July 21-23 Hybrid/Coastal Storm

[Stormlover74]

Looks like rain is about to commence down here in Asbury. Quite windy and 70

[bluewave]

The 18z NAM also has 60+ mph gust potential tonight in the NY Bight. The SST's are plenty warm in the 73 -75 degree range. This will allow the convection to mix the LLJ down. We just saw the convection really intensify over this region a few days ago with the cold front.

 

[SRRTA22]

Wind Advisory issued for NYC

[LongBeachSurfFreak]

Full on sand storm currently at jones beach!! Amazingly people are still here

[OHweather]

I think the wind advisory is a good call.  I'm new to the area and am excited we're getting a pretty legit coastal storm in July of all months not even two weeks after I moved...now let's do it in winter (with a track a few hundred miles farther east please)...

Not sure if being right on the water helps, but normally those model wind gust maps are pretty overdone in warm air advection regimes, which this is.  I really seriously doubt gusts close to hurricane force, though the Euro and HRRR both do show it.  Even so, there should still be a nice breeze...aside from near the coast where the gradient should give a several hour period of 40MPHish gusts with an hour or two of more, it's a really short window.  I'm guessing inland areas will gust into the 20s for a few hours with maybe an hour or two where they can gust higher.  A couple of BUFKIT images for Sandy Hook, which I'm guessing will give about as favorable profile for wind as any in this area...

This is 6z, when the NAM has the strongest LLJ moving overhead.  The momentum transfer tool only shows transfer up to about 400' where the flow is 40kt/46MPH, though it only takes a small amount of imagination to see some ability to mix down from about 1000' where winds are 49kt/56MPH.  In general, in a WAA regime, the average wind speed in the mixed layer will give you a better idea of typical gusts than the speed at the very top of it...eyeballing the lowest 1k feet the average is probably about 40kt, maybe a bit more...which does suggest gusts to around 50MPH.

Now, here's the next hour as we start getting into the warm sector and actually destabilize a bit more in the low levels.  The strong LLJ is quickly lifting north, and winds in the lowest 1k feet are 35kt or less...though it's somewhat unstable up to around 3500', so there'd be some potential to tap int close to 50kt winds still, especially with any convection. 

The winds from there on out continue to gradually weaken while also veering more towards the due south.

So all in all, a brief window for decent winds.  Along the coast, despite the WAA regime and stable low levels, gusts to 40MPH or higher for a few hours starting around 9-10pm seem likely just due to the pressure gradient and decent fetch for winds to pick up speed off the water.  The winds right along the coast may be able to hit close to 50MPH gusts from the gradient alone...they're already getting gusts into the 30s down the south on the coast and the gradient is expected to tighten considerably as the low moves north over the next several hours.  As shown above, there's a brief window along the coast right on the edge of the warm sector before the LLJ starts relaxing where winds near 60MPH could be tapped...in a WAA regime I wouldn't count on it in most instances, though any convective elements could improve chances for local gusts close to 60MPH along the coast.  Perhaps those would be handled with SVRs from the NWS. 

More than a few miles inland, I suspect that due to friction and perhaps slightly cooler surface temps/even more stable low-levels that gusts just from the gradient will probably be in the 20-30MPH range...however, even inland, there may be a narrow window right around or just after midnight when the warm sector starts moving in for higher gusts...suspect that inland any gusts over 40MPH will be pretty dependent on convection on the edge of the warm sector dragging down stronger winds...though again, winds of 60MPH could be tapped, so it may be enough for some sort of Severe Thunderstorm Warning for affected areas if it pans out...but probably only for very localized areas.

As for the heavy rain, there's a brief period of impressive lift on the nose of the very strong LLJ this evening...however, with a lack of upright instability at that point (slantwise sure, but no real CAPE on the soundings then at any level) suspect rates will be under half an inch per hour...and that will lift north across the area fairly quickly.  There will be a window overnight where some upright convection will actually be possible as the warm sector builds in with PWATs greater than 2"...that could bring much higher rates, though in most cases it looks like it should keep moving.  I know it doesn't take much for some street flooding in the very urban areas in and surrounding NYC, so that would be possible with any convection...though it's been dry for a few days and overall totals will likely be pretty manageable (probably a widespread 0.75-1.25"), so other than some mainly brief urban issues in the middle of the night with any convection I kind of doubt there's significant flooding. 

