Jump to content
  • Member Statistics

    17,601
    Total Members
    7,904
    Most Online
    ArlyDude
    Newest Member
    ArlyDude
    Joined

Tn Valley Severe Weather


jaxjagman
 Share

Recommended Posts

4 hours ago, WeatherNow said:

What you're saying is completely unreal. Link works for me and is a very original site. The problem is entirely yours and related to the sites you entered before.

Yeah, no. Doesn’t work like that, buddy. I experienced the same issue as @Windspeed

A similar issue was previously noted on AmWx some time ago. Sometimes it’s the result of malicious script injected w/o the webmaster’s knowledge; other times, an ad can be the culprit. 

Perhaps don’t be quite so abrasive in the future. 

Link to comment
Share on other sites

This site is safe, but…
It asks for personal information and is not well established with the Norton Community. Use caution when entering any of your information on this site. 
Visit 
to learn more about personal information risk on Web sites.
 
Age: 
New
This website has been available for a short time.
 
Prevalence: 
Few Users
Very few Norton community members have used this site.
Link to comment
Share on other sites

Since no one else has yet, I'll point out that there's a Day 4 risk area out for much of the TN Valley/Dixie Alley region. As usual still a lot of pieces to come together as to exactly how this will play out. Could be about as significant as last Saturday, or more, or less. Worth noting though since model trends have been upward for the possibility of severe weather in the area on Sunday.

  • Like 2
  • Thanks 1
Link to comment
Share on other sites

https://www.ustornadoes.com/2019/03/01/spring-2019-seasonal-tornado-outlook/

 

Using analogs of 1995 we had our most  3rd ranked severe of all time,of course during this time frame we was A MORE neutral enso coming of an Nina.Also during this time frame from 1990-1997 we never had a SSWE,would really like to see more study into SSWE's.The last split which was similar to this years was in a weak NINA in 1984 ,on Dec 31st,we broke our  all-time record lows  temps in Nashville in Jan of 1985

 


 

The tornado outbreak in May of 1995 

 

https://en.wikipedia.org/wiki/May_1995_tornado_outbreak_sequence

 

Edit:I took out some of the post out because i found some conflicting aspects.Wiki seems to be going by reported tornadoes and not confirmed.80 confirmed tornadoes seemed to be really extreme to me.This by OHX back on May 18,1995, looks more realistic

https://www.weather.gov/ohx/19950518 

 

Some of the tornado reports were also wind,hail and thunderstorm reports.But either way that was a heck of a day

 

https://www.spc.noaa.gov/climo/online/sp3/plot.php?lat=32.810&lon=87.408&zoom=70&mode=1&bdate=19950518/1200&edate=19950519/1200&torflag=1&windflag=1&hailflag=1&t01=0&t02=5&t03=0&t04=9999&t05=0&t06=9999&t07=0&t08=9999&t09=0&t10=9999&h01=0&h02=9999&w01=0&w02=9999&showt=0&legend=1&showh=-1&showw=-1

 

 

  • Thanks 1
Link to comment
Share on other sites

Well at SPC Broyles goes ENH for Sunday southeast Alabama into parts of southwest Georgia, including 10% hatched tornado. It's aggressive but some CAMs have broken cells. I'm not too interested. Terrain is mostly poor except south side of ENH.

The 700 mb level offers wind direction challenges, except farther ahead of the trough. I suppose best cells would be ahead of the main line. Positive tilt just does not give me that feeling. Though 925 mb may be less veered ahead of the line. We'll see.

Probably should post in the Southeast Region but I have not been in here for 3-4 days. Happy weekend!

