Long range HRRR at the tail end is a problem for Alabama and Mississippi. I think enchanced is possible for both tommrow and Wednesday
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5/5-5-6 2026 severe threat
- Thread starter Justin Hindman
- Start date
RFD66
Member
The interesting thing off the 00Z HRRR tonight, as I just selected the TEHI at 22Z Wednesday afternoon and it plots a 3.6 value over western Madison County and a plot of 6.4" 0-3km EHI over the same area. 0-6km Bulk Shear is near 80knts and Surface CAPE is near 2300 J kg. HRRR is quite aggressive.
At 23Z, it then raises the TEHI value to 4.2 over western Jackson Co. Little hard to just ignore this.
Will watch future model runs and see how the trends go. Wednesday may be a little interesting after all
00Z NAM and HRRR are pretty darn concerning, taken verbatim. This sounding, which isn't cherry-picked, believe it or not, is off the 3km NAM from pretty close to home. There's a little contamination but it still portrays the environment pretty accurately. CAMs develop a pretty strong corridor with an environment favorable for significant tornadoes on Wednesday night across Mississippi, Alabama and Georgia. The HRRR and NAM diverge in what convective evolution looks like, as per usual. I side more with the NAM given the synoptics, with things more likely to go linear/QLCS. However, the NAM 3km shows a QLCS with what are clearly embedded supercells making their way across MS/AL/GA over the course of the evening. The WRFs, which I haven't included here, have similarly concerning solutions.
Taken altogether, with the obvious caveat that the CAMs are the CAMs, and you've got a fairly substantial risk here across the Southeast, including what constitutes a fairly rare type of severe setup for Georgia. Thermodynamics will wane as the evening matures, but will linger to a significant degree thanks to it being May. While the larger synoptic pattern isn't quite what might be called a "classic" type of look, it strikes me as fairly worrying on the whole. There's still some details to iron out, and I'd want to get closer to let the CAMs hopefully get a better handle on things, folks in the Deep South should definitely keep an eye on Wednesday. The wind threat is pretty much unconditional, as is typically the case with QLCS setups like this, and the tornado threat, while conditional on a matter of convective coverage overlapping our areas of greatest environmental favorability, is also noteworthy. Regions of greatest focus for activity seems to run from the Arklamiss corridor, across Alabama and into Georgia, up to I-85.
Taken altogether, with the obvious caveat that the CAMs are the CAMs, and you've got a fairly substantial risk here across the Southeast, including what constitutes a fairly rare type of severe setup for Georgia. Thermodynamics will wane as the evening matures, but will linger to a significant degree thanks to it being May. While the larger synoptic pattern isn't quite what might be called a "classic" type of look, it strikes me as fairly worrying on the whole. There's still some details to iron out, and I'd want to get closer to let the CAMs hopefully get a better handle on things, folks in the Deep South should definitely keep an eye on Wednesday. The wind threat is pretty much unconditional, as is typically the case with QLCS setups like this, and the tornado threat, while conditional on a matter of convective coverage overlapping our areas of greatest environmental favorability, is also noteworthy. Regions of greatest focus for activity seems to run from the Arklamiss corridor, across Alabama and into Georgia, up to I-85.
KakashiHatake2000
Member
Kds86z
Member
Weatherguyx
Member
WeathermanLeprechaun
Member
Recent CAMs have slightly downtrended on instability, and even trend messier as a mode in general. This could mean a very small window for anything significant to develop. But just given the ABSURDITY of these wind profiles, I still think even a embedded storm mode would still be capable of strong tornadoes.
03z has a supercell left over in the open warm sector which would stil be capable of sig all hazards.
As for Wednesday, I'm not too concerned just yet. Semi-discrete storm mode leaning towards messier with a low end chance for a few tornadoes. Profiles are ideally more supportive of large hail than tornadoes too in my opinion given weak low level shear and a slack LLJ.
03z has a supercell left over in the open warm sector which would stil be capable of sig all hazards.
