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Severe WX Severe Weather Threat - February 15-16, 2023

xJownage said:
Synoptic pattern is everything. Positively tilted troughs don't preclude severe weather. I have a feeling we're going to see another last minute uptrend on both days.

What's pissing me off today is people calling Forecasted Convective Amplification Deficiency 3 days out. We've seen a bunch of events do exactly this and look like garbage thermos-wise until the last minute. To call Forecasted Convective Amplification Deficiency on such a strong system 3 days out is irresponsible at best.
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Yep I don’t get it either
 
This has so many similarities to Jan 12th in my opinion. Even the global models trended down before CAM range and the turds on wxtwitter were proclaiming Forecasted Convective Amplification Deficiency.

Also this has a similar morning setup on Thurs like Jan 12th had.
 
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xJownage said:
Synoptic pattern is everything. Positively tilted troughs don't preclude severe weather. I have a feeling we're going to see another last minute uptrend on both days.

What's pissing me off today is people calling Forecasted Convective Amplification Deficiency 3 days out. We've seen a bunch of events do exactly this and look like garbage thermos-wise until the last minute. To call Forecasted Convective Amplification Deficiency on such a strong system 3 days out is irresponsible at best.

As for the NAM, the NAM is notorious for being both cool and dry in the winter months. The only model that's stayed mildly consistent with its output throughout this entire forecast has been the Euro. Everything else is all over the place.
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Stop taking my talking points hahah
 
But for real, depending on how the mesoscale features go this could be one of our more memorable tornado events for February in the deep south in recent memory. If your worried about a positive tilt trough look at the February 28th 2009 event.

Any event with a decent EML and general 500mb westerly winds in the south with moderate instability and moderate shear is a red flag at the possibility of a bad weather day. Trey from convective chronicles noted on his deep south events that those parameter spaces give a good chance for tornadic storms in the south along with other factors.
 
15z rap indicates mid 60 dewpoints across Alabama later afternoon wensday setting up a mositure rich atmosphere over the twin states. After the MCS.

18z model suites should start or wrap up soon
 
You're gonna have a 24 degree temperature drop between Wednesday and Friday. That difference is just asking for trouble not to mention highs in upper 60s/low to mid 70s Wednesday and Thursday. Also next Tuesday, my forecasted high is 75. Next week will definitely need to be watched and I think @Taylor Campbell mentioned that earlier. Whenever you have highs in the 70s during the winter, you can expect severe weather most of the time.
 
Trey says, a widespread severe event still expected , the question now moving forward is the intensity of the storms.

He also notes globals have started shifting (trending) to a more netrual tilt which could enhance severe potential more
 
ashtonlemleywx said:
330831429_536610981933449_1461630029296650186_n.png


Latest C-Shield updraft helicity for Wed/Wed night

330826493_922943372069860_7547053332944329579_n.png


Latest C-Shield updraft helicity for Thursday.
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Oh HELL. Those tracks in South AL go right through my area…
 
JPWX said:
You're gonna have a 24 degree temperature drop between Wednesday and Friday. That difference is just asking for trouble not to mention highs in upper 60s/low to mid 70s Wednesday and Thursday. Also next Tuesday, my forecasted high is 75. Next week will definitely need to be watched and I think @Taylor Campbell mentioned that earlier. Whenever you have highs in the 70s during the winter, you can expect severe weather most of the time.
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I have been studying temperature and dewpoint over the past 6 months in relation to violent tornadoes. From what I have seen violent tornadoes tend to be on days when warm moist air sustains itself for at 6+ hours followed by a powerful cold front or dryline. I would say sustained temp in the 67.0°F to 77.0°F range for a number of hours and sustained dews in the 58.0°F to 68.0°F also for a number of hours. During the typical mid April to late June tornado season temperatures tend to range from 74.0°F to 84.0°F range for many hours and dews in the 65.0°F to 75.0°F as well. This is also if other ingredients/parameters are in place for a major tornado outbreak.
 
xJownage said:


Perfect representation of just how cold/dry the NAM runs in the winter months.
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Big difference, it makes you wonder if some of the eastward extent of that moisture plume migrates and stagnates over Alabama ahead of the system, would really boom the environment if the moisture is already there when the sun comes up thursday.

With the environment supportive of isolated cells a confluence band or outflow boundary could start initiating supercells possibly ahead of the main gist of the action around noon or peak heating

If you already have those mid 60s dewpoints by the start of the morning over the state of Alabama and get some cloud clearing you could see some 2500-3000j of sbcape
 
KevinH said:
I have heard this before as well
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Well soundings from Alabama support it almost, with 7+ lapse rates usually you see higher surface lapse rates with a bunch of sunlight. Curious is if modeling is picking up on this, if it is then I really doubt instability is anywhere near correct over Alabama and portions of Mississippi

There pretty impressive lapse rates for Alabama. It'd be impressive for a spring and this is winter.

*Latest sounding had lower lapse rates than the 12z actually. Just checked
 
UncleJuJu98 said:
Well soundings from Alabama support it almost, with 7+ lapse rates usually you see higher surface lapse rates with a bunch of sunlight. Curious is if modeling is picking up on this, if it is then I really doubt instability is anywhere near correct over Alabama and portions of Mississippi

There pretty impressive lapse rates for Alabama. It'd be impressive for a spring and this is winter.

*Latest sounding had lower lapse rates than the 12z actually. Just checked
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When do the high res model runs come out? Lol

Those UDH tracks got my attention.
 
UncleJuJu98 said:
Serious question @xJownage or anybody else that has knowledge. Wouldnt the MCS precip shield that works over the deep south early Thursday morning and the EML in place limit cloud cover. I've heard after precipitation cloud cover will clear some. I'm wondering if this will be a factor in Thursday
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Sure, if you get downwards motion/subsidence/divergence behind the MCS. But then you need enough time for airmass recovery, and that subsidence can cause issues too when an EML is present even if your WAA is really strong. This is why events with morning MCS' are often so hard to forecast. They can be constructive or destructive to the environment, and which can often be hard to predict in advance before you get sounding data in its wake.
 
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