Severe Weather Thread - New England

[TalcottWx]

From the National Weather Service @ BOX 

 

"Good afternoon everyone, the main concern revolves around the expected scattered strong to severe storms that will cross the region from NW to SE between 1-8p tomorrow. SPEC SREF indicates probs of MLCAPE exceeding 2000 j/kg across portions of the region along with steep low level lapse rates and DCAPE values > 900 j/kg. That coupled with a ribbon of 30-40 kt at 700-850mb layer result in the greatest threat being strong to damaging wind gusts. While deep layer shear is more limited than we like to see for severe weather in the 500-600mb layer, we feel the parameters mentioned earlier are enough for severe weather. The CAMs are pretty aggressive with this activity showing flooding potential for bowing line segments, PWATs near 2.0 will also result in the threat of brief torrential rainfall/localized street flooding."

[TalcottWx]

This is from latest BOX AFD: 

 

2) Severe Weather: The main concern will revolve around the likelihood of scattered strong to severe thunderstorms; roughly between 1 and 8 PM on Tuesday. This a result of an approaching shortwave in westerly flow aloft. Given heat & humidity; the SPC SREF indicates modest probabilities of MLCapes exceeding 2000 J/KG across a good portion of the region. Guidance is also forecasting steep low level lapse rates with a ribbon of 30-40 knots of flow in the 850-700 mb layer. The one limiting factor is weaker winds in the 500-600 mb layer, which keeps effective shear values lower than we normally want to see for a severe weather event. That being said, high resolution CAM simulations are pretty aggressive with impressive 2-5 KM updraft helicity swaths depicted by the 3 KM NAM and even the 18z HRRR to some extent. The 4 hour max updraft product is lit up quite a bit on the HREF too across southern New England. So in a nutshell, scattered strong to severe thunderstorms are expected to sweep across the region from northwest to southeast between 1 and 8 pm Tuesday. Steep low level lapse rates along with modest DCape values > 800 J/KG suggest strong to damaging wind gusts are the main threat with this activity. While storms will be moving, PWATs near 2 inches also support brief torrential rain/localized street flooding particularly if activity moves across urban centers. Lastly, we can not rule out an isolated large hail report or two given even modest steep ML Lapse rates. We opted to included enhanced wording in the forecast.

[Henry's Weather]

we need wiz

[TalcottWx]

4 minutes ago, Henry's Weather said:

we need wiz

he is currently finishing up his bottle of valium. Moving on to alprazolam, he is pacing himself. If he doesn't self medicate he will be posting in caps here until 1pm tomorrow.

Glass of wine and a xanax. The housewife special. 

[Henry's Weather]

Just now, DotRat_Wx said:

he is currently finishing up his bottle of valium. Moving on to alprazolam, he is pacing himself. If he doesn't self medicate he will be posting in caps here until 1pm tomorrow.

Glass of wine and a xanax. The housewife special. 

Lol I can relate. I lose like half of my regular sleep leading up to snowstorms

[TalcottWx]

1 minute ago, Henry's Weather said:

Lol I can relate. I lose like half of my regular sleep leading up to snowstorms

I'm in my own world of medicating pain @Ginx snewx style for the past week or two.

Unfortunately due to methadone mile it's nearly impossible to get any help. It's infuriating. 

[Henry's Weather]

3 minutes ago, DotRat_Wx said:

I'm in my own world of medicating pain @Ginx snewx style for the past week or two.

Unfortunately due to methadone mile it's nearly impossible to get any help. It's infuriating. 

hang in there man

[weatherwiz]

Definitely will see scattered-to-numerous thunderstorms tomorrow. Going to be very difficult to get organized or widespread severe given the poor mid-level wind fields and not great forcing. Think severe will be isolated despite the good CAPE

[CT Rain]

2 hours ago, weatherwiz said:

Definitely will see scattered-to-numerous thunderstorms tomorrow. Going to be very difficult to get organized or widespread severe given the poor mid-level wind fields and not great forcing. Think severe will be isolated despite the good CAPE

I think the good flow at 700mb and nice 0-3km CAPE and decent lapse rates make up for some of this. I bet it's a pretty active day. 

[weatherwiz]

29 minutes ago, CT Rain said:

I think the good flow at 700mb and nice 0-3km CAPE and decent lapse rates make up for some of this. I bet it's a pretty active day. 

DCAPE is pretty impressive. With that and the steep llvl lapse rates certainly can’t rule out a decent amount of wind damage reports. 

[DavisStraight]

17 minutes ago, weatherwiz said:

DCAPE is pretty impressive. With that and the steep llvl lapse rates certainly can’t rule out a decent amount of wind damage reports. 

Looks like CT and RI shore gets the worst, you buying that Wiz?

[moneypitmike]

Not related to the severe potential, but we have a storm come through at 3:00a.m. that dropped about .25" very quickly.  Not a ton of thunder with it, but one that was a simultaneous flash/crack.  I love a good night storm.

[PowderBeard]

Wouldn't be surprised if someone in Mass/CT/RI got a "burst" today. 

Obligatory weenie image given my statement:

[CoastalWx]

Wagons SW.

[Damage In Tolland]

23 minutes ago, CoastalWx said:

Wagons SW.

W/C Mass/ CT

[Ginx snewx]

Lots of debris clouds

[Hoth]

1 hour ago, CoastalWx said:

Wagons SW.

Hello.

