NYC/PHL Jan 25-27 Potential Bomb Part 5

[IsentropicLift]

If seasonal trends alone are any indication, the final result may end up being quite different than what is currently being depicted. I will say though, for the first time this season we seem to have fairly good agreement with regards to track. I'm a tad suprised, that with a track inside the benchmark and a low thats deepening the whole way that CCB doesn't get going sooner. If you go back a few days to when the globals first began latching onto the idea of a miller A the GFS was showing a very consolidated system even over the SE with very intense banding to the north and northwest of the low. Hence the 2" + QPF totals area wide it spit out for those runs. The NAM seems to be having a hard time developing a consolidated low, the EC seems most like the old GFS runs albeit colder and further offshore and the 12z GFS seems to split the difference. The EC has been getting better and better for our area the last few runs and if it holds serve or improves this run I would say my confidence of a widespread warning criteria snowfall would be > 70%. Much more than that, its way too close to call. BTW FWIW, here is the 12z GFS through hr 90. Indicates more of a freezing rain threat just NW of the cities and JP's SNE with the snow. We may actually get 4th period watches with this one.

[EasternUSWX]

Most guidance is still a miss for us besides the UK and EURO so far.

Even the GGEM misses us with the heavy precip now.

ya the ggem has been doing really good. First over baltimore now off shore. Throw that thing out.

[A-L-E-X]

I imagine this is one of those forecasts where the spreads for snow totals have to be significantly wider. I mean, if you're forecasting for the NYC metro, you'd almost have to put the low end at around 2" and the high end at 10", which is obviously way too wide, But if you call for 5-10", it's highly possible the low end won't verify. With that in mnd, I'm thinking 3-6" or 4-8" is the call for the immediate NYC metro area at this time, with a good chance that could change in either direction.

Obviously, many things can change right up to (and maybe even including the event), but I think 3-6 is a nice number as of now. Of course, if we get an average of 3, many will think the forecast will have busted because they expected the high end of the scale.

[A-L-E-X]

JFK is not a good reflection of what would transpire in NYC, EWR, TEB or even LGA in this setup.

It depends on how quickly the changeover to snow happens-- if its like Xmas 2002 it could be a situation of the whole area getting a nice snowfall. Im still thinking that Xmas 2002 is the best analog as of now (at least for our area.)

[cut]

This looks like a really tough call for Fairfield County. I have been back and forth in the NYC thread and the New England thread - I am going to get a personality disorder. It is tough to decide which thread to read more of here. I wish there were a "Tri State" thread!!!! Oh well, on with the models.

[goldstar]

I get a feeling that this storm is going to trend colder as per the seasonal trend, this is not based on the models btw, just on the seasonal trend.

[Alpha5]

This looks like a really tough call for Fairfield County. I have been back and forth in the NYC thread and the New England thread - I am going to get a personality disorder. It is tough to decide which thread to read more of here. I wish there were a "Tri State" thread!!!! Oh well, on with the models.

Or a SW CT thread

[RUNNAWAYICEBERG]

I get a feeling that this storm is going to trend colder as per the seasonal trend, this is not based on the models btw, just on the seasonal trend.

there is no "it will trend colder" seasonal trend....

[TheTrials]

Snow to rain to heavy snow for the nyc metro

http://www.meteo.psu.edu/ewall/CMC_12z/cmcloop.html

big change from all its other runs.

[Noreaster07]

[NJwinter23]

Sounds like youre starting to change your mind about this being predominantly a rain system even half and half would be just fine

Not necessarily as there is still plenty of rain to deal with for the cities and just east on the models. Or at least warm surface temps to cut back on accumulation. But with the track being so offshore now and coming in so later that the high pressure is so long gone we do not get strong east/se winds, then I guess you can say I'm more optomistic for somethign a little mor emeaningful along and just east of i95. Even with the gfs solution though we do not get a ton of snow by any means no more than 3-6 and it is a near best case scenario.

12z gfs Bufkit using the max temp in profile algorithm

LGA: 0.5" onset, rain/ZR in between, 5" on the backend

JFK: sleet/rain onset then about 3" of snow at the end

EWR: about 4-5" from Wed. evening into Thur morning

RUTG: 1" onset, ZR in between(likely just rain and 32), 3-4" at the end

MMU: 3-4" a little freezing rain depicted.

PHL: snow at onset 0.5-1.0", rain/zr in between, 2-3" at the end

TTN: 1-2" onset, rain/ZR in between, 1-2" at end

HPN: depicts about 4.5" by the end of the storm, all snow, 5-6" probably falls though with some melting.

