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Severe Weather Threat Week...so many threats!!!


weatherwiz
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15 hours ago, dendrite said:

Guess where most of the action was this afternoon.

image.png

Biggest rains were south of there, like the Pit 2 region, but we did ok.  The morning showers faded as they neared us, so 3 hours of showers amounted to just 0.19".   The one-boom TS 4:30-4:45 dumped 0.44" and probably had 3"/hr rate at peak.  July will still finish BN unless the late week action brings 1.16" or more - very doubtful.  That would make 3 BN months in a row and 8 of the last 10.

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I think the biggest challenge overall is how these events are perceived. There seems to be a mindset that every single setup has to result in a widespread outbreak or all parameters need to be perfect. Was yesterday really a bust? I mean there were some severe weather reports but was it a bust? This answer is tied into how an individual is perceiving the potential and what they're expecting. 

image.png.2e91c1d17ce6f5b4a79c1a94c1b05359.png

When we look at and discuss parameters whether it be shear, CAPE, lift, lapse rates, height falls, forcing, etc. there is a tendency to only look for what is typically found with high end events. High end events don't happen often and there is a reason for that. Even other areas of the country where sure they have a higher tendency for higher end events, but they still don't happen with a high frequency. 

At the end of the day, no setup is ever going to have perfect parameters, not every setup is going to produce as a high end event, but does that mean every single event that doesn't mean these criteria is a bust? I mean when it comes to convective forecasting how can an event be a bust anyways? 

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1 hour ago, weatherwiz said:

I think the biggest challenge overall is how these events are perceived. There seems to be a mindset that every single setup has to result in a widespread outbreak or all parameters need to be perfect. Was yesterday really a bust? I mean there were some severe weather reports but was it a bust? This answer is tied into how an individual is perceiving the potential and what they're expecting. 

image.png.2e91c1d17ce6f5b4a79c1a94c1b05359.png

When we look at and discuss parameters whether it be shear, CAPE, lift, lapse rates, height falls, forcing, etc. there is a tendency to only look for what is typically found with high end events. High end events don't happen often and there is a reason for that. Even other areas of the country where sure they have a higher tendency for higher end events, but they still don't happen with a high frequency. 

At the end of the day, no setup is ever going to have perfect parameters, not every setup is going to produce as a high end event, but does that mean every single event that doesn't mean these criteria is a bust? I mean when it comes to convective forecasting how can an event be a bust anyways? 

If not a bust for severe, it was once again a bust for needed rain. Generally in a situation with mid 70's dews and an approaching cold front, most get their share of a soaking shower/thunder shower. Yesterday, the allocation to most was miserly to say the least.

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6 minutes ago, Hailstoned said:

If not a bust for severe, it was once again a bust for needed rain. Generally in a situation with mid 70's dews and an approaching cold front, most get their share of a soaking shower/thunder shower. Yesterday, the allocation to most was miserly to say the least.

Well the same logic would apply with that. With convective events and convective setups you're generally not going to get a widespread much needed rain. On a magnitude of scale, convection is just too small. You're always going to have a case where some towns get hit while others don't (now some situations more will get hit than not) but you can't rely on convection to provide a widespread much needed rain. This is why we rely quite a bit on getting at least seasonal snowfall totals and at least a few spring nor'easters to build up water tables for the summer and then for fall nor'easters to replenish what is lost during the summer. 

What we have lacked out a bit on the past few years is widespread synoptic rains which tend to be associated with warms fronts. 

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2 hours ago, weatherwiz said:

I think the biggest challenge overall is how these events are perceived. There seems to be a mindset that every single setup has to result in a widespread outbreak or all parameters need to be perfect. Was yesterday really a bust? I mean there were some severe weather reports but was it a bust? This answer is tied into how an individual is perceiving the potential and what they're expecting. 

image.png.2e91c1d17ce6f5b4a79c1a94c1b05359.png

When we look at and discuss parameters whether it be shear, CAPE, lift, lapse rates, height falls, forcing, etc. there is a tendency to only look for what is typically found with high end events. High end events don't happen often and there is a reason for that. Even other areas of the country where sure they have a higher tendency for higher end events, but they still don't happen with a high frequency. 

