Tn Valley Severe Weather

[jaxjagman]

 Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1255 AM CDT Wed Mar 13 2019

   Valid 141200Z - 151200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE TENNESSEE
   VALLEY NORTHWARD TO SOUTHERN LOWER MICHIGAN...

   ...SUMMARY...
   Strong to severe thunderstorms are possible from portions of
   Mississippi and Alabama northward through central Tennessee and
   Kentucky into Indiana, western Ohio and southern Michigan. Damaging
   winds, hail and tornadoes will all be possible from midday through
   the evening hours.

   ...Synopsis...
   The intense mid/upper trough over the mid-MO Valley will continue to
   shift east/northeast toward the Great Lakes and eastern Ontario by
   Friday morning. This will maintain a roughly 80-100 kt southwesterly
   midlevel jet streak across the Lower Ohio Valley toward Lake
   Ontario. At the surface, a still strong but filling cyclone will
   spread northeast in tandem with the upper level trough, arriving in
   the vicinity of James Bay by Friday morning. As the low lifts
   northeast, a cold front, oriented south-southwest from eastern IA to
   central AR to near the TX Gulf Coast at the beginning of the period,
   will shift eastward across the Midwest to the Lower MS Valley region
   by Thursday evening. 

   ...Lower Ohio Valley Vicinity...
   A strong south/southwesterly low level jet will transport Gulf
   moisture fairly far northward for this time of year, with at least a
   narrow corridor of low 60s F dewpoints as far north as the Lower
   Ohio River, and low-to-mid 50s F dewpoints into southern Michigan.
   While the better quality moisture will remain confined to the Deep
   South, forcing for ascent and deep layer shear are much more
   impressive from the Ohio Valley into southern MI. Additionally,
   midlevel lapse rates are expected to steepen from KY/IN into MI as
   stronger height falls and colder temperatures aloft overspread the
   region ahead of a midlevel dryslot by midday. 

   All of this combined leads to a narrow warm sector characterized by
   500-1000 J/kg MLCAPE, 6.5-7.5 C/km midlevel lapse rates,
   impressive/large curved low level hodographs and 45+ kt effective
   shear. While this parameter space is more than capable of supporting
   widespread severe, including damaging winds and possible strong
   tornadoes, quite a bit of uncertainty still exists. This is due in
   part to several rounds of showers and thunderstorms expected in the
   Day 1/Wed period, with ongoing convection possible in warm advection
   regime at the start of the Day 2/Thu period. Impacts of this
   convection/residual cloud cover on destabilization, and how
   far/quickly the surface cold front progresses by Thursday morning
   makes for a quite conditional scenario. As a result, have opted to
   expand the Slight risk northward across the Mid-South into southern
   MI. Uncertainty and conditional nature of the threat will preclude
   higher probs at this time across parts of KY/IN/MI/OH, but potential
   certainly exists for a higher-end threat to materialize across this
   region, as implied by various CAMs in the 18-00z time frame.
   Observational and numerical guidance trends will be monitored
   closely. 

   ...TN Valley toward the Central Gulf Coast...

   Poorer lapse rates and much weaker forcing is expected with
   southward extent as the upper trough ejects away from the region.
   Near-neutral height tendancies and warmer temperatures aloft will
   result in weaker lapse rates compared to further north. Still, deep
   layer shear (45+ kt effective shear) will remain more than capable
   of sustaining organized convection. With mid-to-upper 60s F
   dewpoints resulting in 500-1000 J/kg MLCAPE, supporting bowing line
   segments or supercells. Damaging winds and perhaps a tornado will be
   possible with any sustained storms that can develop, but the lack of
   stronger forcing will generally limit storm coverage.

[nrgjeff]

Mid levels look a little warm (SPC notes poor lapse rates / neutral heights) and no clear 2nd boundary is noted. Guess there's always the differential heating between CHA and HSV/BNA. 

2 hours ago, jaxjagman said:

 Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1255 AM CDT Wed Mar 13 2019

   Valid 141200Z - 151200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE TENNESSEE
   VALLEY NORTHWARD TO SOUTHERN LOWER MICHIGAN...

   ...TN Valley toward the Central Gulf Coast...

