NYC/PHL Dec 26-27 Potential - Part 4

[A-L-E-X]

I think it's a decent likelihood right now that from the William Floyd Parkway east (roughly Shirley to Rocky Point), a warning criteria snow takes place. The twin forks might actually get a really good event from this, like 8 or 10"+. These setups are very fragile though, especially since a heavy band loves to set up on the NW fringe of the cold conveyor belt and easily double or more the expected totals there. Or it could fall apart like the 12/19 event and leave less than expected.

There were quite a few events like that back in the early 90s when the east end got some nice snowfalls and we went like 10 years between 10 inch snowfalls lol.

[IsentropicLift]

provided it remains possible that a 50 mile shift to the west puts NYC in warning criteria snows through 12z tomorrow I think they have to issue watches for passaic county NJ on eastward up into upstate NY, the city, Long Island and Southern CT with the afternoon package. I would normally side on the conservative route but were talking about a major travel day being affected and the general public needs to be warned in advance. There is a reason why they call it a watch afterall...and not a warning. I would even argue that Mt. Holly probably will need watches at some point for all its coastal locals and you could also include Morris and Sussex counties.

[Collegestudent11]

provided it remains possible that a 50 mile shift to the west puts NYC in warning criteria snows through 12z tomorrow I think they have to issue watches for passaic county NJ on eastward up into upstate NY, the city, Long Island and Southern CT with the afternoon package. I would normally side on the conservative route but were talking about a major travel day being affected and the general public needs to be warned in advance. There is a reason why they call it a watch afterall...and not a warning. I would even argue that Mt. Holly probably will need watches at some point for all its coastal locals and you could also include Morris and Sussex counties.

Sussex would really be a strech for any watch package. I would figure Mt. Holly should the GFS hold, and the other look like it, issue one for Monmouth, Ocean, Atlantic, Cape May, Middlesex (maybe), Mercer (maybe).

There should be interoffice cooperation between Holly, and Upton here, as if Middlesex is in a watch, and Union is not, then someone might be confused.

[SnowGoose69]

In a strong Nina like this, it's almost inevitable that we revert to a Lakes Cutter/SW flow pattern at some point. The second the blocking up north retreats, that's the first thing we'll see. Maybe we can get a few inches from a lucky overrunning setup, but in all likelihood this is the most favorable pattern we have until very late in the season. This definitely won't be anything like the strong Nino last year.

I posted yesterday afternoon that at this point I'm happy to get some sort of long duration overrunning event that changes to sleet or rain at the very end and pick up 4-5 inches...I don't like strongly negative NAOs in a La Nina because it tends to suppress the pattern and lacking a southern branch that tends to screw you...we're best off with a weakly -NAO...sort of like we have right now where the SE Canda vortex is less likely to squash systems coming from the west...combine that with a weak -PNA and -EPO and we're in business....a very -NAO with either a negative or positive PNA does not work in mod-strong La Ninas....especially a -PNA.

[Dsnowx53]

Although the GFS significantly improved aloft, and the Euro improved slightly, the GFS shifting west could just be a product of being on the left side of its ensemble members. Think about it, conceivably, any operational run should most likely be somewhere in the range of its ensemble members--it could be on the western side, eastern side, or center side. The side the OP has been on WRT to its ensembles has been varying, but it's never not been within the range of its ensembles. So, I'm not really convinced that this is an actual trend, yet.

[weathercoins]

provided it remains possible that a 50 mile shift to the west puts NYC in warning criteria snows through 12z tomorrow I think they have to issue watches for passaic county NJ on eastward up into upstate NY, the city, Long Island and Southern CT with the afternoon package. I would normally side on the conservative route but were talking about a major travel day being affected and the general public needs to be warned in advance. There is a reason why they call it a watch afterall...and not a warning. I would even argue that Mt. Holly probably will need watches at some point for all its coastal locals and you could also include Morris and Sussex counties.

