NYC/PHL Jan 18-19 Potential Threat Thread

[tombo82685]

there is fast southerly flow in se canada for monday night's event. there is no way we get snow out of this.

yup, only way we can is to get that northern stream storm to go south of us, and that looks like a no as of now.

[forkyfork]

yup, anyway we can is to get that northern stream storm to go south of us, and that looks like a no as of now.

i really like the look of day 7. that digging mauler should give us a snow event

[tombo82685]

i really like the look of day 7. that digging mauler should give us a snow event

yea it has like 1-3 for us, with frigid temps...850s -12 to -16

[SnowGoose69]

there is fast southerly flow in se canada for monday night's event. there is no way we get snow out of this.

I agree, with the depiction the Euro shows the high is too far south and hence the flow would be due south, if the high is centered more over NE you'd get a SE or ESE flow which often can sustain snow longer...the Euro is likely an all rain event.

[tombo82685]

if you hate cold, then you better go somewhere else, cause after that cutter, its just down right frigid...pretty dry though besides forky's mauler.

[SnowGoose69]

if you hate cold, then you better go somewhere else, cause after that cutter, its just down right frigid...pretty dry though besides forky's mauler.

I think that blast will be a very glancing blow, with the +NAO it may be mainly just a N NE event, I could see a case where Boston drops to -5 and NYC maybe only to 8 or 10.

[tombo82685]

the pna ridge is absolutely nuts at hr 240...534 thickness to about the arctic ocean with 552 thickness in the northwest territories and western alaska

[tombo82685]

I think that blast will be a very glancing blow, with the +NAO it may be mainly just a N NE event, I could see a case where Boston drops to -5 and NYC maybe only to 8 or 10.

well through this run its brutal...and the nao shows no signs of going negative. I dont see how you would get a neg nao with how the ridge/trof orientation sets up...you would almost need the whole vortex to drop south then maybe pinch it off

[SnowGoose69]

well through this run its brutal...and the nao shows no signs of going negative. I dont see how you would get a neg nao with how the ridge/trof orientation sets up...you would almost need the whole vortex to drop south then maybe pinch it off

We'll see what happens but if we can get a -EPO and -AO its probably better than a -EPO/-NAO/+AO because sometimes the -NAO does you little good if you can't get the cold air source into the US in the first place...93-94 and December 2000 are good examples of how a -AO is better than a -NAO...I believe the NAO actually was positive for a decent part of December 2000 though it averaged negative...that is to an extent what caused several inland storm tracks.

[tombo82685]

We'll see what happens but if we can get a -EPO and -AO its probably better than a -EPO/-NAO/+AO because sometimes the -NAO does you little good if you can't get the cold air source into the US in the first place...93-94 and December 2000 are good examples of how a -AO is better than a -NAO...I believe the NAO actually was positive for a decent part of December 2000 though it averaged negative...that is to an extent what caused several inland storm tracks.

but yea, your right on the first blast its a glancing blow, but there is another one right behind the mauler, that is a little -more direct, puts the -10 isotherm in north carolina

[atownwxwatcher]

Slightly colder on the 850s but more inland with the area of low pressure at 120. More west of its 120 hr OP postion

[SnowGoose69]

The GFS is really starting to get it now...really starting to breakout that snow ahead of the low

[Quakertown needs snow]

0z and 6z gfs take a different route compared to 0z euro

[Voyager]

0z and 6z gfs take a different route compared to 0z euro

I left for work before 6z GFS was finished running, but the 0z looked qute a bit colder than previous runs.

[atownwxwatcher]

FWIW the 6 Z NOGAPS

[Rainshadow]

Its the case that I have seen over the years of watching the models when it comes to winter storms. I remember plenty of storms where we were suppose to change over to plain rain etc on the ECM...but we ended up with alot more frozen..its just something that i guess you could say chops up to experience.....

FWIW here is the 00z NOGAPS

ABE does have one of the higher incidences of freezing rain of airports in the northeast, most often in these situations you find that the coastal plain warms ok, but the above freezing line struggles once it has to start climbing the fall line.

[Mikehobbyst]

LGA and JFK do not look free of significant snow and some ZR 1/18/2011 based on latest trending and excellent CAD damming. Coastal hugger with significant SN to ZR for even LI. Plain rain very slight chance as it looks now. Deep snow cover with low level NE flow will keep this event in the 29-30 degree range at best. Remember all the busted forecast with changing to rain or rain in 94 winter that never happened. Well think of this upcoming event.

