October Comes Early: Late September Multi-Hazard Hybrid Storm

[Chrisrotary12]

NYC gonna flood with this thing right?

[Brian5671]

7 minutes ago, CoastalWx said:

OKX should have a high wind warning for LI and maybe even srn CT. JMHO.

May see it later...

[Chrisrotary12]

God this storm is annoying from a forecast perspective. Some models bring rain in here tomorrow. Others don’t until Sunday. 

[WinterWolf]

7 minutes ago, Chrisrotary12 said:

God this storm is annoying from a forecast perspective. Some models bring rain in here tomorrow. Others don’t until Sunday. 

There won’t be any rain there tomorrow imo. 

[TauntonBlizzard2013]

3 hours ago, WinterWolf said:

Shocking.  Are you ever sold?  I mean you’re never sold until the storm ends at your house.  

I mean this is a hybrid type storm in a transition season.

Im sure it’ll be breezy at least, but I don’t think it’s crazy to envision lots of dry periods followed by quick downpours rotating through.

Some areas will do well, but I wouldn’t expect like 2+ totals to be widespread 

[kdxken]

29 minutes ago, WinterWolf said:

And with a high pressure of that magnitude also…that’s highly anomalous too in September. 

Yeah something strange is going on. Probably happened back in the 1700s too. 

 

 

 

[kdxken]

5 minutes ago, TauntonBlizzard2013 said:

I mean this is a hybrid type storm in a transition season.

Im sure it’ll be breezy at least, but I don’t think it’s crazy to envision lots of dry periods followed by quick downpours rotating through.

Some areas will do well, but I wouldn’t expect like 2+ totals to be widespread 

How much for Taunton?

[kdxken]

16 minutes ago, Chrisrotary12 said:

God this storm is annoying from a forecast perspective. Some models bring rain in here tomorrow. Others don’t until Sunday. 

Book a tee time. It'll rain. Hard.

[dryslot]

4 hours ago, kdxken said:

Jessuss! You're a shoe in to take the Halloween contest. 

I should've zigged when i zagged?

[vortex95]

This is a much "warmer" type ET to ST/T suggested transition.  The ET surface low has developed in a more tropical-type atmosphere.  As noted earlier, the low is located S of the 576 dm 1000-500 thickness line, and as it develops, a pool of 576 closes off over it.

Also, initial ET development to ET peak to ST/T transition can occur very quickly at times. The system off the Mid-Atlantic/New England coasts in mid-January 2023 went ET to ST rather fast (personally I think this was tropical and a hurricane), developing a distinct, persistent eye and remarkably deep convection for a winter atmosphere.  See sat loops here:
https://x.com/WxTca/status/1615532584016162822
https://x.com/burgwx/status/1615099242728628231
 

If this can occur in January, there is no reason to think this can not occur here in September over significantly warmer SSTs and a less overall sharp baroclinic environment!
 

The point being extraordinary/outlier patterns often result in extraordinary/outlier individual wx events, so we need to adjust/adapt for that and think outside the box in such cases.
 

[vortex95]

Concerning @CoastalWx's "garbage model" and how it handles TCs...

Given the RRFS is new, I am not sure it handles TCs.  I asked the modeling group if it handles TCs well.  They said it should, but they said ti defer to the HAFS and the like.  This event will be a good test at least when it comes to ET to ST/T transition.

The RRFS is about 10 mb deeper than the other models, and shows a tight inner core pressure gradient eventually.  That indicates tropical structure.

[vortex95]

19 hours ago, Prismshine Productions said:

Unnamed Subtropical Storm 1968
85mph
979mb


 

Wow, I had no idea there were STS in HURDAT2 that had winds in excess of 60 kt.

Since NHC started declared ST systems regularly in the late 1990s, the has never been a "subtropical hurricane."  The reasoning I heard is that if a ST system gets winds strong enough to reach hurricane-strength, it is can called fully tropical, which doesn't make any sense really.  65 kt is not some magic number that changes the structure of a storm.  Many ET storms have sustained winds well over 65 kt, and there is nothing says they can't still have 65 kt when they go ST!
 

[WxWatcher007]

17 minutes ago, vortex95 said:

This is a much "warmer" type ET to ST/T suggested transition.  The ET surface low has developed in a more tropical-type atmosphere.  As noted earlier, the low is located S of the 576 dm 1000-500 thickness line, and as it develops, a pool of 576 closes off over it.

Also, initial ET development to ET peak to ST/T transition can occur very quickly at times. The system off the Mid-Atlantic/New England coasts in mid-January 2023 went ET to ST rather fast (personally I think this was tropical and a hurricane), developing a distinct, persistent eye and remarkably deep convection for a winter atmosphere.  See sat loops here:
https://x.com/WxTca/status/1615532584016162822
https://x.com/burgwx/status/1615099242728628231
 

If this can occur in January, there is no reason to think this can not occur here in September over significantly warmer SSTs and a less overall sharp baroclinic environment!
 

