March 30th & 31st Severe Weather for Southern Plains & Dixie Alley, Very Dangerous Nighttime Outbreak ongoing in Alabama

[brianc33710]

Could this resemble the AM (NOT PM) 27 April 2011 system over AL? That featured the derecho & embedded EF2-3s in the QLCS. Easter 2020 had EF2-3s in a QLCS line as well.

Birmingham, AL has "benefited" from flooding rains that have worked to stabilize the atmosphere repeatedly since last March. But those also caused death & destruction.

Notice I said AM NOT PM for 27 April 2011!  Those were separate systems to an extent in AL & I don't want to include/confuse it with the "generational" event later that day!  

[brianc33710]

7 hours ago, CheeselandSkies said:

I think I've yet to see a high risk solely for wind actually verify, in the sense of producing an outcome so exceptional and impactful that it seemed worthy of such an unusual forecast. The only ones that would meet that criteria IMO are the May 30-31, 1998 Great Lakes derecho and the August 2020 Iowa derecho; both of which maxed out at Moderate for the derecho itself (5/31/98 got a high risk in parts of NY/PA for tornadoes later in the day, after the initial derecho had weakened).

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Even if not High Risk, could this result in a PDS Severe Thunderstorm Watch situation? Or could/would the tornado threat still be too high for that? It appears the SPC issued PDS Tstm last July cause of 90 mph straight line winds but the tornado threat was lower then than now. 

[nwohweather]

6 minutes ago, brianc33710 said:

Even if not High Risk, could this result in a PDS Severe Thunderstorm Watch situation? Or could/would the tornado threat still be too high for that? It appears the SPC issued PDS Tstm last July cause of 90 mph straight line winds but the tornado threat was lower then than now. 

Yeah I believe projected winds around 100 MPH are required for a PDS T-Storm Watch

[Iceresistance]

1 minute ago, nwohweather said:

Yeah I believe projected winds around 100 MPH are required for a PDS T-Storm Watch

I saw one that had 90 mph wind gusts.

[Iceresistance]

Storms are starting to develop in Southern Kansas, this is likely the start of what it could be the Late March 2022 Severe Weather Outbreak.

[cheese007]

50mph+ gusts here in DFW

[KSWx]

Supercell just W of Loup City, NE showing some pretty strong rotation.

[CheeselandSkies]

4 hours ago, brianc33710 said:

Even if not High Risk, could this result in a PDS Severe Thunderstorm Watch situation? Or could/would the tornado threat still be too high for that? It appears the SPC issued PDS Tstm last July cause of 90 mph straight line winds but the tornado threat was lower then than now. 

It depends on how things evolve tomorrow, but I'm thinking the threat of QLCS tornadoes will be substantial enough with the forecasted low-level wind profiles that they'll go with tornado watches.

[Chreeyiss]

11 minutes ago, TheSuckZone said:

I'd agree with that. I'm also not a fan of T-Storm watches with "couple tornadoes possible". Has this always been a deal? I don't remember T-Storm watches ever being like that and I don't understand what the harm is in just making it a Tornado Watch.

I would guess it gives the wrong idea to the public. The subset of people who actually recognize the difference between a svr watch and a tor watch, but aren’t invested enough to frequently check in are probably inclined to view it as a “cry wolf” incident if a tornado watch is issued for a risk that’s so low that only 1 or 2 tornadoes occurs in an entire watch box. Most people in this group are only aware of what’s happening in their city or news coverage that cuts into their tv shows.

[brianc33710]

39 minutes ago, CheeselandSkies said:

It depends on how things evolve tomorrow, but I'm thinking the threat of QLCS tornadoes will be substantial enough with the forecasted low-level wind profiles that they'll go with tornado watches.

Yeah that's my thinking. I don't think we'll get close to PDS Tornado Watch territory but the high-end straight line wind is definitely there. As an aside tonight was great timing for BMX's advanced Skywarn training given its only once per season. 

[Iceresistance]

My Grandmother woke me up for a Tornado Warning over us, it's missed us by 1-2 miles

[Chinook]

The 06z Day-1 outlook has a large moderate risk with a large 15% hatched tornado outlook by the SPC, also including a 45% hatched wind outlook for this same general area that is covered with the 15% on this graphic. Of interest: SPC discusses later evening tornadoes, separate from the main squall line. Below is the 6th paragraph of the discussion text.

