Major Nor'easter snow storm (possible top 20) Noon Wednesday-Noon Thursday Dec 16-17, 2020

[donsutherland1]

4 hours ago, Doorman said:

I think 6 plus for the metro will be a stretch.... this is the noaa metro prog for 7:00 pm Wed night

1 inch prog

the euro has it weaken to about 1004mb trucking east 12 hours later

do the math....

 

https://digital.weather.gov/

where is my mustard....

 

Most of the snow in such places as Newark, New York, and into southern New England occurs after 7 pm on Wednesday.

[lee59]

One thing that has me wondering, if this is a good nor'easter. Why do some models have the storm weakening as it moves off the coast.

[LibertyBell]

1 minute ago, lee59 said:

One thing that has me wondering, if this is a good nor'easter. Why do some models have the storm weakening as it moves off the coast.

occlusion?  that typically happens after storms mature.

[LibertyBell]

1 hour ago, wdrag said:

 

From Topic headline at 6AM Monday 12/14/20.  Please monitor NWS Watch-Warnings for this storm and associated statements and still uncertainty on where highest impact.  There is/was some overall slight southward shift in the guidance in the past 24 hours and so my uncertainty for the forum is northern CT-Catskills,  and LI/I95 southeastward. WPC still has 1.5"+ qpf just s of I80-LI and 3/4" into northern CT. Added the EPS 10 to 1 ratio graphic of both today and Wednesday nights storm. I think that serves as continued good starting point with the usual caveat on the northern and southern fringes. 

If you have travel plans Wednesday into Thursday I95 northwestward from VA through WV, PA, NJ, NYS and southern New England it's probably a good idea to consider changes, based on your NWS or other favorite media outlet forecasts. 

I think this will be a top 20 snow storm for a few parts of our NYC subforum (basically ~ 1 foot will prompt that review) but unsure where. For now between I95 to I84. Anticipating (not guaranteed) widespread closures or delays for all transportation systems I95 corridor northwestward Wednesday evening into Thursday morning,. For those who have access and wish to do so, you can calculate an experimental storm index to get an idea of what is probably coming. I don't want to presume more than Major yet (crippling is the next step up). Here is some information. https://www.ncdc.noaa.gov/snow-and-ice/rsi/?nesis

Still variability in northward extent of heavy 1 foot snow ranging from the NAM Adirondacks to the GFS-RGEM I80-LI. UKMET is still quite far north.  Ensembled r/s line looks to remain mostly south of I80-LI but awfully close, close enough to think sleet, rain or freezing rain mixes in for a time after the initial Wednesday evening thump for LI and s of I80.  EPS continues almost unyielding on the widespread 8-18" snowstorm (isolated 2 feet possible in the banding somewhere north of I80-LI).  Major power outages possible wherever the 6" of 32-33F wet snow accumulates along with wind gusts of 40-50 MPH. If this were to occur, it would most likely develop between 9 PM and midnight Wednesday evening per consistent modeling of snow onslaught and wind gusts increasing past 30 MPH.  Am targeting LI south coast and NJ coast but this will require 6" wet snow (32-33f).  Isolated wind gusts above 50 MPH possible on those coasts.  Snowfall rates of 1-3"/hr possible in northward transiting bands Wednesday-evening/ night.  Where these tend to park on the northern extent of the storm, will probably be the 2 feet of snow, especially with ratios drier than 10 to 1 (maybe 13 to 1). NWS has the multi model ratio blend tool and BUFKIT can assist for those who have that tool. There could be closing bands of moderate snowfall Thursday morning after sunrise into early afternoon as the comma head tends to fold southeastward behind the eastnortheastward departing  storm. 

Clearing the first few inches of snow around 8-10PM Wednesday will make it easier to remove the additional snow Thursday morning. Where it's wet-caution for those with heart conditions., 

This strong easterly surface gradient (northeast wind) between the cold 1035MB high over Quebec and and the probable 995-1000MB low near Cape May early Thursday will produce minor to moderate coastal flooding, for the Thursday morning high tide cycle. Follow NWS statements. 

So the base EPS snowfall graphic is added.  Also multiple locations of whatever is in their climate database (did not check for missing data). This gives us an idea of amount goals to reach top 20... No guarantee anywhere but I would think 1 or 2 of these would make top 20.  

May not comment in detail again til late today or this evening, shifting attention to today. Have a good day and fun debating.  Am still uneasy about the northward extent of the 00z/14 EPS 1" qpf which is still near the MA Pike. 

Hey Walt, can you post a table like this for JFK and LGA also?  Specifically for JFK, I remember that our heaviest snowfalls come when the rain/mix line is just south of us!  Dec 2003 was like this. And wow Mt Pocono had 30" in one day from the famed Feb 1978 blizzard?  Interesting that 1/23/87 is right up there too...1/23 seems to be a rather popular date for HECS although none of the historic east coast storms outside of 1978 are on the MPO list.

Also, is the truly heavy snow going to happen after dark?  I hate that, makes for less photo ops!  It's why I loved J1/2016 long duration and heaviest snow during the day!

