April 13-14 Severe Weather Outbreak

[VOLtage]

Day 1 Outlook:

Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1112 AM CDT Sat Apr 13 2019

   Valid 131630Z - 141200Z

   ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS EAST
   TEXAS...NORTHERN AND CENTRAL LOUISIANA...WESTERN AND CENTRAL
   MISSISSIPPI...

   ...SUMMARY...
   Numerous to widespread severe thunderstorms are expected across
   parts of the south-central to southeast states through tonight. The
   most likely region for strong tornadoes is from east Texas to
   Mississippi, with the most dangerous period for tornadoes being
   between about 2 to 8 PM CDT.

   ...TX to TN Valley...
   No substantial changes to categorical areas with this outlook
   (beyond reducing area behind the convective line in TX).

   Surface cyclone near College Station should move northeast towards
   northwest LA and then across the Mid-South through tonight, as a
   warm front advances north from southeast TX/central LA. Parameter
   space is very supportive of supercells, with persistent
   warm-advection north of the front yielding a risk for large hail.
   Along and south of the front, main uncertainties are longevity and
   discreteness of favorable storm mode. A deeply moist boundary layer
   with upper 60s to lower 70s dew points will spread north, supporting
   preconvective MLCAPE ranging from 2000-3000 J/kg across southeast TX
   and southern LA. Such buoyancy will be quite favorable for all forms
   of severe, amid strengthening deep shear related to the approach of
   the mid/upper trough. Furthermore, low-level shear vectors and
   hodograph sizes will be quite large along and south of the warm
   front (from the Sabine Valley eastward), with forecast soundings
   yielding 250-600 J/kg effective SRH. Any sustained supercells in
   this environment will be capable of significant tornadoes.

   With time this evening and overnight, convection should organize
   into a roughly north/south-aligned band over the Lower Mississippi
   Valley region, as deep convergence becomes better-focused in the
   mass response ahead of the synoptic wave. As this occurs, the main
   threat in a bulk sense may become damaging wind tonight. However,
   given the strong inflow-layer SRH, tornadoes still will be probable
   from both embedded supercells and QLCS mesovortices.

   ...Central/eastern NC...
   Scattered thunderstorms are expected to develop through this
   afternoon, offering the potential for locally strong wind gusts and
   marginally severe hail.

   Mid/upper-level support will be lacking, beneath a belt of 
   southwesterlies aloft. But the region will straddle a low-level
   moist axis characterized by surface dew points generally in the
   mid/upper 60s F, supporting preconvective MLCAPE from 1000-2000
   J/kg. Though low-level flow will be weak, limiting boundary-layer
   shear and hodograph size, the height gradient will remain
   sufficiently tight aloft to support strong storm-relative winds in
   upper levels, and effective-shear around 40-45 kt. As such, a few
   organized multicells and sporadic supercell structures will be
   possible. Storm intensity will diminish after sunset.

 

 

[Chinook]

Tomorrow- convection allowing models show that some storms may be in the vicinity of Nashville or Knoxville. Threat may be mostly east of Nashville. There is not a lot of agreement on any centralized area of severe thunderstorms, so storm reports may be more sparse than the 30% outlook indicates. With 70 kt of deep layer shear, any storm has the possibility to create significant severe weather.

side note: I was looking at the SPC outlook for tomorrow. The biggest cities in the outlook area are Columbus, OH, Charlotte, NC, and Atlanta, GA.  I guess Atlanta is just a small city of 486,000 people. I would have thought Atlanta would have 900,000 given the fact that so many large corporations are headquartered there, including The Weather Channel and Coca-Cola

 

 

[Windspeed]

side note: I was looking at the SPC outlook for tomorrow. The biggest cities in the outlook area are Columbus, OH, Charlotte, NC, and Atlanta, GA.  I guess Atlanta is just a small city of 486,000 people. I would have thought Atlanta would have 900,000 given the fact that so many large corporations are headquartered there, including The Weather Channel and Coca-Cola

Atlanta's population is much larger than that half-a-million figure but their census only includes the Atlanta "metro proper" for its total. However, Fulton Co., which includes a big chunk of Atlanta's residential suburbs has over 1.2 million people alone. Population totals can be confusing with respect to different cities and their zoning. For example, Houston is the exact opposite of Atlanta. Everything inside the Sam Houston Beltway is included in Houston's metro population. Atlanta would be much larger if it incorporated a larger portion of its urban region. Make no mistake though, several million live inside the I-285 loop and around 3-4 million in close proximity to it within the greater Atlanta urban region.

[jaxjagman]

 

 

URGENT - IMMEDIATE BROADCAST REQUESTED
   Tornado Watch Number 55
   NWS Storm Prediction Center Norman OK
   710 PM CDT Sat Apr 13 2019

   The NWS Storm Prediction Center has issued a

   * Tornado Watch for portions of 
     Northern and central Alabama
     Eastern Mississippi

   * Effective this Saturday night and Sunday morning from 710 PM
     until 300 AM CDT.