   Poorer lapse rates and much weaker forcing is expected with
   southward extent as the upper trough ejects away from the region.
   Near-neutral height tendancies and warmer temperatures aloft will
   result in weaker lapse rates compared to further north. Still, deep
   layer shear (45+ kt effective shear) will remain more than capable
   of sustaining organized convection. With mid-to-upper 60s F
   dewpoints resulting in 500-1000 J/kg MLCAPE, supporting bowing line
   segments or supercells. Damaging winds and perhaps a tornado will be
   possible with any sustained storms that can develop, but the lack of
   stronger forcing will generally limit storm coverage.

High resolution models show small cells, indicative of warm mid-levels. Perhaps a few storms can get rooted and going, with less coverage. Also 45 knots shear (vs 60 kt) could be slightly less fast storm motion than previous events. Still looks fast though.

Sometimes less coverage in Dixie Alley means less sloppy, but it depends on the cause. This situation could still be meh/mess, but with less rainfall (good). In the Plains less (slop) can mean more (quality). In Dixie less is usually less.

Almost like snow, Dixie seems like all or nothing. Some statistics actually back up that feeling. Remover the big outbreaks and Dixie is less active than the Plains. Keep the outbreaks and they are equal. This is no outbreak, so I think all is good.

[jaxjagman]

Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1259 AM CDT Thu Mar 14 2019

   Valid 141200Z - 151200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PORTIONS
   OF THE TENNESSEE AND OHIO VALLEYS...

   ...SUMMARY...
   Strong to severe thunderstorms are possible from a portion of the
   Southeast U.S. into the Ohio Valley and southern Great Lakes.
   Damaging wind and a few tornadoes will be possible along with some
   hail.

   ...Synopsis...

   A very strong upper jet will rotate through the base of a potent
   synoptic upper trough and into the middle MS Valley, Ohio Valley and
   upper Great Lakes. Surface low within the exit region of this jet
   will develop northeastward and occlude over WI this afternoon. The
   trailing cold front will stretch from a surface low in IA early in
   the day southward through the lower MS Valley. This front will
   advance east reaching the lower Great Lakes southwest into the
   middle Gulf coast by the end of this period.

   ...Southeast U.S. through Ohio Valley and Great Lakes...

   Initial band of convection developing along warm conveyor belt from
   the TN Valley into the OH Valley will shift northeast and weaken
   early Thursday. However, ageostropic forcing accompanying an
   upstream jet exit region is already spreading through the Southern
   Plains, contributing to thunderstorms development along the front
   over northeast TX. This zone of ascent will continue to spread
   northeast during the early part of the day, and most models develop
   a secondary band of showers and thunderstorms over the middle MS
   Valley that shifts into the OH Valley by mid day. The timing and
   evolution of this early convection and areas of clouds complicate
   the forecast to some degree. Nevertheless, a corridor of mid-upper
   50s dewpoints will advect north into the OH Valley along a strong
   low-level jet, with mid-upper 60s farther south across the Southeast
   States. MLCAPE should range from 1000+ J/kg over the Southeast
   States, where more diabatic heating is possible and higher dewpoints
   will reside, to around 500 J/kg farther north into the OH Valley and
   southern Great Lakes. Current indications are that additional
   thunderstorms will gradually intensify along and just ahead of the
   progressive front from the OH Valley southward into the TN Valley
   from late morning into the afternoon. The stronger forcing will
   exist along and north of the upper jet exit region over the OH
   Valley where instability will be more limited, while farther south
   weaker forcing will exist, but a destabilizing boundary layer and
   low-level convergence should be sufficient to initiate storms. Wind
   profiles will be very favorable for organized severe storms with 50+
   kt effective bulk shear and 300-500 m2/s2 0-1 km storm relative
   helicity. Both discrete supercells and line segments are possible
   with damaging wind and a few tornadoes the main threats, mainly from
   late morning through early evening.

   ..Dial/Gleason.. 03/14/2019

[jaxjagman]

 Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0752 AM CDT Thu Mar 14 2019

   Valid 141300Z - 151200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS
   CENTRAL/EASTERN INDIANA...WESTERN OHIO...CENTRAL KENTUCKY...MIDDLE
   TENNESSEE AND NORTHERN ALABAMA...