Quote

  ...Parts of eastern LA...much of MS...AL...FL Panhandle...
   Southern portions of the front/dryline will move much slower
   compared to farther north, resulting in a longer duration of
   boundary-layer moistening. A line of convection should become
   evident by 21Z from southwest MS into parts of southern LA, moving
   across MS and into north-central AL by about 03Z. The subtle lift,
   combined with ample low-level moisture beneath an intense low-level
   jet, will favor tornadic supercells which may peak during the night.

[brianc33710]

2 hours ago, Chinook said:

The 06z Day-1 outlook has a large moderate risk with a large 15% hatched tornado outlook by the SPC, also including a 45% hatched wind outlook for this same general area that is covered with the 15% on this graphic. Of interest: SPC discusses later evening tornadoes, separate from the main squall line. Below is the 6th paragraph of the discussion text.

I had thought the SPC would expand Moderate a little further east. I guess by now we know they won't go High today-tonight despite the very high straight line wind threats. Could/would the SPC issue a PDS Tornado Watch but for just the 80+ mph straight line winds & not tornadoes? I'm guessing no & the tornado threat is too high not to go with tornado not svr tstm. 

[CheeselandSkies]

17 minutes ago, brianc33710 said:

I had thought the SPC would expand Moderate a little further east. I guess by now we know they won't go High today-tonight despite the very high straight line wind threats. Could/would the SPC issue a PDS Tornado Watch but for just the 80+ mph straight line winds & not tornadoes? I'm guessing no & the tornado threat is too high not to go with tornado not svr tstm. 

I suppose if they think the threat of EF2+ QLCS tornadoes is great enough, they could go with a PDS tornado watch (would have verified on 12/15, lol) but it's unlikely IMO.

They also seem to be thinking there could be a somewhat greater tornado threat with the later storms further south; they could decide that could warrant a PDS by virtue of its timing.

[brianc33710]

11 minutes ago, CheeselandSkies said:

I suppose if they think the threat of EF2+ QLCS tornadoes is great enough, they could go with a PDS tornado watch (would have verified on 12/15, lol) but it's unlikely IMO.

They also seem to be thinking there could be a somewhat greater tornado threat with the later storms further south; they could decide that could warrant a PDS by virtue of its timing.

The NWS has 3 levels of severe tstm warns. I think we'll see the high ends that triggers EMA procedures today/tonight with 80+ mph winds. 

[Mrklem10]

6:10 am here in Arkansas and it's about to crank off... 

[nwohweather]

4 hours ago, Chinook said:

The 06z Day-1 outlook has a large moderate risk with a large 15% hatched tornado outlook by the SPC, also including a 45% hatched wind outlook for this same general area that is covered with the 15% on this graphic. Of interest: SPC discusses later evening tornadoes, separate from the main squall line. Below is the 6th paragraph of the discussion text.

Yeah I’d agree with that. Hi-Res are showing legit supercells firing on the south side of that line in an environment that will have some serious spin. If I’m not mistaken SRH on soundings around Mobile was around 400-500

[DanLarsen34]

The signal for discrete/semi-discrete cells is there for the southern end of the line. 

 

[Iceresistance]

I had a really close call last night with a strong Tornado-Warned Mesocyclone that cleared my house by less than 1 mile. I was woken up by my Grandmother, she said that the winds "Were just crazy & it was strange" She thought that it was "Another ordinary Storm with a lot of Lightning & Thunder"

 

It happened at around 11:38 PM

[Mrklem10]

Multiple TW Storms in the line coming across Arkansas.   Wasn't forcasted to be this robust till it got to the Mississippi River. 

[cheese007]

 Mesoscale Discussion 0354
   NWS Storm Prediction Center Norman OK
   1029 AM CDT Wed Mar 30 2022

   Areas affected...Parts of southeast Texas...western/northern
   Louisiana...southern/eastern Arkansas and adjacent western
   Mississippi and Tennessee

   Concerning...Severe potential...Watch likely 

   Valid 301529Z - 301630Z

   Probability of Watch Issuance...95 percent

   SUMMARY...Intensifying thunderstorm development, including
   supercells, is expected through Noon-2 PM CDT, accompanied by a
   gradually increasing risk for tornadoes and potentially damaging
   wind gusts.

   DISCUSSION...Strong southerly low-level flow, including speeds of
   50-60+ kt around 850 mb, will be maintained across Louisiana coastal
   areas through much of the lower Mississippi Valley into this
   afternoon, in advance of a vigorous short wave trough pivoting in
   negatively tilted fashion across the southern Great Plains.  In
   association with this regime, a more substantive influx of low-level
   moisture is ongoing off the northwestern Gulf of Mexico, across
   upper Texas coastal areas as far north as areas near/east of the
   Ark-La-Tex.  This moistening is forecast to continue gradually
   spreading northeastward and eastward across the lower Mississippi
   Valley into this afternoon.