[greg ralls]

If seasonal trends alone are any indication, the final result may end up being quite different than what is currently being depicted. I will say though, for the first time this season we seem to have fairly good agreement with regards to track. I'm a tad suprised, that with a track inside the benchmark and a low thats deepening the whole way that CCB doesn't get going sooner. If you go back a few days to when the globals first began latching onto the idea of a miller A the GFS was showing a very consolidated system even over the SE with very intense banding to the north and northwest of the low. Hence the 2" + QPF totals area wide it spit out for those runs. The NAM seems to be having a hard time developing a consolidated low, the EC seems most like the old GFS runs albeit colder and further offshore and the 12z GFS seems to split the difference. The EC has been getting better and better for our area the last few runs and if it holds serve or improves this run I would say my confidence of a widespread warning criteria snowfall would be > 70%. Much more than that, its way too close to call. BTW FWIW, here is the 12z GFS through hr 90. Indicates more of a freezing rain threat just NW of the cities and JP's SNE with the snow. We may actually get 4th period watches with this one.

That 2/10" of freezing rain area north & west of Philadelphia is troubling.

[dbc]

Not necessarily as there is still plenty of rain to deal with for the cities and just east on the models. Or at least warm surface temps to cut back on accumulation. But with the track being so offshore now and coming in so later that the high pressure is so long gone we do not get strong east/se winds, then I guess you can say I'm more optomistic for somethign a little mor emeaningful along and just east of i95. Even with the gfs solution though we do not get a ton of snow by any means no more than 3-6 and it is a near best case scenario.

12z gfs Bufkit using the max temp in profile algorithm

LGA: 0.5" onset, rain/ZR in between, 5" on the backend

JFK: sleet/rain onset then about 3" of snow at the end

EWR: about 4-5" from Wed. evening into Thur morning

RUTG: 1" onset, ZR in between(likely just rain and 32), 3-4" at the end

MMU: 3-4" a little freezing rain depicted.

PHL: snow at onset 0.5-1.0", rain/zr in between, 2-3" at the end

TTN: 1-2" onset, rain/ZR in between, 1-2" at end

HPN: depicts about 4.5" by the end of the storm, all snow, 5-6" probably falls though with some melting.

Again good demonstration that JFK will fair worse than everywhere else in terms of frozen vs. liquid if GFS verifies as is.

[jconsor]

It's very rare to see ZR in NYC with a bombing coastal storm. I have to imagine it will be a rain to snow event for NYC with dynamic cooling helping out.

Also, how does HPN only get 4.5" of snow based on GFS BUFKIT? They get 0.97" QPF and should be almost all snow with maybe a little sleet mixed in based on the temp profile on GFS.

Not necessarily as there is still plenty of rain to deal with for the cities and just east on the models. Or at least warm surface temps to cut back on accumulation. But with the track being so offshore now and coming in so later that the high pressure is so long gone we do not get strong east/se winds, then I guess you can say I'm more optomistic for somethign a little mor emeaningful along and just east of i95. Even with the gfs solution though we do not get a ton of snow by any means no more than 3-6 and it is a near best case scenario.

12z gfs Bufkit using the max temp in profile algorithm

LGA: 0.5" onset, rain/ZR in between, 5" on the backend

JFK: sleet/rain onset then about 3" of snow at the end

EWR: about 4-5" from Wed. evening into Thur morning

RUTG: 1" onset, ZR in between(likely just rain and 32), 3-4" at the end

MMU: 3-4" a little freezing rain depicted.

PHL: snow at onset 0.5-1.0", rain/zr in between, 2-3" at the end

TTN: 1-2" onset, rain/ZR in between, 1-2" at end

HPN: depicts about 4.5" by the end of the storm, all snow, 5-6" probably falls though with some melting.

[DerekZ]

Novice question about potential freezing rain for this event:

This morning's Mt. Holly AFD highlighted the possibility for freezing rain, especially west of the Delaware River. The latest GFS soundings for PHL also show the potential for up to 1/4 inch of QPF to fall as freezing rain.

However, this doesn't seem like a typical freezing rain setup for the Delaware Valley since surface temperatures will be near or above freezing until 00z Thursday or beyond. My understanding is that ZR is most likely to occur in a CAD type of scenario, not from a developing coastal.

To me, the setup indicates some snow or sleet to start, changing over to rain, and then changing back to snow as the storm intensifies and 850 temps crash later on.

Is there something I am missing about this event and the potential for freezing rain? I know the GFS precipitation type output should be taken with a huge shaker of salt but obviously 1/4 inch of liquid falling as ZR would be problematic.

Thanks!

[Absolute Humidity]

Obviously, many things can change right up to (and maybe even including the event), but I think 3-6 is a nice number as of now. Of course, if we get an average of 3, many will think the forecast will have busted because they expected the high end of the scale.

I tend to agree for the most part. Xmass 2002 had a very fast West to East changeover thumping all between 4 and 12 even to the coast. Also Dec 5th 2003 I believe was similar except the changeover was not progressive W to E with that, it was more of a flash over area wide from rain to snow. I wouldn't be surprised if this happen as well.

[Noreaster07]

12z JMA

[Ed Lizard]

I remember one significant ice storm in over a decade on Long Island. NYC and East, there is little to trap shallow cold air near the surface. I can believe a sleet sounding from the GFS, but freezing rain is hard to pull off one Long Island.

