Severe WX Multi-day Severe Weather Threat 3/12-3/14/2019

[NorthGaWeather]

We'll see what transpires over the next few hours. The Fayette cell is clearly ingesting better instability, given how quickly the updraft strengthened. The Northwest Walker/Winston cells are on the northern edge of the instability axis. 300m2s2 0-1km ESRH is co-located well with this axis.

 

[David in SW Blount]

Twenty bucks says it's going to go TOR soon. I'm probably going to get some hail here west of Jasper.

I'm watching that one too. Not even under a Tornado Watch here.

 

[Equus]

>65dbz on the Fayette cell, developing that C shape. Wonder if that cell merger it's about to go through is going to help it spin up or slow it down.

 

[Richardjacks]

I fear the Fayette county storm is about to turn into a monster...hopefully I am wrong

 

[Equus]

Headed to downtown Jasper to watch it

 

[Tennie]

Is anyone else here having trouble getting the streams on LiveStormChasing to play? Because I am.

 

[NorthGaWeather]

Thunderstorm in southern Winston continues to strengthen. The Fayette cell merger is occurring too. We'll see if that helps the low level meso.

 

[Chris3024]

Yeah, the storm near Arley seems to be gaining strength.

 

[Justin Hindman Hindy]

Seems like this may be a day where the storms strengthen then weaken before the produce a tornado. Not saying one isn’t possible because there is, but a common thing so far with these storms

 

[Mike]

Anyone watching Brett Adair's live feed? Any issues? Can;t seem to get it running on my laptop..

 

[John Jaye]

Spann is livestreaming now.

 

[Kory]

Seems like this may be a day where the storms strengthen then weaken before the produce a tornado. Not saying one isn’t possible because there is, but a common thing so far with these storms

Wall cloud outbreak.

 

[tennessee storm chaser]

Wall cloud outbreak.

Yep maybe the lack of helicty... preventing them to get down to the surface ....

 

[AL_ham_op]

So what's the outlook now for the Bham and Central AL area? Does it still bear watching at this point?

 

[NorthGaWeather]

Yep maybe the lack of helicty... preventing them to get down to the surface ....

Helicity is good right now. I think its more of an instability/dry air issue, which is hampering updraft strength.

 

[NorthGaWeather]

Cell north of Reform may need a SVR soon.

 

[Tennie]

Helicity is good right now. I think its more of an instability/dry air issue, which is hampering updraft strength.

Well, surface dewpoints are currently in the lower-mid 60s, with dewpoint depressions around 10-15 degrees F. Perhaps what's holding the cells back is higher-level instability or lack thereof...?

 

[Kory]

Wind profiles are funky in the mid levels too. But yeah, lots of dry air. No wonder we're getting big hailers.

 

[jmills]

I think what we're seeing is diabatic heating driving the downward mixture of drier air, which could (at least partially) explain the difficulty in these circulations becoming connected to the ground. Take BMX for example.



The low dew point and near dry adiabatic lapse rate in the area enclosed by the yellow circle is indicative of convective mixing. This results in a mixed layer LCL near 1000 m. This isn't crazy high, but it definitely is on the upper end of climatology for supercells in Central AL.

 

[Kory]

I think what we're seeing is diabatic heating driving the downward mixture of drier air, which could (at least partially) explain the difficulty in these circulations becoming connected to the ground. Take BMX for example.

View attachment 1217

The low dew point and near dry adiabatic lapse rate in the area enclosed by the yellow circle is indicative of convective mixing. This results in a mixed layer LCL near 1000 m. This isn't crazy high, but it definitely is on the upper end of climatology for supercells in Central AL.

View attachment 1218

That was my concern this morning. In this case, sunshine hampering the threat this morning. We broke out into partly sunny skies, which allowed mixing.