DEC 18th-20th 2023--Wet, White, Wind?

I find it interesting how models are bringing the circulations up inside of the coast. Typically, when you see a ridge axis through Idaho, you’re golden to be on the west/cold side of a developing East Coast cyclone. Not too sure I buy such a western track……especially since the cold is pushing.

rb924119 wrote:I find it interesting how models are bringing the circulations up inside of the coast. Typically, when you see a ridge axis through Idaho, you’re golden to be on the west/cold side of a developing East Coast cyclone. Not too sure I buy such a western track……especially since the cold is pushing.

Perhaps the cold isn't pushing as hard as originally thought due to some of the prev stated mechanisms?

amugs wrote:

jmanley32 wrote:I know we all want snow but if the 00z GFS plays out we are in for some serious wind problems HWW criteria for a huge area, gusts near hurricane force along LI elsewhere 50-65mph (yes this is verbatim and likely is not going to be the true outcome, last time was almost nothing so). Just is a much more impressive wind map and dynamic powerful system than last weeks. Compliments of JB.

Reember this is the ensemble and blend from 0z

right so some are higher some lower correct? So I imagine there are some pretty nuts ensembles for these numbers to come from the blend.

So if anyone sees snow this would be a rain to snoe senario correct? Even your idea is of that nature Ray? Sorry I have been super busy and unable to follow fully but am hoping for the snow to go with the forecasted winds boy would that be fun. Rain...not so much, in fact miserable nothing like blasting cold water in your face and comes at rush our and a Monday, my most hated day lol

It’s possible, but geeze this pattern pattern looks awfully good to me for a shift of about 75-150 miles further east. The only thing that I can think of is that it’s because of the negative tilt of the western ridge. As the energy is consolidating over the southeast it’s allowing the downstream flow to back more than it otherwise would, thereby building the pseudo-NAO ridge. But as the northern stream energy dives, I would think that the building Atlantic ridge would force a “squeeze play” as it builds westward, but over the top of the diving northern stream, and not just get “fatter” at the base (for lack of a better description lol), thereby forcing the whole evolution further west. That gets to heehaw’s ridge bridge discussion from earlier, and I agree that I think it would help our situation, because it would induce higher pressures to the north of the storm and allow cold air advection to occur as the storm approaches.

jmanley32 wrote:So if anyone sees snow this would be a rain to snoe senario correct? Even your idea is of that nature Ray? Sorry I have been super busy and unable to follow fully but am hoping for the snow to go with the forecasted winds boy would that be fun. Rain...not so much, in fact miserable nothing like blasting cold water in your face and comes at rush our and a Monday, my most hated day lol

Correct the initial airmass is……crap lol

I mean, the southern stream trough isn’t even going negative until it’s at Florida’s longitude, in most cases, that’s almost too late lol typically, Alabama is the sweet spot, anecdotally.

For what it’s worth, the 12z RGEM and ICON are a little further east and colder, but still not where I think they should be. Definitely an interesting event to track and test ideas on haha

rb924119 wrote:I find it interesting how models are bringing the circulations up inside of the coast. Typically, when you see a ridge axis through Idaho, you’re golden to be on the west/cold side of a developing East Coast cyclone. Not too sure I buy such a western track……especially since the cold is pushing.

Is the cold/polar vort trajectory the issue, rather than the STRENGTH of the push? I feel like if it dives a certain way behind it, more meridionally, it could act as a sort of pivot or fulcrum?

6Z EURO



6Z GFS

Madonne, those winds are high. Granted, we saw how poorly the winds mixed down in last week's storm. But this one has a different look and feel to it. I can see the higher gusts mixing for sure along the coast.

amugs wrote:6Z EURO



6Z GFS

jeeZe, lights out... 12z GFS out? Interesting Euro less than GFS usually it seems the Euro is the most bullish on winds, I bet the NAM 3km spits out some crazy nonsense. I see Hight wind watches going up for most of the area soon today or tomorrow, as frank said especially the coast and just inland, but IMO it may mix even over the land areas its showing.

jmanley32 wrote:

amugs wrote:6Z EURO



6Z GFS

jeeZe, lights out... 12z GFS out? Interesting Euro less than GFS usually it seems the Euro is the most bullish on winds, I bet the NAM 3km spits out some crazy nonsense. I see Hight wind watches going up for most of the area soon today or tomorrow, as frank said especially the coast and just inland, but IMO it may mix even over the land areas its showing.

Upton is underwhelming. FWIW highest gusts that I saw on LI with the last one was 55MPH in Shoreham.