   ...SUMMARY...
   Severe thunderstorms are likely from portions of the Southeast U.S.
   into the Ohio Valley and southern Great Lakes.  Damaging winds and a
   few tornadoes will be possible along with large hail.

   ...Synopsis...
   An upper-level low over Iowa this morning will gradually evolve into
   an open wave as it lifts northeast across the Great Lakes today,
   while a trailing portion of the trough extends southwest into the
   central Plains.  A deep (983 mb) surface low beneath the upper low
   will lift northeast as a trailing cold front moves rapidly across
   the TN/OH Valley region and the lower MS Valley.  Collectively,
   these surface and upper-level features will result in a broad area
   of favorable vertical wind shear for severe storms.  

   ...Southeast U.S. through Ohio Valley and Great Lakes...
   An expansive area of showers and thunderstorms associated with
   warm/moist advection within the warm sector was in progress at 13Z,
   and the effects of ongoing/early day precipitation casts some
   uncertainty on the details regarding severe potential today and
   tonight.  In general, ongoing precipitation should weaken or lift
   northeast of the risk area by midday, with additional thunderstorm
   development in advance of the cold front by afternoon.  

   Low-level moisture remains a limiting factor, with lower/mid 50s
   surface dew points expected as far north as OH/southeast Lower
   Michigan, and mid 60s/upper across the southeast states. 
   Substantial cloud cover combined with modest mid-level lapse rates
   will temper instability, with MLCAPE ranging from 1000+ J/kg over
   the Southeast States, where more diabatic heating is possible and
   higher dewpoints will reside, to around 300-500 J/kg farther north
   into the OH Valley and southern Great Lakes.  The impressive
   low/mid-level wind fields will result in deep-layer shear averaging
   50 kts across the southeast to in excess of 80 kts across the OH
   Valley/Great Lakes, with low-level (0-1 km) SRH in excess of 300
   m2/s2.  

   Thunderstorms should redevelop or intensify in advance of the cold
   front this afternoon as large-scale ascent within the left exit
   region of a 100-kt jet streak approaches the OH/TN Valley region. 
   Farther south, forcing becomes a bit more nebulous however a more
   favorable thermodynamic environment with lower CINH will be in
   place.  Most CAM guidance maintains discrete or semi discrete storms
   initially, with a transition to a more linear structure across
   northern portions of the risk area with time due to stronger
   large-scale forcing. Primary storm modes for storms that can persist
   within the strong shear environment will be supercells and bowing
   segments, with a risk for damaging winds, tornadoes, and large hail.

   Should a corridor of stronger heating/greater instability develop,
   confidence would increase regarding introduction of a significant
   tornado risk area given the very favorable background environment. 
   This may be needed in later outlooks as the effects of ongoing
   precipitation is assessed.

   ..Bunting/Mosier.. 03/14/2019

[Windspeed]

Mesoscale Discussion 0208
   NWS Storm Prediction Center Norman OK
   1147 AM CDT Thu Mar 14 2019

   Areas affected...Northeast Mississippi...Northwest Alabama...and
   southern Tennessee

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

   Valid 141647Z - 141815Z

   Probability of Watch Issuance...80 percent

   SUMMARY...A gradual increase in storms is expected through the
   afternoon. A tornado watch will likely be needed soon.

   DISCUSSION...16Z surface analysis shows much of northeast
   Mississippi and northwest Alabama has warmed 4 to 5 F in the last
   hour despite some cloud cover across the area. This has led to an
   increase in low-level instability to around 750 to 1000 J/kg of
   MLCAPE. Warming is expected to continue with low-level moisture
   advection which will lead to moderate instability by mid-afternoon.
   The recent heating in this area has provided enough instability for
   a reinvigoration of lightning from some of the convection in
   northern Mississippi. Therefore, expect more widespread storm
   coverage within the next hour or two as surface destabilization
   continues to increase. 

   Deep-layer shear in this area is very favorable for supercell and
   low-level mesocyclone development with deep layer effective shear
   around 55 to 60 knots and 0-1 SRH around 350 m2/s2 per GWX VWP.
   Therefore, these storms will pose a tornado threat with the
   potential for strong tornadoes, especially as supercells mature into
   northwest Alabama.