The point being extraordinary/outlier patterns often result in extraordinary/outlier individual wx events, so we need to adjust/adapt for that and think outside the box in such cases.
 

 

Look at that first loop!!!

That's 100% tropical. Look at that convection wrap tightly around the center. Beautiful. Riding right along the Gulf Stream. Perfect location. 

[vortex95]

13 hours ago, WinterWolf said:

Yes, I was being funny.
 

 But let me ask you this, Vortex95 has been talking about ST or even T for a couple days now…even when modeling wasn’t showing that at all.   I didn’t see you mention any of that?  Why is that?  Was he seeing something you weren’t?   

@CoastalWx is by far lopsided and the fully versed weenie guru for winter wx.  He's kinda weak in svr local storms and TCs!  When we worked at WSI, he would always defer to me for those topics!   And his typical reply after I would explain a situation?  "WE'LL SEE!"  LOL.

The biggest contribution I recall I did for him that he has actually acknowledged?  We we discussing the 6/1/11 TOR event and the problem/issues w/ the Springfield warnings, and I said to Scott, "no excuse to hesitate, this day was screaming big a classic spinner day for New England -- situational awareness is huge leading up to such an event!"  And he liked the term "situation awareness!"

[Ginx snewx]

38 minutes ago, TauntonBlizzard2013 said:

I mean this is a hybrid type storm in a transition season.

Im sure it’ll be breezy at least, but I don’t think it’s crazy to envision lots of dry periods followed by quick downpours rotating through.

Some areas will do well, but I wouldn’t expect like 2+ totals to be widespread 

Lol you just described a system that has tropical characteristics 

[WxWatcher007]

18z Euro was pretty wet. 

Sorry if someone posted earlier. 

[WinterWolf]

37 minutes ago, dryslot said:

5 minutes ago, WxWatcher007 said:

18z Euro was pretty wet. 

Sorry if someone posted earlier. 

Yes, but it’s cool Don.  I guess TBlizz didn’t see that run?  That would be widespread 3 inches plus.  

[vortex95]

14 hours ago, jbenedet said:

I don’t think sub 990 mb mslp happens south of 40N in late September unless there is a tropical aspect to the system.

Baroclinicity alone isn’t sufficient for that level of deepening.

Excellent point.  I know of no sub-990 mb case in September for baroclinic deepening alone.  Not that there has not been Nor'easters in Sep before, heck we get them in the summer sometimes, but the sfc low typically doesn't get too deep.  995-1000 usually is the limit.

This event from July 22, 1983 stands out as one of the more impressive sfc lows for mid summer close to New England.  15z satellite image -- low was about 990 mb at this time.


 

[CoastalWx]

17 minutes ago, vortex95 said:

@CoastalWx is by far lopsided and the fully versed weenie guru for winter wx.  He's kinda weak in svr local storms and TCs!  When we worked at WSI, he would always defer to me for those topics!   And his typical reply after I would explain a situation?  "WE'LL SEE!"  LOL.

The biggest contribution I recall I did for him that he has actually acknowledged?  We we discussing the 6/1/11 TOR event and the problem/issues w/ the Springfield warnings, and I said to Scott, "no excuse to hesitate, this day was screaming big a classic spinner day for New England -- situational awareness is huge leading up to such an event!"  And he liked the term "situation awareness!"

[CoastalWx]

Hrrr trying to wrap this towards Wallops Island lol. That’s cute. 

[vortex95]

14 hours ago, CoastalWx said:

I think I did mention that a couple days ago in a post. But honestly to me that doesn’t matter in terms of sensible Weather. I’m just trying to figure out where the storm is going and what the winds and rain will be. It may briefly attain tropical characteristics, but once it gets towards 40 north, it’ll definitely become more subtropical.

This is fascinating evolution and not something that occurs that often.  @CoastalWxneeds to broaden his wx horizons a bit, in addition to within 5 mi of Weymouth! 

Regardless of what the sfc low becomes, yes, it is irrelevant to the sensible wx impacts, unless it get "cute" and retains core TC characteristics as drifts near the S Coast!

[WinterWolf]

4 minutes ago, CoastalWx said:

Hrrr trying to wrap this towards Wallops Island lol. That’s cute. 

That’s way the heck down in the Delmarva lol.

[vortex95]

12 hours ago, Great Snow 1717 said:

Page hits...give it a few more hours and they will have Jim Cantore interviewing Noah with the ark in the background...

