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]

13 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'easter In Sep before, heck we get them in the summer sometimes, 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!"