Tn Valley Severe Weather

[jaxjagman]

Thats what i get when i take my scan off OHX so quick

[janetjanet998]

EVERE WEATHER STATEMENT  
NATIONAL WEATHER SERVICE NASHVILLE TN  
455 PM CDT SAT APR 25 2020  
  
TNC159-252215-  
/O.CON.KOHX.TO.W.0018.000000T0000Z-200425T2215Z/  
SMITH TN-  
455 PM CDT SAT APR 25 2020  
  
...A TORNADO WARNING REMAINS IN EFFECT UNTIL 515 PM CDT FOR CENTRAL  
SMITH COUNTY...  
          
AT 454 PM CDT, A CONFIRMED TORNADO WAS LOCATED NEAR I-40 AROUND 7   
MILES WEST OF GORDONSVILLE, MOVING EAST AT 40 MPH.  
  
HAZARD...DAMAGING TORNADO AND QUARTER SIZE HAIL.  
  
SOURCE...RADAR CONFIRMED TORNADO.  

[Chinook]

I guess this is the TDS for the confirmed tornado near Rome, TN. it's possible the tornado went over I-40

[jaxjagman]

3 minutes ago, Chinook said:

I guess this is the TDS for the confirmed tornado near Rome, TN. it's possible the tornado went over I-40

News said it was,quick mesoscale.Those cells around that area had some clearing earlier

[janetjanet998]

 

[janetjanet998]

RGENT - IMMEDIATE BROADCAST REQUESTED  
TORNADO WATCH NUMBER 148  
NWS STORM PREDICTION CENTER NORMAN OK  
610 PM EDT SAT APR 25 2020  
  
THE NWS STORM PREDICTION CENTER HAS ISSUED A  
  
* TORNADO WATCH FOR PORTIONS OF   
  FAR NORTHERN GEORGIA  
  FAR SOUTHWEST NORTH CAROLINA  
  NORTHWEST SOUTH CAROLINA  
  EASTERN TENNESSEE  
  
* EFFECTIVE THIS SATURDAY EVENING FROM 610 PM UNTIL 1000 PM EDT.  
  
* PRIMARY THREATS INCLUDE...  
  A COUPLE TORNADOES POSSIBLE  
  SCATTERED LARGE HAIL EVENTS TO 1.5 INCHES IN DIAMETER POSSIBLE  
  ISOLATED DAMAGING WIND GUSTS TO 65 MPH POSSIBLE  
  
SUMMARY...MULTIPLE, LOW-TOPPED SUPERCELLS WILL CONTINUE TO POSE A  
RISK FOR A COUPLE TORNADOES AND SEVERE HAIL, BEFORE WEAKENING LATER  
THIS EVENING.  

[Calderon]

Multiple cars damaged and at least 1 semi flipped on I-40 east of Tuckers Crossroads in Wilson County.

[1234snow]

Finally the KY storm is tornado warned. I got -91mph on the last RadarScope scan.

[1234snow]

Couplet has intensified in KY northeast of Pineville:

[Holston_River_Rambler]

Got some pea sized hail with this line as it is coming through Morgan County

[John1122]

Saw a photo of trees and overturned tractor trailers of where the tornado supposedly crossed I-40 earlier. Could have been straight line winds too.  Nothing not extremely heavy rain here and a few thunder claps. 

[nrgjeff]

Always Cookville. Photos on Twitter look grungy though. Jives with lots of rain wrap around on radar up there.

Documented this foot / beaver tail around Ooltewah, before following toward Etowah. No touchdown, I saw the base at times driving. This is where I could safely pull over. It was a low-top mini-sup with tilted updraft. No true wall cloud, but it's gorgeous.

[Runman292]

Maybe it’s just me, but I don’t understand why the threat for severe weather is limited today. It’s a beautiful morning with very little clouds. Doesn’t there need to be mostly cloudy and rain for instability to be limited?

