Short-Term Severe/Flooding Discussion

[SmokeEater]

From BMX's AFD for Monday into Tuesday. Very, very bullish. Make a thread in here, or SE?


The shortwave on Sunday night will serve as a primer wave for the next system developing to our west on Monday. A wide area of rich moisture will be lurking near the Gulf Coast, poised to move inland Monday afternoon and evening as wind fields respond to a shortwave entering the Southern Plains. Models are coming into agreement on a potentially dangerous setup Monday night into Tuesday morning across a large area which includes Alabama. The GFS and ECMWF are in good agreement with the evolution of the synoptic pattern, showing a low-amplitude shortwave taking on a negative tilt Monday night to our northwest. This pattern has the look of a classic severe weather outbreak and would support a rapidly deepening surface low tracking toward the Great Lakes with significant pressure falls extending southward into Alabama. With dewpoints rising into the upper 60s to perhaps 70F, instability appears more than sufficient for deep convection within a very highly sheared environment. Taken at face value, the ECMWF shows semi-discrete supercells capable of producing long-track, significant tornadoes across the northern half of our forecast area on Tuesday morning. The HWO will be updated to include a moderate confidence threat for tornadoes and damaging winds across the entire forecast area. With this threat still around 96 hours out and models subject to change, we will refrain from going all in on the potential for a tornado outbreak.

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[hlcater]

55 minutes ago, SmokeEater said:

From BMX's AFD for Monday into Tuesday. Very, very bullish. Make a thread in here, or SE?


The shortwave on Sunday night will serve as a primer wave for the next system developing to our west on Monday. A wide area of rich moisture will be lurking near the Gulf Coast, poised to move inland Monday afternoon and evening as wind fields respond to a shortwave entering the Southern Plains. Models are coming into agreement on a potentially dangerous setup Monday night into Tuesday morning across a large area which includes Alabama. The GFS and ECMWF are in good agreement with the evolution of the synoptic pattern, showing a low-amplitude shortwave taking on a negative tilt Monday night to our northwest. This pattern has the look of a classic severe weather outbreak and would support a rapidly deepening surface low tracking toward the Great Lakes with significant pressure falls extending southward into Alabama. With dewpoints rising into the upper 60s to perhaps 70F, instability appears more than sufficient for deep convection within a very highly sheared environment. Taken at face value, the ECMWF shows semi-discrete supercells capable of producing long-track, significant tornadoes across the northern half of our forecast area on Tuesday morning. The HWO will be updated to include a moderate confidence threat for tornadoes and damaging winds across the entire forecast area. With this threat still around 96 hours out and models subject to change, we will refrain from going all in on the potential for a tornado outbreak.

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The people in the SE don’t care unless it’s snow and in Georgia/Carolina. Maybe the best spot is Weather Forecasting/Discussion? Since it crosses multiple subs 

[CheeselandSkies]

I first brought it up in TN Valley since that seems to be where most of the Dixie Alley posters live. Also some discussion going in Lakes/OH Valley since it looks like some threat could extend into IN/OH.

[cheese007]

3 hours ago, SmokeEater said:

From BMX's AFD for Monday into Tuesday. Very, very bullish. Make a thread in here, or SE?


 

I made a thread about the event. It's a couple posts below this topic

[MoistWx]

11 hours ago, Chinook said:

Fairly good verification on this day-1 outlook

6 more tornadoes surveyed by LCH today too per the PNS. I believe LIX and SHV might have confirmed a few more as well. 

Public Information Statement
National Weather Service Lake Charles LA
830 PM CDT Fri Nov 2 2018


...NWS Damage Survey for 10/31/18 and 11/1/18 Tornado Event...

.West Bundick Lake Tornado...

Rating:                   EF-1
Estimated Peak Wind:      107 MPH
Path length /Statute/:    1.5 Miles
Path width /Maximum/:     280 Yards
Fatalities:               0
Injuries:                 0

Start date:               OCT 31 2018
Start time:               940 PM CDT
Start location:           10 SE DeRidder/Beauregard/LA
Start Lat/Lon:            30.7193 / -93.2022

End date:                 OCT 31 2018
End time:                 943 PM CDT
End location:             9 SSE DeRidder/Beauregard/LA
End_lat/lon:              30.7389 / -93.1926

Survey Summary: A tornado snapped several trees along Chester Davis Road,
northeast to Lumas Road.