   * Primary threats include...
     A few tornadoes likely with a couple intense tornadoes possible
     Scattered damaging wind gusts to 70 mph likely
     Isolated very large hail events to 2 inches in diameter possible

   SUMMARY...Severe storms are expected to develop and potentially
   increase through late evening across eastern Mississippi into
   northern/central portions of Alabama, with the most intense storms
   favoring a sub-regional area near a warm front where low-level shear
   is maximized. This will include the potential for a few
   semi-discrete supercells, although a mixed convective mode is most
   likely. Tornadoes will be possible, a couple of which could be
   strong, aside from damaging winds and possibly hail.

   The tornado watch area is approximately along and 70 statute miles
   north and south of a line from 55 miles northwest of Meridian MS to
   20 miles northeast of Birmingham AL. For a complete depiction of the
   watch see the associated watch outline update (WOUS64 KWNS WOU

[jaxjagman]

WF is still stuck in around B'ham which is what RAOBS shows,should have been well North or at least north of I-40 

[TellicoWx]

3 minutes ago, jaxjagman said:

WF is still stuck in around B'ham which is what RAOBS shows,should have been well North or at least north of I-40 

Yeah, one of the biggest things models missed on today

[Runman292]

6 minutes ago, jaxjagman said:

WF is still stuck in around B'ham which is what RAOBS shows,should have been well North or at least north of I-40 

Could that have an impact on the storms for tomorrow?

[jaxjagman]

17 minutes ago, Runman292 said:

Could that have an impact on the storms for tomorrow?

Not really sure,models still show a severe threat late morning into early afternoon

 

Edit:That's for you guys in the East,not in the Middle/West Valley

[PowellVolz]

Large tornado on the ground in Starkville Miss




.

[VOLtage]

This is shaping up to be a major tornado outbreak.
 

[VOLtage]

Severe Weather Statement
National Weather Service Memphis TN
1131 PM CDT Sat Apr 13 2019

MSC057-095-140445-
/O.CON.KMEG.TO.W.0021.000000T0000Z-190414T0445Z/
Itawamba MS-Monroe MS-
1131 PM CDT Sat Apr 13 2019

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1145 PM CDT FOR
SOUTHEASTERN ITAWAMBA AND NORTHEASTERN MONROE COUNTIES...

At 1130 PM CDT, a confirmed large and extremely dangerous tornado was
located near Detroit, or 10 miles northwest of Sulligent, moving
northeast at 55 mph.

This is a PARTICULARLY DANGEROUS SITUATION. TAKE COVER NOW!

HAZARD...Damaging tornado.

SOURCE...Radar confirmed tornado.

IMPACT...You are in a life-threatening situation. Flying debris may
         be deadly to those caught without shelter. Mobile homes
         will be destroyed. Considerable damage to homes,
         businesses, and vehicles is likely and complete destruction
         is possible.

Locations impacted include...
Amory, Smithville, New Salem, Hatley, Gattman, Sipsey Fork, Quincy,
Cardsville, Turon, Splunge, Wise Gap, Athens, Greenwood Springs and
Parham.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a large, extremely dangerous and potentially deadly
tornado is on the ground. To protect your life, TAKE COVER NOW! Move
to a storm shelter or an interior room on the lowest floor of a
sturdy building. Avoid windows. If you are outdoors, in a mobile
home, or in a vehicle, move to the closest substantial shelter and
protect yourself from flying debris.

Tornadoes are extremely difficult to see and confirm at night. Do not
wait to see or hear the tornado. TAKE COVER NOW!

&&

LAT...LON 3417 8840 3415 8819 3383 8824 3388 8849
TIME...MOT...LOC 0430Z 202DEG 46KT 3399 8828

TORNADO...OBSERVED
TORNADO DAMAGE THREAT...CONSIDERABLE
HAIL...0.00IN

[yoda]

Mesoscale Discussion 0333
   NWS Storm Prediction Center Norman OK
   1239 AM CDT Sun Apr 14 2019

   Areas affected...portions of Middle Tennessee...northeastern/eastern
   Alabama...and northwestern Georgia

   Concerning...Tornado Watch 55...

   Valid 140539Z - 140645Z

   The severe weather threat for Tornado Watch 55 continues.

   SUMMARY...Either a new Tornado Watch or a replacement Tornado Watch
   for WW 55 will be issued soon.

   DISCUSSION...An ongoing broken band of convection extends from
   northwestern Alabama near MSL southward to near CBM and onward from
   there toward the Mississippi Gulf Coast.  A weakly unstable, yet
   strongly sheared airmass extends just east of this band, spreading
   into southern portions of Middle Tennessee.  This airmass should
   support a continued tornado threat as deeper convection moves
   north-northeastward into the region.  As such, either a new Tornado
   Watch or a replacement Tornado Watch (replacing WW 55) will be
   coordinated with affected offices within the next 15 minutes or so.

   ..Cook/Edwards.. 04/14/2019

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

   ATTN...WFO...MRX...FFC...OHX...BMX...HUN...

[Runman292]

Latest Day 1 Outlook from the SPC has taken the western half of East TN (including Knoxville) out of the enhanced risk. 

[Carvers Gap]

Heads up E TN folks and especially NE TN....MRX update.