   ..Bentley/Thompson.. 03/14/2019

 

[nrgjeff]

I got a thread going. Agree with everything in SPC Mesoscale Discussion 208 just above.

[jaxjagman]

MJO is into the the Maritime but weak signals.The problem with the Euro is with the tropical system(convection) as it moves the MJO  back into the IO.GEFS looks more right to me as it looks to go into phase 4,5 and 6 and potentially into West.Hem./Africa towards the end of the month.

Today there is a trough going through Korea which could give us some thunderstorms into next weekend.The next more bigger potential system right now looks more towards the end of the month,with a trough coming off Mongolia this Wednesday then down into Korea which builds a ridge over Japan.If things teleconnect right this could be a potential good severe.

[jaxjagman]

Euro and GFS don't agree with each other,whats new, into the end of next weekend into the first part of the week after.Euro brings the LP basically through Tn while the GFS shows the system into the lower OV.Even if the GFS is right it looks more wind and hail.

 

We seem to be close to avg. with tornadoes so far.Ironically the third best year was 2010 which was coming off of a strong Nino.I'm not really sure how much the tropics had to do with this.There looks to have been two tropical storms in 2010.Bonnie crossed Florida as a TS but weakened as it went into MS/LA as a depression.TS Richard went into Texas.But,there was no impact from a hurricane that year

 

https://en.wikipedia.org/wiki/Tornado_outbreak_of_April_22–25,_2010

[jaxjagman]

Similar look from what the  Euro seasonals show to what the RRWT shows through spring.What would look to be HP into the GOA and also HP off the Mid-Atlantic into the Carolina's.-PNA.

[jaxjagman]

Looks like a chance of thunderstorms,not really exciting tho from a weak system Sunday into Monday.GFS has even backed down this afternoon with any wind/ hail.

Next system for the Valley should be towards the end of the month still  and the next should be into week one of April

Beyond this we should see what happens with the MJO.The Euro now shows the MJO going now into phase 6 as it has been seeing destructive interference from the ENSO,though weak signals into the COD.So far it still looks like the MJO will be going into phase 7& 8 into the first of April.The Valley shortly after this time frame is starting to get/or is into peak severe season.So all eyes should be watching how amped the MJO gets into the IO and if it stays strong.

[CheeselandSkies]

3 hours ago, jaxjagman said:

Looks like a chance of thunderstorms,not really exciting tho from a weak system Sunday into Monday.GFS has even backed down this afternoon with any wind/ hail.

Next system for the Valley should be towards the end of the month still  and the next should be into week one of April

Beyond this we should see what happens with the MJO.The Euro now shows the MJO going now into phase 6 as it has been seeing destructive interference from the ENSO,though weak signals into the COD.So far it still looks like the MJO will be going into phase 7& 8 into the first of April.The Valley shortly after this time frame is starting to get/or is into peak severe season.So all eyes should be watching how amped the MJO gets into the IO and if it stays strong.

Can you give a little bit of background for what it means for CONUS severe weather which phase the MJO is in? Which phases are favorable and which are not?

[jaxjagman]

3 hours ago, CheeselandSkies said:

Can you give a little bit of background for what it means for CONUS severe weather which phase the MJO is in? Which phases are favorable and which are not?

You want the MJO to have strong signals coming off Africa and into the IO and beyond.Similar to what  shows,least right now.You're also in a +GWO/AAM,So you take this out of a forecast,think Jeff mentioned this above.It still seems possible this could be a crap season with the ENSO.I voted 1.2k to 1.3k but i can see this going below..IMHO.It only takes one big storm to make up a deficit,but will it happen?

[jaxjagman]

Tomorrow's storm doesn't look to be as +titled as what's been shown.Better instability especially  towards the SW portion of the Valley.Wouldn't surprise me to at least see this area upgraded to a slight risk the next update.SREF now has a 15% tornado risk in areas west of I-65.

[jaxjagman]

Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1211 PM CDT Fri Mar 29 2019

   Valid 301200Z - 311200Z

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER A PORTION
   OF THE LOWER MISSISSIPPI...TENNESSEE AND OHIO VALLEYS...