[nrgjeff]

Dewpoints are way behind schedule compared to all 3 CAMs NAM/WRF/HRRR. North Bama dews are in the 50s; it's progged low 60s Td by this time 14Z. I was hoping for a repeat of Saturday structure; but, looks like no dice. Though the LLJ is screaming (and mixing down) it may be shunted east this afternoon. 

Thunderstorms will still develop. Two shortwaves are noted coming through the flow. The first is already into Georgia marked by mid-level cloud signature. Then we have new lift coming from Louisiana, marked by the ribs in the high cloud deck. Mid-levels will also cool with time this afternoon. Thunderstorms yes. Fireworks, probably not.

[Runman292]

2 minutes ago, nrgjeff said:

Dewpoints are way behind schedule compared to all 3 CAMs NAM/WRF/HRRR. North Bama dews are in the 50s; it's progged low 60s Td by this time 14Z. I was hoping for a repeat of Saturday; but, looks like no dice. Though the LLJ is screaming (and mixing down) it may be shunted east this afternoon. 

Thunderstorms will still develop. Two shortwaves are noted coming through the flow. The first is already into Georgia marked by mid-level cloud signature. Then we have new lift coming from Louisiana, marked by the ribs in the high cloud deck. Mid-levels will also cool with time this afternoon. Thunderstorms yes. Fireworks, probably not.

So even though there is plenty of sun, the dew points still aren’t rising enough? I wish there was a way for me to learn more about this stuff and understand everything.

[Windspeed]

So even though there is plenty of sun, the dew points still aren’t rising enough? I wish there was a way for me to learn more about this stuff and understand everything.

In simple terms, the ground temps are cool, airmass humidity is meh and there just may not be enough sunshine to increase both parameters fast enough in the surface-to-low levels of the atmosphere to increase instability. At least the kind of instability needed to drive severe nodes up in the Valley. Inevitably the timing of advancing precip/cloud cover would kill the chance for any of that to occur later this afternoon and evening. Otherwise, you would need strong low-level southerly flow to increase air temps and dewpoints drastically, and that doesn't seem to be occurring. So we'll get showers and storms, but it should remain mostly tame.

[nrgjeff]

Yeah it just clouded up over both areas of surface convergence. Thundershowers are in progress, but it's not not energetic enough. The clouds just blossom on the loop. That'd be great in winter, but lol in spring. Also see Windspeed right above. 

2 hours ago, Runman292 said:

So even though there is plenty of sun, the dew points still aren’t rising enough? I wish there was a way for me to learn more about this stuff and understand everything.

Remember to read SPC discussions, even on the junk days, since it helps discern the good the bad and the ugly. Local office discussions often add more detail. Find it on weather.gov/mrx and the drop-down menu from forecasts to Forecaster's Discussion.

Weather pattern turns incredibly boring after this. See y'all in a couple weeks, lol!

[jaxjagman]

National Weather Service Nashville TN
230 PM CDT Thu Apr 30 2020

.DISCUSSION...

Closed upper low/deep trough over the region continues very slow
eastward track. Instability from cold-core still expected to pop
a few showers along the plateau into the late evening or so. Upper
low currently on a southeast trajectory and will move off the
Atlantic coast late Fri.

Upper ridge will build in behind and bring us dry weather up into
Sun. By early Sun, upper ridge breaking down and by this point a
cold front is sitting just northwest. This frontal boundary will
sink down into the mid-state late in the day, then continue south,
reaching the TN/AL border vicinity toward Mon morning. Airmass
ahead showing signs of pretty decent destabilization and there
seems to be at least a marginal chance of SVR storms, with even a
better chance across the northeast late Sun/Sun night. This will
be helped along by passing weak upper wave. Upper flow shifts more
northwest behind wave Sun night, while system across the plains
retreats frontal boundary back just to our north by Mon evening.
There is quite a bit of elevated instability Mon thus the
scattered strong storm threat continues.

