4/1-4/2 severe threat (southern portion of subforum)

[largetornado]

Multi day severe threat expected for southern portion of subforum 4/1-4/2. As of now, the SPC a 5% risk of tornadoes along I64 for Monday and a 30% general risk for Tuesday. Most concerning to me is the nocturnal threat monday into Tuesday. Biggest question that remains is how veered winds are. 

[MattPetrulli]

I like 4/2's potential a lot. Potential is there for a substantial event.

 

[largetornado]

18z suite continues trend of 12z. Large area of substantial STP.

 

[buckeye]

We’ve had 2 significant tornado events in central Ohio already this season and yesterday there were tornado warned storms just east of us.  I personally know people who suffered structural damage to their homes in each event.   It’s crazy when you consider it isn’t even April.  
Also, ironically this April 3/4 is the 50 year anniversary of Xenia.

[andyhb]

Yeah there's definitely something eerie about a potentially significant severe threat one day before the 50th anniversary of, hands down, the worst tornado outbreak to ever affect the Ohio Valley.

[HighTechEE]

This is scary as not only its the 50th year since Xenia, but this coming Memorial Weekend will be the 5th aniversay of the terrible tornadoes that tore up the Dayton area again! This year with 2 waves of serious tornado out breaks before April in Ohio is NUTS!

[largetornado]

0z HRRR keeps the biggest threats south of the Ohio river. 0z nam brings the threat basically to Michigan. Either way, the hires models are trending towards a significant severe threat on Tuesday. Sounding is north central ohio

NWS ILN current thinking:

Quote

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
CAM guidance continues to show an MCS carving through the Ohio
Valley early Tuesday morning as a stalled frontal boundary remains
laid out through our CWA. The heaviest rain from this complex
appears to be south of I-70, focused more towards the Ohio River. At
this juncture, PWATs will be 200-300% of normal as most of the CWA
will be above 1", with locations near the OH River falling in the
1.25" - 1.50"  PWAT range. Thus, there is a concern of flash
flooding from this complex of storms given the repeated rounds of
rainfall prior to this particular MCS, leading to wet antecedent
soil conditions.

The evolution of storms becomes a bit more murky the rest of the day
on Tuesday because of this MCS. Synoptically, the low pressure
center does become more progressive in its northeastward
propagation, eventually swinging a cold front through. Majority of
models do show the center of this low tracking through a portion of
our CWA, near or just north of the Tristate area. The track of this
low is of concern, primarily for altering the orientation of
surface winds and potentially backing these near-surface winds. This
is resulting in better hodograph curvature in the lowest few
kilometers, increasing the potential for rotating storms. Some
models are much more aggressive in how the environment rebounds,
which would combine favorable thermodynamics along with strong deep-
layer shear, heightening severe weather concerns with all hazards at
play. Will have to monitor how CAMs handle the evolution of the
morning MCS and how the atmosphere responds through the rest of the
day.

 

[nvck]

SPC goes with a d2 enhanced, which makes sense, although I almost expected a 10# risk rather than just a 10. most surprising thing for me is the placement, a lot of models have been showing this a lot further north than the area that the SPC has the enhanced 

[Floydbuster]

My twitter feed is filled with Southern OH chasers crying that the SPC didn't move it further north. I think the rain ahead will limit instability, especially further north. Perhaps there's a slight chance some stronger storms make it as far north as Columbus and Zanesville, but I think the line will arch east-southeast and that's why the SPC is more focused on Kentucky.

[TheWeatherPimp]

I'll be the first to admit that I woke up quite surprised to see the placement of the day 2 outlook. With the dynamics in place across much of Indiana and Western Ohio, it won't take much instability at all to cause trouble, particularly with the guidance shifting the track of the low more northwest. We'll see what their afternoon update shows, but the latest solutions are quite worrisome for much of Central and Southern Indiana and Western/Southwestern Ohio if some recovery/instability occurs tomorrow. 

[CoachLB]

1 hour ago, Floydbuster said:

My twitter feed is filled with Southern OH chasers crying that the SPC didn't move it further north. I think the rain ahead will limit instability, especially further north. Perhaps there's a slight chance some stronger storms make it as far north as Columbus and Zanesville, but I think the line will arch east-southeast and that's why the SPC is more focused on Kentucky.

Well a couple weeks ago the SPC didn't move it north and an EF2 tornado drove right by my house and took out a 25 mile stretch of homes and barns. plus all the damage further north because they thought the same thing. look to be in the danger zone again.

[Floydbuster]

16 minutes ago, CoachLB said:

Well a couple weeks ago the SPC didn't move it north and an EF2 tornado drove right by my house and took out a 25 mile stretch of homes and barns. plus all the damage further north because they thought the same thing. look to be in the danger zone again.

That sucks, man. Sorry to hear that. Hopefully any bad ones stay south of you. You'll be close to the line. Anything will probably be south of 71, but hopefully it stays further south than that and you avoid nasty stuff.