 

 

 

 

 

 

[DirtySnowDen]

Take aways for the LI Waddler:

1. Anomalously (and broad) high-pressure system that is trying to sink South and West.

2. Some sort of Tropical burp that is intensifying. 

3. The lack of an Atlantic Hurricane thus far.

4. The chance of said high pressure system splitting.

5.  One of the strongest El Niños (if not the strongest) on record.

6. SST near or record levels.

6.1 Gas getting close to its record levels (for the generators)

7. Full-moon.

This thing will wreck havoc, 12z runs were the 3-day burp that happens.

[vortex95]

9 hours ago, WxWatcher007 said:

My only concerns with keeping it warm core longer are

1) the SSTs once you pass Cape May

and 2) the amount of time this will need to contract and organize. 

We're not looking at pure TC genesis here, so maybe both those things are moot, but if you want tropical from a sprawling area of low pressure you usually need a lot of time. If this were hanging out over the Gulf Stream longer, sure, but I don't think we'll have that here. 

Don't be too focused on the 26 C SST line.  STS can occur w/ SSTs as low as 15 C, and the Jan 2023 event  (a hurricane IMHO) formed a nice convective ring w/ a persistent eye over 21-23 C SSTs and retained this structure remarkably well to 40N, and still looked really good and tropical-like when it passed Sable Island where SSTs were 7 C.  I posted the sat loop earlier, and you'll see what i mean.  HU Alex in Jan 2016 way out in the Atlantic was like this,  It actually look best when it accelerating N over cooler SSTs w/ a distinct eye!
 

[DirtySnowDen]

It’s gonna ride and a tuck, the west-based high pressure wraps in the upper cold air, while the weaker easterly Atlantic high pressure fuels  it with low level moisture.

[CoastalWx]

Both NAMs figuring it out now. Not trying to bury it immediately towards WAL.

[Masswx]

Hopefully I wake up and it trended 150 miles north on Nams and hrrr

[vortex95]

1 hour ago, kdxken said:

Yeah something strange is going on. Probably happened back in the 1700s too. 

 

 

 

10 to 50 times more likely than *what*?  I see this often and there is no reference context and perspective given!

Here's the problem w/ such stats.

Atmospheric state variables (e.g. temp, vapor pressure, pressure, etc) are integrated into a highly complex, multi-variate, non-linear system.  Axiomatically, meteorological variables exhibit non-Gaussian characteristics. That is, they don't follow a normal (Gaussian) distribution. “Unlikely events” like intense heatwaves, as it turns out, aren't as “unlikely” as it might seem in a non-Gaussian world. 

The wx in the real world doesn’t follow a Gaussian/normal distribution curve.  Extreme events are far more common in a non-Gaussian distribution that reflects the physical world we live in.  Bell curve graphs are an inappropriate use of statistics.  Not only not Gaussian, but also the shape of the distribution changes w/ warming depending on location.

So they apply stats/numbers that do not apply to reality (Gaussian vs non-Gaussian).

When scientifically illiterate ppl try to normalize non-Gaussian disturbed data, you get the current nonsense.  And we go back to the ever present issue, "how to lie w/ statistics" 

And while on the subject, concerning "sigma values" and those "1-in-a-million year events."

Normalized anomalies used to be a good technique in meteorology to compare events by removing the mean and variance calculated from long-term gridded reanalysis data (30 yr), but now it's the hottest thing in climate activism.  Normalized anomalies should not be interpreted as return periods in this way. The distribution of atmospheric variables, including 500 mb geopotential height, is not normal, and the climatology used for these normalized anomalies only contains 30 yr at each grid point w/ a 15-day centered mean and standard deviation.    

You can verify this by scanning the globe at any given time looking at this quantity.  Say there is a Kona low at -5.5 sigma near HI for 500 heights.  Obviously, that's not a 1-in-a-million yr event.  500 heights get extremely low in intense hurricanes in the tropics, and you'll see sigmas like -15.  So that would mean a return rate longer than the Earth has existed.  See how ridiculous this gets?  But you get ppl parading these stats are as if they have any clue as to what they actually mean and how to apply them!

Also, in reference to the above avg SSTs.  You don''t need above avg SSTs to get an intense or record Nor'easter or any baroclinic storm.  What matters most by far is baroclinicity in the atmosphere and jet structure.  They have this vapid notion that things work linear 1-2-3 in the Earth's system, and *one* variable, like air temp or ocean temp, dictates everything else, and all else is trivial.  And feedbacks are rife, furthering the complexity.  An example of this is SSTs and TCs.  All the increased SSTs in the world do not matter of the atmosphere does not cooperate, as in TPW values and wind shear. TC formation alone by far is dictated by atmospheric parameters, not ocean parameters.  If SSTs were the biggest factor, we'd have far more TCs globally each year and they would not be confined to particular times of the year in each ocean basin.
 

[DirtySnowDen]

If you swinr your eyes. You can the eye form