At the end of the day, no setup is ever going to have perfect parameters, not every setup is going to produce as a high end event, but does that mean every single event that doesn't mean these criteria is a bust? I mean when it comes to convective forecasting how can an event be a bust anyways? 

With regard to severe and rainfall, yesterday was a bust IMO. In CT to be specific.

You look at those parameters in place, the fact that we cleared out, and actually had some activity develop in a good environment in the evening and you’d figure that at the very least, there would be some widespread strong storms even and more widespread rainfall. Scattered severe warned stuff at best.

To get nothing close to a warnable storm is a big bust to me. To see a wide swath of the state get very little rainfall is also a bust to me. 

I never expected widespread severe, but we never even came close to even an isolated severe storm. It is what it is, but that’s bad in my book. 

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11 minutes ago, WxWatcher007 said:

With regard to severe and rainfall, yesterday was a bust IMO. In CT to be specific.

You look at those parameters in place, the fact that we cleared out, and actually had some activity develop in a good environment in the evening and you’d figure that at the very least, there would be some widespread strong storms even and more widespread rainfall. Scattered severe warned stuff at best.

To get nothing close to a warnable storm is a big bust to me. To see a wide swath of the state get very little rainfall is also a bust to me. 

I never expected widespread severe, but we never even came close to even an isolated severe storm. It is what it is, but that’s bad in my book. 

I'll admit, I actually did not look at any forecast soundings for this setup which I have no clue why I would not. I got a bit too carried away with just assessing instability, shear, and seeing a forcing mechanism approaching during prime heating. Based on those factors I went a bit overboard. When I saw a tweet last night (actually two) which mentioned drying in the mid-levels and one tweet showed a sounding it hit me. This is why we were seeing dews mix out a bit...due to the deep mixing which was occurring as we got stronger heating and favorable llvl flow for better mixing, drier air in the mid-levels was seeping into the llvls and down to the surface. 

Back to the discussion on the height falls, I don't think the lack of stuff was due to neutral or not really falling heights. Certainly falling heights can enhance the potential for more widespread activity and subsequent severe weather potential but IMO, that tends to be a bigger factor when assessing for widespread severe weather potential, just necessarily widespread convection (unless there are an overwhelming number of unfavorable ingredients). 

Looking back, the dry air advection into the mid-levels and seeping into the lower-levels would make the perfect sense as to convection did not evolve or materialize and this is what the mesos must have been picking up upon. Where convection was able to form there was extra enhancement. One of those areas was farther north where the steepest mid-level lapse rates were present as Brian showed. The second area was again the northern NJ onto Long Island where there was probably enhanced convergence. 

I also don't buy the idea that the convection there robbed us of any potential. I also can't see the morning clouds/precip having had played much of a role either given the fact that we recovered quite well. Temperatures rebounded and met what guidance suggested and instability was plenty. But looking back at it also...given how well we cleared and how quickly we got strong heating...that should have been a clear cut indicator how much drying was really occurring aloft. 

This is why it's imperative to fully assess everything and all factors. All these charts like UD helicity swaths, supercell composite parameter, significant tornado parameter, and the hazard type on the SHARPPy soundings are cute and all, but just like the stupid, ridiculous horseshit model snowfall maps they are leading to bad and lazy forecasting and I got sucked into that hole yesterday. 

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26 minutes ago, WxWatcher007 said:

With regard to severe and rainfall, yesterday was a bust IMO. In CT to be specific.

You look at those parameters in place, the fact that we cleared out, and actually had some activity develop in a good environment in the evening and you’d figure that at the very least, there would be some widespread strong storms even and more widespread rainfall. Scattered severe warned stuff at best.