There's also a narrow window right on the edge of the warm sector where a strong low-level flow that veers with height coincides with some skinny CAPE in which weak, rotating updrafts may be possible.  Generally agree with the 2% TOR risk for areas near the coast...the instability is so meager that anything would be pretty low-topped and may have trouble sustaining itself given the strong winds that can rip apart the updrafts...but with low LCLs and a brief period of high SRH as the low-levels destabilize, there could be a brief tornado with any more robust cells. 

[dmillz25]

15 minutes ago, OHweather said:

I think the wind advisory is a good call.  I'm new to the area and am excited we're getting a pretty legit coastal storm in July of all months not even two weeks after I moved...now let's do it in winter (with a track a few hundred miles farther east please)...

Not sure if being right on the water helps, but normally those model wind gust maps are pretty overdone in warm air advection regimes, which this is.  I really seriously doubt gusts close to hurricane force, though the Euro and HRRR both do show it.  Even so, there should still be a nice breeze...aside from near the coast where the gradient should give a several hour period of 40MPHish gusts with an hour or two of more, it's a really short window.  I'm guessing inland areas will gust into the 20s for a few hours with maybe an hour or two where they can gust higher.  A couple of BUFKIT images for Sandy Hook, which I'm guessing will give about as favorable profile for wind as any in this area...

This is 6z, when the NAM has the strongest LLJ moving overhead.  The momentum transfer tool only shows transfer up to about 400' where the flow is 40kt/46MPH, though it only takes a small amount of imagination to see some ability to mix down from about 1000' where winds are 49kt/56MPH.  In general, in a WAA regime, the average wind speed in the mixed layer will give you a better idea of typical gusts than the speed at the very top of it...eyeballing the lowest 1k feet the average is probably about 40kt, maybe a bit more...which does suggest gusts to around 50MPH.

Now, here's the next hour as we start getting into the warm sector and actually destabilize a bit more in the low levels.  The strong LLJ is quickly lifting north, and winds in the lowest 1k feet are 35kt or less...though it's somewhat unstable up to around 3500', so there'd be some potential to tap int close to 50kt winds still, especially with any convection. 

The winds from there on out continue to gradually weaken while also veering more towards the due south.

So all in all, a brief window for decent winds.  Along the coast, despite the WAA regime and stable low levels, gusts to 40MPH or higher for a few hours starting around 9-10pm seem likely just due to the pressure gradient and decent fetch for winds to pick up speed off the water.  The winds right along the coast may be able to hit close to 50MPH gusts from the gradient alone...they're already getting gusts into the 30s down the south on the coast and the gradient is expected to tighten considerably as the low moves north over the next several hours.  As shown above, there's a brief window along the coast right on the edge of the warm sector before the LLJ starts relaxing where winds near 60MPH could be tapped...in a WAA regime I wouldn't count on it in most instances, though any convective elements could improve chances for local gusts close to 60MPH along the coast.  Perhaps those would be handled with SVRs from the NWS. 

More than a few miles inland, I suspect that due to friction and perhaps slightly cooler surface temps/even more stable low-levels that gusts just from the gradient will probably be in the 20-30MPH range...however, even inland, there may be a narrow window right around or just after midnight when the warm sector starts moving in for higher gusts...suspect that inland any gusts over 40MPH will be pretty dependent on convection on the edge of the warm sector dragging down stronger winds...though again, winds of 60MPH could be tapped, so it may be enough for some sort of Severe Thunderstorm Warning for affected areas if it pans out...but probably only for very localized areas.

