Tn Valley Severe Weather Nov 5-6

[CheeselandSkies]

Nah, I think they didn't use the hatched area because their confidence in a high-end tornado event has decreased.

If the EURO from late last week were to have verified, we should have been looking at at least a 15 hatch MDT if not HIGH risk by now. My how the "King" has been dethroned. Used to be it was the GFS you could always throw out for over-pumping setups in the medium range.

[Araqiel]

That figures, 2018 gonna 2018 after all. 06Z HRRR still looks better than the NAM I'd say but probably not enough to get me up at 3AM to see whats going on.

[jaxjagman]

ay 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0700 AM CST Mon Nov 05 2018

   Valid 051300Z - 061200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
   OF LA/AR/MS/TN/AL...

   ...SUMMARY...
   Severe storms capable of damaging winds and tornadoes are likely
   this evening and overnight across the ArkLaMiss region and Tennessee
   Valley.

   ...Mid-South/ArkLaMiss/Tennessee Valley...
   On the heels of a shortwave trough moving northeastward over the
   Great Lakes, a strengthening polar jet and appreciably amplifying
   shortwave trough will move east/northeast over the Ozarks and a
   broad portion of the Midwest especially late this afternoon through
   tonight.

   Although relatively dry/cool continental air persists inland early
   today (regional 12Z observed soundings), a maritime air mass along
   the TX/LA/MS/AL coasts will quickly develop north-northeastward
   today within an evolving warm sector ahead of a
   southeastward-moving/sharpening cold front. This front will reach
   the Middle Mississippi River Valley and ArkLaTex region by early
   evening. The somewhat modest nature of boundary layer moistening
   with northward extent, coincident with the strongest dynamical
   forcing for ascent later today, will likely preclude a
   higher-caliber severe episode, although an appreciable severe risk
   will nonetheless exist including the possibility of corridors of
   damaging winds along with some tornadoes, a few of which could be
   strong (EF2+).

   Considerable mass response will occur tonight as the upper trough
   centered over IA/MO/IL takes on an increasingly negative tilt.
   Significantly strengthening deep-layer southwesterly winds,
   highlighted by 55-75 kt winds at 850 mb and 70-100 kt winds at 500
   mb, will largely overlie areas of at least modest boundary-layer
   moisture/destabilization this evening into the overnight.

   Initial thunderstorm development over the Ozarks should largely be
   elevated this afternoon with a relatively limited severe risk (some
   hail possible). However, the potential for surface-rooted storms is
   likely to increase toward and after 00Z/6pm CST initially in areas
   near/just of west of the MS River including eastern AR, with more
   isolated storm development possible southwestward across the
   ArkLaTex vicinity. MLCAPE to upwards of 500-1000 J/kg (highest
   across the ArkLaTex) will be more than adequate for surface-based
   supercells within a highly sheared environment. While some hail may
   initially occur with supercell development early this evening,
   damaging winds and the potential for tornadoes will be the most
   likely hazards much of the evening into the overnight. Continued
   boundary-layer moistening after sunset, along with an overall
   increase in forcing for ascent and deep-layer/low-level shear will
   support a steady upswing in storm coverage/intensity this evening
   particularly across western/central KY, western/middle TN and
   northern MS. A transitional mixed convective mode is likely to be
   prevalent during the mid-evening hours, which may be the peak risk
   for tornadoes, a few of which could strong given adequate moisture
   and robust low-level SRH.

   Given the previously described dynamical scenario, the regional
   severe risk will likely continue well into the overnight/pre-dawn
   hours of Tuesday. As the squall line accelerates east-northeastward
   and firms in integrity late tonight (55+ kt storm motions are
   plausible), damaging winds along with at least some QLCS-related
   tornado risk may occur as far northeast as eastern portions of KY
   and TN on the windward side of the Appalachians, even with minimal
   surface-rooted buoyancy.

[Araqiel]

And the 10% hatched returns. =) Quite a shift in the focus of the earlier stuff too.

 

 

 

[Araqiel]

Whole lot of cloud around today.

[nrgjeff]

That hatched is back! Maybe within a QLCS but it is a tough forecast. Also, welcome Araqiel! Here is my take.

Event is looking less like a super cell laden tornado outbreak. QLCS tornadoes are certainly on the table.

As I type elevated convection is in progress over Arkansas. Late this afternoon it should become rooted and/or new stronger storms will develop in the Mid South and Delta including around Memphis. Those may be messy, but the only chance of a daytime chase.

Rain should reach Nashville with late afternoon daylight, but I doubt those leading thundershowers will be significant into BNA.

Appears the line actually strengthens into the evening hours after dark from Middle Tenn back into Mississippi; then, moving into North Alabama. Should be more straight line wind. May be a few QLCS tornadoes. Looks like JIT (just-in-time) moisture and perhaps not juxtaposed with the best dynamics; so, maybe Dixie can avoid a night time mauler.