   ...SUMMARY...
   A few strong to severe thunderstorms are possible on Saturday across
   a portion of the lower Mississippi, Tennessee and Ohio Valleys.
   Isolated damaging wind should be the primary threat.

   ...Lower Mississippi, Tennessee and Ohio Valleys...

   Shortwave trough now moving through the central Rockies will
   continue into the central Plains early Saturday, before reaching the
   middle MS Valley and western portions of the TN and OH Valleys late
   Saturday afternoon and evening. In response to this feature, a
   surface low will develop over the middle MS Valley along a front and
   continue northeast into the OH Valley. Trailing cold front will move
   southeast through the lower MS and TN Valley regions during the
   afternoon into the evening. A corridor of modified continental polar
   air with upper 50s to near 60 F dewpoints will advect through the
   pre-frontal warm sector beneath modest mid-level lapse rates. This
   in conjunction with modest diabatic warming of the surface layer
   will contribute to marginal instability with MLCAPE from near 500
   J/kg over southern portions of the OH Valley to 1000 J/kg over the
   lower MS Valley. Current indications are that a remnant mid-level
   capping inversion will probably limit thunderstorm development in
   warm sector. However, forcing within frontal zone should be
   sufficient to initiate storms as it intercepts the destabilizing
   boundary layer. Wind profiles with 40-50 kt 0-6 km shear will
   support potential for organized structures within the line including
   bowing segments and possibly a few embedded rotating updrafts. Given
   potential limiting factors imposed by an expected overall marginal
   thermodynamic environment, will maintain marginal risk category for
   this outlook, but a slight risk might be needed in day 1 updates.

[jaxjagman]

East Asia looks active the next several days.The jet extension as the MJO passes into/through the PAC should keep us into a more wet pattern until it breaks down.So there still looks to be systems tomorrow,week one and another in wk.2 of April.After this there would be uncertain into the longer range where the MJO is.The GEPS and GEFS  shows the pineapple  express (troughs)stopping through East Asia into wk 2 of April

[jaxjagman]

 Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1254 AM CDT Sat Mar 30 2019

   Valid 301200Z - 311200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL AND
   NORTHEAST MS...NORTHWEST AL AND PARTS OF CENTRAL TN...

   ...SUMMARY...
   A few strong to severe thunderstorms are possible this afternoon and
   evening across a portion of the lower Mississippi, Tennessee and
   Ohio Valleys. Damaging wind should be the primary threat, though
   hail also is possible.

   ...Synopsis...
   An upper trough will deepen and shift eastward across the Midwest
   today.  A cold front extending from northern IN southwestward into
   north TX will shift eastward through the period, extending from the
   Mid-Atlantic to the central Gulf Coast by Sunday morning. Elevated
   convection will be ongoing this morning on the cool side of the
   frontal boundary in isentropic ascent from eastern OK into southern
   IN. Further south, an elevated mixed layer from TX into the Lower MS
   Valley vicinity will limit convection for most of the morning across
   the Deep South to central KY.  Modest boundary layer moisture with
   dewpoints from the upper 50s to lower 60s F will extend from the
   lower MS Valley toward the TN Valley, with low to mid-50s F
   northward toward the lower OH Valley vicinity. The EML is expected
   to erode by mid-to-late afternoon as stronger forcing along the
   front encroaches on better warm sector environment. Strong to severe
   storms are possible along the front from the afternoon into the
   evening, with hail and strong wind gusts being the main concern.

   ...Lower MS Valley to Middle TN...

   Temperatures are expected to warm into the upper 60s F north to mid
   70s F south. This will lead to mixing of modest boundary layer
   moisture and only weak destabilization (MLCAPE around 500-1000 J/kg)
   forecast. Convection is expected to develop as increasing ascent
   along the front aids in erosion of the weak EML. Higher cloud bases
   (LCLs around 2-3 kft) resulting from boundary layer mixing will aid
   in development of some strong, possibly damaging, wind gusts as low
   level flow increases to 35+ kt around 2-4 kft. Nearly unidirectional
   vertical shear also will favor linear/bowing line segments, though
   some weak directional shear from south-central TN into central MS
   could result in some rotating structures in strongest storms. This
   could further enhance wind damage potential via mesovortex
   processes. Midlevel lapse rates around 7-7.5 C/km also are expected
   to support severe hail in stronger updrafts. Tornado potential
   appears low at this time given poor quality boundary layer moisture
   and lack of stronger low level directional shear. 