GFS has boundary now just to our north pretty active Mon night
into Tue, bringing a complex down in northwest flow. EURO now also
looking very similar. Areas to our north look to have the biggest
brunt at this point, but just a small deviation south will really
increase widespread strong/severe chance.

Stormy conditions continue after that as well, at least as far as
the GFS in concerned. Tue afternoon, and especially Tue night,
things look to be more organized once again. SBCAPE/MLCAPE shoot
up across KY in the afternoon, then works down here. EBS and SRH
both on the increase, and getting into mid-higher end levels.
EURO however at this point much different. After Mon night
episode, it pretty much favors areas south of us. Be interesting
to see how this evolves. Either way, both models giving us pretty
much a dry Wed into late week.

[Runman292]

Here’s a paragraph from MRX’s latest AFD in terms of the Tuesday timeframe:

Tuesday into Wednesday there is still a lot of uncertainty in
regards to pattern evolution and timing. Monday`s cold front will be
to our south but a new system will be developing across the Great
Plains. As an area of low pressure develops across the Plains,
Monday`s front will transition into a warm front which may lift
north through our area during the day Tuesday. This warm front will
be an area of focus for showers and storms but it`s position is
uncertain at this time. Then, the cold front associated with the low
will sweep through our area Tuesday night into Wednesday morning,
providing additional chances for rain and storms. It`s too early to
go into much more detail at this time due to the aforementioned
model uncertainty. Will keep an eye on this setup though as we
could see some severe weather if things come together. Highs on
Tuesday will be in the lower 70s across northern areas and low 80s
across the southern TN Valley.

[jaxjagman]

Public Information Statement...UPDATED
National Weather Service Nashville TN
419 PM CDT Tue Apr 28 2020

...Very active year for tornadoes across Tennessee...

2020 has been a very active and devastating year for tornadoes
throughout Tennessee. As of today, a preliminary total of 28
tornadoes have touched down across the state since January 1st.
These tornadoes combined have killed 28 people, injured hundreds
more, and caused hundreds of millions of dollars in damage.

Below is a preliminary list of the tornadoes across Tennessee so
far this year. Note that all information is subject to change.

#     Date      Rating     County
-     ----      ------     ------
1     Jan 11    EF-1       Obion
2     Jan 11    EF-0       Fayette
3     Jan 11    EF-0       Weakley
4     Jan 11    EF-0       Claiborne
5     Feb 5     EF-1       Lawrence
6     Feb 5     EF-1       Lawrence
7     Feb 5     EF-0       Bedford
8     Feb 5     EF-0       Warren
9     Feb 5     EF-1       White
10    Feb 5     EF-1       White
11    Feb 12    EF-0       Lawrence
12    Mar 2     EF-1       Gibson
13    Mar 2     EF-2       Carroll
14    Mar 2     EF-2       Benton/Humphreys (1 death)
15    Mar 2     EF-0       Humphreys
16    Mar 3     EF-3       Davidson/Wilson/Smith (5 deaths)
17    Mar 3     EF-0       Putnam
18    Mar 3     EF-4       Putnam (19 deaths)
19    Mar 3     EF-0       Putnam
20    Mar 3     EF-2       Cumberland
21    Mar 3     EF-0       Morgan
22    Mar 24    EF-1       Franklin
23    Mar 29    EF-0       White
24    Apr 12    EF-3       Hamilton/Bradley (3 deaths)
25    Apr 12    EF-2       Bradley
26    Apr 12    EF-1       Bradley
27    Apr 12    EF-1       Bradley/Polk
28    Apr 25    EF-1       Wilson/Smith

West Tennessee Total Tornadoes - 6*
Middle Tennessee Total Tornadoes - 17*
East Tennessee Total Tornadoes - 6

Tennessee Total 2020 Tornadoes - 28*

* Note: One tornado on March 2 crossed from West Tennessee into
  Middle Tennessee and is counted twice

[jaxjagman]

Tomorrow is going to still seemingly be how bad the cap is.This afternoon the GFS has more moisture and the cap isn't as bad but still there. Wind and hail is the primary threat,.