 

[LibertyBell]

14 minutes ago, donsutherland1 said:

Most of the snow in such places as Newark, New York, and into southern New England occurs after 7 pm on Wednesday.

mostly a night time event, Don ?  not very photogenic!

[lee59]

4 minutes ago, LibertyBell said:

occlusion?  that typically happens after storms mature.

Ok. I'm just  thinking a good Nor'easter has a barometric pressure dropping through the 990s  to the 980s.

[LibertyBell]

1 minute ago, lee59 said:

Ok. I'm just  thinking a good Nor'easter has a barometric pressure dropping through the 990s  to the 980s.

also depends on the surrounding airmass if you get a strong high to the north then you still get the big winds.

I'm thinking of historic noreasters that didn't drop well down in the pressure department and you have storms like Feb 1983 and PD2/2003 on that list.

Our best snowstorms throw WAA over an arctic airmass and snow for 24 hours or more.

 

 

[lee59]

2 minutes ago, LibertyBell said:

also depends on the surrounding airmass if you get a strong high to the north then you still get the big winds.

I'm thinking of historic noreasters that didn't drop well down in the pressure department and you have storms like Feb 1983 and PD2/2003 on that list.

Our best snowstorms throw WAA over an arctic airmass and snow for 24 hours or more.

 

 

Yea the strong high to the north should help create good gradient winds.

[tim]

1 minute ago, lee59 said:

Yea the strong high to the north should help create good gradient winds.

...lets hope the 'strong high' wins out..otherwise we rain on LI.

 

[wdrag]

20 minutes ago, LibertyBell said:

Hey Walt, can you post a table like this for JFK and LGA also?  Specifically for JFK, I remember that our heaviest snowfalls come when the rain/mix line is just south of us!  Dec 2003 was like this. And wow Mt Pocono had 30" in one day from the famed Feb 1978 blizzard?  Interesting that 1/23/87 is right up there too...1/23 seems to be a rather popular date for HECS although none of the historic east coast storms outside of 1978 are on the MPO list.

Also, is the truly heavy snow going to happen after dark?  I hate that, makes for less photo ops!  It's why I loved J1/2016 long duration and heaviest snow during the day!

 

I'll add the data shortly...  ONE error on my part ... this data is I think driven by calendar day.  I may add some two day totals to bring better perspective.  Even so,  I think top 20 is possible by midnight Wednesday night. It does appear to me a lot of the big FGEN 1-3"/hr has to be before midnight or earlier for LI/I80) south...  unless the storm slows and I don't think that will happen.  However, I80 ned including LI... i would not be surprised at lagging bands of 1/2MI Snow rolling southeastward after sunrise Thursday as the back side of the comma head moves east (getting what ne PA has all night)--this presuming the EPS is 80% accurate.

[Rjay]

5 hours ago, Doorman said:

Hello Coasty.....see the 1004mb bubble on the euro 

and the match to the wpc  prog....

they get an early looks at things ....the wpc time stamp is just after midnight   0530Z

 

digital snow maps 

I think some forum has a thread for that

 

 

 

 

 

You do this way too often.

Here's the euro at the same time stamp. 12z thursday (pretty much when the storm is over).

 

[wdrag]

Tables for JFK/LGA I think attached.  Have looked at two day (crossover with the midnight climate... tougher for top 20 depending on where all snow but, MPO seems a best fit... others may too-dependent on track and mix potential.  Won't post the two day til late today or tomorrow if that still applies. 

[Rjay]

5 hours ago, Doorman said:

I think 6 plus for the metro will be a stretch.... this is the noaa metro prog for 7:00 pm Wed night

1 inch prog

the euro has it weaken to about 1004mb trucking east 12 hours later

do the math....

 

https://digital.weather.gov/

where is my mustard....

 

 

Your mustard must be in your eyes because either,

A. you're blind

B. you're a troll

C. you're a liar

 

Which is it?

[BxEngine]

1 minute ago, Rjay said:

 

You do this way too often.

Here's the euro at the samw time stamp. 12z thursday (pretty much when the storm is over).

 

The models also come out the same for everyone, there is no “first look”. 

[friedmators]

6z rgem hourly snowfall for posterity


.

[rclab]

6 minutes ago, Rjay said:

 

Your mustard must be in your eyes because either,

A. you're blind

B. you're a troll

C. you're a liar

 

Which is it?

It’s not polite to slam the door shut on the way out, however in this case the action is understandable. As always .....

[wdrag]

NWS collaborated snow amounts in case this hasn't posted yet... only thru 7A Thursday.  Temps will probably be generally 20-25F during the entire snowstorm across nw NJ/seNYS/ne PA and CT.  

[LibertyBell]

26 minutes ago, wdrag said:

I'll add the data shortly...  ONE error on my part ... this data is I think driven by calendar day.  I may add some two day totals to bring better perspective.  Even so,  I think top 20 is possible by midnight Wednesday night. It does appear to me a lot of the big FGEN 1-3"/hr has to be before midnight or earlier for LI/I80) south...  unless the storm slows and I don't think that will happen.  However, I80 ned including LI... i would not be surprised at lagging bands of 1/2MI Snow rolling southeastward after sunrise Thursday as the back side of the comma head moves east (getting what ne PA has all night)--this presuming the EPS is 80% accurate.