As for the heavy rain, there's a brief period of impressive lift on the nose of the very strong LLJ this evening...however, with a lack of upright instability at that point (slantwise sure, but no real CAPE on the soundings then at any level) suspect rates will be under half an inch per hour...and that will lift north across the area fairly quickly.  There will be a window overnight where some upright convection will actually be possible as the warm sector builds in with PWATs greater than 2"...that could bring much higher rates, though in most cases it looks like it should keep moving.  I know it doesn't take much for some street flooding in the very urban areas in and surrounding NYC, so that would be possible with any convection...though it's been dry for a few days and overall totals will likely be pretty manageable (probably a widespread 0.75-1.25"), so other than some mainly brief urban issues in the middle of the night with any convection I kind of doubt there's significant flooding. 

There's also a narrow window right on the edge of the warm sector where a strong low-level flow that veers with height coincides with some skinny CAPE in which weak, rotating updrafts may be possible.  Generally agree with the 2% TOR risk for areas near the coast...the instability is so meager that anything would be pretty low-topped and may have trouble sustaining itself given the strong winds that can rip apart the updrafts...but with low LCLs and a brief period of high SRH as the low-levels destabilize, there could be a brief tornado with any more robust cells. 

Always good to have new people posting here especially a meteorologist! Welcome!

[OHweather]

4 minutes ago, dmillz25 said:

Always good to have new people posting here especially a meteorologist! Welcome!

Thanks!  Hopefully trading lake effect snow and (somewhat) better severe weather for being in the area that sees big coastal storms ends up being a good move, haha 

[LongBeachSurfFreak]

5 minutes ago, dmillz25 said:

Always good to have new people posting here especially a meteorologist! Welcome!

I second that!! Welcome. This is a pretty good area weather wise as we can see pretty much anything nature has to offer! 

[dmillz25]

1 minute ago, OHweather said:

Thanks!  Hopefully trading lake effect snow and (somewhat) better severe weather for being in the area that sees big coastal storms ends up being a good move, haha 

You may be in luck this year with the solar minimum and west based el niño

[USCG RS]

You may be in luck this year with the solar minimum and west based el niño

This year does look rough I'm regards to plenty of snow...

Sent from my SM-N950U using Tapatalk

[Drz1111]

- warm rain process seems active, with the lack of lightning

- good shear showing up with the S-shaped velocity scans

- anything convecting with any depth is showing weak rotation

- I wouldn’t be surprised to see a weak spin up overnight.  Very similar to being on the east side of a TC undergoing ET transition.  Once you get “mini warm sectored”, there’s always a shot at something surface based.  LCLs low enough.

[jm1220]

2 hours ago, OHweather said:

Thanks!  Hopefully trading lake effect snow and (somewhat) better severe weather for being in the area that sees big coastal storms ends up being a good move, haha 

Thanks for the great discussion and welcome! Down here winds are picking up with some 25-30mph gusts and light rain has started. Could be a pretty wicked few hours overnight where I am, maybe strong enough wind for some power outages. 

[NewYorkweatherfan]

Wow you see that rain/snow line approaching?

[CIK62]

The wind (not gusts) is 40mph  just 225 miles south of NYC, and nearing 20mph here.    Storm near  38N   76W at 1004mb. and has a circulation of its own up to 700mb. now.    Above that level it seems to be sharing itself with the GL low pressure area.

[OHweather]

The models really ramp up the easterly LLJ over the next couple of hours, so we'll see if the obs down south along the coast start responding.  So far I guess we're on track, with occasional gusts in the 30-40MPH range showing up on the NJ mesonet and a few ASOS sites near the coast and considerably lower inland.  Nasty area of rain on the west side of the low from DC into PA...as expected looks relatively meh coming into our area, but we'll see how much embedded convection can wrap in as the LLJ intensifies and moves north.

