Severe WX March 23-25th, 2023

[ColdFront]

Thinking a limiting factor maybe lack of actual initiation of storms in the warm sector although the HRRR under forecasted in the past two major forecasted events. And with this one it's already gungho. So id mark that one out...

Maybe mid level lapse rates being on the meager side or low level lapse rates? Doesn't need phenomenal low level lapse rates in the south though. And with the cold air advection in the mid levels I'd say mid level lapse rates should be fine.

Maybe a messy storm mode?

Yeah, I would say those two. Messy mode is always in play in the south if crapvection takes off and everything just congeals into a grungy line and it just eats up the environment from actual cells.

LLLRs would be another - although heating wise, this setup is the best opportunity and primed to reverse our trend of poor LLLRs the past few events.

 

[UncleJuJu98]

Either way tommorow will be a very dangerous day wether it's not a high risk or is. Don't think ef3-ef5s or multiple significant tornadoes follow a guideline of it being high risk or not lol.

In fact the last 2 ef4s have occured on enchanced days.

 

[tornado examiner]

Either way tommorow will be a very dangerous day wether it's not a high risk or is. Don't think ef3-ef5s or multiple significant tornadoes follow a guideline of it being high risk or not lol.

In fact the last 2 ef4s have occured on enchanced days.

If your referring to November 4th….that was a tornado driven moderate risk day…

 

[JBishopwx]

Jackson's AFD:

Active weather will be the story for the beginning of the extended
forecast period as two severe weather events impact the region this
weekend. The main focus will be a significant severe event that is
expected to impact the region Friday night with all hazards
possible, including strong tornadoes. The other looks to be
primarily a hail and wind threat that impacts southern portions of
the area Sunday afternoon.

An upper ridge to the southeast, and upper trough to the northwest,
aid in strong return flow ahead of a potent system Friday night.
Negative tilt of the trough should aid in deepening a surface low
over the the ArLaTex as it traverses northeastward. An upper level
jet associated with this trough will be oriented SW to NE across the
ArkLaMiss. Tightening pressure gradient from the rapidly deepening
low leads to a strengthening low level jet, with speeds of 55-65
kts. Guidance continues to show mid to upper 60s dewpoints, 1000-
1500 J/Kg SBCAPE, and steep low level lapse rates of 8+ C/Km in the
open warm sector. This very unstable airmass coupled with ample deep
layer shear, should lead to robust storm development ahead of a
surface cold front. Discrete supercell mode is expected initially in
the warm sector aided by prefrontal confluence, which will increase
tornado threat, especially strong tornadoes in the late evening
hours. As storms progress across the southern Mississippi Delta,
some storms could congeal into broken line segments, combined with
40-50 kt 0-3 km bulkshear, QLCS tornadoes could be possible. This
will especially be the case in any bowing segments oriented NW to
SE. In addition to the tornado threat, strong damaging wind gusts of
greater than 70 MPH, and large hail up to golf ball size, are
likely, with deep shear and steep mid level lapse rates. SE ridge
influence will diminish severe threat as the storms progress
eastward, generally after 2 - 3 AM Saturday morning, although some
hazards will still be possible before moving out by daybreak.

 

[UncleJuJu98]

If your referring to November 4th….that was a tornado driven moderate risk day…

Wait lol I was thinking of Lee county ef4 and Mayfield. I forgot about the two efs from the Easter 2020 and march 2021 outbreak lol. Those were high risk and moderate but. A lot of significant tornadoes happen no matter the risk line or areas.

 

[ColdFront]

Wait lol I was thinking of Lee county ef4 and Mayfield. I forgot about the two efs from the Easter 2020 and march 2021 outbreak lol. Those were high risk and moderate but. A lot of significant tornadoes happen no matter the risk line or areas.

I think Mayfield was a Moderate too. IIRC, the only thing that kept them from going high was they had never seen an environment like that at that time of the year so they were in uncharted waters.

 

[tornado examiner]

I think Mayfield was a Moderate too. IIRC, the only thing that kept them from going high was they had never seen an environment like that at that time of the year so they were in uncharted waters.

That environment was comparable to what northern Alabama was like on April 27 2011…the same type of environment responsible for the Hackleburg EF5 is what led to the mayfield EF4. Very similar environments…

 

[UK_EF4]

To me the main failure mode looks to be low level lapse rates - a couple of soundings I have picked out don't have super strong lapse rates in the lower levels. Apart from that, almost everything seems to be on track for a very significant event. I am also thinking HRRR and other CAMS could increase the signal for discrete warm sector convection.

 

[UncleJuJu98]

I have a very short work day tommorow so thankfully. I'll be able to get home and watch things if the unfold.

 

[tornado examiner]

To me the main failure mode looks to be low level lapse rates - a couple of soundings I have picked out don't have super strong lapse rates in the lower levels. Apart from that, almost everything seems to be on track for a very significant event. I am also thinking HRRR and other CAMS could increase the signal for discrete warm sector convection.

What will those lower lapse rates do? Well….what could they do?

 

[UK_EF4]

What will those lower lapse rates do? Well….what could they do?

Can tamper the development of updrafts, especially in the warm sector. I am not massively concerned about this thought, in terms of lowering tornado threat.

 

[tornado examiner]

So…how likely is a high risk issuance actually?

 

[UncleJuJu98]

So…how likely is a high risk issuance actually?

It'll depend on day of mesoscale analysis probably

 

[UncleJuJu98]

From Brett Adair he does a lot of storms chasing

 

[MichelleH]

From Brett Adair he does a lot of storms chasing

Brett is also a meteorologist.

 

[tornado examiner]

Nam is doing nam things and trying to drive the temperatures into the ground preventing sustained convection lol

 

[ColdFront]

Nam is doing nam things and trying to drive the temperatures into the ground preventing sustained convection lol

yeah not really sure what the NAM 3Km is doing. It’s 18z run is a nothing sandwich UH wise over the ArkLaMiss

 

[UncleJuJu98]

yeah not really sure what the NAM 3Km is doing. It’s 18z run is a nothing sandwich UH wise over the ArkLaMiss

That's typical of the nam 3km.

 

[tornado examiner]

Nam suuuucccks

 

[JayF]

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