To get nothing close to a warnable storm is a big bust to me. To see a wide swath of the state get very little rainfall is also a bust to me. 

I never expected widespread severe, but we never even came close to even an isolated severe storm. It is what it is, but that’s bad in my book. 

Mm... not quite.

The day was marginally unstable, with a good shear mechanics.  Noormally, that's a good - not great ... - but good combination.   But, not when it is cloudy for the first 2/3rds of the high sun hours.  It was not enough, not in time. 

Yeah, it cleared ...but it's not black or white - as in, 'cleared' or 'did not cleared'     It wasn't enough...  

There's also some noise that got in the way too... I noticed that a modest/ill-defined prefrontal trough situated along and E of the Berks over western zones, ...roughly around the time that clearing began to take place.   That backed the wind more west and seeya' later DPs... That started the pseudo dry-line evac.  That's not an uncommon feature with those W-E orient summer fropas around here.  Typical to see the DPs crash ahead of the cold front, with line(s) of premature ethunderulation along with it.   It wasn't hugely obvious that was taking place, but it smacked somewhat of having that tendency at the same time it cleared.   My temp bounced from 81 to 87 when it cleared, but the DP corrected from 74 to 64 and we had zero CU when that happened.   Then, the cfront limped through with a line of transparent sunset CB and that's the ball game.

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17 minutes ago, weatherwiz said:

I'll admit, I actually did not look at any forecast soundings for this setup which I have no clue why I would not. I got a bit too carried away with just assessing instability, shear, and seeing a forcing mechanism approaching during prime heating. Based on those factors I went a bit overboard. When I saw a tweet last night (actually two) which mentioned drying in the mid-levels and one tweet showed a sounding it hit me. This is why we were seeing dews mix out a bit...due to the deep mixing which was occurring as we got stronger heating and favorable llvl flow for better mixing, drier air in the mid-levels was seeping into the llvls and down to the surface. 

Back to the discussion on the height falls, I don't think the lack of stuff was due to neutral or not really falling heights. Certainly falling heights can enhance the potential for more widespread activity and subsequent severe weather potential but IMO, that tends to be a bigger factor when assessing for widespread severe weather potential, just necessarily widespread convection (unless there are an overwhelming number of unfavorable ingredients). 

Looking back, the dry air advection into the mid-levels and seeping into the lower-levels would make the perfect sense as to convection did not evolve or materialize and this is what the mesos must have been picking up upon. Where convection was able to form there was extra enhancement. One of those areas was farther north where the steepest mid-level lapse rates were present as Brian showed. The second area was again the northern NJ onto Long Island where there was probably enhanced convergence. 

I also don't buy the idea that the convection there robbed us of any potential. I also can't see the morning clouds/precip having had played much of a role either given the fact that we recovered quite well. Temperatures rebounded and met what guidance suggested and instability was plenty. But looking back at it also...given how well we cleared and how quickly we got strong heating...that should have been a clear cut indicator how much drying was really occurring aloft. 

This is why it's imperative to fully assess everything and all factors. All these charts like UD helicity swaths, supercell composite parameter, significant tornado parameter, and the hazard type on the SHARPPy soundings are cute and all, but just like the stupid, ridiculous horseshit model snowfall maps they are leading to bad and lazy forecasting and I got sucked into that hole yesterday. 

It's a situation where it did not help to have unimpressive lapse rates.   

Marginal instability means ... you don't have room to f around with clouds and light rain spritzing through 3pm...   that's A.   

B, falling heights means d(t)/dz is occurring, and that's your offset instability if/when these other parameters might be getting punked by covnective residue.  Almost irrelevent hgt falls --> less d(t)/dz --> not getting the help.  

I saw that band, calculated it's residence timing to be 8 am through 2pm, and pulled the curtains.  No sense or feeling of being boned - it wasn't going to happen, when then adding the fact that the 582 dm contour moved like 30 miles during the course of the afternoon.