 

 

 Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1229 PM CDT Sat May 02 2020

   Valid 031200Z - 041200Z

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE OZARKS
   TO THE MID ATLANTIC...OVER CENTRAL TEXAS...AND OVER THE NORTHERN
   HIGH PLAINS...

   ...SUMMARY...
   A few severe thunderstorms producing hail or damaging winds are
   possible Sunday from the Ozarks eastward across Kentucky, Tennessee
   and toward the Delmarva. Additional isolated severe storms are
   possible across the northern and central High Plains, and over a
   small portion of west-central Texas.

   ...Ozarks, OH/TN Valleys, Mid Atlantic...
   A shortwave trough will move across the Great Lakes on Sunday, with
   secondary disturbance farther south from the Ozarks into the OH
   Valley. As the upper wave amplifies late in the day, a surface
   trough will deepen across the Mid Atlantic, extending westward
   across KY and TN. High pressure will remain over the Southeast, with
   a narrow zone of higher dewpoints spreading across the lower MS
   valley, and extending northeast across TN and KY. Meanwhile, strong
   heating over VA may lead to increased evapotranspiration.

   Isolated storms are expected by late morning from the Ozarks
   eastward into KY and TN, aided initially by warm advection within
   the moist axis. Forecast soundings reveal warm temperatures around
   700 mb, and models are not consistent regarding low-level lapse
   rates and capping. However, a conditional threat of localized
   damaging wind or hail exists.

   Farther east from KY to the Delmarva, better large-scale lift will
   develop, with a cold front surge during the evening. While warm
   temperatures near 700 mb will exist here as well, strong westerlies
   and deep-layer shear as well as cold upper-level temperatures may
   support severe wind or hail, and possibly an MCS. However, questions
   exist regarding thermodynamic profiles. 

   Portions of this extensive Marginal Risk could require targeted
   upgrades to Slight as predictability increases in later outlooks.

[jaxjagman]

National Weather Service Nashville TN
216 PM CDT Sat May 2 2020

.DISCUSSION...

Surface high currently located along the southern Atlantic coast,
Southwesterly flow now in place across the area with warm temps in
the upper 70s to lower 80s. Skies are mostly sunny and dewpoints
have been inching upward.

The next 24 to 72 hours is looking rather unsettled. A surface
boundary will be on approach by tomorrow afternoon. Instabilities
will increase substantially by that time as the forcing from the
north approaches. Latest 12Z models are leaning toward better
organization in regard to dynamics by afternoon. Shear values not
overly strong with 25 kts at 850 mb. However, lapse rates of -7.5C
and -10c to -30c capes of around 1000 look to be in place. We are
outlooked as marginal at this time. Latest Hrrr shows storms moving
into our northwest around 3PM and moving southeastward through the
area. Looks like hail and winds will be the primary threat. Much of
the southern half of the mid state will be more of a momentum impact
with the winds, as storms slowly lose intensity in the evening.
Otherwise, boundary is oriented parallel to the storm motion so
could see some training with localized heavy rainfall pockets,
particularly north of I-40. SPC may or may not upgrade us to a
slight so stand by for that, sometime tonight.

Moving on, models are further south with the eastward track of the
surface low on Monday night. It appears the low will move across
southern KY with w-e elongation present. This spells out that the
better instabilities will be further south for the Monday aft and
evening period. Organized forcing looks rather sketchy the further
south you go. Thus, not really seeing much severe potential for Mon
aft and evening.

Tuesday afternoon, the surface boundary will still be located across
the mid state. Instabilities, south of the boundary will again soar
with the boundary beginning to move southward by evening. Forcing
organization will pick up across southern areas with the best chance
of strong to severe storms over that area. Again, wind and hail will
be possible.

