Wednesday, July 29, 2015   |   Case Studies, Critical Weather

Manitoba Tornado – July 27, 2015

A powerful supercell thunderstorm moved through southwestern Manitoba, Canada on July 27, 2015, producing a tornado that was on the ground almost continuously for nearly 3 hours, affecting the towns of Melita through Tilston and north through Virden, as well as adjacent farmland in between. Despite the tornado occurring 20-65 miles north of the US/Canada border, radar data from the MBX NEXRAD radar, as well as Baron value-added data, tracked the tornado throughout its lifetime.

At 8:35pm, reflectivity shows a strong storm to the northwest of Melita. A low-level Baron Shear Maker and a Shear SCIT (Storm Cell Identification and Tracking) arrow have triggered, indicating the presence of 81 mph of wind shear.

7_27_manitoba_835p_ref

 

 

 

 

 

 

 

As the storm continued moving north-northeast, De-aliased Velocity data shows over 100 mph of rotation (41 mph toward/63 mph away).

7_27_manitoba_900p_vel

 

 

 

 

 

 

 

25 minutes later, the Baron Button, a value-added product, continues to indicate over 100 mph of shear with the storm, indicating a tornado is likely occurring.

7_27_manitoba_925p_bb

 

 

 

 

 

 

 

The storm also produced a large amount of hail. Another Baron value-added product, Dual-Pol Hail, shows the parts of the storm where hail is likely occurring showed a large area being affected by hail at 9:28 pm.

7_27_manitoba_928p_hail_core

 

 

 

 

 

 

 

At 9:34pm, the Baron Shear Rate product shows a large amount of wind shear between Melita and Virden in the exact location where the tornado is occurring.

7_27_manitoba_934p_shear_reate

 

 

 

 

 

 

 

On the 9:54pm reflectivity scan, a very distinct and impressive hook echo can be seen, with Shear SCIT arrows present on the north and south sides of the hook echo.

7_27_manitoba_954p_ref

 

 

 

 

 

 

 

The storm continued to move north-northeast late into the evening. A circulation remained present with the storm as it moved to the south of Virden. Low-level Baron Shear Markers help show the area of intense circulation in velocity data.

7_27_manitoba_1014p_vel

 

 

 

 

 

 

 

The value-added Baron Hail Swath shows the large extent of areas that likely received hail from this storm over a 2-hour period through the evening.

7_27_manitoba_hail_swath

 

 

 

 

 

 

 

The Baron Shear Swath reveals a 2-hour swath where the highest amounts of shear had occurred. This correlates well with the tornado’s path.

7_27_manitoba_1037p_shear_swath