SVR potential late Sat June 27?

[wdrag]

Good Wednesday morning everyone,

Unsure whether this will happen but mass field signals seem to me to flag potential for one or two bands of svr storms racing east

in strong low level WAA (and moist too-CAPE, and KI modeled going way up).  Early max gust signal of 40+ knot in the EC for 5 consecutive

cycles upstate NY and far northwest PA toward 00z/Sunday the 27th.  So,  I'll just wait this out... see what happens (see if EC is too robust?).  

00z/24 GEFS and EPS  similar on wind fields 850, 500mb.  You're welcome to add on and I'll post the SPC SVR reports image, Sunday the 27th,

after 12z.  It's possible the heat here on Saturday (90-95F non marine influenced) could be minimized if the storms arrive too soon, but my guess, per modeling

seen early this Wednesday June 24, is that the SVR event would occur (IF??) in our area between 6P Saturday and 4A Sunday. If you wish to see any graphics

I've referenced, let me know.  I may not reply immediately.

[IrishRob17]

Clearly you’re on to something Walt as the SPC has some of us in the Slight area. 

[wdrag]

We'll see how it goes:  They have increased their D2 with "enhanced" risk over MI.  I could see one band of marginal dying svr scraping NNJ-NYC/CT around 12z, then it heats up to 90-95 at 4P, refires in the late afternoon.  It sort of looks like a dual thunderstorm episode day to me.  

Convective debris-timing will make some difference in results.  Pretty clear to me that the wind fields will be there, and that there is strong WAA, strong instability advection with late day sfc based Cape 1000-2000J all along I80. Sometimes the Cape is there because of previous convection which can make the Cape misleading. So, in my mind, as of 20z/25... my concern is whether the primary convective band is midday Saturday, or do we have sort of a wfrontal strong convective band at 12z/27, then a developing line of severe nearly overhead late in the day-eve?  Don't know, but I think it's worth keeping an eye on.   (i never like it when the back edge of the svr risk is shifted into our area... I always like it better when the final big band of thunderstorms has developed upstream and rolls into better instability over our area.  Unknowns for me, especially not with tools that I used to have in NWS. 

Just dont know for sure what will happen but I think its worth the heads up to witness the evolution, good or bad. 

[wdrag]

Good Friday morning everyone,

You've seen the D2 from SPC issued earlier this morning.  Convective debris (leftover) in the morning may minimize potential, but for now... I think a potentially substantial outbreak of SVR, especially near I80 in n PA/extreme s NYS with a possible bookend vortex crossing NYC area (IF---and only IF it's maintained in future NAM/HRRR modeling through the 12z/27 cycle. 

I'm viewing this as a two thunderstorm episode day, one early near 12z/27, the other as per GFS/NAM modeling for 22zish. The 06z/26 HRRR has the 12z/27 nicely suggested for our area but I'm hoping the 17z/27 band is wrong (too fast). The HRRR agrees more with the EC.  Myself, in heavy convection, I favor the GFS-HRRR. 

For mariners, the SPC HREF ens MAX gust is provocative and not sure it can verify?  It has the strongest wind in the entire ne USA over eastern LI and adjacent LI waters between 22z/27 and 00z/28.  Cold water makes me wonder but what it suggests to me, all of LI is in the mix for a svr episode late Saturday, provided the event occurs after 21z with no convection between 14z-21z over LI. 647A EDT/26

[gravitylover]

So this is an I80/495 special? How about the 84 corridor, do we get to look south and see the clouds or do we get to play along?

[wdrag]

Unsure...

 

What I do know is that the big stuff tends to turn right (south) of modeled (along 1000-500mb thick), because it wants instability-heat to drive it.  so for me, Its between BGM-POU-GON south to I195 (TTN) on Saturday....  I'd go w local NWS experts including SPC discussion info, and high resolution CAMS models (if you can get access to them).  I prefer no convection NYC metro 1330z-220z to get this to work to its potential. 850 winds are pretty strong. 

May post mid afternoon?

 

Later,

Walt

[Allsnow]

11 minutes ago, wdrag said:

Unsure...

 

What I do know is that the big stuff tends to turn right (south) of modeled (along 1000-500mb thick), because it wants instability-heat to drive it.  so for me, Its between BGM-POU-GON south to I195 (TTN) on Saturday....  I'd go w local NWS experts including SPC discussion info, and high resolution CAMS models (if you can get access to them).  I prefer no convection NYC metro 1330z-220z to get this to work to its potential. 850 winds are pretty strong. 

May post mid afternoon?