  • Like 2
  • Thanks 1
Link to comment
Share on other sites

Unfortunately today's event is already the deadliest tornado outbreak since the April 27th-28th outbreak in 2014. I believe there were 34 deaths as a result of that event, though that outbreak covered a much larger region of the country. Of course it only takes one strong EF3+ tornado tracking through a residential area to have a significant number of deaths. The toll in Lee County, Ala. alone stands at 22 and may rise further unfortunately. Datasets located here:

http://spc.noaa.gov/climo/torn/fatalmap.php

  • Sad 2
Link to comment
Share on other sites

Sunday tornadoes were an example of intersecting boundaries again. While the synoptic WF made it into the Carolinas, the former coastal front became another warm front in South Georgia. Coldest air hanged back in Tennessee, even as the cold front had made it to eastern Alabama. Hence, arctic air did not surge into the risk area.

Alabama cold front acted more like a pre-frontal trough, with the coldest air back in Tenn. Georgia warm front intersected Bama trough in Lee County. Damaging tornadoes continued east from there along the WF. Other tornadoes were in the free warm sector. SPC did a good job going hatched in spite for CAMs slop/lines. Of course our thoughts and prayers are with the victims.

Next chance of Dixie Alley severe is back in our region, but Day 6 nobody needs to worry yet. If moisture returns (currently questionable after arctic front) the Mid South should see a potent short-wave on Saturday. Main storm system ejects north. Southern energy is progged however, including gradual turning with height. (remember just day 6 models)

Later next week, out around Day 9, is another possible day. A little more moisture may be available. First system would start that process, if its front does not get to the Gulf Coast. Both of these could be nothing though. Just things to watch in March.

  • Like 3
  • Thanks 3
Link to comment
Share on other sites

Day 4-8 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0400 AM CST Tue Mar 05 2019

   Valid 081200Z - 131200Z

   ...DISCUSSION...
   Medium-range models are in reasonable agreement through roughly Day
   5 (Saturday 3-9), with respect to spatial positioning of the main
   synoptic features.  The GFS remains the more aggressive model with
   respect to deepening of the upper trough as it crosses the Rockies
   Day 4 and the Plains Day 5, and thus likewise depicts a much
   stronger surface cyclone during the Day 5 period.

   Beyond Day 5, the faster GFS outpaces the slower ECMWF, to the
   degree that confidence in the potential for accuracy in a convective
   forecast beyond Day 5 is too low to warrant any areal inclusions.

   In the Day 4 to 5 time range, when model agreement is higher, it
   appears that elevated convection will evolve across portions of
   Oklahoma and Kansas, and possibly northward into Nebraska.  However,
   confidence is not high enough that any hail risk evident at this
   point warrants a Day 4 area.

   Day 5, a surface cold front is progged to sweep across the central
   and southern Plains and into Missouri/Arkansas through the day, and
   then quickly eastward across the Mississippi River into the Ohio and
   Tennessee Valleys overnight.  While the strongest large-scale ascent
   is progged at this time to sweep across the Ozarks vicinity during
   the day, as the trough takes on a negative tilt, substantial
   questions remain as to the degree of moistening/destabilization that
   will be able to occur this far north.  Greater severe risk may
   therefore remain farther south, from east Texas/Louisiana across the
   Lower Mississippi Valley region, and possibly into the central Gulf
   Coast states late.

   Aside from questions regarding instability, this appears likely to
   be a strongly dynamic system with strong flow/shear covering a broad
   area.  As such, damaging winds, and potential for tornadoes, is
   evident at this time.  At this time, a large 15% probability area
   will be issued centered on a north-south zone from Missouri to the
   Lower Mississippi Valley, with additional areal, and risk-level,
   refinements to be made in subsequent outlooks.

   ..Goss.. 03/05/2019
  • Like 1
  • Thanks 1
Link to comment
Share on other sites

ay 4-8 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0400 AM CST Wed Mar 06 2019

   Valid 091200Z - 141200Z

   ...DISCUSSION...
   Medium-range models appear to be in reasonably good agreement over
   the U.S. through Day 6 (Monday 3-11), with the main upper feature
   early in the period being a negatively-tilted upper trough that will
   move quickly out of the central and southern Plains, across the
   Upper Midwest, and into the Upper Great Lakes Day 4 (Saturday 3-9). 
   As this system continues to progress into eastern Canada and the
   northeastern U.S. Day 5 (Sunday 3-10), a strengthening trough
   farther west is progged to be digging southward along the West
   Coast, before shifting more eastward/inland Day 6.  At this point,
   model agreement deteriorates significantly with eastward
   progression/evolution of this system, and thus forecast confidence
   remains low during the second half of the period.

