Lab 12 - Wisconsin Tornado Outbreak June 22nd, 2011
For this lab, I will go back to my previous lab 5 where I analyzed the Tornado outbreak in Wisconsin on June 22nd, 2011. To get a general overview of the setup for this extreme outbreak, below is shown a corrected reflectance satellite image from June 22nd, 2011.
Terra Corrected Reflectance - 06/22/11
From the above image of corrected reflectance, we notice the massive synoptic cyclone spinning in the northern midwest states on this date. The associated cold front is what sprung the highly convective cells along the advancing cold front. To help better visualize the area of which these convective lines developed, below is shown a radar reflectivity loop from the same date (used in Lab 5) helping to showcase the progressing lines as they passed through Wisconsin on this date.
Base Reflectivity (From Lab 5) - June 22nd, 2011
Looking at both the large-scale synoptic satellite view, as well as the radar imagery above, we notice the strong lines of convection occurring along the advancing cold front associated with the wide-scale synoptic cyclone shown in the first image. While most of the intense cells that produced strong winds, hail, as well as 6 confirmed tornadoes, the satellite imagery is from a few hours past when these tornadoes were observed to be on the ground.
Limitations with satellite imagery are often seen with only satellite images occurring around 1:30 local time as seen in the first imagery. Shown in the following image is the surface precipitation rate zoomed in on our area of interest, solely to show the change in time from when the strongest of cells were produced, to when the satellite image was actually taken on this date.
Corrected Reflectance/Surface Precipitation Rate (mm/hr)
From the satellite image above, overlayed with the surface precipitation rate, we notice that the majority of the strong rainfall is occurring much farther east than noticed in our radar image above. From the above image at this time (1:30 Local Time), we see the strongest of precipitation is falling at around 20mm/hr in the locations colored for surface precipitation rate.
Due to the limitations of satellite imagery, it is fairly hard to discern any severe weather features seen on satellite. With this storm associated with a synoptic cyclone, we can expect that if we were to have timely satellite data, most of the severe weather features, such as overshooting tops and discrete supercells, may not be visible from satellite as the wide swath of cloud cover is seen to reduce our visibility in that region from the advancing synoptic storm.
Corrected Reflectance/Cloud Top Height (km)
From the above image, we see the same image of corrected reflectance, with now cloud top height overlayed in the colored regime. In the areas of most intense convection (and precipitation) at this time, we see cloud top heights on the furthest end of the spectrum, with some reaching upwards of 15km in height. Now again with this satellite image being taken a few hours after the tornadoes were reported on this day, the strongest of cells may not be shown with the cloud top heights seen above. Still, with cloud top height values upwards of 15km, we can tell that the convection occurring in the area of our storm and severe phenomena is extremely strong, and may be producing overshooting tops that are not explicitly visible from the limitations of satellite imagery on a daily basis.
Lastly, I want to show the cloud top temperatures from the satellite view of this storm system as it progressed through Wisconsin. Below is the cloud top temperatures overlayed on the visible satellite imagery.
Corrected Reflectance/Cloud Top Temperature (K)
From the image above, we can see the distinct cyclone signature of the synoptic storm. The extremely high top clouds seen along the advancing cold front are shown to have cloud top temperatures of near 150K, showing very cold and high clouds tops in the associated regions where the highly convective storms developed earlier this day and on. Moreso, the image above gives a great representation of the progression of this large-scale system as it continued to drive precipitation to upper Wisconsin and on into the Great Lakes region later in the day on June 22nd, 2011.
Hey Tim, your post about the Wisconsin tornado outbreak of June 2011 was really neat! I enjoyed seeing images used from the Terra satellite data, as my blog post was focused more on the Aqua satellite data. Your final figure of the cloud top temperatures really stood out to me because of the mixing of such drastic temperatures. It's clear that two different air masses are mixing together to form this intense severe cyclone. Overall super cool post!
ReplyDeleteHi Tim, great post! I also had trouble discerning severe weather signatures due to satellite limitations, but your post really came together with that last image. You can see the cyclonic structure of the clouds so clearly!
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