NYC/PHL Dec 26-27 Potential - Part 7

[snowman21]

It takes some time to decipher what it will do....remember that snow made it into SNJ at 1am during the 12/2009 event and did not get to NYC til 1-2pm the next afternoon....we're well more saturated this time around in the mid and lower levels at 31/15 30/17...so it will certainly make it easier for thing to get going earlier.

Yeah I mentioned this in the NE thread... we're not stuck with 20-30 degree dew point depressions and a steady supply of dry air eating away hours and hours of snow. I remember a ton of 20s/-0s type obs on 12/19/09 and watching it snow on radar overhead for many hours before the column finally saturated.

[LVblizzard]

Yes, I know it's the backup RUC...

[Voyager]

It's been flurrying off and on here for the past hour, so yes, we are a bit more saturated.

[bluewave]

Very impressive...

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...

A MAJOR WINTER STORM WILL IMPACT THE TERMINALS SUNDAY THROUGH MONDAY

WITH HEAVY SNOW AND HIGH WINDS.

VFR CONDITIONS THROUGH MORNING. CIGS LOWER TO MVFR WITH VERY LIGHT

NON ACCUMULATING SN IN THE AM. EXPECT SN TO BLOSSOM ON THE LOCAL RADAR

AROUND MID DAY RESULTING IN A RAPID DETERIORATION OF CONDITIONS.

BANDED +SN TO THE NW OF THE SFC LOW IS LIKELY WITH THIS STORM WITH

ITS PRESSURE FALLING RAPIDLY. THIS BAND MAY VERY LIKELY BE OVER

THE NY METRO WITH 1+" PER HOUR SN RATE POSSIBLE AFTER 19Z AND

MORE LIKELY BY 21Z. THUNDER SNOW POSSIBLE AS WELL (NOT IN TAF) IN

THE BAND.

SNOW TOTALS OF 12-15" EXPECTED.

WINDS BUILD IN THE AFTN WITH PEAK GUSTS UP TO 50 KT NOT OUT OF THE

QUESTION IN THE 00-03Z.

http://www.weather.gov/view/prodsByState.php?state=NY&prodtype=discussion#AFDOKX

[NortheastPAWx]

It's been flurrying off and on here for the past hour, so yes, we are a bit more saturated.

Yeah that's the good news, so we shouldn't lose too much to virga.

[David Reimer]

[Isotherm]

Looks like the 12z and 18z model guidance has held serve. Christmas now winding down, let the games begin. I don't think I've ever been in a better mood on Christmas.

[Snowlover11]

been flurrying here in E. Stroudsburg for the past hour or so, so def the air is saturated

[Isotherm]

been flurrying here in E. Stroudsburg for the past hour or so, so def the air is saturated

I've got 77% RH here in CNJ. Usually about 80-85% is enough for steady snow.

[David Reimer]

I've got 77% RH here in CNJ. Usually about 80-85% is enough for steady snow.

80% RH here in Marlton.

[nzucker]

I've got 77% RH here in CNJ. Usually about 80-85% is enough for steady snow.

28.1/19 here

RH 69%

High was only 29.6F, one of the coldest Christmas days in recent memory.

[LIsevereWX]

Can't beleive we can finally say this but game on!!

[chazman]

Light snow is already creeping up into southern NJ; any concerns that this starts quite a bit earlier than expected?

Lee G was mentioning this am that there was a chance of light snow overnight/Sunday am leading to slippery driving conditions, etc.

[Wannabehippie]

I already have moved my car in to a spot anticipating alternate side parking will be cancelled monday. It is also a spot that will be easily shoveled out once the plows come thru.

Go Snow!

Lee G was mentioning this am that there was a chance of light snow overnight/Sunday am leading to slippery driving conditions, etc.

[Jaguars]

Wow, a true GOMEX miller a classic. Someone wlll be over 2' . Enjoy boys and girls. Christmas coming late for ya'll, lots and lots of moisture to tap.

[MJO812]

I'm talking to my friend from Virginia and he already has 2 inches of snow. This thing is going to come in earlier than expected.

Mildothian,Virginia

[psuhoffman]

reports of 2" around Roanoke VA so far. 1-2" just north of Richmond. The radar echoes from the instability snowshowers over the midwest and PA are moving westward. FLow is really starting to back in now as the upper energy has begun to phase into the system. Echoes over the southeast are pivoting to the left. It looks good right now.

[Solo2]

I'm talking to my friend from Virginia and he already has 2 inches of snow. This thing is going to come in earlier than expected.

What part of VA?

[ArtRosen]

I wonder... are TV Mets under-doing the amounts? This is a GULF low - not some little clipper... this baby is a TRUE Nor'Easter.... same energy source as Hurricane Katrina. Can someone really see less than a foot if there are no mixing issues?

