Severe Weather Threat May 7-10, 2024

[Clancy]

Casual, late afternoon petite supercell going up south of Birmingham.

 

[Clancy]

Severe Thunderstorm Watch out.

 

[UncleJuJu98]

The supercells are starting to fire now

 

[wx_guy]

The new Storm Watch is well-met, I think. Somewhat unexpected given the models, but the mesoanalysis definitely screams explosive development could occur. Western/Central AL has 5k-5500+ CAPE, 1300-1500 DCAPE, and near-maxed out Microburst Composite and Derecho Composite Parameters, 7.5-8 Low-Level Lapse Rates, and high temperatures and high dew points...the front and outflow boundaries should provide lift needed to get crazy mess going.

 

[UncleJuJu98]

Mesocyclone on the Birmingham storm isn't too shabby. Id watch out for a tornado threat moving forward

 

[JPWX]

Severe Thunderstorm Watch out.

I love those type of watch maps. I just wish they were available for access outside of social media.

 

[Clancy]

Definitely some decent mid-level rotation near Saginaw.

 

[UncleJuJu98]

Definitely some decent mid-level rotation near Saginaw.
View attachment 26999

Impressive hook on it

Severe warned now

 

[jules]

I’d really like to see what that Shelby storm looks like from the ground.

 

[UncleJuJu98]

That rotation is really kicking up a notch now

 

[wx_guy]

The B'ham area storms firing are along the edge of an area where Low Level Lapse Rates and high 3CAPE coincide. And of course I'm watching NW Mississippi, that has over 300 3CAPE (and over 7000 CAPE). Waiting to see if anything happens there.

 

[Justin Hindman]

Gonna be like summer storms near bham

 

[Clancy]

Cell near Columbus, MS now exhibiting decent rotation.

 

[wx_guy]

Only a few storms showing up on radar right now, but you can see where storms are building. This is where the radar will soon light up.

 

[wx_guy]

Interesting mathematical quirk. I've shown here the STP (fixed), one of the two widely-used STP formulas. I've also shown the Violent Tornado Parameter, which is meant to distinguish between strong (EF2+) tornadoes and violent (EF4/5) tornadoes. However, notice how crazy different they are here! In NW Mississippi, the VTP is nearly maxed out, but the STP is just about 1. What gives?

There really isn't extreme chances of a violent tornado in MS or anything like that. There's actually not particularly good chance for tornadoes at all there right now (I believe the SPC has a 5% for that area). This is due to the formula for the VTP. It uses 3CAPE and 0-3 km Lapse Rates, in addition to the usual STP parameters, because in the research these were shown most strongly to discriminate conditions that created violent tornadoes from those that just created strong tornadoes. In today's setup, though, we have 3CAPE and 0-3 km Lapse Rates that are very high, so the VTP is pushed to very artificially high levels. The VTP probably shouldn't be that high, but the math of these types of combined indices are rarely perfect in every situation. Good lesson to not blindly trust the indices, models, and outputs. (which I've done all too often). Interesting stuff.

 

[Clancy]

Helicity remains weak (50 m2/s2 or less) and will more or less remain that way, so I don't think there will be too much in the way of a tornado threat, definitely not like yesterday, obviously. That being said, some lovely structure on some of these cells in AL.

 

[Bama Ravens]

Impressive severe storm that just crossed into AL from MS.

 

[jmills]

Interesting storm split east of Columbus. The right mover is developing a mesocyclone. It bears watching - as it moves right of the mean storm motion vector it will “experience” some locally enhanced storm relative helicity

 

[Clancy]

Storm near Carrolton, AL bears close observation. Has developed a notable meso.

 

[Ledian]

Storm near Carrolton, AL bears close observation. Has developed a notable meso.

Yeah, i'm glad it passed Columbus when it did. I have family over there, and some of them are without power at this time. Several trees are down, one of which was uprooted