Severe WX Severe Weather Event 3/28/17-3/31/17

[Richardjacks]

Ok concerning tomorrow's threat here are my current thoughts.. Granted small scale issues could completely bust this but here is why I am seeing a major tornado outbreak for tomorrow. The NAM is showing zero convection on the gulf coast which is makes me feel confident that the flow won't be cut off. The NAM is pretty reliable as well. I also expect to see the risk area expanded and/or increased! My areas of primary concern are Ne MS, Nw AL, and all of middle TN! I am expecting a few long track intense tornadoes as well. I believe this is the storm that my data was pointing to months ago. Time will tell but it fits my March 23rd-April 3rd time line. We will see I expect quite a show!

I have looked over everything and I basically agree, not sure about long-track/strong tornadoes though. I don't think storms to our south will be a huge limiting factor-but I am wondering about the leftovers of the squall line, also I could see the storms making very slow progress into Alabama during the late afternoon, if this is true, highest risk would be well west of I65.

 

[Justin Hindman Hindy]

Chill man, I think you're going a little overboard here.

I don't think so. If the convection isn't there in the morning, with Temps, DP, and helicity all in place, wouldn't surprise me if one or 2 storms produced tornadoes and stayed down 15-25 minutes. Not really going to know until the morning of. Should be interesting. I do think the mdt risk won't be expanded to much further east, if it does, should stay from Pickens county, to Walker, up to Morgan and points west.

 

[Bama Ravens]

I don't think so. If the convection isn't there in the morning, with Temps, DP, and helicity all in place, wouldn't surprise me if one or 2 storms produced tornadoes and stayed down 15-25 minutes. Not really going to know until the morning of. Should be interesting. I do think the mdt risk won't be expanded to much further east, if it does, should stay from Pickens county, to Walker, up to Morgan and points west.

I'm not denying that there could be tornadoes, but I don't know if the phrase "major tornado outbreak" should be used to characterize this event.

 

[Xenesthis]

I'm not denying that there could be tornadoes, but I don't know if the phrase "major tornado outbreak" should be used to characterize this event.

I respectfully disagree. I believe if things play out without any small scale issues all data points to a outbreak. I do believe when we see all the damage done the word major will have been used correctly. I could be wrong of course but I have a very strong feeling about this one!

 

[Evan]

About an hour ago a definite touchdown (TDS screenshot below) west of Farrsville.

 

[Kory]

HRRR has this a pretty much non event. It's gonna be interesting how convection along the coast plays out...

 

[Matt Grantham]

Ok concerning tomorrow's threat here are my current thoughts.. Granted small scale issues could completely bust this but here is why I am seeing a major tornado outbreak for tomorrow. The NAM is showing zero convection on the gulf coast which is makes me feel confident that the flow won't be cut off. The NAM is pretty reliable as well. I also expect to see the risk area expanded and/or increased! My areas of primary concern are Ne MS, Nw AL, and all of middle TN! I am expecting a few long track intense tornadoes as well. I believe this is the storm that my data was pointing to months ago. Time will tell but it fits my March 23rd-April 3rd time line. We will see I expect quite a show!

I hope you're not being serious. The NAM and reliable shouldn't be used in the same sentence.
From a synoptic standpoint, the 500 mb trough appears to have messy gradients which leads to my next sentence. From a mesoscale view, warm sector contamination looks like a problem.



You also went way overboard on the March 25th threat.

Northern most extent has the highest tornado threat... Tennessee valley heads up.... Bad outbreak no but a couple significant tornadoes seem likely

 

[TWBot]

MD 0370 CONCERNING TORNADO WATCH 98... FOR PORTIONS OF LA...WESTERN MS...SOUTHEAST AR

​

Mesoscale Discussion 0370
NWS Storm Prediction Center Norman OK
0550 PM CDT Wed Mar 29 2017

Areas affected...Portions of LA...western MS...southeast AR

Concerning...Tornado Watch 98...

Valid 292250Z - 300045Z

The severe weather threat for Tornado Watch 98 continues.

SUMMARY...The risk for severe thunderstorms and tornadoes continues
across Tornado Watch 98, and will spread east-northeastward and
northeastward through the evening and overnight hours. An additional
Watch will likely be required prior to the 02Z expiration of Watch
98.