[jaxjagman]

Early Tuesday into the afternoon should be some possible strong storms.By the Euro this time frame will have the best LLShear passing through west to east but the better lapse  are towards the south for a better hail chances,least right now,like Nashville mentions

[Runman292]

MRX:

Tomorrow, we have a southward sagging cold front that will drop down
out of the Ohio River Valley. This front is associated with an upper
level low across Quebec. With the front to our north and the
flattening high to our south, zonal flow will be in place across the
region. We`ve got two areas to watch for shower and storm
development tomorrow. We should see showers and storms redevelop
along the cold front, to our north, tomorrow afternoon and drift down
into southwest VA and northeast TN by early evening. The other area
to watch will be across the central and northern Cumberland Plateau.
Several CAMs show showers and storms developing across western TN/KY
early tomorrow afternoon and progressing eastward through the day
and onto the Plateau by early evening. These showers and storms
develop due to an impulse moving out of the Central Plains
tomorrow morning and riding along the cold front.

The better dynamics will be well of to our north but we will be on
the extreme southern fringe of the upper jet. We may be close enough
to get enough upper level support to see a few strong to possibly
severe storms from early evening through midnight. 850 mb flow is
also marginal with westerly flow around 20 to 30 kts. So if we do
get the upper support, some storms have the potential to become
strong to severe as instability will be moderate with MLCAPE
values around 1000 J/kg. If we don`t see the upper support, we
should still see showers and storms move through but they will be
more of the garden variety and shorter lived. Having said that, even
these garden variety storms can produce hail and gusty winds given
enough instability but the better chances of seeing anything
severe would come from longer lived cells. The main threat area
looks to be along I-40 and northward. The SPC has placed this area
in a marginal risk for severe weather for tomorrow. The main
threats will be isolated damaging wind gusts and small hail.

[jaxjagman]

See if the RAP is hinting at something.As the boundary slips Southward the 3Capes at least get up to mid to upper 70's even around 80 east of Nashville,so this could become more surface based into the Mid  afternoon with steep lapse rates so  could see some weak supercells by SARS.Wind and hail still looks like the primary

[jaxjagman]

Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0756 AM CDT Sun May 03 2020

   Valid 031300Z - 041200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE OZARKS
   AND TENNESSEE VALLEY TO CENTRAL APPALACHIANS...

   ...SUMMARY...
   Severe thunderstorms are possible from the Ozarks eastward across
   Kentucky, Tennessee and toward the southern Delmarva today into this
   evening. Additional isolated severe storms are possible across the
   northern and central High Plains, and over a small portion of
   west-central Texas mainly late this afternoon and evening.

   ...Ozarks and Kentucky/Tennessee to the Southern Delmarva...
   Multiple east/southeastward-moving mid-level impulses will be
   influential today, roughly coincident with a
   south/southeastward-spreading cold front that will roughly extend
   west/southwest to east/northeast across these regions. A
   southwesterly low-level influx of moisture precedes the front, while
   a strong elevated-mixed-layer, as noted in 12Z regional observed
   soundings, puts the southern extent of the severe risk a bit into
   question across the Tennessee Valley/Mid-South.

   Related to a low-amplitude but amplifying mid-level shortwave trough
   and early-day warm/moist advection regime, a relatively
   well-organized cluster of currently elevated strong/severe
   thunderstorms is ongoing across southeast Kansas as of 13Z. While
   not well handled by short-term guidance, there may be enough
   ascent/mesoscale organization to allow a southeast continuation of
   some early day severe potential along the front, although a
   weakening low-level jet/abating warm advection could ultimately
   influence a weakening trend later this morning. 

   Regardless, while the specific longevity of this stronger early-day
   convection is not certain, possible MCV augmentation and downstream
   differential heating should be sufficient to, at the very least,
   focus surface-based thunderstorm redevelopment into the afternoon
   near the southward-sagging front and nearby warm sector, on the
   northern fringes of an otherwise stout elevated-mixed-layer/cap.
   This includes parts of southern Missouri/northern Arkansas into
   Kentucky/western Tennessee. Damaging winds and severe hail will be
   possible.