[ChescoWx]

Latest Wxsim module with 06z data now keeps the NW Philadelphia burbs below freezing the whole event with around 0.52" of liquid. Basically 2" of snow and then IP and ZR for the duration. Monday night arrival toward midnight and continuing into early tuesday afternoon.

[ChescoWx]

Mike

Just a little early to say rain is now only a slight chance....don't be surprised if 12z runs bring rain back across the big cities in the NE...including NYC, PHL etc.

LGA and JFK do not look free of significant snow and some ZR 1/18/2011 based on latest trending and excellent CAD damming. Coastal hugger with significant SN to ZR for even LI. Plain rain very slight chance as it looks now. Deep snow cover with low level NE flow will keep this event in the 29-30 degree range at best. Remember all the busted forecast with changing to rain or rain in 94 winter that never happened. Well think of this upcoming event.

[am19psu]

This is going to be a tricky little event to forecast the p-type. I tend to think the coastal plain will be mostly rain, but trying to figure out the interior is going to be a bear right up until the event.

[Rainshadow]

0z and 6z gfs take a different route compared to 0z euro

Basically that is what you would need, a flatter more progressive system vs the other modeling. It does look kind of odd on e-wall with those parade of bowling ball short waves. Who knows for sure at this point.

Every GEFS member off the 00z run is changing over ABE, PHL & HPN over to rain (lets say at 3000 feet at least) after an advisory type snow accumulation. There are a couple of members that are keeping Scranton all non-liquid.

[nzucker]

This is going to be a tricky little event to forecast the p-type. I tend to think the coastal plain will be mostly rain, but trying to figure out the interior is going to be a bear right up until the event.

This event is going to be messy once you get outside the major cities into the elevated NW suburbs, unless it trends towards a massive cutter. Antecedent airmass is extremely cold following the clipper, as NWS is forecasting a low of around 10F Sunday night here in Dobbs Ferry even with some passing cloud cover, and I'm within the urban heat island. It looks as if 850s drop to around -14C as the clipper moves through, so we're going to have a very cold antecedent airmass, a potential for widespread ageostrophic flow, and deep snowpack with very cold roadway surfaces. I can't imagine not starting as frozen here at 350' north of NYC.

Every GEFS member off the 00z run is changing over ABE, PHL & HPN over to rain (lets say at 3000 feet at least) after an advisory type snow accumulation. There are a couple of members that are keeping Scranton all non-liquid.

I'm near HPN and that's what I'm expecting...snow-->ice-->rain. This doesn't look like a huge snow threat, nor a washout. It'll probably be a mixed bag type of deal like the 1/28/2009 SW flow event that dropped 5" snow here following by some freezing rain. There could be a large gradient between JFK receiving almost nothing frozen and the suburbs seeing a solid advisory event. This is how we typically catch up to the coastal stations for seasonal snowfall.

[Alpha5]

This event is going to be messy once you get outside the major cities into the elevated NW suburbs, unless it trends towards a massive cutter. Antecedent airmass is extremely cold following the clipper, as NWS is forecasting a low of around 10F Sunday night here in Dobbs Ferry even with some passing cloud cover, and I'm within the urban heat island. It looks as if 850s drop to around -14C as the clipper moves through, so we're going to have a very cold antecedent airmass, a potential for widespread ageostrophic flow, and deep snowpack with very cold roadway surfaces. I can't imagine not starting as frozen here at 350' north of NYC.

I'm near HPN and that's what I'm expecting...snow-->ice-->rain. This doesn't look like a huge snow threat, nor a washout. It'll probably be a mixed bag type of deal like the 1/28/2009 SW flow event that dropped 5" snow here following by some freezing rain. There could be a large gradient between JFK receiving almost nothing frozen and the suburbs seeing a solid advisory event. This is how we typically catch up to the coastal stations for seasonal snowfall.

Im in a similar situation. Although out of the UHI effect, I'm around 350' as well.

LIke you I expect a decent front end dump to a mix, the most likely rain. How much will be determined later...but NYC's suburbs see 4"+ most of the time with these events.

BTW, when we define coastal plain lets be sure were all talking about the same place:

This is the coastal plain

[nzucker]

Im in a similar situation. Although out of the UHI effect, I'm around 350' as well.

LIke you I expect a decent front end dump to a mix, the most likely rain. How much will be determined later...but NYC's suburbs see 4"+ most of the time with these events.

BTW, when we define coastal plain lets be sure were all talking about the same place:

You radiate way better than I do, probably being a bit farther from NYC. It really depends on where you put your thermometer though, as I guarantee there were some single digits in the nature preserve behind my house which gets to 425' elevation with some nice frost hollows. Quite a bit of variation around here...HPN apparently hit 5F last night in a rural field around 400'. They're well northeast of me, though.