DISCUSSION...Clusters of thunderstorms, including embedded rotating
updrafts and bowing segments, continue in the vicinity of the lower
Sabine Valley. Inflow for this activity is characterized by around
500-2000 J/kg of MLCAPE (higher buoyancy amid richer moisture with
southward extent), based on modifications to the 18Z Lake Charles
and Shreveport observed soundings. This activity lies within the
warm sector of a broader extratropical cyclone, within which modest
positive theta-e advection will continue during the next several
hours.

As a result, convection will continue to spread east-northeastward
and northeastward into the evening and overnight hours. This will
occur while ascent attendant to the right-entrance region of a
midlevel speed maximum encourages both (1) the maintenance of at
least modest instability, and (2) a low-level mass response
supporting moderate low-level shear and isentropic ascent. Moreover,
with 40-55 kt of effective shear attendant to the speed maximum,
organized convective modes will continue to be favored.

While damaging winds and sporadic severe hail will be the primary
concerns with this activity, tornado potential will exist with
embedded supercell structures and meso-vortices. This would
especially be the case as strengthening low-level shear juxtaposes
increasing boundary-layer theta-e through the night. Accordingly, a
new watch will likely be issued from parts of southern LA to the
ArkLaMiss region prior to the expiration of Tornado Watch 98.

..Cohen/Edwards.. 03/29/2017

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

ATTN...WFO...JAN...LIX...LZK...LCH...SHV...

LAT...LON 31839094 30869140 29849232 29729387 30009428 30459432
31519353 33199273 33959204 34029100 33249064 31839094


Read more

For additional SPC information click here

 

[Xenesthis]

I hope you're not being serious. The NAM and reliable shouldn't be used in the same sentence.
From a synoptic standpoint, the 500 mb trough appears to have messy gradients which leads to my next sentence. From a mesoscale view, warm sector contamination looks like a problem.



You also went way overboard on the March 25th threat.

I agree this event didn't produce. My wording wasn't overly strong there. You even quoted me as saying "bad outbreak no". I was expecting a couple more tornadoes then what we got. Down in central AL where your located doesn't seem as big a threat. I think we will have a good idea of the severity by morning. I respect your insight since you do this for a living!

 

[TWBot]

MD 0371 CONCERNING TORNADO WATCH 99... FOR PORTIONS OF THE OZARKS AND VICINITY

​

Mesoscale Discussion 0371
NWS Storm Prediction Center Norman OK
0608 PM CDT Wed Mar 29 2017

Areas affected...PORTIONS OF THE OZARKS AND VICINITY

Concerning...Tornado Watch 99...

Valid 292308Z - 300045Z

The severe weather threat for Tornado Watch 99 continues.

SUMMARY...A gradual increase in the threat for tornadoes and
damaging winds may materialize across parts of southern/central
Missouri over the next few hours.

DISCUSSION...Visible satellite and radar data early this evening
depict growing convection within the warm sector across the Ozarks
and vicinity. Within bands of persistent pre-frontal confluence
here, more vigorous, deeper updrafts should organize this evening,
aided by an uptick in southerly low-level flow across
central/eastern Missouri. In response to very modest near-surface
moisture advection from the south/southeast and gradual cooling
aloft, MLCAPE values upwards of 500-1000 J/kg may be realized.
Despite narrow buoyancy, amplifying low-level shear will potentially
favor a greater tornado threat over eastern portions of the tornado
watch this evening, especially as cells approach the warm front. As
such, an eastward expansion of the ongoing watch could be needed
across the Springfield, MO CWA.

Farther northwest, thunderstorms have organized near the Kansas City
metro area in response to large-scale ascent related to the main
mid-level vorticity maximum. A few of these cells may briefly pose a
threat for severe hail after crossing north of the warm front this
evening. However, this threat should remain brief/marginal north of
the ongoing watch.

Lastly, isolated cells developing along frontal convergence across
northeast Oklahoma may briefly reach severe limits as they interact
with ample deep-layer shear and steep low-level lapse rates. This
convection should remain sparse in coverage as it evolves into
southwestern portions of the ongoing tornado watch this evening.

..Picca.. 03/29/2017

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

ATTN...WFO...LSX...SGF...EAX...TSA...TOP...ICT...

