Severe Weather Threat 3/27/21 - NETX/LA/AR

[cstrunk]

This originally looked like a threat farther east of this region, but it has shifted further into our area. Latest short term models show supercells developing in NETX and points northeast by around 2-4 pm. All hazards are included in the threat with some being significant.

 

[janetjanet998]

FYI

 

[WhirlingWx]

I think this one does apply more to this sub, so I'll post it here. 150-200 m2/s2 seems like the lower-end for "strong" tornado potential, but SPC thinks something's up so I guess we'll see

Mesoscale Discussion 0280
   NWS Storm Prediction Center Norman OK
   0216 PM CDT Sat Mar 27 2021

   Areas affected...Portions of northeast TX...northern LA...and much
   of southern/central/eastern AR

   Concerning...Severe potential...Tornado Watch likely 

   Valid 271916Z - 272045Z

   Probability of Watch Issuance...80 percent

   SUMMARY...The threat for tornadoes, some of which may be strong,
   very large hail, and damaging winds will increase this afternoon.
   Tornado Watch issuance will likely be needed.

   DISCUSSION...The airmass across the ArkLaTex region continues to
   destabilize this afternoon, with surface temperatures generally
   reaching into the 70s and low 80s at 19Z. Rich low-level moisture
   already in place across this region combined with steep mid-level
   lapse rates of 7-8 C/km are supporting MLCAPE of 1500-2000 J/kg.
   Strong deep-layer shear of 50+ kt will easily favor discrete
   supercells with initial development. Given a lack of obvious
   large-scale forcing for ascent, the primary uncertainty is when
   robust storms will form. Best estimate is that with continued
   diurnal heating and weak low-level convergence along/south of the
   warm front, storms will probably initiate by 20-21Z as a weak
   low-level cap continues to gradually erode.

   Large to very large (2+ inch) hail will likely be the main threat
   with supercells initially, as low-level shear is not very strong at
   the moment. But, a low-level south-southwesterly jet should
   strengthen later this afternoon into the early evening, and tornado
   potential with any discrete storms will increase. A strong tornado
   appears possible given 150-200 m2/s2 of effective SRH by mid-evening
   if storms can remain generally discrete. An increasing threat for
   damaging winds may also eventually unfold later this evening as
   upscale growth occurs. Based on towering cumulus becoming evident on
   visible satellite imagery across AR, a Tornado Watch will likely
   need to be issued.

[cstrunk]

Tornado watch issued. 70/60 probs...

[Ed, snow and hurricane fan]

Sun breaking out in Houston, and a couple of convergence zones seem apparent.  Down here, CAP forecast to produce 'squegee line' of showers/storms with actual front, UTS/CLL edge of Marginal.

[Ed, snow and hurricane fan]

Anyone else hate new NWS public radar format?

[cstrunk]

6 minutes ago, Ed, snow and hurricane fan said:

Anyone else hate new NWS public radar format?

Yes, it is unusable, IMO. Did they not test it out before making the switch?? Takes forever to load and is very glitchy.

[cstrunk]

Very strong rotation on the tornado warned cell near Rusk, TX.

[Ed, snow and hurricane fan]

OT- is there a large fire somewhere near Austin?  Seeing something that looks like a stationary point source.  Thought it was a new T-storm at first///

[StormySquares]

Sig tor on going southeast of Carthage, TX

[Indystorm]

Aiming for Shreveport environs.....be on guard and in a safe place.

 

[WhirlingWx]

5 hours ago, TexMexWx said:

150-200 m2/s2 seems like the lower-end for "strong" tornado potential

Well this aged poorly.

[StormySquares]

Just now, TexMexWx said:

Well this aged poorly.

VAD from Shreveport had around 300 0-3km SRH 

[WhirlingWx]

2 minutes ago, StormySquares said:

VAD from Shreveport had around 300 0-3km SRH 

Yeah, and with the storm turning even harder to the right it very well could be tapping into even higher SRH