As for Wednesday, I'm not too concerned just yet. Semi-discrete storm mode leaning towards messier with a low end chance for a few tornadoes. Profiles are ideally more supportive of large hail than tornadoes too in my opinion given weak low level shear and a slack LLJ.
12z HRRR is robust for today and tommrow. A little more isolated
- Moderator
- #29
Regarding Wednesday...
...TX to MS/AL...
Further south from northeast TX into MS/AL, strong destabilization
is forecast where deep boundary layer moisture and stronger daytime
heating occurs. MLCAPE in the 2000-3000 J/kg range appear possible
in particular across northern LA into MS. Midlevel southwesterly
flow is expected to increase by late afternoon into the evening as
early capping will be overcome as the surface front begins to
develop south/southeast. Convection along the cold front may quickly
transition to linear/bowing segments given deep shear parallel to
the surface boundary. However, low-level flow in latest model
guidance does not appear to be overly veered, especially near
northern LA into MS. Forecast hodographs indicate enlarged,
favorably curved hodographs across this area. If open warm sector
supercells develop, a risk for tornadoes (perhaps a couple strong
tornadoes) will be possible. Furthermore, steepening midlevel lapse
rates are evident in forecast soundings, along with
elongated/straight hodographs and 45+ kt effective shear magnitudes.
This indicates any semi-discrete supercells could pose a risk for
large to very large hail. With time during the evening/nighttime
hours, convection should generally congeal into a line or bowing MCS
and spread eastward across the TN Valley toward the southern
Appalachians, posing a risk for damaging gusts. Higher tornado and
hail probabilities were considered across parts of the Lower MS
Valley, however, given uncertainty in storm mode and coverage of
discrete supercells, will hold at level 2 (Slight) risk for now.
...TX to MS/AL...
Further south from northeast TX into MS/AL, strong destabilization
is forecast where deep boundary layer moisture and stronger daytime
heating occurs. MLCAPE in the 2000-3000 J/kg range appear possible
in particular across northern LA into MS. Midlevel southwesterly
flow is expected to increase by late afternoon into the evening as
early capping will be overcome as the surface front begins to
develop south/southeast. Convection along the cold front may quickly
transition to linear/bowing segments given deep shear parallel to
the surface boundary. However, low-level flow in latest model
guidance does not appear to be overly veered, especially near
northern LA into MS. Forecast hodographs indicate enlarged,
favorably curved hodographs across this area. If open warm sector
supercells develop, a risk for tornadoes (perhaps a couple strong
tornadoes) will be possible. Furthermore, steepening midlevel lapse
rates are evident in forecast soundings, along with
elongated/straight hodographs and 45+ kt effective shear magnitudes.
This indicates any semi-discrete supercells could pose a risk for
large to very large hail. With time during the evening/nighttime
hours, convection should generally congeal into a line or bowing MCS
and spread eastward across the TN Valley toward the southern
Appalachians, posing a risk for damaging gusts. Higher tornado and
hail probabilities were considered across parts of the Lower MS
Valley, however, given uncertainty in storm mode and coverage of
discrete supercells, will hold at level 2 (Slight) risk for now.
Both the 06Z and 12Z HRRR are pretty concerning for much of Alabama and Georgia Wednesday afternoon through early Thursday morning. While favorable kinematics won't be widespread, boundaries may play a role and small corridors with elongated hodographs overlapping with 1,000-1,500 j/kg of SBCAPE appear likely. The NAM shows a QLCS with embedded supercells from Mississippi to Georgia Wednesday evening, with some possible discrete development in central MS. SREF pops 75% and 60% SigTor Ingredient corridors over MS and NE AL/NW GA Wednesday afternoon through evening. Models are just models, but I don't think this signal should be ignored.