   In the meantime, widespread showers and thunderstorms are forecast
   to expand across a large area from eastern portions of the central
   and southern Plains early Day 4, eastward/northeastward across the
   Mississippi Valley and into the Ohio and Tennessee Valleys through
   Sunday morning.  Given the strength of this system, and the
   accompanying/strong kinematic field, risk for at least isolated
   severe storms remains evident -- including potential for damaging
   winds and some tornado risk.  However, a primary limiting factor
   appears likely to be limited CAPE (in part due to the widespread
   convective development).  As such, will maintain only 15% risk at
   this time, though strength of this system and accompanying
   deep-layer wind field warrants attention in future outlooks.

   Day 5, models suggest that continued cold frontal advance across the
   East Coast and Gulf Coast states will occur, with the front
   currently progged to reside near both the Atlantic and Gulf Coasts
   near the end of the Day 5 period.  Ahead of the boundary, modest
   CAPE but strong shear is expected, warranting introduction of a 15%
   risk area from the central Gulf Coast to the eastern Carolinas.  

   With the front largely offshore by Day 6, a lull in severe weather
   risk is evident at this time, prior to the advance of the next
   western upper system.
Link to comment
Share on other sites

On 12Z NAM, hodos are looking very impressive over the AL/MS border region (moreso than further west where instability is greater). Could be another scenario to watch out for prefrontal initiation in that area (as with last Sunday) if it can destabilize.

Sounding attached is from a small pocket of higher CAPE depicted near and south of Columbus (ruh roh), MS. I see some slight backing on the wind barbs between 700 and 500 mb, but that doesn't look like game-breaker levels of VBV.

nam_2019030612_081_33.79--88.44.png

  • Like 2
  • Thanks 1
Link to comment
Share on other sites

6 hours ago, TellicoWx said:

By no means am I saying this is how it will play out, but it is a little unnerving the date of the analogs on the 18z NAM. April 1998 was the F5 in Davidson Co.

nam_2019030618_072_33.78--91.7.png

The EF5 was in Lawrence County.  Only one ever in TN (I think).  Also known as the forgotten one.  The Nashville one was EF2/3.

I am thinking the Nam is way off.  We shall see.

Link to comment
Share on other sites

22 minutes ago, Matthew70 said:

The EF5 was in Lawrence County.  Only one ever in TN (I think).  Also known as the forgotten one.  The Nashville one was EF2/3.

I am thinking the Nam is way off.  We shall see.

Yeah, I got the counties crossed. 00z backed off. With the main low trending further north, the threat is lessening some. 

  • Like 1
Link to comment
Share on other sites

The common analog on SARS the last several runs is 4/18/69. That system produced an F4 in Greenville, AL killing 2. A total of 13 tornadoes formed, mostly in the F0-F2 range. A 218 mi path was also recorded in southern GA and rated F2. Storm caused 50 injuries, besides the 2 deaths in the F4.

Link to comment
Share on other sites

SPC AC 080700

   Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0100 AM CST Fri Mar 08 2019

   Valid 091200Z - 101200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
   THE ARKLAMISS INTO NORTHERN MS AND SOUTHWESTERN TN...

   ...SUMMARY...
   Severe thunderstorms may occur Saturday from parts of eastern
   Oklahoma and Texas into the lower/mid Mississippi Valleys, lower
   Ohio Valley, and Southeast. The best potential for scattered
   damaging winds and a few tornadoes appears to be across parts of the
   ArkLaMiss into northern Mississippi and southwestern Tennessee. A
   couple of these tornadoes could be strong.

