The Meteorology Behind Tuesday’s Severe Storms
Radar and Warnings From Tuesday Storms
Typically when severe weather strikes, we expect it in the afternoon and evening. Tuesday, the atmosphere was primed for severe weather by 9 am. Here, we break down the technical weather setup.
An upper-level wave moved into northern Michigan leading to an impressive dynamic and thermodynamic environment capable of sustaining long-lived severe thunderstorms. Dynamics in place were typical of a single event we see every year or two. But with an evolving climate, these events are likely to become more frequent.
Storms started moving into the region around 8 to 9 in the morning. These were our first severe thunderstorm warnings of a very active day (yellow boxes).
Storms continued to track east with the first line around the noon hour dropping some pea to quarter-size hail along the M-55 area, including at 9&10 Headquarters in Cadillac.
A secondary line of storms developed ahead of a cold front in a very unstable atmosphere leading to strong to severe storms. Check out the meteorology below for more in-depth information about how the storms developed.
These storms were not only bringing strong winds, but the winds were rotating. There were NO confirmed tornadoes with this line, however. This was the first of three tornado warnings issued across your area Tuesday (red box). The warnings were issued because winds were rotating, not because of a tornado spotted on the ground.
The second snapshot was during the worst of the damage was occurring from the Chase/Baldwin area to Evart. Damage was widespread with trees and powerlines snapped. Notice the backward “C” shape, that is evident of straight line damaging winds. This cell moved from Mason County to Clare County.
NO tornadoes touched down with Tuesday’s severe storms. All damage was associated with straight-line winds. The wind reports from area airports came in 40 to 55 mph. In between airports, winds likely exceeded 60 mph.
The largest hail recorded of the event was 2.5 inches in diameter, roughly the size of a tennis ball to put that into perspective. The Tennis ball hail was fell in Colfax (Mason County) and Baldwin (Lake County). Cadillac also had 2.0 inches in diameter hail one mile northeast of town.
Check out photos from the storms on Tuesday here.
Meteorology and Synopsis – Data from 16z or 12:00 PM
The 500 mb jet (30,000 feet) dove into Norwest lower Michigan, providing enhanced rising motion at the surface. This lead to the regeneration of storms ahead of a surface cold front and a surface low. The lighter the blue, the stronger the wind.
At 850 mb, a noticeable low level jet (wind max) was nosing into Central Michigan. Upper level data suggested a low level wind max between 30 and 40 knots (34 to 46 mph). There was also an increase in moisture at the 850 mb level as well (3,000 feet). You can see that will the green fill in Michigan.
At the Surface, an area of low pressure was developing, with a cold front extending south from the low. Ahead of the front was a very muggy and warm air in place.
The instability was not off the charts, but Convective Available Potential Energy (CAPE) rooted at the surface was 1,000 to 2,000 j/kg. This is enough to sustain organized storms given the right balance of CAPE and shear.
Another measure for instability is the mid-level lapse rate. This is the measure of how quickly temperature changes with height. The higher the number the quicker the air will rise. Notice the mid-level lapse rates were not as impressive as off to our west, but still sufficient for lift and organized severe storms.
The balance of CAPE and shear was in place, this can be denoted by the Supercell composite parameter. Notice the bullseye across West-Central Michigan. The hardest-hit area on Tuesday was to the east of bullseye.
All the necessary ingredients for severe weather came together for a few hours Tuesday late morning and early afternoon. Much quieter weather is ahead! Check out your 7 day forecast right here.