[dmillz25]

9 minutes ago, OHweather said:

The models really ramp up the easterly LLJ over the next couple of hours, so we'll see if the obs down south along the coast start responding.  So far I guess we're on track, with occasional gusts in the 30-40MPH range showing up on the NJ mesonet and a few ASOS sites near the coast and considerably lower inland.  Nasty area of rain on the west side of the low from DC into PA...as expected looks relatively meh coming into our area, but we'll see how much embedded convection can wrap in as the LLJ intensifies and moves north.

There’s a cell incoming into Brooklyn at the moment 

[OHweather]

6 minutes ago, dmillz25 said:

There’s a cell incoming into Brooklyn at the moment 

It’s the stuff east of the Delmarva that will probably be most interesting as it comes north. 

[forkyfork]

KDOX being down really sucks

[NortheastPAWx]

15 minutes ago, forkyfork said:

KDOX being down really sucks

When doesn't that radar go down during a coastal event?

[qg_omega]

42 minutes ago, OHweather said:

The models really ramp up the easterly LLJ over the next couple of hours, so we'll see if the obs down south along the coast start responding.  So far I guess we're on track, with occasional gusts in the 30-40MPH range showing up on the NJ mesonet and a few ASOS sites near the coast and considerably lower inland.  Nasty area of rain on the west side of the low from DC into PA...as expected looks relatively meh coming into our area, but we'll see how much embedded convection can wrap in as the LLJ intensifies and moves north.

Looks as expected, the furthest West models nailed this storm, NAM from 84hrs out nailed it, Euro was awful

[Stormlover74]

Getting some higher gusts now with the heavier echoes passing through

[Rtd208]

Picked up 0.16" of rain so far.

[Will - Rutgers]

5 hours ago, OHweather said:

Truncated 

Fantastic post and welcome to the area.

P.s. if you want Zach Britton for your bullpen let me know, I know a guy who knows a guy.

Who knows another guy.

Anywho it is cool and rainy and beautiful here in Piscataway.  Enjoy all.  This storm is a rare July treat.

[OHweather]

23 minutes ago, qg_omega said:

Looks as expected, the furthest West models nailed this storm, NAM from 84hrs out nailed it, Euro was awful

These storms in which their deepening is heavily tied to convection will always be kind of tough on models.  The NAM did do well enough with it certainly.

Starting to get a little more interesting now...Upton issued a Marine Warning south of Long Island for 34kt+ gusts and waterspouts...there's a bit of rotation on radar but no low-level instability yet, so I question the waterspout potential with that band.  Velocities on DIX have increased markedly offshore over the last hour, with mesoanalysis showing 50-60kt 925mb winds offshore the Delmarva near that band of better convection.  ASOS sites still pretty meh with winds this hour, but some mesonet sites hitting 40+MPH right along the coast and into the low 20s inland in some areas.  Should ramp up some more as the LLJ intensifies and moves up the coast...that band of convection approaching the southern tip of NJ, if it holds together, would be the one to watch for locally severe gusts and perhaps a tornado risk.  

Just now, Will - Rutgers said:

Fantastic post and welcome to the area.

P.s. if you want Zach Britton for your bullpen let me know, I know a guy who knows a guy.

Who knows another guy.

Anywho it is cool and rainy and beautiful here in Piscataway.  Enjoy all.  This storm is a rare July treat.

Thanks! Heh, I like the guys the Indians got from the Padres.  We need an outfielder though. 

[Rtd208]

Rain and wind picking up in intensity here.

[jm1220]

Cell with the marine warning attached about to come through. Breezy down here but nothing crazy. 

[forkyfork]

1 hour ago, NortheastPAWx said:

When doesn't that radar go down during a coastal event?

the worst was kdix going down during irene

[USCG RS]

Thanks! Heh, I like the guys the Indians got from the Padres.  We need an outfielder though. 

Welcome to the area and welcome aboard. Clear, concise and very informative discussion thus far. You have my thanks.

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[LongBeachSurfFreak]

Pretty meh so far on the island. It seems like the convection pulses over the Gulf Stream and then dies as it heads over cooler water. Still plenty of time as the the low heads north

[MJO812]

Showers right now

 

The rain was heavier earlier this evening