• Hello, please take a minute to check out our awesome content, contributed by the wonderful members of our community. We hope you'll add your own thoughts and opinions by making a free account!

Severe Severe Weather Potential February 23rd

Joined
Jan 5, 2017
Messages
711
Reaction score
1,373
Location
Odenville Alabama
This potential event looks like it will be worth discussing. Looks like this may be the first threat in a while where instability will not be a question.

...DISCUSSION... Medium-range model output continues to indicate strong cyclogenesis will commence across the southern Plains by 12Z Saturday, before continuing northeastward through the Great Lakes region by 12Z Sunday. Guidance indicates that the rapid evolution of a broad and deep cyclone is likely, aided by a vigorous short wave impulse emerging from the Southwest. It appears that this will be accompanied by an intensifying cyclonic mid-level jet, including in excess of 100 kt at 500 mb by midday Saturday across the southern Plains Red River Valley, and 50-80+ kt south/southwesterly 850-700 mb flow across the destabilizing warm sector. This environment may become conducive to the evolution of a significant organized mesoscale convective system, potentially accompanied by considerable damaging wind gusts. Highest severe probabilities appear focused in a swath across parts of the Ozark Plateau and lower Mississippi Valley into the Tennessee and lower Ohio Valleys. A warm front may initially be located along a corridor near or just south of the Ohio River, west southwestward into northwestern Arkansas, near the northern periphery of the currently depicted 15 percent severe probabilities. While the influence of current snow and ice cover near and northwest of this region remains uncertain, this boundary may ultimately remain the focus for the track of the northern flank of an evolving squall line. However, based on the track of the low, aided by strong dynamic forcing, destabilization supportive of severe thunderstorm potential could develop northward into southern portions of the Great Lakes region Saturday night. The southern edge of the 15 percent probabilities is based on the model consensus of the southern periphery of the deeper surface cyclone. The southern flank of an evolving squall line may extend this far south, where boundary-layer moistening and destabilization will likely be most favorable. This environment may also support discrete supercell development in advance of the squall line. In addition to the risk for damaging convective gusts, there appears potential for tornadoes, including some strong.day4prob.gif
 
Even if the threat is only in the form of a mcs or squall line, it won’t take a ton of that wind coming down to the surface to bring down a significant number of trees over a large area, given the saturated ground in so much of the potential shaded area.
 
I've been watching this for a few days now.

Definitely a decent setup for sure, although I'd still like to see more instability.

Even the wind field looks to be veered, which should be conducive for weak (at least) tornadoes.
 
Sounding out ahead of the line, northern MS, very concerning, that’s one high Supercell composite, helluva lot of LLvL shear/SRH, CAPE has been on a upward trend in models aswell, as you can see 1000+ jkg of CAPE is basically throwing gas into the fire, area of dry air aloft is aiding in CAPE by allowing steeper lapse rates, what was looking like a event with poor lapses has changed, the parameters are supportive of strong tornadoes but even with the increase in CAPE, it’s still a limiting factor, I tried to see which hodo matches and I finally found something, sure they may look a bit different but there the closest matches on here A61233E6-60BE-486E-8FA3-7662711AB14C.jpegA3D567E4-F567-4E1D-B5E9-2CC6BF04AD3A.jpeg
 
Sounding out ahead of the line, northern MS, very concerning, that’s one high Supercell composite, helluva lot of LLvL shear/SRH, CAPE has been on a upward trend in models aswell, as you can see 1000+ jkg of CAPE is basically throwing gas into the fire, area of dry air aloft is aiding in CAPE by allowing steeper lapse rates, what was looking like a event with poor lapses has changed, the parameters are supportive of strong tornadoes but even with the increase in CAPE, it’s still a limiting factor, I tried to see which hodo matches and I finally found something, sure they may look a bit different but there the closest matches on here View attachment 16162View attachment 16163

Decent severe weather look, very marginal discrete supercell look.
 
Decent severe weather look, very marginal discrete supercell look.

Agree, There’s so much wind energy, instability is lacking a bit tho, still we need to hope no cells develop out ahead of that line but this setup is more of a squall line/MCS type look
 
Agree, There’s so much wind energy, instability is lacking a bit tho, still we need to hope no cells develop out ahead of that line but this setup is more of a squall line/MCS type look

I think it will be very hard to see anything form ahead of the line. Low 3km cape, marginal low level laspe rates and strong low level winds really argue against it. Probably a good amount of showers ahead of the line which will dampen instability farther.
 
I think it will be very hard to see anything form ahead of the line. Low 3km cape, marginal low level laspe rates and strong low level winds really argue against it. Probably a good amount of showers ahead of the line which will dampen instability farther.

Yup, short range models indicate lots of showers/cloud cover with this setup, 3KM nam really shows what you said with Cape lacking around 3km, even with limited CAPE tho with the amount of wind energy, it’ll be easy to mix winds down to the sfc even its a something like a heavy shower
 
Yea the 0z 3k NAM continues to look not all that impressive. We will see what tomorrow shows.

It actually increased MLcape for some areas, I wonder whether that will happen where short range models increase Instability or that was just a off run
 
Sounding out ahead of the line, northern MS, very concerning, that’s one high Supercell composite, helluva lot of LLvL shear/SRH, CAPE has been on a upward trend in models aswell, as you can see 1000+ jkg of CAPE is basically throwing gas into the fire, area of dry air aloft is aiding in CAPE by allowing steeper lapse rates, what was looking like a event with poor lapses has changed, the parameters are supportive of strong tornadoes but even with the increase in CAPE, it’s still a limiting factor, I tried to see which hodo matches and I finally found something, sure they may look a bit different but there the closest matches on here View attachment 16162View attachment 16163

Excellent write-up! thank you for making it a learning opportunity for those looking to learn!
 
Hrrr was concerning, pretty unstable, more CAPE in the lower levels aswell, mid level drying could add to the strong wind potential, but it’s the LR hrrr lol, anyways id still be worried about some strong winds with these storms, combination of any dry air entrainment and lots of wind energy above our heads, that can easily mix down any strong winds aloft towards the sfc and also through the process of evaporative cooling if there’s any dry air aloft
8E9BAB92-D651-4F49-9788-832A3018E425.jpeg
 
Back
Top