[weatherwiz]

10 hours ago, DavisStraight said:

Looks like CT and RI shore gets the worst, you buying that Wiz?

Yeah I think CT/RI certainly see a good amount of convection today...just not certain how much in the way of severe we see. 

[weatherwiz]

Albany sounding not terrible looking. But this goes to show the best shear is going to be displaced a bit. Despite the fact we'll see numerous convection I think things are really going to struggle to organize 

[klw]

2 hours ago, PowderBeard said:

Wouldn't be surprised if someone in Mass/CT/RI got a "burst" today. 

Obligatory weenie image given my statement:

You could have gone for the Independence Day themed gif:

 

Meanwhile there is a nice looking storm right where NY/Mass/ and Vermont come together.

 

 

[Chrisrotary12]

Yeah...way too much cloud debris.

[ineedsnow]

1 minute ago, Chrisrotary12 said:

Yeah...way too much cloud debris.

Meh suns starting to come out

[weatherwiz]

Tomorrow actually looks better than today I think for severe and some hints at another weak EML (which there is one too just south of us today)

[Typhoon Tip]

My experience in this part of the country is that the morning trends often dictate how the day's convection will tend to play-out.   "Recovery" inside a diurnal time span is only so-so around here; not like over the Plains, with morning MCS and afternoon super cells - there are too many complex 'fuzzy' limiting factors to list here; it just is what it is.

In this case, there is a line of morning TCU extending astride I-90 in NY S.  It appears that is along that 700 mb jetlet SPC was outlining in their morning update ( would seem to fit an explanation for that ..).   That feature probably goes on to demarcate the glaciation fan out axis. This may choke off activity N of there once that happens.  The cells will tend to then slip S of a W-E motion, and that may do it for E - N of CEF-ORH (~) as a light rain anvil positive return on a hashed severe threat typology.  

Lol, I actually have sympathy for SPC.  I mean people have died from stove pipe, urban canal boring twisters before.  And while tremendous strides in science and tech have provided quantifiable positive returns in advanced risk planning, to in the moment detection, out in the Plains, our region continues to elude those techniques. Yet, they happen here. Even though rarely, one does manage to cut through the morass of reasons to fail to actually occur - so they have to hash.  

But for us, it is an exercise in destructive interferences - those that seem to tag-team.  That time 'too many clouds,' this time, 'cells dove right of modeling and ended it early,' some other time, a SSW by SSW by SW wind was quantum therms too cool for just a SSW by SW ..    It's amazing that 1953, Great Barrington's, and Monson's ever happen at all.

[Whineminster]

Any time we depend on a morning mcs to clear out .... It never pans out like tip says.  Usually the MCS makes a better storm then the actual supposed severe event.

[weatherwiz]

These differential heating boundaries should help to enhance llvl convergence across a few zones. I think tomorrow is looking pretty decent...could be rather active from southern VT/NH to just south of the Mass Pike. Could see several rounds of convection. 

[Typhoon Tip]

44 minutes ago, Whineminster said:

Any time we depend on a morning mcs to clear out .... It never pans out like tip says.  Usually the MCS makes a better storm then the actual supposed severe event.

Mm... I actually don't think that is the problem with today. Judging by sat trends, we should get a some good insolation periods mid afternoon.

I think premature detonation out in NYS may be a the issue for us.  Like I was saying, there appears to be a bit of "zygote" convection axis already percolating out there astride I-90;  that morning trend may set the table and it's already S of the northern edge of SPCs hashing.  Then, looking at the 500 mb height lines and geostrophic wind direction, those cells should move S of due E - this latter aspect tends to not end big, with less N-E end of the Pike. They'll turn right - more right of the guidance too ... sending anvil spooge over us...

I'm sure this doesn't happen every time. But, after 30 years of suffering the vicissitudes of convection outlooks in SNE, the first order of business here is 'what can go wrong' will - particularly if you neglected to look for it haha

[weatherwiz]

20 minutes ago, Typhoon Tip said:

Mm... I actually don't think that is the problem with today. Judging by sat trends, we should get a some good insolation periods mid afternoon.

I think premature detonation out in NYS may be a the issue for us.  Like I was saying, there appears to be a bit of "zygote" convection axis already percolating out there astride I-90;  that morning trend may set the table and it's already S of the northern edge of SPCs hashing.  Then, looking at the 500 mb height lines and geostrophic wind direction, those cells should move S of due E - this latter aspect tends to not end big, with less N-E end of the Pike. They'll turn right - more right of the guidance too ... sending anvil spooge over us...

I'm sure this doesn't happen every time. But, after 30 years of suffering the vicissitudes of convection outlooks in SNE, the first order of business here is 'what can go wrong' will - particularly if you neglected to look for it haha

In a way this cloud debris may actually *help* things a bit. Given the high dewpoints and steep mid-level lapse rates we actually are destabilizing quite nicely. This cloud debris though may actually keep the mixed-layer capped a bit longer...holding off convective development. Also, this was really more of a late afternoon/early evening show anyways. Judging by sat trends we will see strong heating and once we really crank that the MLCIN should erode without problem. The RAP is getting MLCAPE upwards of 2500 J/KG which is pretty significant around here. It just sucks the mid-level is so bad...I think that's really going to hurt storm organization and limit how mature convection can get. 

[Whineminster]

clearing here.....off to the races! Go go go!!

[Torch Tiger]

10 minutes ago, Whineminster said:

clearing here.....off to the races! Go go go!!

its all way south of us today.  next