   Farther east, in the wake of early-day/diminishing convection, the
   air mass will become unstable this afternoon along/south of the
   front from central/eastern Kentucky into portions of West
   Virginia/Virginia and the Delmarva vicinity. At least widely
   scattered thunderstorms should develop/intensify this afternoon and
   persist into the evening, with severe hail/wind possible.

[Holston_River_Rambler]

This convective system looks pretty healthy to me, compared to the CAMs anyway:

Good and sunny upstream too, between it and me, although beyond that I'm not too good at ready the mesoscale analysis pages for severe/ strong storm parameters. 

To me it looks like it will make a nice charge Paris -> Nashville -> Crossville -> Knoxville

[jaxjagman]

Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1117 AM CDT Sun May 03 2020

   Valid 031630Z - 041200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
   ACROSS PARTS OF SOUTHERN MISSOURI...NORTHEAST ARKANSAS...EXTREME
   SOUTHERN ILLINOIS...NORTHWEST TENNESSEE...AND WESTERN KENTUCKY....

   ...SUMMARY...
   Severe thunderstorms capable of damaging winds and hail are expected
   today from the Ozarks eastward across western Kentucky and northwest
   Tennessee.  Other strong to severe storms are possible farther east
   in Kentucky into the southern Delmarva, across the northern and
   central High Plains, and over a small portion of west-central Texas.

   ...Southern MO into western KY/TN...
   A fast-moving bow echo has developed across southern MO.  This
   cluster of storms has produced many reports of damaging winds and
   hail this morning, and is tracking into a region where strong
   heating and substantial low-level moisture is present.  This should
   help to maintain intensity through the day as storms track into
   parts of KY/TN.  Therefore have added a small ENH risk for this
   threat.  Refer to MCD #517 for further detail.

   ...Central KY/TN into WV and Mid-Atlantic region...
   Most 12z model guidance shows scattered afternoon convection forming
   along the surface boundary from central KY into northern WV as the
   upper trough approaches.  This activity is likely to be less
   organized than the bowing structure farther west, due to weaker
   instability and rather weak low-level winds.  Nevertheless, a few of
   the storms may pose a risk of locally damaging wind gusts and hail
   through the late afternoon and evening hours.

[jaxjagman]

URGENT - IMMEDIATE BROADCAST REQUESTED
   Severe Thunderstorm Watch Number 158
   NWS Storm Prediction Center Norman OK
   1145 AM CDT Sun May 3 2020

   The NWS Storm Prediction Center has issued a

   * Severe Thunderstorm Watch for portions of 
     Northeast Arkansas
     Extreme Southern Illinois
     Western Kentucky
     Southeast Missouri
     West Tennessee

   * Effective this Sunday morning and evening from 1145 AM until
     600 PM CDT.

   * Primary threats include...
     Widespread damaging wind gusts to 70 mph likely
     Scattered large hail likely with isolated very large hail events
       to 2 inches in diameter possible

   SUMMARY...A fast-moving line of severe thunderstorms over southern
   Missouri will track eastward across the watch area this afternoon,
   posing a risk of damaging wind gusts and hail.

   The severe thunderstorm watch area is approximately along and 60
   statute miles north and south of a line from 20 miles southwest of
   West Plains MO to 20 miles southeast of Clarksville TN. For a
   complete depiction of the watch see the associated watch outline
   update (WOUS64 KWNS WOU8).

[nrgjeff]

Though low level winds are veered off, today could be interesting in the Shelfie category along I-40 especially Plateau and points west. 

Winds surface to 850 all look similar west of south. However there's decent speed for May especially higher up. Good recipe for straight line winds with the CAPE building. 

Some CAMs have cells hooking into southeast Tenn. Others have things stabilizing from the main I-40 show and outflow. 

Finally there's the question about the main show/line east of the Plateau. Can it get to Knoxvegas? Cell and outflow interaction may determine how fast things stabilize this evening.

At least we have something to track. We could use a break from tornadoes, so straight line wind is acceptable.