weatherwiz

Missing the warm nights. Standing outside with shorts/short-sleeved shirt not very fun tonight 

Tuesday may end up holding the day with most potential here for western sections. What happens on Tuesday may end up pushing the boundary well southwest on Wednesday and we end up very stable 

Tuesday shaping up to probably be a tornado outbreak NY/PA and maybe even including SW VT/W MA/W CT so long llvl flow is more southerly. 

The weather pattern across the CONUS the past few months has been dominated by a large ridge of high pressure across the southern Plains with the ridge centered within the New Mexico - Louisiana vicinity. This has resulted in a prolonged period of some extreme heat within this region while also yielding convectively active periods within portions of the Great Plains, upper-Midwest, and Ohio Valley region. Computer forecast models have been consistent in the eastward expansion of this ridge across the deep South with an eastwards shift in the ridge axis farther northeast, potentially into the Mississippi or Tennessee Valley region (this does greatly impact us). The shift in the ridge axis would push the periphery of the jet stream across the northern tier of the Great Lakes region and across New England. 

As we speak, high pressure is building into the region and will dominate through the weekend, however, late Sunday a weak cold front approaches from the north. Computer forecast models then stall the front within the region on Monday and this is where the fun begins. An unseasonably strong northwesterly flow is expected to overspread the region along the periphery of the upper-level ridge early in the week, meanwhile a more westerly surface flow (south of the weak stationary front) will advect warmer and more humid air from the Ohio Valley into the region. Multiple shortwave impulses will traverse the jet, originating from the upper-Midwest/Canada. This will offer the opportunity for multiple thunderstorm clusters to develop across southern Canada and the northern Great Lakes which and traversing the region Monday and again on Tuesday. The biggest key here is where will the instability gradient reside? Historically, this seems to favor New York, Pennsylvania, New Jersey, and perhaps far southwest Connecticut but this is going to be highly dependent on where that stationary front resides and how strong is the push of warmer and more moist low-level air.

The more intriguing day is expected to be on Wednesday. This is when computer forecast model guidance advances a sharper trough across southeast Canada with a cold front moving into the region at the surface with the stationary front perhaps lifting back northeast as a warm front. In addition, there have been some hints at the potential advection of remnant elevated mixed-layer air. In addition, flow aloft, particularly  in the lower levels is expected to increase and should the low-level flow become more southwesterly or southerly, this would result in a greater surge of moisture into the region and potential for moisture pooling. Within the warm sector, 850mb temperatures are forecast to climb to +17C to +20Cwith 850mb dewpoints +15C to +17C. This would yield potential for surface temperatures well into the 80's and surface dewpoints well into the 60's to lower 70's. This combination, potentially under the presence of steep mid-level lapse rates under the presence of an advecting elevated mixed-layer would yield potential for moderate instability (MLCAPE > 2500 J/KG) to develop. 

The combination of a moderate unstable airmass with increasing shear and forcing would net the likelihood for scattered-to-numerous thunderstorms developing during the afternoon on Wednesday; including potential for line-segments and supercells with hazards of damaging wind gusts, large hail, and perhaps even the risk for a few tornadoes if we can get some turning of the low-level flow and enlarged hodographs. At this time, the greatest potential seems to be across Pennsylvania, New York, and northwest New Jersey, however, this is all highly dependent on key surface features but western southern New England would definitely be in play. While the threat for strong-to-severe thunderstorms would gradually wane with the loss of daytime heating, showers and thunderstorms could work their way through the coast Wednesday night. 

Lots of details to iron out over the coming days!

1 minute ago, Damage In Tolland said:

No reason to break the summer pattern. Those two zones locked in , in May and has been relentless with each front 

Well the structure of the pattern is a bit different this go around with the core of the ridging a bit farther north and east so this bodes well for NY into New England. There will be lots of details to iron out too. For example, there will be a weak stationary front within the region which will be the boundary between unseasonably warm/humid weather versus cooler and less humid. This will be critical because this will establish the instability gradient. Secondly, the real big question is EML advection and can we maintain an EML into the region. 

11 minutes ago, bairn said:

Hi guys, hate to interrupt, but my daughter’s getting married 9/5 in Sterling Ct. Ryan’s 10 day looks good, but any thoughts would be greatly appreciated. Cheers

Looks like High Pressure building in late next week behind the passage of the front late Wednesday which would bode well for a dry weekend

18 minutes ago, Damage In Tolland said:

Congrats DXR southwest 

Just now, CoastalWx said:

Congrats NJ to DXR

Ultimately, I can see two corridors, one from SW CT into NJ and a second across NY into northwest MA/VT...this area could have potentially greater severe probabilities and tornado threat, especially if that LLJ ramps up a bit earlier than forecast  

Might start a thread for Monday - Wednesday (with a focus on Wednesday) just because I feel like it and people can post their feels about how they won't get anything 

LFG. 

I take the L on today 

booooooo

probably getting some hail in Ridgebury, CT

Part of the problem is their infrastructure with drainage is crumbling...not too mention everything is clogged with garbage  

6 minutes ago, Typhoon Tip said:

I've noticed that too over recent seasons...  I suspect ( not intending to impugn any organization ) that it's largely cultural/institutional reliance on modelling.  