 

Later,

Walt

Yeah, hopefully the morning convection clears out early enough. This could be similar to what happen in South Jersey a few weeks back but just further north 

[LongBeachSurfFreak]

1 minute ago, Allsnow said:

Yeah, hopefully the morning convection clears out early enough. This could be similar to what happen in South Jersey a few weeks back but just further north 

Seems like our best threat in a while. Damaging winds are a real possibility. Maybe even the D word. I’ll take anything, as long as it comes with heavy rain.

[Brian5671]

The NAM is way north with the storms Sat...

[Ace]

4 hours ago, wdrag said:

Good Friday morning everyone,

You've seen the D2 from SPC issued earlier this morning.  Convective debris (leftover) in the morning may minimize potential, but for now... I think a potentially substantial outbreak of SVR, especially near I80 in n PA/extreme s NYS with a possible bookend vortex crossing NYC area (IF---and only IF it's maintained in future NAM/HRRR modeling through the 12z/27 cycle. 

I'm viewing this as a two thunderstorm episode day, one early near 12z/27, the other as per GFS/NAM modeling for 22zish. The 06z/26 HRRR has the 12z/27 nicely suggested for our area but I'm hoping the 17z/27 band is wrong (too fast). The HRRR agrees more with the EC.  Myself, in heavy convection, I favor the GFS-HRRR. 

For mariners, the SPC HREF ens MAX gust is provocative and not sure it can verify?  It has the strongest wind in the entire ne USA over eastern LI and adjacent LI waters between 22z/27 and 00z/28.  Cold water makes me wonder but what it suggests to me, all of LI is in the mix for a svr episode late Saturday, provided the event occurs after 21z with no convection between 14z-21z over LI. 647A EDT/26

Great discussion. The area you highlighted (N PA/extreme S NY/perhaps Northern NJ) certainly seems to have the best chance at the moment as it appears to be at the intersection of good shear and decent instability. Kinda sucks lapse rates aren't impressive.

The 12z NAM shifts the morning activity north of us (but we still get some debris for a few hours) and keeps us dry in the afternoon too. Parameters still look decent though.  In addition, some of the other CAM's get some good activity going in our area in the afternoon.

We'll see what happens, but if we are able to dodge most of the morning debris, I certainly wouldn't mind an early band coming through (early afternoon)

[winterwx21]

1 hour ago, Brian5671 said:

The NAM is way north with the storms Sat...

But the 12z RGEM has an intense line of storms hitting NYC and most of NJ during the late afternoon. Hopefully RGEM is on the money instead of NAM.

[Stormlover74]

29 minutes ago, winterwx21 said:

But the 12z RGEM has an intense line of storms hitting NYC and most of NJ during the late afternoon. Hopefully RGEM is on the money instead of NAM.

Yes please

 

[forkyfork]

13 minutes ago, Stormlover74 said:

Yes please

 

it showed that the day before the south jersey derecho

[wdrag]

No new answers... see BGM, PHI, OKX, BOX discussions for their take as well as SPC D1,2 updates and of course your favorite model guidance. It's possible that there will only be one big band (early-mid-afternoon).  I do like the 12z 3K NAM, HRRR, SPC HREF options and even the 12z EC still has 35-40 kt gusts sprayed here and there across PA/NNJ to NYC. I still think south is the way to go... near 180 where intersection of best heating/instability advection with speed-directional shear 850-500mb. But. i wouldn't discount near the sfc low ctr nr I90. 

mPing winds-hail may be helpful info as currently vcnty n IL (several pea hail as of 30 minutes ago). System starting to get going in s WI/N IL at this time. 

Walt

[gravitylover]

The northern solution wouldn't surprise me. It's closer to where the wetness has been the last month or so. If the boundary set up along that moist area rather than where it's so dry down here it sort of makes sense to my simple brain. Actually, isn't that where the snow line set up so much of last winter too? 

[wdrag]

I cant comment any further with confidence on best axis for svrz.

 I'm a little disappointed so far,  in midwest svr reports. From what i can tell...general thunder/heavy rain in MI but bigger storms in IL heading ese, so far.  Maybe I'll add something at 730A Saturday, but you're welcome to point out things that have been missed.

When I wake up tomorrow, I expect to be pinging ~ 8a/9A for far nw NJ and hoping enough time to heat up mid afternoon. 

Don't think the models have handled OH storms very well??- could be a sign, south, unless  debris goes so far south, it opens up s NYS faster???  just dont know. 

Gotta rest for now,

Walt

[Rtd208]

 

[Brian5671]

0z NAM continues with the northern theme, very little for anyone in this subforum through tomorrow evening.

[SRRTA22]

35 minutes ago, Brian5671 said:

0z NAM continues with the northern theme, very little for anyone in this subforum through tomorrow evening.

