Tn Valley Severe Weather

[jaxjagman]

Should be an active period coming up,seemingly

[PowellVolz]

Should be an active period coming up,seemingly

Where you getting this?


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[jaxjagman]

1 hour ago, PowellVolz said:

Where you getting this?


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https://atlas.niu.edu/

[Windspeed]

This year in particular has already been a memorable one for tornadoes in the Tennessee Valley. We've not only had destructive touchdowns, but they've unfortunately gone through urban and dense residential areas. So far, one EF2, two EF3s and one EF4 have all been destructive killers in the greater Tennessee Valley region. The season is far from over as well. The pattern in days 5 through 14 is looks suspicious in setup and midrange modeling. We'll have a quiet week. But next week may be active again.

[Carvers Gap]

15 minutes ago, Windspeed said:

This year in particular has already been a memorable one for tornadoes in the Tennessee Valley. We've not only had destructive touchdowns, but they've unfortunately gone through urban and dense residential areas. So far, one EF2, two EF3s and one EF4 have all been destructive killers in the greater Tennessee Valley region. The season is far from over as well. The pattern in days 5 through 14 is looks suspicious in setup and midrange modeling. We'll have a quiet week. But next week may be active again.

Big cutters during April are bad mojo.

[Windspeed]

[PowellVolz]

Very interesting read


https://www.weather.gov/mrx/tornadostudy


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[nrgjeff]

The only time they are worse than in winter.

On 4/13/2020 at 8:07 PM, Carvers Gap said:

Big cutters during April are bad mojo.

 

[jaxjagman]

Have to wait and see what the first system does.But both the Euro and GFS  is hinting at the trough will go -ve tilt somewhere .Euro looks more into the lower Ms/Valley but the GFS is further east around the Friday time frame.GFS  seems to want to make the 2nd system  the dominant storm tonight with even very little inversion.One of them is going to fail seemingly,the first storm or the next system into possibly next weekend

[StormySquares]

11 hours ago, jaxjagman said:

Have to wait and see what the first system does.But both the Euro and GFS  is hinting at the trough will go -ve tilt somewhere .Euro looks more into the lower Ms/Valley but the GFS is further east around the Friday time frame.GFS  seems to want to make the 2nd system  the dominant storm tonight with even very little inversion.One of them is going to fail seemingly,the first storm or the next system into possibly next weekend

00z Euro slowed down, that's a bad look for MS/AL

[jaxjagman]

3 hours ago, StormySquares said:

00z Euro slowed down, that's a bad look for MS/AL

12Z Euro sped up,quite a bit.Sure it will change once again,pretty volatile pattern right now.

[jaxjagman]

Yeah buddy

[PowellVolz]

Yeah buddy

That’s sending the low right across ETn?


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[jaxjagman]

6 hours ago, PowellVolz said:

That’s sending the low right across ETn?


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It's going through Tn on this afternoons run.+ tilt,.looks kinda meh right now unless something changes.Also the Euro shows a potent shortwave around the Gulf  Shores early Thursday.Some KI but the better Showalter and Theta is south

[jaxjagman]

Slightly different look on tonights runs so far

[PowellVolz]

Slightly different look on tonights runs so far

That’s a bad track for the plateau and east of there.


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[Windspeed]

Well then. Definitely going to want to pay close attention to how this evolves over the coming days.

 

[nrgjeff]

I'm skeptical of the sig tor index this setup. Winds shear will be high, but the greatest turning will be GA/SC. Speed shear will be over Bama, but not as much turning. CAPE/LI will be high over Bama with clearing; but, the front will be racing into GA/SC. Believe the STI is over-blown, after drilling down the charts. 

If the short-wave was 12 hours slower, it'd be a bear of a day. Thankfully probably not for our Tennessee Valley. I am honestly worried about Georgia and South Carolina. This human puts the bullseye about a state east of the STP, and with a lower number.

[PowellVolz]

I'm skeptical of the sig tor index this setup. Winds shear will be high, but the greatest turning will be GA/SC. Speed shear will be over Bama, but not as much turning. CAPE/LI will be high over Bama with clearing; but, the front will be racing into GA/SC. Believe the STI is over-blown, after drilling down the charts. 
If the short-wave was 12 hours slower, it'd be a bear of a day. Thankfully probably not for our Tennessee Valley. I am honestly worried about Georgia and South Carolina. This human puts the bullseye about a state east of the STP, and with a lower number.

Anything new?


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[nrgjeff]

I will sleep well tonight. Just checked the CAMs, and more important stability forecasts. Then Thursday looks veered off with lots of storms well to our southeast. 

45 minutes ago, PowellVolz said:

Anything new?

Honestly I was checking radar and surface too much Sun. Apr. 19 - residual nerves after the April 12 tornado. Tonight/Thursday - like 4/19 - we're not even in Slight. Since I both agree with and trust the SPC forecast, I probably won't check as much this second time after. It's a process - even for a Met. 

Good thing for all of us on this forum, we have greater than average knowledge of this stuff. I'm not sure if knowledge is power, but it helps. Remember as the great James Spann says, tornadoes are rare.