   The latest Rapid Refresh suggests that substantive boundary-layer
   destabilization has already been occurring the past few hours across
   much of Louisiana.  As this persists and develops northeastward,
   coupled with strengthening large-scale ascent, weakening mid-level
   inhibition seems likely to allow for increasing and intensifying
   thunderstorm development.  In the presence of wind profiles
   including strong deep-layer shear and large clockwise-curved
   low-level hodographs, the evolution of a few supercell structures
   seems probable.  This may include within a developing line along an
   eastward advancing convectively enhanced surface boundary, and
   isolated discrete cells ahead of it, through 17-19Z.

   ..Kerr/Hart.. 03/30/2022

   ...Please see www.spc.noaa.gov for graphic product...

   ATTN...WFO...MEG...JAN...LZK...LCH...SHV...

   LAT...LON   32609343 34749192 35918979 31769122 30059368 32609343 

[CheeselandSkies]

Seems there was already some pretty significant (probable) tornado damage in Springdale, AR.

[Sydney Claridge]

That talk about supercells makes me wonder if any of these showers and thundershowers ahead of the line, mainly in Louisiana, will try to evolve into a supercell?  Even if one did, it would probably got overtaken by the squall line quite quickly (if it happened with the more developed thundershowers closer to the line).

 

[nwohweather]

Man that atmosphere off to the east is getting absolutely primed. Not there yet though but certainly getting there for around lunch time

[CheeselandSkies]

3 minutes ago, nwohweather said:

Man that atmosphere off to the east is getting absolutely primed. Not there yet though but certainly getting there for around lunch time

I wonder if there's a little more heating today vs. initial forecast thinking over the past few days. Probably not enough to make a huge difference but could contribute to a higher impact event or two.

[nwohweather]

3 minutes ago, CheeselandSkies said:

I wonder if there's a little more heating today vs. initial forecast thinking over the past few days. Probably not enough to make a huge difference but could contribute to a higher impact event or two.

I'd say so, looks like the low is trending a bit stronger than expected thus far. I can say anecdotally it's pretty warm and humid for March here even in South Carolina, I imagine closer to the low dews may take a run at 70 this afternoon. It's a pretty significant moisture transport into this thing, PWAT's are around 1.7 at the line currently

[brianc33710]

I'll remain bearish for areas near Birmingham. Last time stout SE gradient south winds brought warm air but the dewpoints barely cracked 60 in Tuscaloosa. SW flows bring in more moisture. Right now we're 74/51 & our flow is more SE than SW again. The warmth is there but not moisture & instability. Also as I've said before all of our threats since last March were at least somewhatdiminished by lingering convection that gave us very heavy rain. Eventually our "luck" will run out but I don't see that streak ending today/tonight. . 

[Sydney Claridge]

20 minutes ago, nwohweather said:

I'd say so, looks like the low is trending a bit stronger than expected thus far. I can say anecdotally it's pretty warm and humid for March here even in South Carolina, I imagine closer to the low dews may take a run at 70 this afternoon. It's a pretty significant moisture transport into this thing, PWAT's are around 1.7 at the line currently

What is interesting about this setup, though, is the extent of the dry air in-between your location in South Carolina and the humid airmass in place over the Mississippi Valley.  In conjunction with the strong winds, that air is dry enough to prompt SPC to issue a critical fire area across east TN, east KY, and southern OH.  I know some of this is the result of downsloping winds off the Appalachians, but with such a strong storm system it is interesting that we aren't seeing more moisture transport into this region.

[nwohweather]

3 minutes ago, BrandonC_TX said:

What is interesting about this setup, though, is the extent of the dry air in-between your location in South Carolina and the humid airmass in place over the Mississippi Valley.  In conjunction with the strong winds, that air is dry enough to prompt SPC to issue a critical fire area across east TN, east KY, and southern OH.  I know some of this is the result of downsloping winds off the Appalachians, but with such a strong storm system it is interesting that we aren't seeing more moisture transport into this region.

I was thinking the same thing. Ours is obviously being buoyed by the ocean as that mirrors the ocean temp, but dews drop hard to below 50 once you reach even Charlotte. 

[Witness Protection Program]

So, what, 8 simultaneous tor warns in LA right now?