   ...Synopsis...
   A negatively tilted shortwave trough initially over the southern and
   central Plains will move rapidly northeastward to the Upper Midwest,
   Great Lakes, and OH Valley regions by Saturday evening. An
   associated surface low over central KS should develop northeastward
   in the same time frame to the vicinity of eastern IA/northern IL
   while deepening slightly. A cold front attendant to this surface low
   will sweep eastward across much of the lower/mid MS Valley into the
   lower OH Valley and Mid-South through the day. The trailing portion
   of this front should stall over parts of the Southeast Saturday
   night as this boundary becomes increasingly aligned parallel to the
   mid-level flow.

   ...East TX/OK into the Lower/Mid MS Valleys, lower OH Valley, TN
   Valley, and Southeast...
   Increasing ascent associated with the approaching shortwave trough
   and a strengthening low-level jet will likely foster an increase in
   convective coverage and intensity across parts of eastern OK/TX into
   the ArkLaTex region early Saturday morning. These thunderstorms will
   have some potential to be surface-based, especially along and south
   I-40 in central AR where surface dewpoints should reach into the mid
   60s to the south of a warm front. A couple tornadoes and isolated
   damaging winds should be the main threat given the strong low-level
   shear that will be present, although some large hail could also
   occur as far northward as the Ozarks in southern MO with any
   elevated supercells that develop.

   The main uncertainty regarding the overall magnitude of the severe
   threat across the lower MS Valley into the Mid South remains the
   northward extent of potential destabilization. The early morning
   convection should move quickly east-northeastward in tandem with the
   low-level jet and surface cold front. It appears that a greater
   chance for surface-based thunderstorms should occur from parts of
   the ArkLaMiss region into northern MS and southwestern TN from late
   Saturday morning into the early afternoon, where MLCAPE of 500-1000
   J/kg could develop. Low-level shear is forecast to be very strong
   through 18-21Z as a 50-65 kt southwesterly low-level jet overlies
   this region. Forecast soundings show ample effective SRH to support
   rotating updrafts, and a few tornadoes could occur, particularly if
   convection can remain semi-discrete. There is some concern that a
   couple of these tornadoes could be strong given the very favorable
   kinematic environment. Scattered damaging winds may also be possible
   across this region. By late afternoon into the evening, the
   shortwave trough and strongest mid-level flow will become
   increasingly displaced to the north of the greater low-level
   moisture across the TN Valley and Southeast. Still, some severe
   threat may persist into parts of middle TN and northern/central AL.

   Farther north into the mid MS Valley and lower OH Valley, confidence
   in sufficient destabilization to support surface-based convection is
   even more questionable. Regardless, there will be very strong low-
   and mid-level flow present which could support isolated damaging
   winds and perhaps a tornado. This threat should wane with eastward
   extent across southern IN and central KY by Saturday evening as
   low-level moisture and related instability become increasingly
   marginal.

   ...MAXIMUM RISK BY HAZARD...
   Tornado:  10% SIG - Enhanced
   Wind:     30%     - Enhanced
   Hail:     15%     - Slight

   ..Gleason.. 03/08/2019

   CLICK TO GET WUUS02 PTSDY2 PRODUCT

   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z
   CURRENT UTC TIME: 0928Z (4:28AM), RELOAD THIS PAGE TO UPDATE THE TIME

 

day2otlk_0700.gif

Link to comment
Share on other sites

Been in Knoxville for my sons state gymnastics meet ,so i'll miss this one.

 

 Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1133 PM CST Fri Mar 08 2019

   Valid 091200Z - 101200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM THE LOWER
   OH VALLEY INTO WESTERN TN AND NORTHEAST MS...

   ...SUMMARY...
   Severe thunderstorms capable of tornadoes, large hail, and damaging
   gusts are possible across portions of the Mid South today through
   the early evening.  A strong tornado is possible from the confluence
   of the Ohio and Mississippi Rivers southward into parts of northern
   Mississippi and northwest Alabama.

