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Tuesday/Wednesday Storm


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We've had better high shear / low CAPE events than this one but I was okay with what happened. Unlike the more common experience, I saw nice storm structure and experienced some nice wind gusts.

The preliminary shot this afternoon just couldn't get it together and probably hurt us more than anything. Despite the occasional break of sun in S-C NJ, the updraft acceleration wasn't enough or properly balanced with the storm relative wind. I agree with what Ian has been saying as far as the SPC upgrade. We both aren't sure what changed between the 13z and 1630z outlook other than convective development was occurring. However, they noted several times that there were instability issues with the rain ahead of the convection.

Oh well...onto Saturday.... :axe:

Yeah instability was just too meager (00z OKX sounding ~300 j/kg of sbCAPE... models had more modeled) so we couldn't get updrafts to maintain themselves. Storm mode down south was a problem too with things quickly becoming linear.

Oh well.

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Yeah instability was just too meager (00z OKX sounding ~300 j/kg of sbCAPE... models had more modeled) so we couldn't get updrafts to maintain themselves. Storm mode down south was a problem too with things quickly becoming linear.

Oh well.

If OKX had reached >1000 j/kg like some of the modeled solutions were showing, then things might have been a lot more interesting. Then again, who knows what magical buoyancy level would have worked with the amount of wind shear we were dealing with ahead of the main cold front.

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If OKX had reached >1000 j/kg like some of the modeled solutions were showing, then things might have been a lot more interesting. Then again, who knows what magical buoyancy level would have worked with the amount of wind shear we were dealing with ahead of the main cold front.

We would have likely needed some good cape up through 600mb or so in order to probably have enough thermodynamic buoyancy to sustain updrafts through that shear...if we had some solid mid-level lapse rates not only would that have helped with sfc-based instability but would have helped with instability through the column and that may have been enough to do the trick.

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Yeah but high shear, low CAPE events typically don't have great lapse rates. There is something else at play that properly balances the buoyancy and storm relative wind here and it is likely in the synoptics. I think lapse rates are a common scapegoat for busts. It would be like saying that they were a problem in a land falling tropical storm not producing tornadoes. Are you wrong technically? No... but it's not quite the answer IMO.

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Yeah but high shear, low CAPE events typically don't have great lapse rates. There is something else at play that properly balances the buoyancy and storm relative wind here and it is likely in the synoptics. I think lapse rates are a common scapegoat for busts. It would be like saying that they were a problem in a land falling tropical storm not producing tornadoes. Are you wrong technically? No... but it's not quite the answer IMO.

I see what you're saying. There have been plenty of low cape/high shear events which have produced quite well and the lapse rates are garbage. You then start looking at jet quadrants, areas of stronger divergence, DPVA, etc...just perhaps everything here just wasn't aligned perfectly b/c these are things which can certainly act to really enhance lift and could compensate for a weaker thermodynamic environment.

I also wonder if just not having a unique or equal destabilized BL contributes. For example, in a case like today where we kept getting pop up showers everywhere that just leads to BL stabilization and since not everyone sees this activity the BL is just not similar from one location to the next in terms of (in)stability.

The factors could be so mesoscale it may be impossible at this point to completely come to one answer. Hopefully as mesoscale models improve we'll be able to gather more info.

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I see what you're saying. There have been plenty of low cape/high shear events which have produced quite well and the lapse rates are garbage. You then start looking at jet quadrants, areas of stronger divergence, DPVA, etc...just perhaps everything here just wasn't aligned perfectly b/c these are things which can certainly act to really enhance lift and could compensate for a weaker thermodynamic environment.

I also wonder if just not having a unique or equal destabilized BL contributes. For example, in a case like today where we kept getting pop up showers everywhere that just leads to BL stabilization and since not everyone sees this activity the BL is just not similar from one location to the next in terms of (in)stability.

The factors could be so mesoscale it may be impossible at this point to completely come to one answer. Hopefully as mesoscale models improve we'll be able to gather more info.

You have to force parcels when they don't have enough thermodynamically driven buoyancy. This is done with a proper low level front, jet quadrant etc. but also the alignment, as you say, of these features. The events of 2003, for example, had this alignment time and time again.

An ubiquitous BL is certainly an interesting idea and may have possibly helped improve positive buoyancy somewhat with entrainment and QLCS maintenance.