   ...Western/Central KY Vicinity...

   Boundary layer moisture will be even more meager further north, and
   250-500 J/kg MLCAPE is forecast. However, stronger forcing along the
   front should still aid in development of some semi-organized linear
   structures. Where pockets of stronger heating can occur, 40-50 kt
   winds around 1.5 kft could aid in strong wind gusts and modest
   midlevel lapse rates around 6.5-7.0 C/km may support some small hail
   in stronger updrafts. Overall threat is expected to remain marginal
   in the absence of better low level moisture and stronger
   destabilization.

[nrgjeff]

Moisture return is still meh. However temps will get well into the 70s. Perhaps it's a good trade-off. Limit tornado risk, but good visibility if anything happens. Upper winds are OK. Low level turning is barely at threshold (IMHO). 

It's borderline, but it's also almost April. 

[jaxjagman]

Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0243 PM CDT Sat Mar 30 2019

   Valid 302000Z - 311200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE
   MID-SOUTH/TENNESSEE VALLEY REGION AND VICINITY...

   ...SUMMARY...
   Severe thunderstorms are possible through 10 PM CDT across portions
   of Mississippi, Tennessee, Kentucky, and Alabama. Expected hazards
   include isolated to scattered damaging winds, large hail, and a
   couple tornadoes.

   ...Discussion...
   Instability has been slow to develop across the risk area, due to
   widespread cloud cover limiting heating, and dewpoints running a bit
   lower than most model forecasts.  Still, the overall forecast
   appears reasonable, in terms of risk level and areal extent. 
   Therefore, aside from a few tweaks to the thunder line, no
   substantial changes to the outlook are needed at this time, with
   isolated severe risk expected to evolve over the next 1-2 hours.

   ..Goss.. 03/30/2019

   .PREV DISCUSSION... /ISSUED 1125 AM CDT Sat Mar 30 2019/

   ...MS/TN/KY/AL...
   Primary changes are to shift wind probabilities north/east across
   KY, and increase/expand tornado/hail probabilities. These changes
   result in a net expansion of the Slight and Marginal Risks.

   A shortwave trough near Kansas City will move east across the
   Midwest while amplification of a separate trough occurs upstream
   over the Upper Great Lakes region through tonight. Surface wave over
   far southern IL will deepen as it approaches the Lower Great Lakes.
   An attendant stout cold front will push southeast likely passing a
   line from Columbus, OH to Lake Charles by 00Z. Upper 50s to lower
   60s surface dew points will be common ahead of the front from the
   Mid-South southward where moderate boundary-layer heating in cloud
   breaks will drive MLCAPE values to 500-1000 J/kg. An increasingly
   narrow/more marginal moisture plume will exist farther north and
   eventually be occluded by the impinging cold front. 

   Forcing for ascent will be focused in a band near the front,
   stronger north than south, which suggests predominately
   linear/cluster mode north and a mix of discrete cells/clusters south
   as storms mature towards late afternoon. Deep-layer vertical shear
   will be sufficient for splitting supercells with relatively long
   hodographs, and moderate low-level hodograph curvature. The greatest
   combined probabilities should exist surrounding the TN/MS/AL border
   region where all hazards are possible but large hail may be the
   primary threat given the remnant elevated mixed layer and potential
   dominance of left-mover supercells as suggested by most HREF
   members. Isolated to scattered damaging winds will be the primary
   concern with northern extent. The severe threat will wane after
   sunset and should cease by late evening.

[jaxjagman]

National Weather Service Nashville TN
250 PM CDT Sat Mar 30 2019

.DISCUSSION...

