Mid to Late May 2019 Severe Threats

[jpeters3]

Plenty of extreme soundings in the NAM near the warm front and triple point at 00Z, and then down the dryline a tad later.  I'm skeptical at this point as to whether these extreme environments will come to fruition given that the GFS shows a blowup of a mess of convection earlier in the day that inundates the triple point and warm front.  However, the GFS environment out in the less contaminated warm sector is still fairly impressive.  I'd say Monday has as much potential...

[jpeters3]

The last frame of the 06Z NAM nest sets up a pretty volatile environment, with earlier-in-the-day-junk confined pretty close to the warm front/triple point.

[cstrunk]

The new Day 1 Outlook has extended the Enhanced area and 10% hatched tornado area significantly westward, now encompassing most of north and northeast TX, SE OK, NW LA, and a large portion of AR.

[cheese007]

Don't like the DFW metro being in that hatched area. Not one bit

[cheese007]

Warning out for a "large and extremely dangerous tornado" in Coleman county TX

[JakkelWx]

I'm speechless

[cstrunk]

2 minutes ago, cheese007 said:

Warning out for a "large and extremely dangerous tornado" in Coleman county TX

I don't think I've ever seen a precipitation hole as pronounced as this with a tornado. Wow! 

[1900hurricane]

https://twitter.com/VortexChasing/status/1129737108158132229

[cheese007]

New tor watch issued including DFW until 5PM. 60/40 Tor probs

[Indystorm]

Watch coming for se KS and sw MO.  Must admit I did not see this intensity of storms coming this early for today.

 Mesoscale Discussion 0668
   NWS Storm Prediction Center Norman OK
   0938 AM CDT Sat May 18 2019

   Areas affected...Parts of southeastern Kansas...northeastern
   Oklahoma....southwestern Missouri

   Concerning...Severe potential...Watch likely 

   Valid 181438Z - 181645Z

   Probability of Watch Issuance...80 percent

   SUMMARY...Severe weather potential, including the risk mainly for
   potentially damaging wind gusts and perhaps a couple of tornadoes,
   appears likely to continue to increase across parts of northeastern
   Oklahoma and southeastern Kansas into portions of the Missouri
   Ozarks through Noon to 2 PM CDT.  A new severe weather watch
   probably will be needed northeast of tornado watch 181 within the
   next hour or two.

   DISCUSSION...Beneath difluent and likely strongly divergent upper
   flow overspreading the south central Plains, the evolution of a
   large mesoscale convective system is now well underway in the
   presence of moderate to strong instability.  A broad lower/mid
   tropospheric cyclonic circulation is becoming increasingly evident
   on the northern flank of the convective system, coincident with
   intensifying thunderstorm development, which appears likely to
   continue tracking northeastward near/north of the Interstate 44
   corridor of northeast Oklahoma into adjacent southeastern Kansas and
   southwestern Missouri through 17-19Z.  This will be aided by
   advection within southwesterly deep layer ambient mean flow on the
   order of 30-40 kt.  Coupled with storm-scale processes including a
   strengthening surface cold pool, this probably will be accompanied
   by increasing potential for severe wind gusts.  Some of these may
   become locally enhanced, with perhaps a tornado also possible, in
   association with evolving mesovortices along the strengthening gust
   front.

   A stalling outflow boundary, across the Sedalia MO vicinity into
   areas southeast of Wichita KS, appears to provide the general
   northern edge of the area impacted by increasing severe weather
   potential through early afternoon.

[JoMo]

Joplin Memorial Marathon is today. It should be over before the brunt of the storms arrive though. 

[cheese007]

Already 9 tornado reports today

[1900hurricane]

Short term, I'd keep an eye on the semi-discrete cell between Stephenville and Weatherford. Could be a potential issue for the DFW area.

[StormChazer]

Tornado warning here in Broken Arrow, OK where I live. Nothing reported in the ground yet, just rotation, will have to keep watching.

[JMT417]

1 hour ago, JoMo said:

Joplin Memorial Marathon is today. It should be over before the brunt of the storms arrive though. 

Nixa Sucker days ongoing all day(sucker is a fish) lots of people outdoors in downtown Nixa

[cheese007]

SPC trimming back the ENH risk as the line passes. Seems they think the atmosphere will be too worked over to recover behind the line and if anything significant happens it will be out front

[OUGrad05]

New small enhanced risk in NW OK and S C KS.

[Dunkman]

86 mph ASOS gust in Emporia, KS is wild. Don't see that every day.

[Indystorm]

Southern end of the squall line is becoming more discrete as indicated by the recent MD expressing concern for increased severe mode from the TX hill country to ne TX.

[cheese007]

Denton and Tarrant counties severe warned for wind and hail 

EDIT: Collin and Dallas as well

[Indystorm]

New tor watch with 70/40 probs from ne TX on up through much of Arkansas.

[Chinook]

Confirmed tornado over Fort Smith Regional Airport!

[Indystorm]

Thanks for posting....hard to tell on NWS velocity radar but it looked like a nice couplet.

[jpeters3]

DDC already reports EF-3 damage from one of last night's tornadoes near Minneola.

 

https://www.weather.gov/ddc/Meade_to_Stafford_Tornado_May_17_2019

[cheese007]

Tor warning in southern Ellis county in TX

[lokee]

Geronimo Ok. tornado from Sat morning prelim EF-2

[DanLarsen34]

I’m starting to get a bad feeling about Monday. This has very high-end potential. 

[jpeters3]

19 minutes ago, DanLarsen34 said:

I’m starting to get a bad feeling about Monday. This has very high-end potential. 

 

There is certainly *potential,* however, the largely uncapped and nearly saturated low-level environment certainly makes the "grunge mode fail" a possibility.  Think about Apr 13 of this year.  Very high end parameters were forecasted over a large regions, but the models also had this similar nearly-saturated low-level environment.  That event largely busted in the MOD risk region because of widespread crapvection.  

The 18Z NAM NEST shows a mix of both possibilities.  There are some discrete cells in the TX panhandle at 00Z, but they quickly grow upscale.  

There will probably be at least a few tornadoes, but I'm not sold on a major outbreak just yet.  I'd like to see some additional convection allowing guidance.

[Indystorm]

Yes, the talk on social media is for a possible significant or even historic outbreak in OK on Monday.  But I remember these two things.  4/27/11 across MS and AL had synoptics that could be seen a week in advance.  5/3/99 in OK started with a slight risk that ramped up to high during the day itself.  Very challenging predictions for Monday but most likely will focus on day of parameters.

[jpeters3]

You do, however, have to admire these eye candy NAM NEST soundings after dark near the dryline.  Somewhat capped, but 45 kt of 0-1 km shear, and 532 J/kg of 0-1 km SRH.  Effective layer STP of ~ 15.  I have never seen anything like this in a forecast.