Toward 00Z the short-wave trough punches across with vigor; but, then heights almost go neutral overnight (vs falling). Explains some warmer mid-level forecasts. Dixie at night can overcome all that with a forced line. Just does not look like a big tornado outbreak - thankfully.

CAMs offer 3 scenarios and I'd pick the middle ground. HRRR is quite robust overnight; one can almost see predicted QLCS spin-ups. LLJ will be going strong. NAM shows a skinny squall line that appears forced, and probably low-top. ARW (run or WRF like NAM) shows in-between. Strong line looks like it has straight line punch, maybe 1-2 spin-ups. 

No plans to chase. Sloppy storm mode and JIT moisture make an easy stay-home decision. Lack of daylight weighs too. Everyone be safe overnight.

[AMZ8990]

Winds are starting to gust pretty good In west tn now.  Definitely starting to feel this front pushing in.

[Windspeed]

Nah, I think they didn't use the hatched area because their confidence in a high-end tornado event has decreased. If the EURO from late last week were to have verified, we should have been looking at at least a 15 hatch MDT if not HIGH risk by now. My how the "King" has been dethroned. Used to be it was the GFS you could always throw out for over-pumping setups in the medium range.

Yeah, the 00z ECMWF and the 12z even more so backed down on CAPE surface values and timing of surface-level backing winds. There is still strong low-level shear and 0-3km helicity but the mode looks to go quasi-linear early. The threat of discrete super cells from Northern MS to Nashville looks reduced versus runs up to a mere 24 hrs ago. I don't know if the ECMWF has necessarily been "dethroned" but it definitely had been more tornadic versus the GFS through yesterday. That doesn't mean we still won't see some intense action in the hatched region tonight, but it seems strong frontline winds and brief spinups were going to be the order of the night for the majority of the TN Valley regardless.

 

Edit: I originally said the threat "looks nothing like" with regards to N MS to Nashville. That's a bit of hyperbole. I should have said the threat is reduced. There is still a threat for tornadoes, the modeling and forecasted storm mode just looks more linear and messy versus what the global ECMWF had been showing into early weekend runs.

[Windspeed]

Cloud coverage has broken over portions of MS and much of Tennessee. May aid in further destabilization. NE Mississippi and all the northern half of Alabama still looks thick as molasses though.

[Windspeed]

Latest HRRR around 11 PM EST / 10 PM CST.

[Windspeed]

Possible first tornado in LA.

[yoda]

2 minutes ago, Windspeed said:

Possible first tornado in LA.

There was a confirmed TOG near Natchitoches earlier

[yoda]

Severe Weather Statement
National Weather Service Shreveport LA
428 PM CST MON NOV 5 2018

LAC127-052245-
/O.CON.KSHV.TO.W.0101.000000T0000Z-181105T2245Z/
Winn LA-
428 PM CST MON NOV 5 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 445 PM CST FOR
SOUTHWESTERN WINN PARISH...

At 427 PM CST, a confirmed tornado was located 7 miles north of
Montgomery, or 9 miles east of Natchitoches, moving northeast at 30
mph.

HAZARD...Damaging tornado.

SOURCE...Radar confirmed tornado.

IMPACT...Flying debris will be dangerous to those caught without
         shelter. Mobile homes will be damaged or destroyed. Damage
         to roofs, windows, and vehicles will occur.  Tree damage is
         likely.

Locations impacted include...
St. Maurice.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a tornado is on the ground. TAKE COVER NOW! Move to a
basement 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.

&&

LAT...LON 3173 9297 3177 9297 3180 9295 3183 9295
      3182 9294 3185 9292 3185 9291 3186 9290
      3187 9290 3190 9286 3174 9272 3171 9290
      3171 9298
TIME...MOT...LOC 2227Z 238DEG 24KT 3176 9294

TORNADO...OBSERVED
HAIL...<.75IN

[Araqiel]

Looks nasty.

[SmokeEater]

Not a good sign these are discrete and producing so fast.

Sent from my SM-G950U using Tapatalk

[Windspeed]

Supercell near Ringgold is impressive.

[nwohweather]

There has to be a monster north of Natchitoches. Thing has a legit donuthole on the reflectivity, usually only seen with strong tornadoes

[SmokeEater]

There has to be a monster north of Natchitoches. Thing has a legit donuthole on the reflectivity, usually only seen with strong tornadoes

Was 130 kts G2G last scan too.

Sent from my SM-G950U using Tapatalk

[Windspeed]

TOR still going. This cell may be quite the longtracker and not even in the best dynamics yet. Most of this early coverage is within the slight risk.

