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New England Severe weather thread number ...I think XI ?


OSUmetstud

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The degree on instability late Friday into Saturday is the biggest problem and I think it may take its toll. Obviously, the evolution of this system continues to change on the NWP.

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The degree on instability late Friday into Saturday is the biggest problem and I think it may take its toll. Obviously, the evolution of this system continues to change on the NWP.

It's all about whether or not we can get heating. If it's one of those tropical conveyor belts, than probably not. The GFS isn't that bad looking, but we are 4-5 days out. The euro imo, was not great looking as it had periods of rain all day which is quite possible.

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The other issue is that the best low level wind fields are being modeled just offshore, keeping the coastal plain region under the slower cyclonic flow. If we can't even muster up a decent LLJ, then this threat is definitely crap.

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The extended range (mid-late August) has a more promising look for the Northeast again. The ridge in the Plains begins to amplify again with the prospects for troughs to move from the PAC NW into the upper Midwest. This will increase the potential for an EML advection during the second half of AUG.

The ECMWF suite is a lot more bullish of course with this potential so caution should be applied; however, I like that the ensembles look like the op member.

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It's all about whether or not we can get heating. If it's one of those tropical conveyor belts, than probably not. The GFS isn't that bad looking, but we are 4-5 days out. The euro imo, was not great looking as it had periods of rain all day which is quite possible.

If we can get a stern / mean LLJ in a deep moist environment, then I will get excited even if we can only manage little CAPE. In a way, that scenario would mimic our best autumn outbreaks. But the current modeling is not only meager with CAPE, but it is disjointed with the wind fields. As Ian and I were discussing yesterday, this can be the downfall of an upper low. Still plenty of time to get things right again.

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If we can get a stern / mean LLJ in a deep moist environment, then I will get excited even if we can only manage little CAPE. In a way, that scenario would mimic our best autumn outbreaks. But the current modeling is not only meager with CAPE, but it is disjointed with the wind fields. As Ian and I were discussing yesterday, this can be the downfall of an upper low. Still plenty of time to get things right again.

I see that too. a 40kt LLJ would be better about 50+ miles west on Saturday. We'll see what happens I suppose. I wouldn't get excited just yet, but maybe that trough can sharpen enough and develop the LLJ a bit further west.

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I see that too. a 40kt LLJ would be better about 50+ miles west on Saturday. We'll see what happens I suppose. I wouldn't get excited just yet, but maybe that trough can sharpen enough and develop the LLJ a bit further west.

If that can occur, not only will it increase the SRH / LIFT but the CAPE will get a boost too from better theta-e advection. Basically, that LLJ needs to come west. If it does, the threat for low-topped supercells with isolated tornadoes would grow substantially for the coastal plain of New England / Mid Atlantic.

Best threat right now Long Island / coastal New England to DELMARVA?

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If that can occur, not only will it increase the SRH / LIFT but the CAPE will get a boost too from better theta-e advection. Basically, that LLJ needs to come west. If it does, the threat for low-topped supercells with isolated tornadoes would grow substantially for the coastal plain of New England / Mid Atlantic.

Best threat right now Long Island / coastal New England to DELMARVA?

Yup... it's all about getting the LLJ and theta-e plume over the coastal plain Saturday. Right now the GFS is too far east for much fun.

Heating, as Scooter mentioned, will also be an issue.

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Yup... it's all about getting the LLJ and theta-e plume over the coastal plain Saturday. Right now the GFS is too far east for much fun.

Heating, as Scooter mentioned, will also be an issue.

Do you agree that most likely in any scenario, solar heating is going to fail with this setup? I suppose that because it is August, any solar heating will do and probably help out substantially. I just don't see anything other than a few peeks of sun right now (at best).

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Do you agree that most likely in any scenario, solar heating is going to fail with this setup? I suppose that because it is August, any solar heating will do and probably help out substantially. I just don't see anything other than a few peeks of sun right now (at best).

Yeah it's a double edged sword. We want the LLJ and Theta-E plume over us... but that will just put a stronger warm advection/QG lift regime overhead.

Ideally you'd have an ULL well west around 12z moving east during the day with the LLJ/higher theta-e axis moving in. Having it overhead at 12z is likely to cause more of a flash flood threat than severe.

That said for every 10 of these setups probably only 1 delivers. So cautious optimism I guess is the way to go. The fact it's August and we're looking at an unusual synoptic setup may help a bit.

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Yeah it's a double edged sword. We want the LLJ and Theta-E plume over us... but that will just put a stronger warm advection/QG lift regime overhead.

Ideally you'd have an ULL well west around 12z moving east during the day with the LLJ/higher theta-e axis moving in. Having it overhead at 12z is likely to cause more of a flash flood threat than severe.

That said for every 10 of these setups probably only 1 delivers. So cautious optimism I guess is the way to go. The fact it's August and we're looking at an unusual synoptic setup may help a bit.

I agree with your ideal scenario; in which case, I would be screwed here in NJ. ;)

Plenty of time to get this thing to trend correctly.

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The ULL might be too close to the region on Saturday for anything more than flash flooding. On Friday it's further away and would actually allow us to destabilize. I think we might be better off hoping the ULL with climatology will shift a tad north and thus move the warm front north, getting NJ thru SNE into the threat instead of the mid Atlantic. Better this than hoping the threat is Saturday.

Not sure we can make this into a tor threat for all the Delmarva through SNE. It's one region or the other IMO for tornadoes.

It also appears most of the directional shear is at the lower levels, which is good. Deep layer shear might not be great with SW flow at 500mb, but 0-3KM shear, especially if we can get a nice jet at 925mb or 850mb might be good.

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Yeah it's a double edged sword. We want the LLJ and Theta-E plume over us... but that will just put a stronger warm advection/QG lift regime overhead.

Ideally you'd have an ULL well west around 12z moving east during the day with the LLJ/higher theta-e axis moving in. Having it overhead at 12z is likely to cause more of a flash flood threat than severe.

That said for every 10 of these setups probably only 1 delivers. So cautious optimism I guess is the way to go. The fact it's August and we're looking at an unusual synoptic setup may help a bit.

We are probably discussing Saturday more than we should, but the GFS did have a nice piece of mid level drying moving in during the day with the CF to the west. Problem is...the LLJ is displaced further east. Not the easiest thing to do..get these two in sync with each other.

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Record low tornado year, record phail rate on true severe in SNE forum threads.

Really interesting to swing the pendulum so far from last year to this one. Although, much of last year seemed to come in a 3 day explosion - even so, I think it was much more active overall, comparatively.

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