Showers and storms have already fired up to the west along the MS
and OH River Valleys, and models have that line of convection
continuing across the mid state from mid afternoon through the
evening hours. A strong upper level trough will progress eastward
today, and drag a strong cold front through the area late this
afternoon and evening. Consensus between the models shows decent
instability, with MLCAPE values in the 400-1000 J/Kg range, and
0-6km deep layer shear around 50 to 60 knots. 0-1km shear is
moderately strong as well, with values around 20 to 30 knots.
Sounding analysis shows strong low level curvature in the
hodographs, which would not only support rotating updrafts but
even support some isolated tornado potential as well. 0-1km and
0-3km helicity values are also strong as expected with great low
level curvature in the hodographs. With the approaching cold front
providing the lift to keep convection ongoing through the area,
and with the instability/shear environment in place, the main
threat with any strong to severe thunderstorms would be damaging
winds, and isolated tornadoes. Mid level lapse rates do briefly
support some hail potential as well, and would be more likely
should any isolated cells develop ahead of the main line of
convection. After the front passes through the area from west to
east during the evening, severe potential will fall off rapidly as
cold air settles in near the surface and decreases surface based
instability.

[nrgjeff]

Nashville sounds bullish. Moisture return is slower than models have though. Waze app (Google maps) reports repeating multiple accidents I-24 West of Chattanooga. I'm not sure it's rubbernecking, road rage, or both. Regardless I'm not dealing with that on my way.

No storm chase today. NCAA starts in a couple hours anyway.

[jaxjagman]

1 hour ago, nrgjeff said:

Nashville sounds bullish. Moisture return is slower than models have though. Waze app (Google maps) reports repeating multiple accidents I-24 West of Chattanooga. I'm not sure it's rubbernecking, road rage, or both. Regardless I'm not dealing with that on my way.

No storm chase today. NCAA starts in a couple hours anyway.

Don't see  nothing rotating,we're partly cloudy now with the sun out,Storm looks more  depressive as we lost Okeke with a torn ACL that will need surgery.Such a freak non-contact injury

[jaxjagman]

Some rotation showing up into Kentucky and some weaker between Hohenwald and Centerville into Tn,finally seeing some storms though

[jaxjagman]

Tornado by Orlinda,really don't see rotation with this

[jaxjagman]

Rotation with the tornado headed towards Spring Hill which is being shown

[jaxjagman]

Storm around Olinda had reports of 70mph winds with pole and home damage,certainly could be str8 line winds but we'll see when they survey

[jaxjagman]

Tornado shown is from the Centerville cell,weak rotation but it still is ongoing towards Murfreesboro

[jaxjagman]

Storm fizzled out just east of Eagleville,maybe loss of diurnal heating is starting  to factor in

[jaxjagman]

So weird looking.With the jet extension you see westerlies to the west with which looks to be HP into Bermuda/Florida and shortwaves rotating along a negative tilted trough.Try and figure this one out what the Euro shows..lol

[jaxjagman]

US National Weather Service Nashville Tennessee

3 hrs · 

(ALL INFO IS PRELIMINARY & SUBJECT TO CHANGE!)
After surveying the wind damage from the storms on Saturday March 30th, a NWS storm survey team has determined that an 8 mile long by 1 mile wide downburst (straight-line winds) caused the damage in and around Orlinda (Robertson County). Several barns in the area were damaged, a few homes lost shingles, and scattered trees were snapped and uprooted. Winds were estimated from 65 to 75 mph.

Further south, it was determined that a small but severe microburst around 1 mile long by 300 yards wide caused the damage along John Lunn Road just south of Saturn Parkway in Spring Hill (Maury County). These damaging winds were associated with the RFD (rear flank downdraft) of the supercell thunderstorm that moved over the Spring Hill area. One barn was destroyed, several others were damaged, and numerous trees were snapped and uprooted. Winds were estimated up to 80 mph.

[nrgjeff]

Glad I stayed home and watched basketball this past weekend. 

Upcoming Thursday I'm not nearly as impressed as SPC. Just-in-time moisture fails in April, kind of like Fed-Ex drivers running you off the highway rushing their JIT deliveries. Wind shear (speed and directional) is good southern half of Mississippi. However that's almost out of our Region and more Southeast sub-forum. 

Hopefully Wichita State will be playing in the NIT Final Thursday; so, I'll likely be home.