I think wait til 12z then figure out for afternoon update

[SnowGoose69]

I think it's a decent likelihood right now that from the William Floyd Parkway east (roughly Shirley to Rocky Point), a warning criteria snow takes place. The twin forks might actually get a really good event from this, like 8 or 10"+. These setups are very fragile though, especially since a heavy band loves to set up on the NW fringe of the cold conveyor belt and easily double or more the expected totals there. Or it could fall apart like the 12/19 event and leave less than expected.

I don't even feel very good about that right now...I'd say 1-4 right now for NE/SE Suffolk and nothing west of there....the last event I know did go west of where it was forecast to, if this does the same then your scenario could absolutely happen.

[jm1220]

I posted yesterday afternoon that at this point I'm happy to get some sort of long duration overrunning event that changes to sleet or rain at the very end and pick up 4-5 inches...I don't like strongly negative NAOs in a La Nina because it tends to suppress the pattern and lacking a southern branch that tends to screw you...we're best off with a weakly -NAO...sort of like we have right now where the SE Canda vortex is less likely to squash systems coming from the west...combine that with a weak -PNA and -EPO and we're in business....a very -NAO with either a negative or positive PNA does not work in mod-strong La Ninas....especially a -PNA.

I'm wondering how the 1960s were so good to us despite the consistent Nina/-PDO pattern and -NAO. We definitely seem to be shifting into a similar pattern overall now.

[A-L-E-X]

I posted yesterday afternoon that at this point I'm happy to get some sort of long duration overrunning event that changes to sleet or rain at the very end and pick up 4-5 inches...I don't like strongly negative NAOs in a La Nina because it tends to suppress the pattern and lacking a southern branch that tends to screw you...we're best off with a weakly -NAO...sort of like we have right now where the SE Canda vortex is less likely to squash systems coming from the west...combine that with a weak -PNA and -EPO and we're in business....a very -NAO with either a negative or positive PNA does not work in mod-strong La Ninas....especially a -PNA.

It seems that this year has been prone to extremes of various natures. Beginning with the 09-10 winter strong nino plus extreme block, then the torch of a summer and now a mod-strong la nina with another extreme block. Normally, you'd see a big SE ridge with a nina of this sort, but we have an extreme block that not only quashed that, but probably too much for us to get significant events. Maybe there is some sort of feedback mechanism causing these extremes, and it's just not possible for us to sustain a "weak" anything for very long before it flips to either one extreme or another. Weak la nina with a weak neg nao would have been perfect.

[SnowGoose69]

I'm wondering how the 1960s were so good to us despite the consistent Nina/-PDO pattern and -NAO. We definitely seem to be shifting into a similar pattern overall now.

Many of those Ninas were weak, a weak Nina is night and day compared to even a moderate one....the scale for changing seems narrower from weak-moderate Nina wise than it is for El Ninos.

[A-L-E-X]

I'm wondering how the 1960s were so good to us despite the consistent Nina/-PDO pattern and -NAO. We definitely seem to be shifting into a similar pattern overall now.

Back in the 80s and early 90s, I wondered how NYC ever got a big snowstorm. I used to read about old historic snowstorms like I read about the Yanks winning titles back in the 50s and 60s and earlier lol. I never had a single snow day throughout my entire time in public school lol. Nor did the Yanks ever make the playoffs during that time.

[Yorkpa25]

Hard to believe we were looking at a massive hit earlier in the week now basically nothing. I'm not trolling , just was looking for atleast 6 inches, but will need a miracle now for that to happen

[A-L-E-X]

Many of those Ninas were weak, a weak Nina is night and day compared to even a moderate one....the scale for changing seems narrower from weak-moderate Nina wise than it is for El Ninos.

Arent the delineations between weak/mod/strong arbitrary at best though? I've seen some argue that we should drop "moderate" and just go with weak or strong divisions for la nina and el nino.

So basically +/- 1 would be strong and less than that would be weak down to +/- 0.5, where you would have warm neutral, cold neutral, etc.

[SnowGoose69]

Back in the 80s and early 90s, I wondered how NYC ever got a big snowstorm. I used to read about old historic snowstorms like I read about the Yanks winning titles back in the 50s and 60s and earlier lol. I never had a single snow day throughout my entire time in public school lol. Nor did the Yanks ever make the playoffs during that time.

