largetornado

25 minutes ago, nwohweather said:

Might just need a little more humidity for this to really get going. The atmosphere is solid at the moment, I'm shocked nothing is really taking off

There is a dry slot right out in front of these storms. Wonder how much that plays into it. Nothing to the east or south of existing storms has been able  to sustain

On 4/4/2024 at 8:46 PM, CheeselandSkies said:

I mean, it only goes 24 hours out so you wouldn't have the 10 days of hype.

I will say, the simulated reflectivity for the late evening Alabama supercells (that produced Guin, Tanner 1+2, Jasper and Redstone Arsenal) looks somewhat less impressive than I would have expected. Around 02Z-03Z when those storms would have been peaking, it just looks like strung out line segments in the northwest corner of the state, not monster supercells producing some of the most violent tornadoes of what stood as the most prolific tornado outbreak on record for 37 years.

Interestingly, the SPC had a SCTD risk for d1 convective outlook which translates to moderate todays

Found this on Twitter. WRF simulation of 4/3/74. thought it would be interesting to post this and see how a thread would go based on this model output.  https://www.goldenhorseshoewx.ca/case_studies/SuperOutbreak1974/

another model https://x.com/jacob_feuer/status/1775667383816143284?s=46

Dew points rebounding in ky nicely. Winds are pretty veered though. 

Anyone know if the radars being down affect model inputs? (From my understanding, NWS offices can still see their radars but the feed is down.)

SPC sticking with the moderate with a massive hatched tornado risk

Spc basically said ignore the nam 

Quote

It's not entirely clear if ongoing convection will allow the warm front to lift appreciably north of its current position. However, large-scale pattern is quite dynamic and favors surface low deepening over southern Lake MI during the latter half of the pattern. NAM struggles to reflect this scenario, thus weaker instability is forecast at higher latitudes. Tornadoes, damaging winds, and large hail are expected with supercells that evolve across the warm sector. Some tornadoes may be long-lived and strong

.

03z HRRR takes the pressure down to 987. Time for bed and we shall see tomorrow. 

6 minutes ago, andyhb said:

A lot of convection over OK and MO that is going to need to be worked out before we figure what tomorrow's ceiling is. I will say that this is on the "more inhibitive" side in terms of convective coverage from what I've seen in past events.

At this point, will the EML in Arkansas/Southern MO/TN be eroded by that ongoing convection or will it inhibit it? 

3 minutes ago, OHweather said:

Considerable uncertainty, largely driven by ongoing/earlier-day convection, is definitely a familiar feeling for the Ohio Valley. There certainly is higher-end tornado potential if a portion of the warm sector is relatively clear and can recover through at least the mid-afternoon, and I feel like that's more likely than not to occur somewhere in the vicinity of central/southern IN, western/southern OH, and perhaps adjacent northern KY. Where exactly that occurs and how large of an area it is are certainly in question. 

From a messaging perspective this is kind of brutal...I'd consider northern and even central (especially east-central) OH to be on the fringe. If ongoing convection and clouds clear quickly enough there's still a viable scenario where those areas recover enough to have a threat, and given the amount of shear in place that needs to be messaged. However, it's also possible that little happens on that northeastern fringe. We've already gone all-in with a tornado-driven moderate risk, so while I'm personally hoping for (and sort of leaning towards) nothing too noteworthy happening in the Cleveland metro and my immediate vicinity just south of Cleveland, a total whiff in the northern/eastern half of Ohio would be a strike against public trust in the severe wx forecasts. 

Yes from a messaging standpoint, this could be a mess. The miss earlier this month may or may not have played a part with the 15%. I would assume the afternoon outlook was late because there was a significant amount of discussion around the 15%. Realistically I think it’s a good forecast if the area circled in red does not materialize. If it does, the threat for Ohio would likely be significantly degraded. 0z sounding from ILN shows a minor inversion. Might prohibit some early morning convection? 

Some disagreement between rap, hrrr, nam, and nam3k. It’s a wake up and see kind oF a day which is typical for the OV. 

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. 

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. 

An impressive run for sigtor ingredients

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

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.

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

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. 

5 hours ago, andyhb said:

Yes the 18z NAM is absolutely nasty on Tuesday. Granted, that probably won't hold, although its 500 mb setup isn't much different than the other models.

The low levels will make or break this along with prior convection from Monday.

yep, didnt hold in the 0Z suite. However, the warm front on Monday has that look to me and the D2 outlook hits on that. 

NAM not as veered. Sounding from southern Ohio on tuesday

https://x.com/reedtimmerusa/status/1773359186484601075?s=46

Based on the GFS over the past 4-5 days, looks like our next chance of severe is going to be 3/28-4/3. 

37 minutes ago, nwohweather said:

Well said. If I’m not mistaken they were anticipating storms lining up, which never happened. Also, I believe instability and shear were all considerably higher than modeled in the morning.

Still, I’ll admit I didn’t expect to see multiple long track supercells. The Wapakoneta Storm was tornado warned from Indiana to Columbus

ILN was on it. Give them props. 

There will be time for airmass recovery in western Ohio/eastern
Indiana later this afternoon and evening, with model consensus
of lower 60s dewpoints advecting in along and south. A pretty
concerning supercell environment is depicted with a mid level
jet streak providing ample deep layer shear, low level curvature
in the hodographs, and deep instability. Supercell mode is
possible if not likely, thus threats in terms of impact seem to
maximize in the 5P-11P timeframe in southeast Indiana, western
Ohio possibly as far east as central Ohio with large hail and a
a tornado or two.

1 hour ago, IWXwx said:

Where the Taco Bell in Winchester used to be:

Minimum ef4 damage right? Swept off slab?

by my latest count, 4 killed in Winchester and at least 6 killed in Ohio.