[dryslotted]

I wonder... are TV Mets under-doing the amounts? This is a GULF low - not some little clipper... this baby is a TRUE Nor'Easter.... same energy source as Hurricane Katrina. Can someone really see less than a foot if there are no mixing issues?

I was wondering about that earlier myself. I think the answer depends where you are. Eastern Long Island might have lower progged totals due to mixing concerns and my area might have a lower than we think is 'reasonable' low end due to concerns around potential dryslotting.

In short, I suppose it's a hedge on the unexpected...

[SnowGoose69]

I wonder... are TV Mets under-doing the amounts? This is a GULF low - not some little clipper... this baby is a TRUE Nor'Easter.... same energy source as Hurricane Katrina. Can someone really see less than a foot if there are no mixing issues?

Too much goes into these systems on so many levels (LITERALLY!) its very difficult to gauge what will happen on the amounts...the models generally agree on over 1.00 QPF but as we know that is often overdone and the combination of meso bands causing subsidence around them and how the snow growth and frontogenesis works could cause someone to see 9 inches while 10 miles away they get 19....I think the average amount should be near 12-13 inches as of now...if the 00Z runs still show 2.00 or more liquid I'll start thinking about increasing that.

[snowman21]

I wonder... are TV Mets under-doing the amounts? This is a GULF low - not some little clipper... this baby is a TRUE Nor'Easter.... same energy source as Hurricane Katrina. Can someone really see less than a foot if there are no mixing issues?

Nah someone posted an earlier map from one of the TV guys that showed 20+ over the city, NJ, and the lower HV. If you find yourself forecasting beyond the 12-18 inch range, you better start looking for what can go wrong since at that point any slight forecast deviation will result in a bust and people will remember the extreme forecast accumulation. For a big storm, 12-18 is an easy forecast. 12 inches is not that hard to reach around here, and anything over 18 inches will be isolated in nature. Isolated reports don't count against verification as far as the NWS is concerned from what I understand. This means if the NWS forecasts 12-15 in a forecast zone and there's a report of 20 inches amongst a bunch of 10-15 inch reports it still verifies as a correct forecast.

[psuhoffman]

I was wondering about that earlier myself. I think the answer depends where you are. Eastern Long Island might have lower progged totals due to mixing concerns and my area might have a lower than we think is 'reasonable' low end due to concerns around potential dryslotting.

In short, I suppose it's a hedge on the unexpected...

its very fast moving. The runs of the euro that were massive ammounts of snow had the storm stall. It looks unlikely to happen now and its really truckin. The heavy snow only lasts about 12 hours. It would take absolutely sick snowfall rates to get more then 10-15" in only 12 hours.

[LVblizzard]

SREFs hold serve from 9z and 15z, 1" line covers the entire state of NJ except for extreme NW NJ, and it's still snowing. Also it looks like there's less spread, which means the members are converging on a solution.

[gibson16]

i know where banding sets up is always different in every storm but usually with these types of storms isn't nw of phl always great for banding or no

[Zir0b]

SREFs are out and are as bullish as ever....at 30 hours the mean has a 980 low well inside the benchmark, perhaps uncomfortably too inside for some...

The 18z RGEM was most likely an off run...I'm throwing it out

[jdt]

21z SREF SLP http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/sref/21/images/sref_bsp_036s.gif

everything looks to be on target!

[jdt]

i know where banding sets up is always different in every storm but usually with these types of storms isn't nw of phl always great for banding or no

It does seem quite often a heavy band of snow does well NW of the SLP closer to the western edge of the precip shield. It is not always the case but definitley does occur many times. I cannot say what specific features result in that occuring or not but will be on thing to keep an eye tomorrow as this all comes together

[SnowGoose69]

i know where banding sets up is always different in every storm but usually with these types of storms isn't nw of phl always great for banding or no

Depends on the central pressure of the storm and location...in this storm if its 982mb 50 miles east of central NJ, the heaviest bands will likely be over NYC, in a 995-998mb low in that spot, near PHL would be the spot to be...a stronger low is going to wrap those bands closer into the center in most cases.

[chrisNJ]

The metro airports in NYC handle the snow well, minus LGA which closes more frequently...I expect its likely one of the big three closes at some point for snow removal early Monday AM or late Sunday evening.

This was why I took the safe side and changed my flight out of LGA from Sunday at 330 pm to Monday at 1215 pm. I did not want to risk sitting in an airport, stuck with a 4 yr old overnight. Yes, there is a small chance that the flight would make it out tomorrow, but not worth the risk. I'll enjoy the storm in the meantime!