Inland, where hills and mountains form vallies, its different.

[tombo82685]

alright the euro has started i will update when it gets closer

[earthlight]

12z tombo has initialized

[A-L-E-X]

Not necessarily as there is still plenty of rain to deal with for the cities and just east on the models. Or at least warm surface temps to cut back on accumulation. But with the track being so offshore now and coming in so later that the high pressure is so long gone we do not get strong east/se winds, then I guess you can say I'm more optomistic for somethign a little mor emeaningful along and just east of i95. Even with the gfs solution though we do not get a ton of snow by any means no more than 3-6 and it is a near best case scenario.

12z gfs Bufkit using the max temp in profile algorithm

LGA: 0.5" onset, rain/ZR in between, 5" on the backend

JFK: sleet/rain onset then about 3" of snow at the end

EWR: about 4-5" from Wed. evening into Thur morning

RUTG: 1" onset, ZR in between(likely just rain and 32), 3-4" at the end

MMU: 3-4" a little freezing rain depicted.

PHL: snow at onset 0.5-1.0", rain/zr in between, 2-3" at the end

TTN: 1-2" onset, rain/ZR in between, 1-2" at end

HPN: depicts about 4.5" by the end of the storm, all snow, 5-6" probably falls though with some melting.

How do you feel about the Xmas 2002 analog?

[tombo82685]

hr 24 has a sub 1012 low foriming south of la in the gulf...Everything is pretty close to 0z, the trof in the center may be a little more pos tilted.

[A-L-E-X]

I tend to agree for the most part. Xmass 2002 had a very fast West to East changeover thumping all between 4 and 12 even to the coast. Also Dec 5th 2003 I believe was similar except the changeover was not progressive W to E with that, it was more of a flash over area wide from rain to snow. I wouldn't be surprised if this happen as well.

Yeah, I think Xmas 2002 would be a best case scenario in case "everything goes right." The other end of the spectrum would be just some light snow at the tail end and a flash freeze-- which isnt a pleasant experience either!

[ChescoWx]

The Wxsim program's timing etc for the NW Philly burbs has continued the westward "trend" with much more precip then 6z. It now indicates around 0.82" of precip falling and all of it is frozen. Here is the rundown with the 12z data incorporated.

Sleet arrives by 9am temp 24.0

Mix IP/ZR from 230 -430pm temp 30.4

Heavy IP by 5pm temp 29.1

Mix with and change to snow late evening

End by midnight

Looks like between 3 and 4" of Snow/Sleet accumulation with close to 10" on the ground by storm ending here in the Philly burbs

[A-L-E-X]

I remember one significant ice storm in over a decade on Long Island. NYC and East, there is little to trap shallow cold air near the surface. I can believe a sleet sounding from the GFS, but freezing rain is hard to pull off one Long Island.

Inland, where hills and mountains form vallies, its different.

You must be talking about Jan 1994 which gave us over 2 inches of ice! What a tremendous storm that was. We've had a few others that were close, like the Feb and Mar 2007 sleet storms that changed to freezing rain at the end. And two that I dont remember occurred in Jan 1973 and Dec 1977 which also brought a crippling amount of ice to the area. Mar 1984 is another one, and I dont remember the details of that one either lol.

[tombo82685]

hr 36 has a sub so far the low is weaker, still a sub 1012 over the mobile area... compared to 0z and trof is a little more positive tilted...

[ace0927]

I tend to agree for the most part. Xmass 2002 had a very fast West to East changeover thumping all between 4 and 12 even to the coast. Also Dec 5th 2003 I believe was similar except the changeover was not progressive W to E with that, it was more of a flash over area wide from rain to snow. I wouldn't be surprised if this happen as well.

if my memory serves me correctly, at least at my latitude, there was no rain at all in Dec 2003. a matter of fact i drove from NYC to Philly that day and it snowed the entire ride until we arrived at Philly proper.

[tombo82685]

hr 42 has a sub 1008 low on se alabama...trof still alittle pos tilted centered over miss river. its trying to get a closed h5 at the 552 hgt

[FPizz]

You must be talking about Jan 1994 which gave us over 2 inches of ice! What a tremendous storm that was. We've had a few others that were close, like the Feb and Mar 2007 sleet storms that changed to freezing rain at the end. And two that I dont remember occurred in Jan 1973 and Dec 1977 which also brought a crippling amount of ice to the area. Mar 1984 is another one, and I dont remember the details of that one either lol.

Did the 93-94 winter have 2 ice storms? I remember the Jan one, but for some reason I thought there was another one not quite as large. I remember my brother and I looking at the temps outside and seeing 17 degrees and it was pouring for the Jan. storm.

[A-L-E-X]

if my memory serves me correctly, at least at my latitude, there was no rain at all in Dec 2003. a matter of fact i drove from NYC to Philly that day and it snowed the entire ride until we arrived at Philly proper.

Different storm. Youre thinking about the blizzard that happened after that which gave us 14-20 inches of snow in Nassau County (less west more east) over two days.