 

[nvck]

12z HRRR for E IN and W OH ... one of the most impressive runs in quite some time

[andyhb]

12z HRRR was knocking on the door of a high risk for IN/OH.

[buckeye]

1 hour ago, CoachLB said:

Well a couple weeks ago the SPC didn't move it north and an EF2 tornado drove right by my house and took out a 25 mile stretch of homes and barns. plus all the damage further north because they thought the same thing. look to be in the danger zone again.

Yea, spc dropped that ball.  I'm not even sure we were in the marginal risk area at that time....even hours before the supercells started forming.    HRRR started picking it up but was by itself.   ILN was pretty bullish early on as well.

[nvck]

Not really impacting this area, but a hail-driven MDT was added for what I believe is the first MDT of the year? Also, a large area of 10# tornado, with the 5% coming maybe a bit more east than the previous outlook

[largetornado]

While tomorrow is looking very volatile, the nocturnal threat tonight is not something to sleep on. 

[TheWeatherPimp]

The SPC Day 2 outlook is......real late. I hear via chat that a Moderate Risk is coming. 

[OHweather]

A large and moist warm sector with well-established return flow beneath a remnant EML plume, along with the exit region of a ~100kt 500mb jet streak nosing into the warm sector during the afternoon and evening, is a very concerning synoptic signal in IN/OH/possibly northern KY and adjacent areas. In all likelihood the 850mb flow will be pushing or exceeding 50 knots as well. There is some uncertainty regarding the degree of destabilization farther north, how backed the surface flow is, and the exact convective evolution per CAMs.

My gut feeling is that if AM clouds/rain get out of the way that the strong kinematics and rich warm sector could allow for rapid recovery (as we saw on March 14th), and the strengthening nature of the surface low should back the low-level flow more (along the lines of the NAM/HRRR/RRFS, as opposed to the ARW and to some extent NSSL which are a bit more paltry with the low-level backing and resultant SRH). Shear vectors oriented about 45 degrees to the cold front should lead to a period in which discrete or semi-discrete right-moving supercells are favored before growing upscale. 

This area-averaged HRRR sounding from a chunk of NW/central OH ahead of the supercells it has at 22z tells us there's very high-end potential if everything comes together correctly:

[yoda]

2 minutes ago, TheWeatherPimp said:

The SPC Day 2 outlook is......real late. I hear via chat that a Moderate Risk is coming. 

Correct, MOD up for most of OH

[OHweather]

WOW

[andyhb]

Outbreak potential with intense/long-tracked tornadoes mentioned in that outlook.

[WXMan42711]

been a long time since this verbiage was used in the IN/KY/OH neck of the woods:

 

"THE GREATEST RISK, WHICH WILL INCLUDE POTENTIAL FOR A COUPLE OF INTENSE/LONG-TRACK TORNADOES, SHOULD BEGIN ACROSS INDIANA, AND THEN SPREAD ACROSS OHIO THROUGH THE AFTERNOON AND EVENING, POTENTIALLY REACHING AS FAR EAST AS WESTERN PORTIONS OF WEST VIRGINIA AND FAR WESTERN PENNSYLVANIA INTO THE EVENING.  EASTWARD ADVANCE OF THE RISK INTO CENTRAL PENNSYLVANIA WILL LIKELY REMAIN LIMITED, BUT OTHERWISE THREAT MAY SPREAD INTO WESTERN PORTIONS OF VIRGINIA AND THE CAROLINAS LATE."

[largetornado]

An impressive run for sigtor ingredients

[CheeselandSkies]

48 minutes ago, andyhb said:

Outbreak potential with intense/long-tracked tornadoes mentioned in that outlook.

Well that was a change-up.

[crossbowftw3]

And when was the last 15 hatch across Ohio again?

[largetornado]

13 minutes ago, crossbowftw3 said:

And when was the last 15 hatch across Ohio again?

11/17/13 is only event i recall but the tor risk only extended into western ohio. 3/2/12 was mainly kentucky and SW ohio. For the entirety of ohio, nothing comes to mind. 

[Sydney Claridge]

22 minutes ago, largetornado said:

11/17/13 is only event i recall. 3/2/12 was mainly kentucky. 

The High Risk on March 2, 2012 did get into Ohio, with the 15% hatched (and MDT) encompassing the Columbus metro, but the sigtor threat didn't really materialize north of the Ohio River Valley in the state of Ohio. I'm getting flashbacks to that day looking at the model runs and SPC outlook, although SPC currently has the greatest risk for tomorrow outlined northeast of where they had the highest risk on 3/2/12.

It looks like this CIPS analog run is showing 3/2/2012 (3/3/2012 at 0z) as the top analog for tomorrow, interestingly enough.

[largetornado]

18z HRRR isnt backing down. Brings the threat more towards indy and reflectivity is showing a more discrete environment, with cells starting to grow upscale after crossing into ohio. 

[nwohweather]

WOW

Of course I’m out of town too. Would’ve posted up in Van Wert for sure