Back-to-back powerful Pacific storm systems to impact the Pacific Northwest and northern California through the end of this week with heavy rain, flooding, strong winds, and higher elevation mountain snow. A strong, long-duration atmospheric river will accompany the Pacific storms, bringing excessive rainfall and flash flooding to southwest Oregon and northwest California through the week. Read More >
Overview
During the late afternoon and evening of Wednesday, June 16, a slow-moving thunderstorm lingered over the Dupree, South Dakota, area for more than three hours and produced tornadoes, damaging straight-line winds, and torrential rainfall that caused widespread flooding. Law enforcement, local spotters, and storm chasers observed 16 tornadoes from southwest of Dupree to north of town. Multiple tornadoes were ongoing at the same time. Significant damage occurred in Dupree, where several mobile homes were smashed, grain bins were blown over, roofs were damaged, and trees were downed. Two people were injured in Dupree. A storm survey conducted by the NWS determined the damage in Dupree was caused by a combination of straight-line winds and tornadoes. The tornadoes in the town of Dupree were likely rain-wrapped and not visible. Due to the widespread damage from straight-line winds, the exact tracks of the tornadoes could not be determined, although the damage pattern did reveal tornadic rotation. The extent of the damage indicated wind speeds of 120 to 130 mph, which is rated an EF-2 on the Enhanced Fujita (EF) Scale. |
Several tornadoes near Dupree, SD; the right photo shows a "satellite" tornado around the main tornado (Photos courtesy of Roger Hill) |
Several tornadoes near Dupree, SD (Photos courtesy of Roger Hill) |
Tornadoes:
Tornadoes - Dupree, SD
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 |
Flooding
During the evening of 16 June 2010, four to seven inches of rain fell in the area around Dupree, SD, producing widespread flash flooding, and causing many roads to become impassable. Flash flooding occurred in Dupree and along Bear Creek, Ash Creek, and along the Moreau River. Several homes flooded from the heavy rain and several sections of Highway 212 were covered with water of at least a foot deep, and in some places of Highway 212 water was estimated to be over a half mile wide.
Radar-Estimated Rainfall
Radar-estimated rainfall over and around Ziebach County, SD, with a maximum estimate of near 15 inches. |
Photos & Video
Additional Tornado Pictures
Tornadoes near Dupree, SD (Photos courtesy of Robert Shannon & Gary Cudmore) |
Tornado near Dupree, SD (Photo courtesy of Robert Shannon) | Tornado near Dupree, SD (Photo courtesy of Bob Menzel) |
NWS Damage Survey Photos
Storm Damage in Dupree, SD (NWS photos) |
Storm Damage in Dupree, SD (NWS photos) | Storm Damage in Dupree, SD (Photos courtesy of Robert Shannon) |
Storm Damage in Dupree, SD (Photo courtesy of Robert Shannon) |
Storm Damage around Dupree, SD (Photos courtesy of the Civil Air Patrol) |
Radar Animation
This is a radar animation centered around Dupree, SD, from 3:04 pm MDT to 9:56 pm MDT on 16 June 2010. The time between radar images is 4 to 5 minutes. Red polygons show tornado warnings; yellow polygons show severe thunderstorm warnings; and green polygons show flash flood warnings.
Storm Reports
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON... ..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE.... ..REMARKS.. 0504 PM TORNADO 7 S RED ELM 44.95N 101.79W 06/16/2010 ZIEBACH SD LAW ENFORCEMENT SHERIFF SAW BRIEF TORNADO SOUTH OF RED ELM. TORNADO WAS ON THE GROUND FOR LESS THAN ONE MINUTE. 0515 PM HAIL 3 NE RED ELM 45.09N 101.75W 06/16/2010 E0.88 INCH ZIEBACH SD TRAINED SPOTTER HAIL LASTED FROM 515 PM TO 525 PM MDT. 0532 PM HAIL RED ELM 45.06N 101.79W 06/16/2010 E1.00 INCH ZIEBACH SD PUBLIC 0625 PM TORNADO 4 W DUPREE 45.05N 101.67W 06/16/2010 ZIEBACH SD LAW ENFORCEMENT 0640 PM TSTM WND DMG 2 W DUPREE 45.05N 101.63W 06/16/2010 ZIEBACH SD LAW ENFORCEMENT POWER POLES DOWNED 1 TO 2 MILES WEST OF DUPREE ALONG HIGHWAY 212. 0745 PM HEAVY RAIN 18 NNW DUPREE 45.29N 101.73W 06/16/2010 M2.25 INCH ZIEBACH SD PUBLIC RAINFALL TOTAL OVER LAST 90 MINUTES. 0745 PM HAIL DUPREE 45.05N 101.59W 06/16/2010 E1.50 INCH ZIEBACH SD PUBLIC 0745 PM TSTM WND GST 18 NNW DUPREE 45.29N 101.73W 06/16/2010 E60.00 MPH ZIEBACH SD PUBLIC 0815 PM FLASH FLOOD 5 E RED ELM 45.06N 101.69W 06/16/2010 ZIEBACH SD LAW ENFORCEMENT UP TO 3 FEET OF WATER OVER HIGHWAY 212 BETWEEN RED ELM AND DUPREE. 0915 PM FLASH FLOOD DUPREE 45.05N 101.59W 06/16/2010 ZIEBACH SD FIRE DEPT/RESCUE NUMEROUS HOMES FLOODED AND A CAR FLIPPED OVER IN DUPREE. 0915 PM FLASH FLOOD 3 E DUPREE 45.05N 101.53W 06/16/2010 ZIEBACH SD FIRE DEPT/RESCUE ONE FOOT OF WATER OVER 2 MILES OF HIGHWAY 212 EAST OF DUPREE.
Rainfall Reports
Here are the rainfall reports (inches) from near Dupree, SD, for the 16–17 June 2010 flash flood event.
Rainfall reports (inches) from NWS COOP and volunteer CoCoRaHS observers for 16–17 June 2010. |
Environmental Summary
The atmosphere was very unstable on 16 June 2010 across western South Dakota. First, the surface map (first image below) showed a warm front just southwest of Faith, SD (dashed orange line). Tornadoes commonly occur along and just north of warm fronts. In addition, the Rapid City balloon information (first two images of the second row below) showed a lot of buoyancy and instability, along with moderate vertical wind shear -- all of which are critical to tornado formation. Finally, the significant tornado parameter (STP) showed increasing values from 3 pm to 6 pm MDT (bottom four images). STP values of 1 are considered the lower threshold for getting strong tornadoes. In this case, STP values were well above 1, increasing from a max of 4 at 3 pm to max values of 6 to 9 from 5 to 6 pm MDT.
Surface Weather Map (6 pm MDT on 16 June 2010) |
Rapid City sounding (6 pm MDT on 16 June 2010) | Rapid City hodograph (6 pm MDT on 16 June 2010) | Significant Tornado Parameter (3 pm MDT on 16 June 2010) |
Significant Tornado Parameter (4 pm MDT on 16 June 2010) | Significant Tornado Parameter (5 pm MDT on 16 June 2010) | Significant Tornado Parameter (6 pm MDT on 16 June 2010) |
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