   ...Synopsis...
   A vigorous, negatively tilted mid-level shortwave trough will move
   from the central/southern Great Plains to the lower MO Valley by mid
   afternoon and subsequently into the Great Lakes after dark.  An
   intense 90kt 500mb speed max will translate east-northeast from OK
   into the lower OH Valley by early evening.  In the low levels, a
   surface low will develop northeast from central KS to the IA/IL/MO
   border by 6pm and into the central Great Lakes overnight.  A warm
   front over the Mid South will advance northward into the lower OH
   Valley by peak heating and a composite dryline/Pacific front will
   arc south-southeast from the low into eastern AR and southwestward
   into east TX by mid afternoon before sweeping east across the OH
   Valley late.

   ...Eastern OK/TX into the mid-MS/lower OH Valleys...
   A complex forecast scenario with associated uncertainty
   appropriately describes the risk for severe thunderstorms and
   possible tornadoes across portions of the Mid South into the lower
   OH Valley today.  At the start of the period, a couple of clusters
   of strong to severe thunderstorms are forecast across western
   portions of the larger-risk area in parts of northeast TX into
   eastern OK/western AR.  Varying possible solutions are evident in
   model data whether all or parts of this activity moves downstream
   with intermittent intensification into the MS Valley during the day
   or whether some of this activity weakens on the southern portion
   near the Ark-La-Tex during the late morning.  Hail, wind, and
   perhaps a tornado or two are possible with the early-day storms over
   the Ark-La-Tex vicinity.

   Farther east, an adequately moist/destabilizing warm sector will
   spread north and northeast in wake of the warm front with surface
   dewpoints ranging from near 60 degrees F in the lower OH Valley to
   the middle 60s farther south into TN/AR/MS/AL.  Model guidance
   correspondingly indicates weaker buoyancy will exist farther north
   (MLCAPEs at or below 500 J/kg north of the OH river to 750-1250 J/kg
   farther south) but extreme low-level shear.  Hodographs become very
   large by early-mid afternoon with flow increasing from 70-90kt in
   the 850-500mb layer over the northern half of the Enhanced Risk
   area.  It seems plausible some attempts at storm development will
   occur during the afternoon near the leading edge of the mid-level
   dry slot.  If the stronger updrafts become sustained, they will
   likely evolve into supercells with tornado potential.  A corridor of
   possibility for supercell tornadoes (perhaps strong) appears
   greatest from the OH/MS confluence southward into northern portions
   of MS on the trailing portion of large-scale ascent moving away from
   the area.  As storms encounter weaker buoyancy farther east and
   northeast during the evening, a transition to linear structures
   capable primarily of damaging winds may occur.
Link to comment
Share on other sites

5 hours ago, jaxjagman said:

Been in Knoxville for my sons state gymnastics meet ,so i'll miss this one.

 


 Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1133 PM CST Fri Mar 08 2019

   Valid 091200Z - 101200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM THE LOWER
   OH VALLEY INTO WESTERN TN AND NORTHEAST MS...

   ...SUMMARY...
   Severe thunderstorms capable of tornadoes, large hail, and damaging
   gusts are possible across portions of the Mid South today through
   the early evening.  A strong tornado is possible from the confluence
   of the Ohio and Mississippi Rivers southward into parts of northern
   Mississippi and northwest Alabama.

   ...Synopsis...
   A vigorous, negatively tilted mid-level shortwave trough will move
   from the central/southern Great Plains to the lower MO Valley by mid
   afternoon and subsequently into the Great Lakes after dark.  An
   intense 90kt 500mb speed max will translate east-northeast from OK
   into the lower OH Valley by early evening.  In the low levels, a
   surface low will develop northeast from central KS to the IA/IL/MO
   border by 6pm and into the central Great Lakes overnight.  A warm
   front over the Mid South will advance northward into the lower OH
   Valley by peak heating and a composite dryline/Pacific front will
   arc south-southeast from the low into eastern AR and southwestward
   into east TX by mid afternoon before sweeping east across the OH
   Valley late.