 

Thats from the leftover debris from the lakes tomorrow AM. We want that north of us if we want a severe threat tomorrow afternoon. June 3rd, the debris moved into our area overnight, and southern NJ got hammered. Im still thinking this is a south of I-78 special but we'll see

[wdrag]

Good Saturday morning everyone, 

My feeling is that there may not be enough instability (heat, Cape) in advance for much svr,  but some of the modeling as per SPC D1 545z discussion still gives opportunity. Just looks to me like primary event is a bit too soon this afternoon and with cloud cover, the best heat 90+ looks south of our area. Therefore, think best chance severe is I80-i78 as someone previously mentioned.  So for this NYC metro forum,  would think it will rain and if we get lucky, a few spots near I80 should pick up 0.5-1.5" in heavy convection this afternoon-evening w still a small chance svr.  Suspect, there will be better days this summer for westerly flow severe in NYC. Just has trended a little further south and faster since Wednesdays post (result less primed prior instability)

Follow SPC, your local NWS forecast offices for updates from their view, and your other knowledgeable resources-friends. If I do manage a svr storm, I'll post here. Otherwise, it's an mPing day. 

Walt

552A/27

[SRRTA22]

1 hour ago, wdrag said:

Good Saturday morning everyone, 

My feeling is that there may not be enough instability (heat, Cape) in advance for much svr,  but some of the modeling as per SPC D1 545z discussion still gives opportunity. Just looks to me like primary event is a bit too soon this afternoon and with cloud cover, the best heat 90+ looks south of our area. Therefore, think best chance severe is I80-i78 as someone previously mentioned.  So for this NYC metro forum,  would think it will rain and if we get lucky, a few spots near I80 should pick up 0.5-1.5" in heavy convection this afternoon-evening w still a small chance svr.  Suspect, there will be better days this summer for westerly flow severe in NYC. Just has trended a little further south and faster since Wednesdays post (result less primed prior instability)

Follow SPC, your local NWS forecast offices for updates from their view, and your other knowledgeable resources-friends. If I do manage a svr storm, I'll post here. Otherwise, it's an mPing day. 

Walt

552A/27

Good morning and Thank you for your update  

[crossbowftw3]

Yeah up here north of 84 we might be stuck in the rain from the complex for almost the entirety of the morning with potential cloud debris to be trailing behind for longer than that even. By 1300 I expect the slight risk to be cut some--but I can see why they'd keep it in because some redevelopment will still happen this afternoon. Just not nearly as much as what could've been.

[wdrag]

Saw the 13z D1 update and I like it.  I really like the 12zHRRR... but whether it comes to pass is questionable.  I suggests a bow echo and possible northern bookend to the bow.  Till it degrades, still worthy of monitoring.  (we had sprinkles here in Wantage around 830A-845A)

Walt  1311z/27

[hudsonvalley21]

10 minutes ago, wdrag said:

Saw the 13z D1 update and I like it.  I really like the 12zHRRR... but whether it comes to pass is questionable.  I suggests a bow echo and possible northern bookend to the bow.  Till it degrades, still worthy of monitoring.  (we had sprinkles here in Wantage around 830A-845A)

Walt  1311z/27

We’ll see what happens. As crossbowftw3 mentioned, us folks north of the city might be stuck in this slowly decaying area of showers.

 

[crossbowftw3]

18 minutes ago, hudsonvalley21 said:

We’ll see what happens. As crossbowftw3 mentioned, us folks north of the city might be stuck in this slowly decaying area of showers.

 

Only barely north of 60 as of this hour at my house in Sullivan. Back end of the shield is on the way but I doubt it'll make it/collapse entirely before noon. Reminds me of a setup from last July where I struggled to make 70 amidst a rain shield/WF scenario while everywhere south warmed to almost 90 and had a subsequent severe episode.

[Allsnow]

The area of showers ended up further south then nam and other models had. I think the best chance of storms are I78 south this afternoon 

[Poker2015]

What time this afternoon? Supposed to have some people over around 1pm to swim...hoping it holds off until 4 or so...

[Rtd208]

3 minutes ago, Poker2015 said:

What time this afternoon? Supposed to have some people over around 1pm to swim...hoping it holds off until 4 or so...

Best chances for severe storms will be from 2-8 pm but more likely anytime after 4 pm. This is obviously dependent on how quickly we clear out over the next hour or so.

[gravitylover]

Radar kind of looks like this first round is going to stay north, I got a few drops but that's it so far. I'm right on the Putnam/Westchester line for reference.

[EJ123]

Mount Holly:

Convection-allowing models appear to
suggest this will set up near or even just north of the northern
CWA boundary. Based on radar/satellite trends early this
morning, this seems a little too far north. This bias is
common, and current thinking is that the greater threat of more
significant convection is farther south into the CWA (say
roughly between the I-78 and I-76 corridors). Areas near/north
of I-80 may remain in denser cloud cover much of the day, with
highs near or even below 80 degrees.