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You have to force parcels when they don't have enough thermodynamically driven buoyancy. This is done with a proper low level front, jet quadrant etc. but also the alignment, as you say, of these features. The events of 2003, for example, had this alignment time and time again.

A ubiquitous BL is certainly an interesting idea and may have possibly helped improve positive buoyancy somewhat with entrainment and QLCS maintenance.

That is why it's extremely hard to get these events to perform to their fullest potential, you need everything to align perfectly...I guess you can say that for any weather event but if you don't have everything in place to act and counteract you're not going to get the fullest of the potential to realize.

That's what makes forecasting these types of event so difficult and personally I think these are one of the hardest events to forecast b/c it just all comes down to trying to pain a mental image in your head of how convection and activity will evolve in this type of environment. You have some here who when you first make these threads already write them off b/c of what's happened in the past or b/c of the region we're in, etc and if it doesn't pan out they claim victory...that's not victory in my book...you just can't write off something b/c we had a setup in the past that didn't pan out or b/c that's what typically happens in your region. The potential was certainly there today and it has to be watched closely and projected to the public accordingly...when issuing watches they are issued b/c the conditions in the atmosphere are favorable and that's exactly what the case was today. You just don't know how these setups are going to unfold...even hours beforehand...you just have to watch as it's unfolding and go from there.

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That is why it's extremely hard to get these events to perform to their fullest potential, you need everything to align perfectly...I guess you can say that for any weather event but if you don't have everything in place to act and counteract you're not going to get the fullest of the potential to realize.

That's what makes forecasting these types of event so difficult and personally I think these are one of the hardest events to forecast b/c it just all comes down to trying to pain a mental image in your head of how convection and activity will evolve in this type of environment. You have some here who when you first make these threads already write them off b/c of what's happened in the past or b/c of the region we're in, etc and if it doesn't pan out they claim victory...that's not victory in my book...you just can't write off something b/c we had a setup in the past that didn't pan out or b/c that's what typically happens in your region. The potential was certainly there today and it has to be watched closely and projected to the public accordingly...when issuing watches they are issued b/c the conditions in the atmosphere are favorable and that's exactly what the case was today. You just don't know how these setups are going to unfold...even hours beforehand...you just have to watch as it's unfolding and go from there.

I agree with your post. The problem is that you have a lot of uneducated people in media, including meteorologists, who do not understand SPC products. Even today, I saw on-air weather forecasters saying "10% chance for a tornado" and showing the various SPC products to the public. As far as the public is concerned, the weather will have appeared "bad enough" today that the tornado watch will make sense to them (and that's fine). As for the people who know better, there is no excuse if you cannot properly interpret SPC products and understand how severe weather works.

The tale of the 1938 hurricane is the epitome of what you are describing about naysayers. Ultimately, this type of mindset will get you major league failure.

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I agree with your post. The problem is that you have a lot of uneducated people in media, including meteorologists, who do not understand SPC products. Even today, I saw on-air weather forecasters saying "10% chance for a tornado" and showing the various SPC products to the public. As far as the public is concerned, the weather will have appeared "bad enough" today that the tornado watch will make sense to them (and that's fine). As for the people who know better, there is no excuse if you cannot properly interpret SPC products and understand how severe weather works.

The tale of the 1938 hurricane is the epitome of what you are describing about naysayers. Ultimately, this type of mindset will get you major league failure.

This is why I typically try not to share SPC products with people I know...every once in a while I'll post SPC graphics. For example, if we have a moderate risk I won't post the "mod" but I'll post the 45% contour and explain what that 45% means. Or if we have 10% or higher TOR probs I'll show the graphic, however, I'll explain what it refers to and what it means.

Showing the public graphics that totally mean nothing to them give them the complete wrong idea and they won't have the correct understanding and it then it terms leaves them to believing something completely wrong and then forecasters get blamed.

It's fine to show these products but you better make sure that 1) The presenter has the correct understanding of the product being displayed and 2) He/she can convey what the graphic is displaying and explain it in terms simple enough for the public to understand. Otherwise it leads to more harm than good.

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Very much like a winter southerly flow / fropa. You can have 90 knots at 850 and still it's sort of meh. Good to get some wind though either way and some heavy rain

Yeah good storm. Something interesting for once. Gusting to practically 50 in September outside of a tropical system or convection is pretty good.

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