Heavy Rain and Flash Flooding Concerns in California; Heavy Snow in the Sierra

An atmospheric river will bring heavy rainfall to lower elevations of California this week, and heavy snow to the Sierra Nevada mountains. Flash flooding, some of which may be locally considerable, will be a concern on the western foothills of the Sierra Nevada mountains through Tuesday. Landslides, rockfalls and mudslides are possible in the Southern California mountains. Read More >

***All information is considered preliminary until investigations are finalized***

Overview

During the afternoon and evening hours of May 12, 2022, a strong line of thunderstorms developed across southern Nebraska and quickly raced northeast into eastern South Dakota and western Minnesota. As these storms moved north, they produced extreme winds across portions of the Northern Plains. Widespread straight-line winds between 50 and 70 mph were reported, with embedded areas of 80 to 100 mph winds. The highest wind gust reported included a measured 94 mph gust in Madison, MN.

Caption


SPC Day 1 Categorical Outlook	Local Storm Reports	Severe Weather Warnings

Tornado
Wind
Photos & Video
Storm Reports
Environment
Additional

Tornadoes: *Preliminary*

Tornado #1 - Madison, MN
Lac Qui Parle County

Date	5/12/2022
Time (Local)	6:09 - 6:11pm
EF Rating	EF1
Est. Peak Winds	100 mph
Path Length	0.9 miles
Max Width	TBD
Injuries/Deaths	0/0
Summary: This tornado moved across the southeast section of Madison. A house had its roof removed, a camper was rolled, and three light poles in the baseball field were bent over, with 1 having the cement support ripped out of the ground. There was also extensive tree damage as well. The tornado was on the ground for 0.9 miles. It was rated EF1 with estimated maximum winds of 100 mph.

Track Map

Downloadable KMZ File

Tornado #2 - Louisburg, MN
Lac Qui Parle County

Date	5/12/2022
Time (Local)	6:19 - 6:21pm
EF Rating	EF1
Est. Peak Winds	105 mph
Path Length	1.1 miles
Max Width	TBD
Injuries/Deaths	0/0
Summary: This tornado caused major damage to a house, which had its roof completely removed and several walls then collapsed. The garage was destroyed. Many trees were broken or snapped. The tornado was on the ground for 1.1 miles. It was rated EF1 with estimated maximum winds of 105 mph.

Track Map

Downloadable KMZ File

Tornado #3 - Alexandria, MN
Douglas County

Date	5/12/2022
Time (Local)	7:12 - 7:15pm
EF Rating	EF1
Est. Peak Winds	110 mph
Path Length	2.5 miles
Max Width	TBD
Injuries/Deaths	0/0
Summary: A quick moving tornado touched down near the south side of Darling lake in Alexandria, where it caused significant damage to many houses. It tracked across the lake before causing more tree and home damage just east of county roads 11 and 34. It then moved across a small part of lake Carlos before dissipating on the west side of lake Carlos. Its path length was 2.5 miles. The tornado was rated a strong EF1 with estimated maximum winds of 110 mph.

Track Map

Downloadable KMZ File

Tornado #4 - Clarissa, MN
Todd County

Date	5/12/2022
Time (Local)	8:33 - 8:37pm
EF Rating	EF1
Est. Peak Winds	90 mph
Path Length	3.3 miles
Max Width	TBD
Injuries/Deaths	0/0
Summary: Hundreds of trees were uprooted or broken. several outbuildings lost roofs. The damage pattern in this part of Todd county was very complicated, but ground and aerial surveys revealed a tornado moved through part of Clarissa. The path length was 3.3 miles. It was rated EF1 with estimated maximum winds of 90 mph.

Track Map

Downloadable KMZ File

Tornado #5 - Cushing, MN
Morrison County

Date	5/12/2022
Time (Local)	8:46 - 8:48pm
EF Rating	EF0
Est. Peak Winds	80 mph
Path Length	2.9 miles
Max Width	TBD
Injuries/Deaths	0/0
Summary: This tornado broke or uprooted hundreds of trees and partially took the roof off two buildings in Cushing. It dissipated just northeast of Cushing after being on the ground for 2.9 miles. The tornado was rated EF0 with estimated maximum winds of 80 mph.