For North Georgia folks, this may well be a threat with more thermodynamic legitimacy than we're used to. While there's definitely a couple hang-ups with this setup, I really don't think it should be slept on for MS/AL/GA, particularly within the general vicinity of the I-20 corridor. Dixie can easily support tornadoes, even significant ones, with modest but curved wind profiles, and I don't have to go into detail with how it operates with limited instability. It's likely that the productivity of convection will depend on pockets of enhanced kinematics along a probable QLCS. Where that can happen, all hazards are possible.
For North Georgia folks, this may well be a threat with more thermodynamic legitimacy than we're used to. While there's definitely a couple hang-ups with this setup, I really don't think it should be slept on for MS/AL/GA, particularly within the general vicinity of the I-20 corridor. Dixie can easily support tornadoes, even significant ones, with modest but curved wind profiles, and I don't have to go into detail with how it operates with limited instability. It's likely that the productivity of convection will depend on pockets of enhanced kinematics along a probable QLCS. Where that can happen, all hazards are possible.
bckhd2
Member
To be honest, I've lived in the ATL area my whole life, and most people in this area started to take an "I'll believe it when I see it" approach to severe threats. Just about every time we have any chance at some storms, a threatening line of storms fizzles out almost completely as it approaches I-285. Significant severe storms just cannot seem to make it into the core metro (with some exceptions like 3/14/2008 and the 1998 Dunwoody tornadoes). I mean look at the warnings map from 4/27/2011 - they split into two lines going right around the city as if they went out of their way to avoid getting near the metro! I guess we are too far displaced from the best dynamics with no direct access to the Gulf moisture, and timing-wise the storms come out of Alabama into Georgia in the night when heating is gone. On 4/12/20 we were in a moderate risk the whole day and all people said was "it'll blow over, it never happens in Atlanta," and lo and behold - I think there were 5 wind reports and 1 EF0 in the whole of Fulton County. The Atlanta metro is way overdue for a big-time storm. People think it'll never happen here.
All that to say, not saying by any means this event will turn out to be a significant severe threat, just noticing that it's gonna be hard to get people aware and prepared for a marginal-to-slight risk, conditional overnight threat. Definitely will be keeping an eye on this one. Don't often see that level of helicity and UH tracks coming through Fulton.
All that to say, not saying by any means this event will turn out to be a significant severe threat, just noticing that it's gonna be hard to get people aware and prepared for a marginal-to-slight risk, conditional overnight threat. Definitely will be keeping an eye on this one. Don't often see that level of helicity and UH tracks coming through Fulton.
NorthGaWeather
Member
I think this is pretty spot on. Yes, there are aspects of this setup that may cap it somewhat, mainly messy storm mode, but the environment will support a more substantial threat if everything works out. But then again, you can say that about every severe threat. Hodo's are sufficient for tornadoes with some guidance showing more curvature and elongation of shear vectors.
I almost wanna say we see a small enchanced corridor for tornado potential in North Central Arkansas
slenker
Member
Being from Columbus, OH I know this feeling very well. But I think it’s important to mention that significant severe weather outbreaks have occurred all around Columbus and Atlanta in past events, and just because it keeps fizzling out before it hits the cities specifically gives laymen the false idea that it isn’t possible where they live if they’re in these areas. The fact that the Carolinas have had significant tornado outbreaks, like 4/16/11, which are further east than Atlanta is, really makes me think something is possible there given the right trough timing.
For Columbus, 4/3/74 and 5/31/85 prove to me that something significant is definitely possible here, since we’re between those two areas of interest. It just takes the right timing of the trough, which seems to be a difficult thing for this region to achieve. I’m guessing Atlanta is the same.
bckhd2
Member
I can't upload images but I got a 12Z NAM sounding for roughly the Georgia Tech campus at 03Z Thursday. A little contamination but still gives a decent look at the environment available. 412 m2/s2 SRH and 2-4 STP at 11pm definitely jumps out. CIN is pretty low though so I agree that as Clancy said, likely a QLCS with a chance for a potentially significant storm where forcing can be locally maximized. But all things considered a pretty supportive environment taken verbatim for near-midnight in Georgia in May.