As for winds during this event, there`s an increasing chance of
at least advisory-criteria winds - particularly for coastal
sections. Winds at 925mb are progged at 60-80 kt along with
50-65 kt at 950 mb over coastal sections late Sunday night/early
Monday morning. It appears that the low level inversion will be
at least a little weaker than with this past weekend`s storm as
temps aloft would be cooler with SE winds instead of S-SW like
the previous system. Thinking there`s potential for 60-70% of
the 925mb winds to mix down to the surface, especially in
heavier downpours. Might even need to eventually consider high
wind watches over at least eastern Long Island.

sroc4 wrote:

jmanley32 wrote:

amugs wrote:6Z EURO



6Z GFS

jeeZe, lights out... 12z GFS out? Interesting Euro less than GFS usually it seems the Euro is the most bullish on winds, I bet the NAM 3km spits out some crazy nonsense. I see Hight wind watches going up for most of the area soon today or tomorrow, as frank said especially the coast and just inland, but IMO it may mix even over the land areas its showing.

Upton is underwhelming. FWIW highest gusts that I saw on LI with the last one was 55MPH in Shoreham.  


As for winds during this event, there`s an increasing chance of
at least advisory-criteria winds - particularly for coastal
sections. Winds at 925mb are progged at 60-80 kt along with
50-65 kt at 950 mb over coastal sections late Sunday night/early
Monday morning. It appears that the low level inversion will be
at least a little weaker than with this past weekend`s storm as
temps aloft would be cooler with SE winds instead of S-SW like
the previous system. Thinking there`s potential for 60-70% of
the 925mb winds to mix down to the surface, especially in
heavier downpours. Might even need to eventually consider high
wind watches over at least eastern Long Island.

With what I am seeing Wind Advisory Criteria will likely be met for coastal areas, nothing more. Pressure falls are pretty impressive but we have a rather stable airmass, and not a significant amount of momentum transfer to the surface. Anyone away from the immediate coast shouldn't be worried, unless you are at a high elevation and the LLJ comes screaming across you.

EURO ticked east/colder. It’s not by much. But I’m looking at these maps, and I have to be honest - I think I’ll be going down with this ship. Not because it’s my longstanding idea. I mean, yeah, that’s an underlying bias, but putting that aside, this setup is SCREAMING “SURPRISE!” to me for anybody west of the Delaware River. I have reasons for saying this that I won’t be able to elaborate on until later this evening after I get out of work, but basically, not only do I think this has room to come east a bit, but this is a pretty extreme frontogensis event, and I think there’s an inability by the models to resolve it. We still have three days to go, so there’s definitely time for further adjustments, but yeah, idk. It doesn’t seem right to me verbatim right now.

Quietace wrote:

sroc4 wrote:

jmanley32 wrote:

amugs wrote:6Z EURO



6Z GFS

jeeZe, lights out... 12z GFS out? Interesting Euro less than GFS usually it seems the Euro is the most bullish on winds, I bet the NAM 3km spits out some crazy nonsense. I see Hight wind watches going up for most of the area soon today or tomorrow, as frank said especially the coast and just inland, but IMO it may mix even over the land areas its showing.

Upton is underwhelming. FWIW highest gusts that I saw on LI with the last one was 55MPH in Shoreham.  


As for winds during this event, there`s an increasing chance of
at least advisory-criteria winds - particularly for coastal
sections. Winds at 925mb are progged at 60-80 kt along with
50-65 kt at 950 mb over coastal sections late Sunday night/early
Monday morning. It appears that the low level inversion will be
at least a little weaker than with this past weekend`s storm as
temps aloft would be cooler with SE winds instead of S-SW like
the previous system. Thinking there`s potential for 60-70% of
the 925mb winds to mix down to the surface, especially in
heavier downpours. Might even need to eventually consider high
wind watches over at least eastern Long Island.

With what I am seeing Wind Advisory Criteria will likely be met for coastal areas, nothing more. Pressure falls are pretty impressive but we have a rather stable airmass, and not a significant amount of momentum transfer to the surface. Anyone away from the immediate coast shouldn't be worried, unless you are at a high elevation and the LLJ comes screaming across you.

yeah nothing mentioned in HWO at all, doesn't seem like this will be much more than a dreary rainstorm, surprising for such a strong LP, is it mainly because it gets strung out? Though in recent runs it appears to have formed better. I dunno havent had time to look at much, other than wind hahaha. What else is there for me, not snow thats for sure.

I think they should do away with these wind maps or incorporate more accurately the mix down rate of what will actually show at the surface. I don't understand why that is not already the case. if these most often never pan out even close (ocasionally they do, and something about this tells me they might) then why bother and freak out the media as JB is always posting them.

jmanley32 wrote:

Quietace wrote:

sroc4 wrote:

jmanley32 wrote:

amugs wrote:6Z EURO



6Z GFS

jeeZe, lights out... 12z GFS out? Interesting Euro less than GFS usually it seems the Euro is the most bullish on winds, I bet the NAM 3km spits out some crazy nonsense. I see Hight wind watches going up for most of the area soon today or tomorrow, as frank said especially the coast and just inland, but IMO it may mix even over the land areas its showing.

Upton is underwhelming. FWIW highest gusts that I saw on LI with the last one was 55MPH in Shoreham.  