.Southwest Sugartown Tornado...

Rating:                   EF-1
Estimated Peak Wind:      104 MPH
Path length /Statute/:    2.6 Miles
Path width /Maximum/:     300 Yards
Fatalities:               0
Injuries:                 0

Start date:               OCT 31 2018
Start time:               1143 PM CDT
Start location:           6 SW Sugartown/Beauregard/LA
Start Lat/Lon:            30.8151 / -93.1132

End date:                 OCT 31 2018
End time:                 1146 PM CDT
End location:             4 SSW Sugartown/Beauregard/LA
End_lat/lon:              30.8140 / -93.0702

Survey Summary: A tornado started east of Rutherford Road, and moved
across Vaughn Road, ending near Smyrna Road. Several trees were snapped.

.Oakdale/Turkey Creek Tornado...

Rating:                   EF-2
Estimated Peak Wind:      118 MPH
Path length /Statute/:    13.3 Miles
Path width /Maximum/:     900 Yards
Fatalities:               0
Injuries:                 0

Start date:               NOV 01 2018
Start time:               1217 AM CDT
Start location:           1 S Oakdale/Allen/LA
Start Lat/Lon:            30.7914 / -92.6606

End date:                 NOV 01 2018
End time:                 1233 AM CDT
End location:             4 NW Turkey Creek/Evangeline/LA
End_lat/lon:              30.9027 / -92.4782

Survey Summary: A strong tornado started south of Highway 10, and as it crossed
the highway it snapped several power poles. The tornado then moved down Cypress
Creek Road, where it snapped numerous trees and power lines. In Evangeline Parish,
it moved from Cypress Creek Road to Cypress Road and Red Lick Road, before
dissipating south of the Rapides Parish line. Many trees and power lines were down.

.Hessmer Tornado...

Rating:                   EF-2
Estimated Peak Wind:      122 MPH
Path length /Statute/:    13.6 Miles
Path width /Maximum/:     800 Yards
Fatalities:               0
Injuries:                 0

Start date:               NOV 01 2018
Start time:               1250 AM CDT
Start location:           2 SE Cheneyville/Rapides/LA
Start Lat/Lon:            30.9874 / -92.2640

End date:                 NOV 01 2018
End time:                 106 AM CDT
End location:             4 NE Hessmer/Avoyelles/LA
End_lat/lon:              31.0786 / -92.0629

Survey Summary: The tornado started near US Highway 71 near Cheneyville, snapping
several power poles. As it moved northeast, it blew down many trees and power lines.
The most significant damage was to a new home on Bordelon Road, built of steel beams
and metal sheets. A large roll up door was blown in, and picked up an outside AC unit,
tossing it into the garage. The steel beams were bent in three-fourths of the building.
Half of the metal roof was blown off, and what remained shifted several inches. One
exterior wall shifted several inches. Several other homes on Bordelon Street had part
of their roofs removed. Many trees were snapped and power lines were downed. Tree
damage was noted on Highway 115 south of Hessmer, and the tornado dissipated before
it reached Highway 1 in Mansura.

.Russells Landing Tornado...

Rating:                   EF-1
Estimated Peak Wind:      107 MPH
Path length /Statute/:    9.9 Miles
Path width /Maximum/:     350 Yards
Fatalities:               0
Injuries:                 0

Start date:               NOV 01 2018
Start time:               113 AM CDT
Start location:           4 ENE Marksville/Avoyelles/LA
Start Lat/Lon:            31.1468 / -91.9918

End date:                 NOV 01 2018
End time:                 127 AM CDT
End location:             14 NE Marksville/Avoyelles/LA
End_lat/lon:              31.2513 / -91.8780

Survey Summary: A tornado started in remote areas east of Marksville, and moved across
Lake Ophelia Wildlife Refuge, where numerous trees were blown down or snapped. At
Russells Landing, many trees were blown down or snapped. One landed on an RV. The
tornado dissipated northeast of that region in the wildlife refuge.

EF Scale:  The Enhanced Fujita Scale Classifies Tornadoes into
the following categories.

EF0...Weak......65 to 85 MPH
EF1...Weak......86 to 110 MPH
EF2...Strong....111 to 135 MPH
EF3...Strong....136 to 165 MPH
EF4...Violent...166 To 200 MPH
EF5...Violent...>200 MPH

Note:
The information in this statement is preliminary and subject to
change pending final review of the events and publication in NWS
Storm Data.