From 1987-1994 my district did not have a snow day, that probably will never happen again, they also went from March of 96-March of 99 without one too as I know from my younger siblings....the 93 event obviously would have closed everyone but it came on a weekend....its also likely the 1/11/91 event would have too but it came on a Friday afternoon and night.

[RutgersWx92]

I posted yesterday afternoon that at this point I'm happy to get some sort of long duration overrunning event that changes to sleet or rain at the very end and pick up 4-5 inches...I don't like strongly negative NAOs in a La Nina because it tends to suppress the pattern and lacking a southern branch that tends to screw you...we're best off with a weakly -NAO...sort of like we have right now where the SE Canda vortex is less likely to squash systems coming from the west...combine that with a weak -PNA and -EPO and we're in business....a very -NAO with either a negative or positive PNA does not work in mod-strong La Ninas....especially a -PNA.

Yeah, this strong -NAO really doesn't seem to be working out for us during moderate to strong Ninas. Everything is getting suppressed. Our last Nina winter (07-08) mainly had a +NAO and little blocking, and it actually ended up being better around here than this winter has been so far because at least we got some front end snow/sleet from several events before a changeover. At least we were getting SOMETHING from that pattern.

[IsentropicLift]

I think wait til 12z then figure out for afternoon update

I said exactly that lol go one more model cycle of the Euro and make the call with the afternoon package.

[Absolute Humidity]

Interesting 48h Sim radar on HRW

[SnowGoose69]

Yeah, this strong -NAO really doesn't seem to be working out for us during moderate to strong Ninas. Our last Nina winter (07-08) mainly had a +NAO and little blocking, and it actually ended up being better around here than this winter has been so far because at least we got some front end snow/sleet from several events before a changeover. At least we were getting SOMETHING from that pattern.

Same in 98-99, the early January event dropped 4-6 prior to the changeover and the flukey Christmas Eve one produced 3-4 in some places....then we got the classic late season Miller A in mid-March...its pretty typical though that in stronger Ninas, NYC often reaches February in danger of a top 10 least snowiest winter, usually though they escape with a last second event.....99-00, CPK was 6 days away from entering February with 0.0 for snow...not even a trace...that probably will never occur, its remarkable it event occurred that year.

[A-L-E-X]

From 1987-1994 my district did not have a snow day, that probably will never happen again, they also went from March of 96-March of 99 without one too as I know from my younger siblings....the 93 event obviously would have closed everyone but it came on a weekend....its also likely the 1/11/91 event would have too but it came on a Friday afternoon and night.

Feb 1983 would have closed things for us too, but it came late on a Friday-- so we just got a 15 min early close lol. We didnt have a single 10 inch event between Feb 1983 and March 1993-- and I would hesitate to include March 1993 since it changed to a very heavy rain-- so you can say we didnt have a true north east big snowstorm between Feb 1983 and January 1996. Most of those years we didnt even have a single 6" snowstorm. As a matter of fact, I grew to treasure surprise 4" snowfalls, because I knew that was the best I could expect back then.

[A-L-E-X]

Same in 98-99, the early January event dropped 4-6 prior to the changeover and the flukey Christmas Eve one produced 3-4 in some places....then we got the classic late season Miller A in mid-March...its pretty typical though that in stronger Ninas, NYC often reaches February in danger of a top 10 least snowiest winter, usually though they escape with a last second event.....99-00, CPK was 6 days away from entering February with 0.0 for snow...not even a trace...that probably will never occur, its remarkable it event occurred that year.

I was thinking about this earlier SG; Philly is probably the northernmost city on the east coast that has a reasonable chance of completely whiffing on a snow season. History seems to indicate that its much less likely to happen in NYC or Long Island-- even in our worst winters, although one never knows.....

By "whiffing" I mean T or less snowfall, although I dont think any of our metro stations have ever recorded less than 1" either. Has any of them ever had a season without a single 1" event?

[tmagan]

We could probably use a new thread.

[RutgersWx92]

I was thinking about this earlier SG; Philly is probably the northernmost city on the east coast that has a reasonable chance of completely whiffing on a snow season. History seems to indicate that its much less likely to happen in NYC or Long Island-- even in our worst winters, although one never knows.....