   ...Eastern OK/TX into the mid-MS/lower OH Valleys...
   A complex forecast scenario with associated uncertainty
   appropriately describes the risk for severe thunderstorms and
   possible tornadoes across portions of the Mid South into the lower
   OH Valley today.  At the start of the period, a couple of clusters
   of strong to severe thunderstorms are forecast across western
   portions of the larger-risk area in parts of northeast TX into
   eastern OK/western AR.  Varying possible solutions are evident in
   model data whether all or parts of this activity moves downstream
   with intermittent intensification into the MS Valley during the day
   or whether some of this activity weakens on the southern portion
   near the Ark-La-Tex during the late morning.  Hail, wind, and
   perhaps a tornado or two are possible with the early-day storms over
   the Ark-La-Tex vicinity.

   Farther east, an adequately moist/destabilizing warm sector will
   spread north and northeast in wake of the warm front with surface
   dewpoints ranging from near 60 degrees F in the lower OH Valley to
   the middle 60s farther south into TN/AR/MS/AL.  Model guidance
   correspondingly indicates weaker buoyancy will exist farther north
   (MLCAPEs at or below 500 J/kg north of the OH river to 750-1250 J/kg
   farther south) but extreme low-level shear.  Hodographs become very
   large by early-mid afternoon with flow increasing from 70-90kt in
   the 850-500mb layer over the northern half of the Enhanced Risk
   area.  It seems plausible some attempts at storm development will
   occur during the afternoon near the leading edge of the mid-level
   dry slot.  If the stronger updrafts become sustained, they will
   likely evolve into supercells with tornado potential.  A corridor of
   possibility for supercell tornadoes (perhaps strong) appears
   greatest from the OH/MS confluence southward into northern portions
   of MS on the trailing portion of large-scale ascent moving away from
   the area.  As storms encounter weaker buoyancy farther east and
   northeast during the evening, a transition to linear structures
   capable primarily of damaging winds may occur.

Can tell a difference in the air mass this morning versus yesterday morning, most certainly feels like a late Spring morning, hope we can get a pass on this one too!

  • Like 1
Link to comment
Share on other sites

Saturday March 9, 11:30 central time: Differential heating boundary is evident in North Mississippi, noted by 70s temps south and thicker clouds north. This is south of the synoptic WF which is in Kentucky.

The Miss boundary should lift to the Tennessee border, perhaps into West Tenn. As the Arkansas front/dry line approaches, it should create intersecting boundaries, Low level convergence is forecast to increase in MS/TN when the Arkansas front approaches. Conceptual and some numerical models have slightly higher storm relative helicity near the lifting MS/TN boundary. SPC and some CAMs have started to highlight this more southern boundary intersection. Compared to the Kentucky triple point, storms should move slower in the Mid South, esp down in Mississippi. Upper winds are strong both areas, but not quite as much South.

Storms are a mess in the Delta right now. We'll see if the line breaks up a bit into Mississippi later this afternoon. We can do without human impacts either way. Perhaps the strongest upper dynamics will outrun surface features, but still plenty of winds aloft into evening.

  • Like 1
Link to comment
Share on other sites

 Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0754 AM CDT Wed Mar 13 2019

   Valid 131300Z - 141200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PORTIONS
   OF EASTERN ARKANSAS...SOUTHWEST TENNESSEE...NORTHEAST LOUISIANA AND
   NORTHWEST MISSISSIPPI...

   ...SUMMARY...
   Severe thunderstorms associated with wind damage and an isolated
   tornado threat are expected to develop across parts of the lower to
   mid Mississippi Valley this afternoon and evening.  Isolated severe
   storms are also possible over portions of northern Kansas and
   southern Nebraska.

   ...Synopsis...
   Upper-level low pressure over southeast Colorado will deepen early
   Wednesday while lifting northeast towards southeast Nebraska late
   Wednesday night.  Intense surface low pressure will remain
   vertically aligned with the upper system, resulting in very strong
   low/mid-level wind fields across the central/southern Plains east to
   the lower/mid-Mississippi Valley region.  An occluded front will arc
   northeast from the surface low across Iowa by 00Z and then extend
   south/southwest as a cold front from eastern sections of Missouri
   into western Louisiana.  

