July 21st 2012 Hail and Wind Damage

July 21st 2012 Hail and Wind Damage

On the early morning of July 21, 2012 a cold front was generating showers and thunderstorms across central Upper Michigan. One of the thunderstorms passed just south of the Republic area, causing fairly extensive wind and hail damage. One of our local weather spotters, Rod, took numerous photos of this damage.

HPC Surface analysis archive overlaid with radar imagery from 5 AM EDT July 21, 2012. A cold front is seen

generating thunderstorms across central Upper Michigan.


Storm 3 Miles South Of Republic: Radar Data

Above is an image of radar data from 5:05 AM EDT at 12, 000 ft off the ground. On the left is reflectivity, which essentially shows us the size of the particles in the air. Pinks, whites and purple usually indicate hail (or large particles). You can see the hail is suspended 12,000 feet off the ground. On the right is correlation coefficient. The blues and greens (left bottom side of picture) shows what is known as a three body scatter spike, which typically shows up when there is large hail.


This image shows a cross section, or a vertical slice through a storm. On the vertical axis is how high above the ground the reflectivity (how big the particles are) is. This was taken at 5:05 AM EDT. You can see there is hail suspended in the updraft of the storm to 30,000 ft! Also note that there are lower reflectivities near the surface.


The images above show the storm at 5:10 AM EDT. On the top showing the reflectivity close to the surface (0.5 Deg), and on the bottom is a cross section showing the higher reflectivities descending downward (was near 30-40Kft in previous picture, now near 10-15Kft). This is likely when the hail started falling south of Republic near M-95.


This image shows the 5:15 AM EDT  base reflectivity on the lowest slice of the radar (0.5 Deg) on the top, and another cross section of the reflectivity on the bottom. This was after the hail fell south of republic, as the highest core is now to their east. Hail was still falling at this point, however because the area further east of M95 is uninhabited, we did not receive any reports.


This image above shows the base reflectivity (lowest radar slice) at 5:20 AM EDT. It was likely

still hailing at this point, however no reports were received because it is an uninhabited area.


Damage Photos From the Storm

Supplied by Storm Spotter Rod Wallberg who was in the area a couple hours after the storm passed. More images will be posted.