And the other:

"Public Information Statement
National Weather Service Lake Charles LA
241 PM CDT Fri Nov 2 2018

...NWS Damage Survey for 11/01/18 Tornado Event...

.Iowa Tornado...

Rating:                   EF-1
Estimated Peak Wind:      90 MPH
Path length /Statute/:    0.97 Miles
Path width /Maximum/:     75 Yards
Fatalities:               0
Injuries:                 0

Start date:               Nov 01 2018
Start time:               1230 AM CDT
Start location:           5 SSW Iowa/Calcasieu/LA
Start lat/lon:            30.1758/-93.0467

End date:                 Nov 01 2018
End time:                 1232 AM CDT
End location:             5 SSW Iowa/Calcasieu/LA
End lat/lon:              30.1660/-93.0349

Survey Summary: A weak tornado formed north of Nick Martone Road
and moved to the southeast. The tornado crossed Nick Martone Road
where it damaged two outbuildings. The tornado then dissipated in
a field south of Nick Martone Road.

EF Scale:  The Enhanced Fujita Scale Classifies Tornadoes into
the following categories.

EF0...Weak......65 to 85 MPH
EF1...Weak......86 to 110 MPH
EF2...Strong....111 to 135 MPH
EF3...Strong....136 to 165 MPH
EF4...Violent...166 To 200 MPH
EF5...Violent...>200 MPH

Note:
The information in this statement is preliminary and subject to
change pending final review of the event and publication in NWS
Storm Data."

[Chinook]

45 tornadoes have been listed on Wikipedia as confirmed from Oct. 31 to Nov. 1. Nearly all of these are listed as tornadoes of Oct. 31 on SPC's page.  About 31 of them were after midnight local time but before 12z, which is the cutoff for the SPC's list. So there you go, not exactly springtime storm chasing, but this does significantly add to the number of tornadoes in 2018. Note: SPC has 62 (unfiltered) on Oct. 31 and 2 (unfiltered) on Nov. 1.

[CheeselandSkies]

What was initially looking like another TN Valley/Dixie event has trended more to west of the Arklatex, at least for Friday. SPC introduced a small hatched area on the updated Day 2 outlook for the possibility of very large hail in the area including the DFW metro. Isolated tornadoes are also possible anywhere from there east to the lower MS valley.

[cheese007]

As if DFW needs any more hail after the past couple years

[andyhb]

Will likely be driving southbound on 35 tomorrow towards Austin, wonder if I might take a detour or two along the way...

I have strong doubts that initiation will hold off until 00z given the synoptic setup. That is a pretty potent, negatively tilted wave ejecting right overtop of the warm sector, which should provide plenty of forcing for ascent and the cap is not overly strong. Have seen some funky looking wind fields in a few forecast soundings, but most of them don't seem to be too crippling in terms of storm mode problems. Speaking of storm mode given the degree of forcing, have to wonder if it is a relatively quick transition to linear, some more low level backing would certainly help.

[Jim Martin]

Am hearing some chatter that the setup for tomorrow is looking more and more interesting across the Ark La Tex.

[cheese007]

Enhanced risk dropped for most of DFW, no more sig hail hatched area either. However a 10% hqtched for sig tors now exists in the ArkLaTex

[CheeselandSkies]

Wow, 12Z NAM STP values jump up to over 3 by 03Z tonight across parts of southeast Oklahoma and northeast Texas. Between terrain/trees and darkness, this is a bad combination for residents and chasers.

Can someone explain how on this forecast sounding, there is so much SRH despite the fact that the winds only gradually back with height, and in fact are depicted as pretty much unidirectional from 850 almost up to 500 mb?

Even so, hodograph looks decently curved at the low levels although a little funky higher up. Although, I have never fully wrapped my head around interpreting hodographs so I prefer to use the wind barbs on the right of the sounding to visualize the shear profile with height.

Lapse rates, while not particularly steep, don't look like an instability killer as in some other setups this year.

[CheeselandSkies]

HRRR and 3KM NAM break out a lot of discrete convection over OK/TX/AR/LA tonight, but forecast updraft helicity isn't all that impressive except in isolated pockets.

[janetjanet998]

thread for the event today into tommorrow

..

[jojo762]

Looks like things have came together for a potentially interesting day in the TX PH... 5% TOR from SPC. 