As a preview, I suspect Friday we have the same aspects to contend with... although, the trough appears a little more differential aloft, so it may not be an ideal analog either.  

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9 minutes ago, Typhoon Tip said:

Mm... not quite.

The day was marginally unstable, with a good shear mechanics.  Noormally, that's a good - not great ... - but good combination.   But, not when it is cloudy for the first 2/3rds of the high sun hours.  It was not enough, not in time. 

Yeah, it cleared ...but it's not black or white - as in, 'cleared' or 'did not cleared'     It wasn't enough...  

There's also some noise that got in the way too... I noticed that a modest/ill-defined prefrontal trough situated along and E of the Berks over western zones, ...roughly around the time that clearing began to take place.   That backed the wind more west and seeya' later DPs... That started the pseudo dry-line evac.  That's not an uncommon feature with those W-E orient summer fropas around here.  Typical to see the DPs crash ahead of the cold front, with line(s) of premature ethunderulation along with it.   It wasn't hugely obvious that was taking place, but it smacked somewhat of having that tendency at the same time it cleared.   My temp bounced from 81 to 87 when it cleared, but the DP corrected from 74 to 64 and we had zero CU when that happened.   Then, the cfront limped through with a line of transparent sunset CB and that's the ball game.

That's another good point regarding the pre-frontal trough which obviously was the source for the wind shift. Perhaps all that was described above could be attributed to the pre-frontal trough and it's timing. But you're right...this feature is very common with W-E cold fronts here and more times than not it is the pre-frontal trough which is the driver for the development of convection as opposed to the actual cold front. Days in which instability is rather robust you may see some additional development with the fropa but it's very isolated...sort of like what occurred yesterday. 

3 minutes ago, Typhoon Tip said:

It's a situation where it did not help to have unimpressive lapse rates.   

Marginal instability means ... you don't have room to f around with clouds and light rain spritzing through 3pm...   that's A.   

B, falling heights means d(t)/dz is occurring, and that's your offset instability if/when these other parameters might be getting punked by covnective residue.  Almost irrelevent hgt falls --> less d(t)/dz --> not getting the help.  

I saw that band, calculated it's residence timing to be 8 am through 2pm, and pulled the curtains.  No sense or feeling of being boned - it wasn't going to happen, when then adding the fact that the 582 dm contour moved like 30 miles during the course of the afternoon.

As a preview, I suspect Friday we have the same aspects to contend with... although, the trough appears a little more differential aloft, so it may not be an ideal analog either.  

Regarding the lapse rates/height falls are those really more important when assessing the potential for severe weather on a widespread level as opposed to just aerial coverage of thunderstorms...well at least lapse rates, height falls do have a strong(er) correlation to aerial coverage. 

But I think this all makes sense now!

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13 hours ago, weatherwiz said:

I think the biggest challenge overall is how these events are perceived. There seems to be a mindset that every single setup has to result in a widespread outbreak or all parameters need to be perfect. Was yesterday really a bust? I mean there were some severe weather reports but was it a bust? This answer is tied into how an individual is perceiving the potential and what they're expecting. 

image.png.2e91c1d17ce6f5b4a79c1a94c1b05359.png

When we look at and discuss parameters whether it be shear, CAPE, lift, lapse rates, height falls, forcing, etc. there is a tendency to only look for what is typically found with high end events. High end events don't happen often and there is a reason for that. Even other areas of the country where sure they have a higher tendency for higher end events, but they still don't happen with a high frequency. 

At the end of the day, no setup is ever going to have perfect parameters, not every setup is going to produce as a high end event, but does that mean every single event that doesn't mean these criteria is a bust? I mean when it comes to convective forecasting how can an event be a bust anyways? 

Was there even a legitimate severe thunderstorm? Not those fake New England severe ones.

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