts. SUN...Mainly VFR. Slight chc TSRA/MVFR. Wind SW 10-15 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && DISCUSSION...JPC AVIATION...JPC
Hazardous Weather Outlook National Weather Service Twin Cities/Chanhassen MN 611 AM CDT Wed Jun 12 2024 MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028- 130800- Douglas-Todd-Morrison-Mille Lacs-Kanabec-Stevens-Pope-Stearns- Benton-Sherburne-Isanti-Chisago-Lac Qui Parle-Swift-Chippewa- Kandiyohi-Meeker-Wright-Hennepin-Anoka-Ramsey-Washington- Yellow Medicine-Renville-McLeod-Sibley-Carver-Scott-Dakota- Redwood-Brown-Nicollet-Le Sueur-Rice-Goodhue-Watonwan-Blue Earth- Waseca-Steele-Martin-Faribault-Freeborn-Polk-Barron-Rusk- St. Croix-Pierce-Dunn-Pepin-Eau Claire- 611 AM CDT Wed Jun 12 2024 This Hazardous Weather Outlook is for portions of central and southern Minnesota, and west central Wisconsin. .DAY ONE...Today and Tonight. Thunderstorms will move across the area this morning into the early afternoon. Some storms may be severe, with large hail and damaging winds possible. Another round of thunderstorms is possible across parts of the area this afternoon into tonight. If storms do occur, they would likely be severe with large hail, damaging wind, and tornadoes possible. Exact timing and location of storms is still uncertain. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday. Flooding along area rivers will hold steady or steadily fall over the next few days. Rain from upcoming events could prolong crests. .SPOTTER INFORMATION STATEMENT... SKYWARN spotter activation may be needed at times through tonight.
The Sioux Falls radar (KFSD), 164 km away, was scanning. The volume nearest the first event began at 11:26 UTC.
16 hail, 13 thunderstorm wind. Local standard time, as filed.
The hail measurement was provided by a broadcast meteorologist. Time estimated via radar.
The spotter also reported wind gusts up to 45 mph.
The hail was reported at Concorde Bank.
Several trees were knocked down or broken.
The deck of a house was damaged. A grill was blown off the deck. A shed was also damaged. A home weather station measured 79 mph. A lean-to was also torn off a horse barn at the neighboring farm.
There was a photo of a downed tree in Twin Lakes. Time estimated via radar.
Multiple trees were down within town.
Several trees were toppled onto power lines.
A tree was downed along the road.
Two to three dozen trees, some of which were 50 feet tall, were broken or uprooted. They were scattered across an area north and northeast of St. Anthony.
Many trees were down. A machine shed was blown across the road and destroyed. Time estimated via radar.
Large branches were down in Sartell.
Large tree limbs were broken.
A tree was downed.
A photo showed penny sized hail near the intersection of 30th St NE and Hwy 23.
A three to four foot diameter tree was uprooted with numerous large branches snapped.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Minnesota in 2024Every state in 2024This day in weather historyWarnings in Minnesota, June 2024
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: 1199180, 1199181, 1199182, 1208139, 1208140, 1199395, 1199183, 1199184, 1199185, 1199187, 1199186, 1199397, 1208143, 1208145, 1199398, 1199400, 1199401, 1199402, 1199403, 1199404, 1199188, 1199190, 1199198, 1199199, 1199200, 1199201, 1199202, 1199203, 1199405.