[jaxjagman]

Hanks pretty damn brave,Oklahoma yesterday,but some great footage

 

 

[PowellVolz]

I will sleep well tonight. Just checked the CAMs, and more important stability forecasts. Then Thursday looks veered off with lots of storms well to our southeast. 
Honestly I was checking radar and surface too much Sun. Apr. 19 - residual nerves after the April 12 tornado. Tonight/Thursday - like 4/19 - we're not even in Slight. Since I both agree with and trust the SPC forecast, I probably won't check as much this second time after. It's a process - even for a Met. 
Good thing for all of us on this forum, we have greater than average knowledge of this stuff. I'm not sure if knowledge is power, but it helps. Remember as the great James Spann says, tornadoes are rare.

ETn joined the party today. SPC a little more bullish than I expected.


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[nrgjeff]

Re: the Hanks video, I'm amazed the power stayed on. Traffic light appears to be working right after the tornado crossed the power lines; however, we only get a second or two of that before he moves. Later in the video power lines elsewhere are down. He is too close though. Tornadoes can and do rapidly/instantly widen. Bad move there.

Moving on, today has a conditional Slight for parts of the Valley and Plateau. Is today Thursday? Anyway new development could be low top, low probability, but high visibility. And in the daytime - what a novel idea around here! Roger Edwards says it best. Here's our section of the 13Z Day 1.

Severe potential still exists with a possible second episode,
   along/ahead of the cold front from the Tennesseee Valley region
   southward, but is very conditional.  Substantial stabilization to
   near the Gulf Coast is associated with the leading MCS.  Only a
   narrow back door of at least marginally favorable theta-e advection
   and related airmass recovery will exist to the west, which comes
   with offsetting influences:
   1.  Southwesterly near-surface flow ahead of the front will yield
   the best trajectories for theta-e recovery around the morning MCS
   outflow, but also contribute to relatively reduced low-level shear
   and convergence. 
   2.  Any southerly to southeasterly trajectories from the MCS passage
   will be more convectively stabilized. (no dice there - me)

   Still, a narrow plume of favorable buoyancy may develop -- with
   MLCAPE ranging from around 500-1000 J/kg in the north where deep
   lift, cooling aloft and shear will be greatest, to around 2000 J/kg
   in the south under weaker ascent and shear.  With uncertain
   coverage, duration and intensity of convection in this regime, the
   risk level is not as great as farther southeast, and should diminish
   markedly after dark.

[PowellVolz]

Some clearing trying to move East. Seems like getting dry slotted would give us sunshine but would also lower boundary layer moisture.


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[PowellVolz]

Sun is in and out at the moment. I’ll say that it’s really juicy out here. Completely different feel to the air from just a few hours ago.


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[John1122]

That tornado video was way closer than I ever want to be to one. I imagine the power for the traffic lights was probably underground or possibly even on a solar back up. I wonder what the f rating was on that tornado?

I was in the slight risk area but that seems to have been downgraded to marginal at this point. So once again the non-stop heavy rains are the bigger issue here. Going to approach 10 inches again this month it looks like, possibly exceed it. I've not actually looked at the rain gauge yet from today's rain but I was at 7.43 inches coming into this event and it rained heavily overnight into this morning.

[Holston_River_Rambler]

There's a storm in N AL that's looking healthy. 

[Windspeed]

Re: the Hanks video, I'm amazed the power stayed on. Traffic light appears to be working right after the tornado crossed the power lines; however, we only get a second or two of that before he moves. Later in the video power lines elsewhere are down. He is too close though. Tornadoes can and do rapidly/instantly widen. Bad move there.
Moving on, today has a conditional Slight for parts of the Valley and Plateau. Is today Thursday? Anyway new development could be low top, low probability, but high visibility. And in the daytime - what a novel idea around here! Roger Edwards says it best. Here's our section of the 13Z Day 1.

Severe potential still exists with a possible second episode,  along/ahead of the cold front from the Tennesseee Valley region  southward, but is very conditional.  Substantial stabilization to  near the Gulf Coast is associated with the leading MCS.  Only a  narrow back door of at least marginally favorable theta-e advection  and related airmass recovery will exist to the west, which comes  with offsetting influences:  1.  Southwesterly near-surface flow ahead of the front will yield  the best trajectories for theta-e recovery around the morning MCS  outflow, but also contribute to relatively reduced low-level shear  and convergence.   2.  Any southerly to southeasterly trajectories from the MCS passage  will be more convectively stabilized. (no dice there - me)  Still, a narrow plume of favorable buoyancy may develop -- with  MLCAPE ranging from around 500-1000 J/kg in the north where deep  lift, cooling aloft and shear will be greatest, to around 2000 J/kg  in the south under weaker ascent and shear.  With uncertain  coverage, duration and intensity of convection in this regime, the  risk level is not as great as farther southeast, and should diminish  markedly after dark.

Hank is an intelligent chaser and is usually cautious but, yeah, he was too close there. I'd imagine his wife will tan his hide over that one. Even the best chasers are still human and prone to mistakes. Being a professional storm chaser is a life that is susceptible to risks.

[jaxjagman]

Short range models don't even agree with the synoptic for Sat,whats new

Mid week, next week the Euro has a system that goes -ve tilt somewhere around the Cen/Plains.Something to watch anyways at this range.

Longer range into May could be a Kelvin passing through,but thats to far out to believe and or timing

[nrgjeff]

Marginal. Saturday. That's a go!

Of course it's garbage weak moisture return and all. However a surface trough and backed winds tracks through (during the daytime - what a novel idea!) Tenn. Could be low top, low probability, but decent visibility. So much for the latter on Thursday, lol! 

If the 12Z guidance is the same to more robust, Saturday might be a chase day. Um, urr, I mean, go to one of those State Parks that are opening.