Looks like the coastal plain to me...I feel sort of in between because I live close to NYC in mileage but the climate is vastly different at 350' in the suburbs...this event has way more potential here than in Central Park.

[SnowGoose69]

This event is going to be messy once you get outside the major cities into the elevated NW suburbs, unless it trends towards a massive cutter. Antecedent airmass is extremely cold following the clipper, as NWS is forecasting a low of around 10F Sunday night here in Dobbs Ferry even with some passing cloud cover, and I'm within the urban heat island. It looks as if 850s drop to around -14C as the clipper moves through, so we're going to have a very cold antecedent airmass, a potential for widespread ageostrophic flow, and deep snowpack with very cold roadway surfaces. I can't imagine not starting as frozen here at 350' north of NYC.

I'm near HPN and that's what I'm expecting...snow-->ice-->rain. This doesn't look like a huge snow threat, nor a washout. It'll probably be a mixed bag type of deal like the 1/28/2009 SW flow event that dropped 5" snow here following by some freezing rain. There could be a large gradient between JFK receiving almost nothing frozen and the suburbs seeing a solid advisory event. This is how we typically catch up to the coastal stations for seasonal snowfall.

The high was in terrible position for that 1/28/09 event, similar to where the Euro shows it on this event and LGA/NYC/EWR still saw 3 inches before the changeover...JFK got 2 by the way...exactly why I said I'd be blown away if we didnt see at least 2-4 inches before a changeover, even at the coast.

[Alpha5]

You radiate way better than I do, probably being a bit farther from NYC. It really depends on where you put your thermometer though, as I guarantee there were some single digits in the nature preserve behind my house which gets to 425' elevation with some nice frost hollows. Quite a bit of variation around here...HPN apparently hit 5F last night in a rural field around 400'. They're well northeast of me, though.

Looks like the coastal plain to me...I feel sort of in between because I live close to NYC in mileage but the climate is vastly different at 350' in the suburbs...this event has way more potential here than in Central Park.

My thermometer is about 30 feet away from my house, in the open, and I generally have the same temps as HPN, which makes sense considering Im less than 5 miles from the airport.

Were not the coastal plain, go to South NJ and you'll see what the coastal plain is like, flat....here there are too many hills and too much rocky terrain. Thanks glaciers

[nzucker]

My thermometer is about 30 feet away from my house, in the open, and I generally have the same temps as HPN, which makes sense considering Im less than 5 miles from the airport.

Were not the coastal plain, go to South NJ and you'll see what the coastal plain is like, flat....here there are too many hills and too much rocky terrain. Thanks glaciers

I agree, we're not really the coastal plain. The Hudson Valley is quite hilly...even here in Southern Westchester, there's an amazing variation in the landscape from places right near sea level on the Hudson River to rocky ridges and outcroppings in the 450' elevation range. Really quite an amazing area when you think about it geologically and geographically, and some interesting climate differences across short distances.

[Alpha5]

I agree, we're not really the coastal plain. The Hudson Valley is quite hilly...even here in Southern Westchester, there's an amazing variation in the landscape from places right near sea level on the Hudson River to rocky ridges and outcroppings in the 450' elevation range. Really quite an amazing area when you think about it geologically and geographically, and some interesting climate differences across short distances.

Very true, and the same applies to the panhandle of CT.

Even only 5 miles from the Sound to the NY border, living with elevation and away from the sound, you see 5-10" more each year, and there have been plenty of times where there is a noticeable difference with snow accumulation during marginal events.

Even still, the north shore of the sound does better than Long Island or the city

[WeatherX]

I agree, we're not really the coastal plain. The Hudson Valley is quite hilly...even here in Southern Westchester, there's an amazing variation in the landscape from places right near sea level on the Hudson River to rocky ridges and outcroppings in the 450' elevation range. Really quite an amazing area when you think about it geologically and geographically, and some interesting climate differences across short distances.

It's 8 miles from the coast to nearly 700' here, lol.....another 8 miles and you're near 900' in Ridgefield...truly one of the more remarkable micro climates' in on the EC...

[Alpha5]

It's 8 miles from the coast to nearly 700' here, lol.....another 8 miles and you're near 900' in Ridgefield...truly one of the more remarkable micro climates' in on the EC...

Agreed, I remember last year I think it was the 12/8 event....I had nearly 5" by sunrise at 300-400 feet. I was talking to my friend who lives at about 100, not even right on the sound, and he said he had no snow whatsoever.

We live maybe 4 miles apart