[Indystorm]

Confirmed tornado sw of Cactus TX in the panhandle with warning till 6 central time.  And another skinny funnel near Vega west of Amarillo.

[AfewUniversesBelowNormal]

Yeah, I deleted my thread too early. Several tornado warning cells. 

[Indystorm]

Tennis ball size hail and 70 mph winds aiming for Amarillo.   Now under tor warning due to radar indicated rotation.

 

[Wmsptwx]

Amarillo storm looks mean def some rotation.

[Indystorm]

Funnel cloud reported in west Amarillo

 

[Paulie21]

An interesting little setup in central OK later today. 

Looks like the HRRR wants to initiate near the triple point with 50+ kts of bulk shear essentially orthogonal to a boundary into 1500+ j/kg surface based CAPE. This should promote discrete storms to go off near OKC. Comparing to current obs it's doing decently well with dews and they're progged to be reaching near 60° by 22 - 23Z  in some areas. With a 50kt mid level jet streak over Oklahoma and (at least) southerly flow at surface, it will create enough shear for rotating updrafts, however, due to meager low level flow in general, it may suppress the overall tornado potential. Lapse rates in general look impressive as you advect in steep lapse rates and continue with daytime heating now that cloud debris has moved off to the east. 0-3km CAPE will be impressive later today and wouldn't be surprised to see a brief couple tors in C OK. Or as Reed Timmer tweeted earlier today..."Danger Noodles".


RAP progged 0-3 km MLCAPE and sfc vorticity for 23Z. Has a decent handle currently on what's going on.

 

[CheeselandSkies]

Reminds me a bit of the late March 2015 setup that produced the EF2 in Moore, when conditions were expected to be generally unfavorable for tornado formation (just a blue box in effect).

[Upper Level LOL]

Well a severe watch is up.  https://www.spc.noaa.gov/products/watch/ww0031.html

[David Reimer]

It's always nice when I can 'chase' severe weather from my porch. Had three separate rounds of hail today. First was this morning, the second was this evening, and the third (and largest) was about five minutes after the second. Ended up getting quarters and a half-dollar or two with the third round. 

[cheese007]

D1 slight out for hail and wind

[cheese007]

D1 enhanced now for ArkLaTex along with Southern MO/IL

[cheese007]

Severe watch up spanning from north Texas to southern Illinois. Already several warned storms, one of them with a tor warning in Missouri

[Indystorm]

BULLETIN - EAS ACTIVATION REQUESTED  
SEVERE THUNDERSTORM WARNING  
NATIONAL WEATHER SERVICE FORT WORTH TX  
637 PM CDT SUN MAR 24 2019  
  
THE NATIONAL WEATHER SERVICE IN FORT WORTH HAS ISSUED A  
  
* SEVERE THUNDERSTORM WARNING FOR...  
  SOUTHERN COLLIN COUNTY IN NORTH CENTRAL TEXAS...  
  
* UNTIL 730 PM CDT.  
  
* AT 636 PM CDT, A SEVERE THUNDERSTORM WAS LOCATED OVER ALLEN, MOVING  
  SOUTHEAST AT 20 MPH.  
  
  THIS IS A VERY DANGEROUS STORM.  
  
  HAZARD...BASEBALL SIZE HAIL AND 65 MPH WIND GUSTS.  
  
  SOURCE...RADAR INDICATED.  
  
  IMPACT...PEOPLE AND ANIMALS OUTDOORS WILL BE SEVERELY INJURED.   
           EXPECT SHATTERED WINDOWS, EXTENSIVE DAMAGE TO ROOFS,   
           SIDING, AND VEHICLES.  
  
* THIS SEVERE THUNDERSTORM WILL BE NEAR,   
  ALLEN AROUND 645 PM CDT.  
  FAIRVIEW AND PARKER AROUND 650 PM CDT.  
  LUCAS AND LOWRY CROSSING AROUND 655 PM CDT.  
  RICHARDSON, SACHSE AND MURPHY AROUND 700 PM CDT.  
  WYLIE AROUND 705 PM CDT.  

[cheese007]

Whole line lit up with warnings. Center of Collin county getting baseball sized hail. Meanwhile 15 miles to the south it's been a very pleasant evening

[cheese007]

Rotation with the Collin Storm as it has taken a turn to the south into Dallas County. Spotters have an eye on it