Edit: More like may not be the longtracker. lol, not long after I made this post, the Natchitoches cell fell apart.

[jaxjagman]

Tornado Watch

TORNADO WATCH OUTLINE UPDATE FOR WT 423
NWS STORM PREDICTION CENTER NORMAN OK
700 PM CST MON NOV 5 2018

TORNADO WATCH 423 IS IN EFFECT UNTIL 300 AM CST FOR THE
 FOLLOWING LOCATIONS

TNC003-005-015-017-021-023-031-033-037-039-043-047-053-055-069-
071-075-077-079-081-083-085-099-101-109-111-113-117-119-125-135-
147-149-157-159-161-165-167-169-181-183-187-189-060900-
/O.NEW.KWNS.TO.A.0423.181106T0100Z-181106T0900Z/

TN
.    TENNESSEE COUNTIES INCLUDED ARE

BEDFORD              BENTON              CANNON
CARROLL              CHEATHAM            CHESTER
COFFEE               CROCKETT            DAVIDSON
DECATUR              DICKSON             FAYETTE
GIBSON               GILES               HARDEMAN
HARDIN               HAYWOOD             HENDERSON
HENRY                HICKMAN             HOUSTON
HUMPHREYS            LAWRENCE            LEWIS
MACON                MADISON             MARSHALL
MAURY                MCNAIRY             MONTGOMERY
PERRY                ROBERTSON           RUTHERFORD
SHELBY               SMITH               STEWART
SUMNER               TIPTON              TROUSDALE
WAYNE                WEAKLEY             WILLIAMSON
WILSON

[jaxjagman]

 Tornado Watch Number 423
   NWS Storm Prediction Center Norman OK
   700 PM CST Mon Nov 5 2018

   The NWS Storm Prediction Center has issued a

   * Tornado Watch for portions of 
     Southeastern Arkansas
     Northern Mississippi
     Western and middle Tennessee

   * Effective this Monday night and Tuesday morning from 700 PM
     until 300 AM CST.

   * Primary threats include...
     A few tornadoes likely with a couple intense tornadoes possible
     Scattered damaging wind gusts to 70 mph possible

   SUMMARY...As the air mass moistens and destabilizes from southwest
   to northeast, the potential for tornadoes and damaging gusts will
   increase, with a band of storms moving rapidly across the Mid-South
   tonight.

   The tornado watch area is approximately along and 80 statute miles
   east and west of a line from 55 miles east southeast of Pine Bluff
   AR to 45 miles west northwest of Nashville TN. For a complete
   depiction of the watch see the associated watch outline update
   (WOUS64 KWNS WOU3).

   PRECAUTIONARY/PREPAREDNESS ACTIONS...

   REMEMBER...A Tornado Watch means conditions are favorable for
   tornadoes and severe thunderstorms in and close to the watch
   area. Persons in these areas should be on the lookout for
   threatening weather conditions and listen for later statements
   and possible warnings.

[Windspeed]

First tornado warning in the strong QLCS line just east of Clarksdale, MS.

[jaxjagman]

[jaxjagman]

Picking up in Ms

[jaxjagman]

URGENT - IMMEDIATE BROADCAST REQUESTED
   Tornado Watch Number 424
   NWS Storm Prediction Center Norman OK
   1030 PM CST Mon Nov 5 2018

   The NWS Storm Prediction Center has issued a

   * Tornado Watch for portions of 
     Northern Alabama
     South-central Kentucky
     Middle to eastern Tennessee

   * Effective this Monday night and Tuesday morning from 1030 PM
     until 600 AM CST.

   * Primary threats include...
     A few tornadoes possible
     Scattered damaging wind gusts to 70 mph possible

   SUMMARY...Isolated, sporadic circulations developing within a band
   of storms may pose a tornado/wind risk over the watch area through
   the next several hours.

   The tornado watch area is approximately along and 55 statute miles
   east and west of a line from 40 miles east southeast of Columbus MS
   to 90 miles north of Crossville TN. For a complete depiction of the
   watch see the associated watch outline update (WOUS64 KWNS WOU4).

[southmdwatcher]

Northside of Tupelo MS, clear TDS for 5+ scans

[Wmsptwx]

Tupelo under TOR warning.

[Wmsptwx]

Confirmed TOR near Tupelo.

[Chinook]

possible tornado near the NW corner of Alabama

[Chinook]

this is a radar confirmed tornado about 33 mi SW of Nashville

Quote

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1145 PM CST FOR NORTHERN
MAURY...WESTERN WILLIAMSON AND SOUTHEASTERN HICKMAN COUNTIES...
        
At 1118 PM CST, a confirmed tornado was located 14 miles northwest of
Columbia, or near Williamsport, moving northeast at 50 mph.

HAZARD...Damaging tornado.