Track Map

Downloadable KMZ File

Tornado #6 - 6N Randall, MN
Morrison County

Date	5/12/2022
Time (Local)	8:51 - 8:54pm
EF Rating	EF1
Est. Peak Winds	90 mph
Path Length	3.6 miles
Max Width	TBD
Injuries/Deaths	0/0
Summary: Hundreds of trees were uprooted or snapped as it moved along the east side of Lake Alexander. many trees came down on vehicles, sheds and cabins. Its path length was 3.6 miles. The tornado was rated EF1 with estimated maximum winds of 90 mph.

Track Map

Downloadable KMZ File

The Enhanced Fujita (EF) Scale classifies tornadoes into the following categories:

EF0 Weak 65-85 mph	EF1 Moderate 86-110 mph	EF2 Significant 111-135 mph	EF3 Severe 136-165 mph	EF4 Extreme 166-200 mph	EF5 Catastrophic 200+ mph

Wind:

Widespread straight-line wind damage occurred throughout western Minnesota as the derecho moved through during the late afternoon and evening. Many sheds, outbuildings, and barns were badly damaged or destroyed along with numerous of trees snapped and uprooted. One fatality occurred near Blomkest, MN when a grain bin struck a vehicle with an occupant inside. Three weather stations in western Minnesota measured wind gusts over 74 mph; the strongest occurring in Madison, MN of 94 mph.


A wall of dust along the leading edge of the derecho near Redwood Falls, MN. (Credit: Jon Markuson)	Photo of leading edge of the line of storms near Willmar, MN. (Credit: Doug Kiesling)	Shelf cloud near St. Augusta, MN. (Credit: Jacob Dvorak)	Wall of dust along leading edge of the derecho near Worthington, MN. (Credit: Darcy Ross Spies)

Damage Photos

Tornado Damage


Toppled stadium light pole in Madison, MN.	Badly damaged house with a destroyed garage near Louisburg, MN.	House with its roof torn off by Lake Darling near Alexandria, MN.	House with most of its roof lifted and destroyed by Lake Darling near Alexandria, MN.

Wind Damage


Large grain bins destroyed in Bellingham, MN.	Significant damage to farmstead northeast of Madison, MN.	Grain bins damaged and destroyed in Dawson, MN.	Hangar wall blown out at the airport in Morris, MN (Credit: Nick & Amanda Elms)

Storm Reports

Link for storm reports on the Storm Prediction Center's website.

Environment

Amplified upper-level troughing crossing the Rockies allowed for strong northward moisture and temperature advection into the Northern Plains. This allowed for the atmosphere to become very unstable before the trough slid east to supply lift for thunderstorms.


7pm 250mb map shows an amplified, negatively-tilted trough over the High Plains.	7pm 850mb map shows ample moisture along with a strong southerly LLJ over the Upper Midwest.	7pm surface map shows a surface low over SD with a cold front extending south. Meanwhile, a warm front extends through central MN. Temperatures are in the 90s south of the warm front.

Atmospheric parameters showed a volatile environment for severe weather across the Northern Plains Thursday afternoon and evening.


4pm map of CAPE shows very high instability over eastern SD and southwest MN.	Wind shear is very favorable for severe weather over the Dakotas and western MN at 4pm.	4pm map showing a lot of spin in the low-levels of the atmosphere. This is generally considered to be favorable for tornadoes.

Additional severe weather parameters and soundings from Chanhassen, MN and Aberdeen, SD supported the high likelihood of severe weather.


Significant Tornado Parameter at 4pm shows a bullseye over eastern SD and western MN.	4pm sounding from Chanhassen, MN	4pm sounding from Aberdeen, SD

Additional Information

The Forecast


SPC Day 3 Categorical Outlook	SPC Day 3 Probabilistic Outlook	SPC Day 2 Categorical Outlook	SPC Day 2 Wind Outlook

SPC Day 1 Categorical Outlook	SPC Day 1 Tornado Outlook	SPC Day 1 Hail Outlook	SPC Day 1 Wind Outlook