at 8:20 PM by Pierce Larkin

WxRecap: Storm Insanity Has Ruled Bowling Green

That really did escalate quickly this afternoon.

h/t giphy.com
h/t giphy.com

There had been a strong vorticity maximum across eastern Kansas this morning, moving eastward as time progressed. It was forcing a decaying mesoscale convective system (MCS) as it moved east; however, it had the precipitation.

The vorticity maximum that moved eastward towards us. h/t SPC
The vorticity maximum that moved eastward towards us. h/t SPC

As this was progressing eastward, the atmosphere across southern Kentucky was seeing plentiful sunshine. This continued through the morning and into the afternoon hours, and led to fairly significant destabilization across the region. Additionally, moisture in the lowest portion of the atmosphere was very, very abundant, helping further destabilize the atmosphere.

Mixed-layer CAPE across the region was fairly high, indicating an unstable environment. h/t SPC
Mixed-layer CAPE across the region was fairly high, indicating an unstable environment. h/t SPC
PWAT values across the region were very high, indicating a very moist atmospheric profile. h/t SPC
PWAT values across the region were very high, indicating a very moist atmospheric profile. h/t SPC

Throw the vorticity max and decaying MCS back into the picture. These were moving eastward into a very warm, moist and unstable environment. The storms began to intensify over southern Missouri and northern Arkansas, beginning to produce wind damage as the progressed eastward.

The storm reports for today. h/t SPC
The storm reports for today. h/t SPC

By early afternoon, they were knocking on western and southern Kentucky’s door, and had developed a fairly strong and established cold pool. This allowed for the convection to remain organized and it continue to strengthen, producing severe wind gusts along the way.

Radar velocities for the line to our west. h/t Radarscope
Radar velocities for the line to our west. h/t Radarscope
Note the 58 mph wind gust across western Kentucky. That is severe strength. h/t KY Mesonet
Note the 58 mph wind gust across western Kentucky. That is severe strength. h/t KY Mesonet

As this was occurring, convection was forming ahead of this line in south-central KY, near BG. One of these storms became intense pretty quickly, and was the main culprit for damaging winds across the Warren county region. Widespread reports of tree and powerline damage was reported within the city, and over 15,000 people in total were without power after the storm.

These storms actually acted to weaken the main line of storms as it moved towards our region, sparing us more wind damage than we already had. Check out some of the damage from across town.

And that is just some of it. The complex eventually weakened as it moved southeastward through Tennessee.

…And this insanity has continued almost non-stop since I wrote this post last evening. The downburst and associated wind damage across SoKY last evening was just merely the beginning of a very long, long 24 hours.

Soon after the storms exited our region last night, the WPC issued a mesoscale discussion highlighting heavy rainfall across our region.

h/t WPC
h/t WPC

Now, the hi-res models had been painting this scenario a bit leading up to it, but come on. After an atmospheric overturning like the one we took just hours before? That couldn’t happen…

h/t giphy
h/t giphy

…but it did. Within a strong regime of warm air advection at the top of the boundary layer (850 mb), we saw instability that had been building in Missouri and Arkansas advect into the region.

Very strong upward motion across western and southern KY last night. h/t SPC
Very strong upward motion across western and southern KY last night. h/t SPC

Additionally, this matched up with a mid-level speed max and shortwave that slowly moved across the region. This provided favorable upward motion across our region, allowing for deep convection to be sustained. In addition to this, a very deep and moist boundary layer was present, with highly anomalous precipitable water present and plentiful moisture at 850 mb.

The precipitable water values across the region last night. h/t SPC
The precipitable water values across the region last night. h/t SPC
The 850 mb dewpoints and flow across the state last night. h/t SPC
The 850 mb dewpoints and flow across the state last night. h/t SPC

These storms moved very slowly within the atmospheric flow, and DUMPED water onto of us. The worst of the flooding was to our west, but we were still hit hard with repeated training thunderstorms overnight.

h/t NWS Louisville
h/t NWS Louisville

The training of the rainfall and resultant flooding was so bad that both Kentucky and Tennessee have declared State of Emergencies for the affected areas. 

Then we get to this afternoon. If I could set up the morning any more similar to yesterday, I would have done it. But the set up this morning was very eerily similar to yesterday’s severe weather event.

h/t giphy.com
h/t giphy.com

The clouds from the overnight MCS broke quickly by mid-morning, leading to fairly significant sunshine by that time.

Visible satellite from early this afternoon. h/t SPC
Visible satellite from early this afternoon. h/t SPC

There were a few things that made this morning and early afternoon differentiated from yesterday. First of all, the ground was extremely saturated across the region. This lead to surface dewpoints being anomalously high across the region. Early this afternoon, there were some Mesonet stations that record dewpoints approaching the mid 80s.

h/t KY Mesonet
h/t KY Mesonet

That is absolutely insane. Straight up. I haven’t seen an 80 degree dewpoint in Kentucky in a long time (I’m not totally sure I have seen one), and this was really an ideal set up for quick destabilization across the western portion of the state. As sunshine heated the surface, the temps rose into the mid 80s. This combined to yield a very, very unstable environment across this region.

Mixed layer CAPE early this afternoon. We had plenty of instability. h/t SPC
Mixed layer CAPE early this afternoon. We had plenty of instability. h/t SPC

The similar things to yesterday included:

  • A strong vorticity maximum
  • A decaying MCS
  • A quickly destabilizing atmosphere ahead of said MCS
  • Incredible amounts of moisture

The MCS was actually fairly strong as it moved through central Missouri this morning, but weakened rapidly as it advanced eastward. However, as it moved into the unstable environment across southern Illinois, southeastern Missouri and western and southern Kentucky, the storms rapidly intensified, leading to a Severe Thunderstorm Watch being issued.

h/t SPC
h/t SPC

To complicate things even further, convection formed out ahead of the main line across south central KY. This created additional flooding and wind damage problems, as reports flooded in (no pun intended). Nearly 10,000 people we left without power again today after the storms.

This severe thunderstorm warning does show the initial convection just outside of the warning, and the main squall line. h/t @NWSSevereTstorm
This severe thunderstorm warning does show the initial convection just outside of the warning, and the main squall line. h/t @NWSSevereTstorm

The past couple days have been fairly exhausting for yours truly, with the consistent coverage here on the blog and forecasting for these events. This has actually been one of the more active timespans that I have been associated with at WxOrNotBG. We have had severe weather everyday this week except for Tuesday, and we are expecting more tomorrow. Some of the images since last night are incredible.

 Holy moly; that is a LOT of rainfall.

I do thank you all for trusting WxOrNotBG to keep you up to date with the latest real-time weather information. Be sure to check back in tomorrow morning, as we will have a fresh forecast post up for you detailing the severe threat for tomorrow afternoon and evening!