   ...East Texas/Arklatex to the mid-Mississippi Valley...
   Remnants of overnight linear MCS should continue to weaken this
   morning as instability diminishes with eastward extent, however an
   isolated severe gust will remain possible as stronger convective
   elements developing ahead of the gust front transport higher
   momentum air to the surface in the presence of a very strong (60 kt)
   low-level jet. 

   Despite generally weak mid-level lapse rates, a narrow corridor of
   lower 60s surface dew points will contribute to surface-based
   instability of 500 to locally 1000 J/kg by late afternoon/evening
   just ahead of the cold front from the vicinity of southeast Missouri
   southward. Strong wind fields will result in deep-layer shear on the
   order of 60 kts, with curved low-level hodographs supportive of
   supercells and bowing segments.  One limiting factor remains the
   lack of greater instability, and with large-scale lift shifting
   north of the area with time, there remains uncertainty regarding
   storm coverage. High-resolution guidance suggests that
   redevelopment/re-intensification of thunderstorms with the cold
   front remains possible, along with more discrete thunderstorm
   development within the favorable shear-instability region preceding
   the front.  Damaging winds will be primary threat with these storms,
   and some tornado potential will exist with the more discrete storms
   and QLCS circulations.  No major changes have been made to the risk
   categories/probabilities with this outlook. 
Link to comment
Share on other sites

 Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0754 AM CDT Wed Mar 13 2019

   Valid 131300Z - 141200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PORTIONS
   OF EASTERN ARKANSAS...SOUTHWEST TENNESSEE...NORTHEAST LOUISIANA AND
   NORTHWEST MISSISSIPPI...

   ...SUMMARY...
   Severe thunderstorms associated with wind damage and an isolated
   tornado threat are expected to develop across parts of the lower to
   mid Mississippi Valley this afternoon and evening.  Isolated severe
   storms are also possible over portions of northern Kansas and
   southern Nebraska.

   ...Synopsis...
   Upper-level low pressure over southeast Colorado will deepen early
   Wednesday while lifting northeast towards southeast Nebraska late
   Wednesday night.  Intense surface low pressure will remain
   vertically aligned with the upper system, resulting in very strong
   low/mid-level wind fields across the central/southern Plains east to
   the lower/mid-Mississippi Valley region.  An occluded front will arc
   northeast from the surface low across Iowa by 00Z and then extend
   south/southwest as a cold front from eastern sections of Missouri
   into western Louisiana.  

   ...East Texas/Arklatex to the mid-Mississippi Valley...
   Remnants of overnight linear MCS should continue to weaken this
   morning as instability diminishes with eastward extent, however an
   isolated severe gust will remain possible as stronger convective
   elements developing ahead of the gust front transport higher
   momentum air to the surface in the presence of a very strong (60 kt)
   low-level jet. 

   Despite generally weak mid-level lapse rates, a narrow corridor of
   lower 60s surface dew points will contribute to surface-based
   instability of 500 to locally 1000 J/kg by late afternoon/evening
   just ahead of the cold front from the vicinity of southeast Missouri
   southward. Strong wind fields will result in deep-layer shear on the
   order of 60 kts, with curved low-level hodographs supportive of
   supercells and bowing segments.  One limiting factor remains the
   lack of greater instability, and with large-scale lift shifting
   north of the area with time, there remains uncertainty regarding
   storm coverage. High-resolution guidance suggests that
   redevelopment/re-intensification of thunderstorms with the cold
   front remains possible, along with more discrete thunderstorm
   development within the favorable shear-instability region preceding
   the front.  Damaging winds will be primary threat with these storms,
   and some tornado potential will exist with the more discrete storms
   and QLCS circulations.  No major changes have been made to the risk
   categories/probabilities with this outlook. 

 

image.png.a185a202c6ef97a89dc962b46cc00b75.png

Link to comment
Share on other sites

Guest
This topic is now closed to further replies.
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...