WeathermanLeprechaun
Member
Intense tornado or two will be possible today. Getting increasingly concerned about potential for 1.5k-2k SBCAPE by 03z with these kinematics in place. These more isolated high ceiling setups find it easier to verify than full fledged outbreaks (take 4/23 of this year for example. High ceiling event, more isolated in nature and verified)
NE AR, watch tonight VERY CLOSELY.
NE AR, watch tonight VERY CLOSELY.
Central Ohio Wx
Member
I feel ya, man. I call it the "government-funded Columbus weather shield" because that's what it feels lilke - storms die the second they get a taste of Franklin County. 4/3/1974 somehow didn't affect Central Ohio despite having an F5 in Xenia, 5/31/1985 fired off just northeast of us, 5/27/2019 died as it moved into the metro, as did 3/14/2024. What's interesting is that Columbus has gotten significant tornadoes, but they were all pre-1980.
The unfortunate part is that nothing supernatural is going on, it's just luck. And at some point that luck will run out, and there will be deaths when it does. There's no other way to put it. Hopefully it's not when I work at 10TV and have to deal with that crapshow, but you really never know.
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The Georgia Brick Wall is definitely a real thing. At this point I'm convinced it's partially just the interaction of climate and geography, our tendency for Appalachian CAD wedges, and the fact that we often get displaced from greater synoptic forces. At the same time, we still get occasional significant events, and our position geographically makes it harder to appropriately broadcast threat magnitude; the 2021 Newnan tornado comes to mind.
Treys new video for today and tommrows threat says strong tornadoes.
Kds86z
Member
New day 1
HRRR TIME-LAGGED RUNS
THIS MORNING SHOW A FEW SUPERCELLS WITH ONE MORE LONGER TRACK STORMS
MOVING DEVELOPING AND MOVING EAST ACROSS CENTRAL AR IN A LARGER SRH
ENVIRONMENT. AN ALL HAZARDS SEVERE RISK MAY ACCOMPANY THE STRONGER
STORMS IN AR BEGINNING LATER THIS AFTERNOON AND POSSIBLY PERSISTING
THROUGH THE EVENING AS THIS ACTIVITY MOVES EAST TOWARDS THE MS
RIVER. A STRONG TORNADO IS POSSIBLE WITH A SUSTAINED DISCRETE
SUPERCELL. UPSCALE GROWTH INTO A CLUSTER OR BAND OF STORMS IS
EXPECTED AS MODERATELY STRONG SOUTHWESTERLY 850 TO 700-MB FLOW IS
MAINTAINED ACROSS THE MID SOUTH. DAMAGING GUSTS AND PERHAPS A
LINGERING TORNADO RISK WILL POSSIBLY SPREAD EAST TONIGHT BEFORE
STORMS WEAKEN LATE.
HRRR TIME-LAGGED RUNS
THIS MORNING SHOW A FEW SUPERCELLS WITH ONE MORE LONGER TRACK STORMS
MOVING DEVELOPING AND MOVING EAST ACROSS CENTRAL AR IN A LARGER SRH
ENVIRONMENT. AN ALL HAZARDS SEVERE RISK MAY ACCOMPANY THE STRONGER
STORMS IN AR BEGINNING LATER THIS AFTERNOON AND POSSIBLY PERSISTING
THROUGH THE EVENING AS THIS ACTIVITY MOVES EAST TOWARDS THE MS
RIVER. A STRONG TORNADO IS POSSIBLE WITH A SUSTAINED DISCRETE
SUPERCELL. UPSCALE GROWTH INTO A CLUSTER OR BAND OF STORMS IS
EXPECTED AS MODERATELY STRONG SOUTHWESTERLY 850 TO 700-MB FLOW IS
MAINTAINED ACROSS THE MID SOUTH. DAMAGING GUSTS AND PERHAPS A
LINGERING TORNADO RISK WILL POSSIBLY SPREAD EAST TONIGHT BEFORE
STORMS WEAKEN LATE.