July 7th Tornadoes...

Overview: July 7th, 2016 Tornadoes

The combination of weak surface low pressure in south central Kansas and an outflow boundary oriented from west to east across central and eastern Kansas led to the development of thunderstorms on the evening of July 7th, 2016. Given recent heavy rains, ample daytime heating allowed dew point temperatures to reach the mid to upper 70s. These very moist low levels worked in concert with modestly steep mid-level lapse rates to allow an extremely unstable atmosphere, characterized by 6000+ J/kg of surface based CAPE, to develop. The extreme instability was also met with 40-50 knots of effective bulk shear and decent directional shear with height, as shortwave energy gradually clipped the region from the north. With all of the ingredients necessary for severe storms, by the late afternoon and early evening hours a cumulus field had developed and was oriented from west to east across the state along the residual outflow boundary. As convergence continued to increase along this boundary, multiple thunderstorms began to erupt around the Chase, Lyon, Greenwood county borders. One dominant right moving supercell began to take over as it dropped southeast across Greenwood county producing multiple tornadoes. The strongest tornado developed northwest of Eureka, where high-end EF-3 damage was found. As the storm cycled and continued to move towards Eureka, an EF-2 tornado developed on the northwest side of the city and moved southeast across the city before dissipating. There were also brief touchdowns in far southeast Chase county and northwest Wilson county.

Photo of the tornado illuminated by cloud-to-ground lightning as it moved across Eureka, Kansas. Photo courtesy of Jason Keller via Twitter @jasonkellerpt

Base reflectivity and storm relative velocity showing multiple tornado touchdowns across Greenwood County, including the tornado that devastated parts of Eureka, Kansas.

Reflectivity loop showing rotation about the surface low pressure anchored in south central Kansas on the evening of July 7th, 2016.

Tornado
Storm Reports and Warnings
July Tornado Stats

Tornadoes:

Tornado - NW of Eureka, Kansas (~10 miles NW of Eureka)
Greenwood County

Date	July 7th, 2016
Time (Local)	9:10-9:40pm
EF Rating	EF-3
Est. Peak Winds	165 mph
Path Length	6.7 miles
Max Width	1/2 mile
Injuries/Deaths	0
Summary: Damage that occurred near the Otis Creek Reservoir was determined to be thunderstorm wind damage from the rear flank downdraft. The tornado touched down north of the reservoir and tracked southeast before wrapping back around to the northeast and eventually west, and southeast again as the updraft occluded. *** The tornado track is not an exact depiction and should be used for reference purposes only.

Track Map


		Picture courtesy of NWS Wichita from storm damage survey showing what is left of a residence that sustained a direct hit. Note the significant tree damage as well.

Tornado - Eureka, Kansas
Greenwood County

Date	July 7th, 2016
Time (Local)	9:41-9:50pm
EF Rating	EF-2
Est. Peak Winds	135 mph
Path Length	3.67 miles
Max Width	150 yards
Injuries/Deaths	0
Summary: As the circulation to the north of town weakened, a new updraft rapidly developed over Eureka and produced another tornado. The tornado damaged multiple structures and trees from northwest to southeast across Eureka. *** The tornado track is not an exact depiction and should be used for reference purposes only.

Track Map


Mobile home destroyed with debris blow away. Photo courtesy of NWS Wichita.	Residence that lost its roof. Photo courtesy of NWS Wichita.	Barns near the local grain elevator destroyed. Photo courtesy of NWS Wichita.	Roof damage. Photo courtesy of NWS Wichita.

View of supercell from a baseball field in Wichita. Picture by Kevin Darmofal.

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

Storm Reports

July Tornado Stats

With the handful of tornadoes that hit Chase, Greenwood and Wilson counties during the late evening hours on July 7th, one may inquire about the rarity of July Kansas tornadoes. According to the Storm Prediction Center's tornado database, 318 July Kansas tornadoes have occurred from 1950 through 2015. This averages out to roughly five July tornadoes per year across the state.

So at first glance, this was not an overly unusual event. However, when taking into account tornado strength, this was a rare occurrence. Out of the 318 July Kansas tornadoes, only four have been rated EF3 or stronger, with the Greenwood county EF3 on July 7th increasing that number to just five. No July Kansas tornado has ever been rated stronger than EF3. The last time a July EF3 tornado occurred across the state was last year on the 13th near Nickerson in Reno county. Before that was July 20, 1958 in Wallace county.

Kansas July EF3 Tornadoes 1950-2016
Date	County	Length (Miles)	Width (Yards)	Injuries	Fatalities
July 15, 1956	Lincoln	7.1	880	0	0
July 20, 1956	Anderson	69.5	880	0	0
July 20, 1958	Wallace	3.3	700	4	0
July 13, 2015	Reno	5.32	350	0	0
July 07, 2016	Greenwood	1.72	1365	0	0
*Note: No Kansas July tornado has ever been rated stronger than EF3.

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