You read my mind, Walt, I was going to ask for two day storm totals which would include most of the bigger storms.

 

[wdrag]

Just now, LibertyBell said:

You read my mind, Walt, I was going to ask for two day storm totals which would include most of the bigger storms.

 

Need to wait til 4P....thanks

[jm1220]

Just now, friedmators said:

6z rgem hourly snowfall for posterity


.

RGEM is absolute beauty for this area, but 6z NAM and Euro looked more amped. We really don't want that getting out of hand-this needs to start making a beeline east once it gets to around Cape May. 

[donsutherland1]

50 minutes ago, LibertyBell said:

mostly a night time event, Don ?  not very photogenic!

Unfortunately, that’s the case this time around.

[LibertyBell]

12 minutes ago, wdrag said:

Tables for JFK/LGA I think attached.  Have looked at two day (crossover with the midnight climate... tougher for top 20 depending on where all snow but, MPO seems a best fit... others may too-dependent on track and mix potential.  Won't post the two day til late today or tomorrow if that still applies. 

an excellent list! Thanks Walt!  I cant wait to see your two day lists for the above locations plus MPO, NYC and EWR.  A couple of notes - the number of 20" snowfalls will increase since these are the ones most affected by two day totals.

That will put both Feb 1961 and Feb 1969 over the 20 inch mark at both JFK and LGA.   Jan 1996 and Feb 1983 will also go over the 20 inch mark (the latter at JFK at least.)  Boxing Day 2010 should be close to 20 inches at both.  I'm also curious to see what the full storm total was from Feb 1978 at MPO.  And I didn't know that JFK got 9.6 inches in one day in 1/88, I'd be curious to see if they hit double digits for that storm total as that was an era with few or no double digit snowstorms.

 

 

[LibertyBell]

5 minutes ago, jm1220 said:

RGEM is absolute beauty for this area, but 6z NAM and Euro looked more amped. We really don't want that getting out of hand-this needs to start making a beeline east once it gets to around Cape May. 

I have hopes that even if it just goes slightly south of us we'll be fine, this is a cold storm not unlike the Millenium storm.

 

[Rjay]

10 minutes ago, rclab said:

It’s not polite to slam the door shut on the way out, however in this case the action is understandable. As always .....

We let a ton slide.  One thing we don't let slide is lying or intentionally posting incorrect info.  

[crossbowftw3]

10 minutes ago, wdrag said:

NWS collaborated snow amounts in case this hasn't posted yet... only thru 7A Thursday.  Temps will probably be generally 20-25F during the entire snowstorm across nw NJ/seNYS/ne PA and CT.  

Makes the most sense as of this moment. Might even drop to 15 degrees at my house if point and click is to be believed.

[LibertyBell]

18 minutes ago, BxEngine said:

The models also come out the same for everyone, there is no “first look”. 

what is this, a news station?  And here's a first look at the weather, the latest news is a weenie suicide watch is in effect from  4 PM Wednesday to 9 AM Thursday....

[jm1220]

Just now, LibertyBell said:

I have hopes that even if it just goes slightly south of us we'll be fine, this is a cold storm not unlike the Millenium storm.

 

It’ll definitely be cold and I think everyone gets pounded for a while regardless of the track because of the cold to start but if we want to avoid the dryslot and mix issues eventually we want the 700 and 850 lows to go SE of us. The more amped models have those pretty close by which introduce mixing chances. This will only be able to get so far north anyway because of the blocking setup and 50-50 low, eventually it will have to get shunted out. 

[LibertyBell]

12 minutes ago, wdrag said:

NWS collaborated snow amounts in case this hasn't posted yet... only thru 7A Thursday.  Temps will probably be generally 20-25F during the entire snowstorm across nw NJ/seNYS/ne PA and CT.  

question about the snowfall gradient is this based on the idea that long island will mix or change to rain or more because of the temps involved mean lower ratios and wetter snow?

On this it looks like snowfall gets less at Scranton and points north and once east of Morristown?

 

[LibertyBell]

Just now, jm1220 said:

It’ll definitely be cold and I think everyone gets pounded for a while regardless of the track because of the cold to start but if we want to avoid the dryslot and mix issues eventually we want the 700 and 850 lows to go SE of us. The more amped models have those pretty close by which introduce mixing chances. This will only be able to get so far north anyway because of the blocking setup and 50-50 low, eventually it will have to get shunted out. 

where were those lows during the Millenium storm- I think they passed just east of us over Suffolk County?

 

[SnoSki14]

5 minutes ago, NJsnow89 said:

Euro ensembles are even further NW. cuts totals down even more for the metro areas 

The storm is likely going to correct south soon. The high is too powerful to the north. A gfs/euro compromise is most likely.

I've never seen a case where the low trended north with such a strong CAD in place. 

What i predict is that certain models will look amped the day before but the storm corrects south & east as it develops.