As for winds during this event, there`s an increasing chance of
at least advisory-criteria winds - particularly for coastal
sections. Winds at 925mb are progged at 60-80 kt along with
50-65 kt at 950 mb over coastal sections late Sunday night/early
Monday morning. It appears that the low level inversion will be
at least a little weaker than with this past weekend`s storm as
temps aloft would be cooler with SE winds instead of S-SW like
the previous system. Thinking there`s potential for 60-70% of
the 925mb winds to mix down to the surface, especially in
heavier downpours. Might even need to eventually consider high
wind watches over at least eastern Long Island.

With what I am seeing Wind Advisory Criteria will likely be met for coastal areas, nothing more. Pressure falls are pretty impressive but we have a rather stable airmass, and not a significant amount of momentum transfer to the surface. Anyone away from the immediate coast shouldn't be worried, unless you are at a high elevation and the LLJ comes screaming across you.

yeah nothing mentioned in HWO at all, doesn't seem like this will be much more than a dreary rainstorm, surprising for such a strong LP, is it mainly because it gets strung out? Though in recent runs it appears to have formed better. I dunno havent had time to look at much, other than wind hahaha. What else is there for me, not snow thats for sure.

It is not as simple as it seems.
If you want to generate strong surface-based winds, a robust pressure gradient at the surface is needed. While this low is progged to be sub 980, the overall pressure gradient lacks significant intensity. A strong pressure gradient requires an inversely strong high pressure.

Conversely, if you aim for potent surface-based winds descending from say the mid-levels, a mechanism for bringing them down is necessary. This can be achieved through strong mixing and general surface based instability, or robust downward momentum. In our case, a low-level inversion is present (it is fairly stable), and strong downward momentum is largely absent, except in the most intense rain bands.

This is why wind forecasts may not be as remarkable as shown on models. These are the factors the NWS  typically considers when analyzing BUFKIT data for their wind forecasts.

rb924119 wrote:EURO ticked east/colder. It’s not by much. But I’m looking at these maps, and I have to be honest - I think I’ll be going down with this ship. Not because it’s my longstanding idea. I mean, yeah, that’s an underlying bias, but putting that aside, this setup is SCREAMING “SURPRISE!” to me for anybody west of the Delaware River. I have reasons for saying this that I won’t be able to elaborate on until later this evening after I get out of work, but basically, not only do I think this has room to come east a bit, but this is a pretty extreme frontogensis event, and I think there’s an inability by the models to resolve it. We still have three days to go, so there’s definitely time for further adjustments, but yeah, idk. It doesn’t seem right to me verbatim right now.

Not sure about anyone else but I don't think this snow threat is dead by an stretch. I think you've been pretty clear that interior has the best shot at 'something' from the onset.

jmanley32 wrote:I think they should do away with these wind maps or incorporate more accurately the mix down rate of what will actually show at the surface. I don't understand why that is not already the case. if these most often never pan out even close (ocasionally they do, and something about this tells me they might) then why bother and freak out the media as JB is always posting them.

This delves more into the general physics and mechanisms behind how numerical weather prediction (models) work, but this is a known bias, and it's typically accounted for by forecasters. Just like all guidance, taking things at face value rarely works out in your favor .

Quietace wrote:

jmanley32 wrote:I think they should do away with these wind maps or incorporate more accurately the mix down rate of what will actually show at the surface. I don't understand why that is not already the case. if these most often never pan out even close (ocasionally they do, and something about this tells me they might) then why bother and freak out the media as JB is always posting them.

This delves more into the general physics and mechanisms behind how numerical weather prediction (models) work, but this is a known bias, and it's typically accounted for by forecast. Just like all guidance, taking things at face value rarely works out in your favor .

Yeah can be said for all those clown snow maps too, never a perfect science, in fact far from it. We have ages to go if ever to perfect weather to a exact science. Thanks for explaining, kinda knew this already from years of previous explanations but never know for sure if there is good mixing and atmospheric conditions as you stated and seems there are many involved. This fascinates me with wind even more.

Very impressive transport of warm air with this system. 50F all the way up to eastern Labrador, CA for Dec 19 that'd be a record. Sadly ski resorts in NY/NE are going to take quite a beating with this...

As Rb said this bad boy to an east hop.

https://www.weather.gov/media/okx/12152023_pmPUBLIC.pdf

weatherwatchermom wrote:

Frank_Wx wrote:Madonne, those winds are high. Granted, we saw how poorly the winds mixed down in last week's storm. But this one has a different look and feel to it. I can see the higher gusts mixing for sure along the coast.

Of course son traveling home from school on Monday...

NWS seems to feel that highest potential is 55mph for extreme eastern LI and most of CT to NYC is 30-40mph gusts, just a breezy rainy day def not a major storm as they are calling it.

I wouldn't call it just a breezy rainstorm, we could see some real flooding problems if this is the case. They have been raising the rainfall total the last 24 hours.