Area Forecast Discussion...UPDATED
National Weather Service Morristown TN
1102 AM EDT Sun Apr 14 2019

.DISCUSSION...
The initial line of storms has weakened considerably as it moves
into the eastern half of our area. Satellite shows clearing skies
over Middle TN that will allow for good surface heating and
destabilization this afternoon, in addition to strong warm
advection with the southerly flow. SBCAPE values are expected to
rise into the 1500-2000 J/kg range, and perhaps higher than that
in the southern Valley. This, combined with the dry air aloft and
continued high deep layer shear, will result in another round of
severe storms in the 3 pm to 9 pm time frame. Hi-res models show
redevelopment of storms near the I-75 corridor, taking the form of
supercells that evolve into a line as it moves east across NE TN
and SW VA. Damaging winds will be the greatest threat due to the
dry air and strong winds aloft, and potential for bow segments
along the line. LCL heights and 0-1 SRH values also support a
tornado threat for the whole area, but favoring areas along I-75
as backing of surface winds may be difficult to achieve in the
shadow of the mountains in the northern Valley. Hail may also be a
threat given the low WBZ heights, but it appears marginal (dime
to quarter- size) looking at CAPE profiles in forecast soundings.
Hi-res models are in good agreement that the storms will exit our
area around 10 pm.

[Holston_River_Rambler]

Thought some might find this thread from one storm yesterday interesting:

 

 

[nrgjeff]

Please summarize that paper. Downloads PDF.

Separately, let's please post text/photo of confirmed tornado by spotter. Radar images or even, confirmed by radar, is not the same. Confirmed by radar is debris and almost always caused by a tornado. Still not the same as a spotter report.

Thursday is the next chance for Dixie. MCS on the Gulf Coast could cut off AL/TN. On the other hand North Bama is in the right rear/entrance region of a speed max, which is a favored area iff not cut off by MCS. Also Alabama to Indiana is more favored than the Delta this time of year. We'll see.

Please, no personal forecast requests. Starting now I will not answer unless it's related to storm chasing together. 

[Holston_River_Rambler]

Is this what you were looking for Jeff, regarding the paper?

https://t.co/keKEHDA2Gj 

 

 

[jaxjagman]

Mesoscale Discussion 0343
   NWS Storm Prediction Center Norman OK
   0200 PM CDT Sun Apr 14 2019

   Areas affected...Portions of Eastern Tennessee and Northwest Georgia

   Concerning...Severe potential...Watch possible 

   Valid 141900Z - 142100Z

   Probability of Watch Issuance...60 percent

   SUMMARY...Storms have begun to initiate along a confluence zone in
   eastern Tennessee. Further development southward into northwest
   Georgia is possible. Strong wind fields will support organized
   storms capable of all severe hazards. A tornado watch is possible
   within the next hour.

   DISCUSSION...In the wake of early morning convection, modest
   boundary layer recovery has occurred across eastern Tennessee. An
   area of agitated cumulus has developed along a confluence zone just
   east of Crossville, TN. Surface observations from the last hour have
   indicated that boundary layer moisture has mixed out to a degree.
   Nonetheless, dewpoints in the upper-50s to low 60s have contributed
   to MLCAPE values around 1000 J/kg. As storms are now beginning to
   develop on the north end of the confluence band, the expectation is
   for continued development southward, as supported by some CAMs.
   Given the strong wind fields -- effective bulk shear of 60-75 kts
   per objective mesoanalysis -- organized convection capable of all
   hazards is expected. A tornado watch is possible within the next
   hour.

[Carvers Gap]

From MRX on FB....

[Runman292]

Severe Thunderstorm Watch has been issued for the Eastern Half of East TN (Knoxville and east) until 10:00 PM EST.

[jaxjagman]

2 hours ago, nrgjeff said:

Please summarize that paper. Downloads PDF.

Separately, let's please post text/photo of confirmed tornado by spotter. Radar images or even, confirmed by radar, is not the same. Confirmed by radar is debris and almost always caused by a tornado. Still not the same as a spotter report.

Thursday is the next chance for Dixie. MCS on the Gulf Coast could cut off AL/TN. On the other hand North Bama is in the right rear/entrance region of a speed max, which is a favored area iff not cut off by MCS. Also Alabama to Indiana is more favored than the Delta this time of year. We'll see.

Please, no personal forecast requests. Starting now I will not answer unless it's related to storm chasing together. 

Yeah,i agree.Though right now there is some timing differences for Thursday.The better look in our area right now seems to be in N/AL like you said.Though i would certainly not rule out anything severe into Mid/Tn during diurnal heating

[Windspeed]

Blue skies past hour after several hours of showers. Temperatures have responded accordingly, up to 74° from 63° earlier, and it actually feels humid, which may aid in destabilization for strong cells by the time the boundary rolls through KTRI.

[John1122]

There were 0 severe storms here but the long duration strong wind event bent a huge metal pole that held signage for a restaurant near I-75, broke a power pole, and blew the roof off two of my outbuildings along with countless trees down. I'd say we had some 70+mph gusts.