LAT...LON 37469144 36719150 36539231 36429473 36749529 38369531
38499524 39149463 39199407 38909273 37949169 37469144


Read more

For additional SPC information click here

 

[HazardousWx]

People, people...must we fuss? Thats part of the reason I got less active on the old board. Hold it together.

 

[WesL]

Afternoon folks. Let's just place our bets and see what happens. Prepare for the worse and hope for the best. No need to get tangled up in each other. This is a great opportunity to see how each of us interpret data, make a prediction and learn from the results.

 

[Justin Hindman Hindy]

People, people...must we fuss? Thats part of the reason I got less active on the old board. Hold it together.

I blame the bot

 

[NorthGaWeather]

I have looked over everything and I basically agree, not sure about long-track/strong tornadoes though. I don't think storms to our south will be a huge limiting factor-but I am wondering about the leftovers of the squall line, also I could see the storms making very slow progress into Alabama during the late afternoon, if this is true, highest risk would be well west of I65.

I completely agree. The squall line and its progression is the biggest concern. Coastal convection is far less of one in my opinion. If the line kicks east or decays...the MDT risk area looks good. if not, say goodbye to the MDT and enhanced risk.

 

[WesL]

I blame the bot

LOL he just wants yall to be aware of fire risks... Just sayin'

 

[Justin Hindman Hindy]

LOL he just wants yall to be aware of fire risks... Just sayin'

Smokey the bear would be proud

 

[TWBot]

MD 0370 CONCERNING TORNADO WATCH 98... FOR PORTIONS OF LA...WESTERN MS...SOUTHEAST AR

​

Mesoscale Discussion 0370
NWS Storm Prediction Center Norman OK
0550 PM CDT Wed Mar 29 2017

Areas affected...Portions of LA...western MS...southeast AR

Concerning...Tornado Watch 98...

Valid 292250Z - 300045Z

The severe weather threat for Tornado Watch 98 continues.

SUMMARY...The risk for severe thunderstorms and tornadoes continues
across Tornado Watch 98, and will spread east-northeastward and
northeastward through the evening and overnight hours. An additional
Watch will likely be required prior to the 02Z expiration of Watch
98.

DISCUSSION...Clusters of thunderstorms, including embedded rotating
updrafts and bowing segments, continue in the vicinity of the lower
Sabine Valley. Inflow for this activity is characterized by around
500-2000 J/kg of MLCAPE (higher buoyancy amid richer moisture with
southward extent), based on modifications to the 18Z Lake Charles
and Shreveport observed soundings. This activity lies within the
warm sector of a broader extratropical cyclone, within which modest
positive theta-e advection will continue during the next several
hours.

As a result, convection will continue to spread east-northeastward
and northeastward into the evening and overnight hours. This will
occur while ascent attendant to the right-entrance region of a
midlevel speed maximum encourages both (1) the maintenance of at
least modest instability, and (2) a low-level mass response
supporting moderate low-level shear and isentropic ascent. Moreover,
with 40-55 kt of effective shear attendant to the speed maximum,
organized convective modes will continue to be favored.

While damaging winds and sporadic severe hail will be the primary
concerns with this activity, tornado potential will exist with
embedded supercell structures and meso-vortices. This would
especially be the case as strengthening low-level shear juxtaposes
increasing boundary-layer theta-e through the night. Accordingly, a
new watch will likely be issued from parts of southern LA to the
ArkLaMiss region prior to the expiration of Tornado Watch 98.

..Cohen/Edwards.. 03/29/2017

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

ATTN...WFO...JAN...LIX...LZK...LCH...SHV...

LAT...LON 31839094 30869140 29849232 29729387 30009428 30459432
31519353 33199273 33959204 34029100 33249064 31839094


Read more

For additional SPC information click here

 

[TWBot]

MD 0371 CONCERNING TORNADO WATCH 99... FOR PORTIONS OF THE OZARKS AND VICINITY

​

Mesoscale Discussion 0371
NWS Storm Prediction Center Norman OK
0608 PM CDT Wed Mar 29 2017

Areas affected...PORTIONS OF THE OZARKS AND VICINITY

Concerning...Tornado Watch 99...