When and if a TC is born out of an invest, if/when it occurs ahead of the modeling, that's when we get the jump - because they can't wait for the models, if the TC is there, it's there. 

Along these lines, the model reliance is also why sometimes you look out there and see an impressive wave that even appears to be closing off a circulation, yet NHC has the basin in a nada status. It's because no model has it developing.  The models went through an evolutionary upgrade over the last 10 to 15 years. Katrina and Maria's sort of lit a candle under the ass of R&D. Proven in their forecast statistics.  They became objectively better at initialization, improving over human intuition and monitoring of prior generations.

I don't personally have any issue with the model reliance - their performance is what it is.  They may not be ideal with aspects like RI this or shear that after the fact, but in so far as putting the TC on the map -

That's an interesting take. And by no means am I speaking negatively about the NHC or questioning this in a negative manner, its just an observation. At least with Dolly, I'm a bit surprised at the "comeback" made over the last 24-hours. It was clearly being impacted by a hostile environment but it survived and, at least for a brief period, is in a less hostile environment. 

What's with this recent uptick of tropical systems going straight from Invest to Tropical Storm

Nice mid-level meso on that cell headed towards Fairfield County. 

1 minute ago, Brian5671 said:

had a quick shower here but everything's hitting a brick wall around the CT/NY border

This is a good thing...allowing more breaks of sun and stronger instability to build. There is a subtle pre-frontal trough back across eastern PA to west of the Hudson. This should slide east during the day and that's when we'll see storms develop across the Hudson and western MA/CT...at least this is what I ws envisioning yesterday occurring but guidance does show this eastward shift. I still think it will be an active day for western sections 

3 minutes ago, Torch Tiger said:

next Tuesday could be fun, esp. SW NE?

Its a really good pattern for MCS developing across the Great Lakes and propagating ESE across the Northeast (whether that ends up being just to our southwest or more across northern VT/NH and ME). One thing really lacking is some stout EML advection, though the GFS does hint at some plumes of steeper lapse rates trying to move in at times but they lose their integrity. If we can get a clear signal for EML advection we could rock next week

2 minutes ago, Typhoon Tip said:

A little more encouraged re convection today as the orientation of the fields has a better change for residuals chugging E of the ignition region

Agreed. Models too continuing to show enlarging of the hodographs through the day as well with decent instability. 

Kind of surprised we don't have a marginal tomorrow. I guess that will come at 1730

The slight east has been expanded eastward. Will be a fun day into MA/CT 

6 minutes ago, Typhoon Tip said:

I'm actually quite interested in the test for RONI

In physics, physicists are always chomping at the bit for natural extremes, because it is at the boundaries of what is conceived as possible, that the boundaries finally get to be tested.  

RONI isn't exactly an offset factor to the prior generational ENSO, whereby a laboratory test can be very readily examined (... droll understatement).    In fact, there is NO way to do that. It has to be tested by the vagarious doings of the wholesale atmospheric hemisphere(s) over time.  

This is one of those times.  Agreed.  The extremeness of +ENSO definitely puts a plan in place that gives RONI ( I suspect...) it's best test to date.  If this were to say go over the unthinkable 3.5 ...then a 2.7 equivalent attack on the canonical climate pathways should be observable.   I mean if this ENSO gets out of whack and STILL there were comparatively/relatively minor impacts, then the amount of RONI's current importance/significance gets a side eye look as not being enough - and vice versa. etc

Same here.

I've been wanting to dig into this more too but I'm really curious as to the LA Nina events of 2017-2018, 2020-2021, and 2021-2022...for some reason these seasons exhibit some larger spread in the trimonthly numbers versus the traditional ONI and ENS-ONI. Even 2025-2026 I think had this to some degree. 

5 minutes ago, Brian5671 said:

what am I missing-models don't have much for the coast at least-looks well N and W

Activity will be more on the widespread side into western CT...probably up to the CT River. Activity begins isolated but should quickly organize into short lines and clusters.

1 minute ago, Chrisrotary12 said:

Earthquake caused an avalanche that transitioned into a flash flood?

Sounds like the Earthquake caused an avalanche and the snow/ice dumped into a river and caused a major blockage, allowing the water to build up and unfortunately cause the flooding. Heartbreaking. I can't imagine being in a situation like that, trying to run with essentially nowhere to go and not a chance to outrun it. 

5 minutes ago, Damage In Tolland said:

Yesterday tomorrow had potential, now it’s mainly a dry fropa. 
Pass

The front comes through on Friday, anything tomorrow would be pre-frontal trough related. Hudson Valley to the CT River will see scattered storms develop during the afternoon, perhaps evolving into multiple lines but there won't be much in the way of west-to-east progression, will be more southwest-to-northeast so probably will see some flash flooding where storms train...probably within the CT River Valley and Naugatuck Valley (should start mentioning them too for future reference because of the rate they flood in these setups).  

8 minutes ago, CoastalWx said:

Oh boy the excitement 

Friday could be a sneaky severe weather risk for eastern sections