By "whiffing" I mean T or less snowfall, although I dont think any of our metro stations have ever recorded less than 1" either. Has any of them ever had a season without a single 1" event?

Philly has already completely whiffed on a snow season: It only recorded a trace from the winter of 1972-1973. Shows that strong El Ninos can suck royally as well.

[SnowGoose69]

I was thinking about this earlier SG; Philly is probably the northernmost city on the east coast that has a reasonable chance of completely whiffing on a snow season. History seems to indicate that its much less likely to happen in NYC or Long Island-- even in our worst winters, although one never knows.....

By "whiffing" I mean T or less snowfall, although I dont think any of our metro stations have ever recorded less than 1" either. Has any of them ever had a season without a single 1" event?

I don't believe so, the 72-73 event more or less hit everyone with the 1-3 inches...DCA has twice had nearly nothing in both 72-73 and 97-98....NYC of course came very close in 97-98....in recent times the other close calls were 94-95, and 91-92...both were one event away from being nearly snowless.

[A-L-E-X]

I don't believe so, the 72-73 event more or less hit everyone with the 1-3 inches...DCA has twice had nearly nothing in both 72-73 and 97-98....NYC of course came very close in 97-98....in recent times the other close calls were 94-95, and 91-92...both were one event away from being nearly snowless.

Yeah, I think PHL had two T seasons.... one in 72-73 and the other in 97-98..... did we get one decent late season event in 97-98 from being a total screwup?

91-92 was at the peak of that huge solar max period when we went 22 out of 24 months above normal and set some amazing records including back to back +8 /40 avg months Jan and Feb of 1990 with mid to upper 80s for spring break in the middle of March in 1990..... and this was after a -10/26 month in Dec with 1 inch of snowfall lol. The only decent snowfall that season was in November. 1991-92 just picked up where 1989-90 and 1990-91 left off lol. We had a record scorcher summer in between, 1991, many of whose records stood until last summer.

[SnowGoose69]

See the pattern at 500mb setting up on tonight's Euro at 240 hours....exactly what we mentioned above....strong arctic high over the NE part of the U.S. and a system forming in the TX/OK pahandles headed ENE.

[RutgersWx92]

Yeah, I think PHL had two T seasons.... one in 72-73 and the other in 97-98..... did we get one decent late season event in 97-98 from being a total screwup?

No, Philly's only trace season was 72-73...it got 0.7 inches from 97-98.

[A-L-E-X]

No, Philly's only trace season was 72-73...it got 0.7 inches from 97-98.

So 72-73 was worst and 97-98 second worst? Interesting that both were strong el ninos. We've also had a couple of great strong el ninos (57-58, 09-10) and one that was fairly good (82-83). It shows that while enso does have an effect, NAO matters more for us.

[tombo82685]

See the pattern at 500mb setting up on tonight's Euro at 240 hours....exactly what we mentioned above....strong arctic high over the NE part of the U.S. and a system forming in the TX/OK pahandles headed ENE.

yea that looks like a good pattern. Nice ridge out west. cold arctic high close by. Looks like a gradient pattern kind of. IAs of now it looks like january is going to start of cold, after the new years lake cutter.

[famartin]

Outside of the Interstate 95 corridor, I can't think of any large American cities that see major snowstorms with great frequency other than Denver. Chicago and Minneapolis do, from time to time and Cleveland has a good lake effect set up..but that's about it...

Note: I do not consider Syracuse or Buffalo "large" cities. I suppose SLC is borderline.

I think SLC is large. Metro area is over 1 mil I believe.

[A-L-E-X]

Outside of the Interstate 95 corridor, I can't think of any large American cities that see major snowstorms with great frequency other than Denver. Chicago and Minneapolis do, from time to time and Cleveland has a good lake effect set up..but that's about it...

Note: I do not consider Syracuse or Buffalo "large" cities. I suppose SLC is borderline.

Denver has an interesting climate in that it can easily be 60 one day and snowing heavily the next day-- very variable. Are they the snowiest city with a population of 1 million or more?