Valid 292308Z - 300045Z

The severe weather threat for Tornado Watch 99 continues.

SUMMARY...A gradual increase in the threat for tornadoes and
damaging winds may materialize across parts of southern/central
Missouri over the next few hours.

DISCUSSION...Visible satellite and radar data early this evening
depict growing convection within the warm sector across the Ozarks
and vicinity. Within bands of persistent pre-frontal confluence
here, more vigorous, deeper updrafts should organize this evening,
aided by an uptick in southerly low-level flow across
central/eastern Missouri. In response to very modest near-surface
moisture advection from the south/southeast and gradual cooling
aloft, MLCAPE values upwards of 500-1000 J/kg may be realized.
Despite narrow buoyancy, amplifying low-level shear will potentially
favor a greater tornado threat over eastern portions of the tornado
watch this evening, especially as cells approach the warm front. As
such, an eastward expansion of the ongoing watch could be needed
across the Springfield, MO CWA.

Farther northwest, thunderstorms have organized near the Kansas City
metro area in response to large-scale ascent related to the main
mid-level vorticity maximum. A few of these cells may briefly pose a
threat for severe hail after crossing north of the warm front this
evening. However, this threat should remain brief/marginal north of
the ongoing watch.

Lastly, isolated cells developing along frontal convergence across
northeast Oklahoma may briefly reach severe limits as they interact
with ample deep-layer shear and steep low-level lapse rates. This
convection should remain sparse in coverage as it evolves into
southwestern portions of the ongoing tornado watch this evening.

..Picca.. 03/29/2017

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

ATTN...WFO...LSX...SGF...EAX...TSA...TOP...ICT...

LAT...LON 37469144 36719150 36539231 36429473 36749529 38369531
38499524 39149463 39199407 38909273 37949169 37469144


Read more

For additional SPC information click here

 

[TWBot]

MD 0372 CONCERNING TORNADO WATCH 100... FOR PORTIONS OF FAR NORTHEAST TEXAS...WESTERN/CENTRAL ARKANSAS...AND FAR SOUTHEAST OKLAHOMA

​

Mesoscale Discussion 0372
NWS Storm Prediction Center Norman OK
0734 PM CDT Wed Mar 29 2017

Areas affected...PORTIONS OF FAR NORTHEAST TEXAS...WESTERN/CENTRAL
ARKANSAS...AND FAR SOUTHEAST OKLAHOMA

Concerning...Tornado Watch 100...

Valid 300034Z - 300200Z

The severe weather threat for Tornado Watch 100 continues.

SUMMARY...Some potential for occasional damaging winds and a tornado
or two continues across eastern portions of the watch. Farther
southwest near the Arklatex, thunderstorms may increase in coverage
through the evening, with a conditional threat for a few damaging
wind gusts and perhaps a tornado.

DISCUSSION...The ongoing threat for damaging winds and a couple
tornadoes is focused over northeastern portions of Tornado Watch 100
this evening. Several cells in this area have exhibited supercell
structures, with occasional mid/low-level rotation noted on regional
radars. The 00Z LZK sounding as well as recent VWP data indicate
sufficient veering of low-level flow with height, supportive of
occasional rotation as these cells interact with a corridor of upper
50s/lower 60s dew points. This zone of favorably backed surface flow
ahead of ongoing convection should continuing shifting northeast
towards Missouri over the next few hours, with the resultant spatial
maximum in tornado/damaging-wind potential also gradually lifting
into Missouri later this evening.

Farther southwest, sustained convection has struggled to organize
near the Arklatex, likely due to some subsidence aloft in the wake
of prior ascent. However, as another wave of ascent rotates around
the main trough and reaches the region late this evening,
moistening/cooling aloft may sustain more organized convection, with
an attendant threat for a few damaging wind gusts and perhaps a
tornado.

..Picca.. 03/30/2017

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

ATTN...WFO...LZK...SGF...SHV...TSA...

LAT...LON 33059495 34389466 36549305 36489158 35099238 33389343
32939423 33059495


Read more

For additional SPC information click here

 

[CoreyandFrosty]

Smokey the bear would be proud

I always thought that Smokey the bear was the same bear that was in Jungle book. You gotta admit they look very similar. I think the same artist painted that bear.