Wintry events possible I84 corridor down to near I80 next week (14th-18th)

[jm1220]

16 minutes ago, NEG NAO said:

Good Luckas for 12/16 event I would be concerned about much accumulating snow south of I78 - unless the EURO starts trending south - still a wide range of solutions from the wound up warm 0Z EURO OP to the 0Z very cold Canadian OP............

Haven’t been following this very closely yet but it wouldn’t surprise me if the second wave for Weds trended more amped due to the not great PNA. Gives the trough more room to amplify in the East and force a NW track. The blocking up north does force it to redevelop somewhere but hopefully it’s not when we’re already flooded in warm air. A primary that hangs on too long (never a problem here  ) also sends warm air aloft in which means a lot of sleet. Still long ways to go though. 

[MJO812]

Eps with the 1st wave north again. Looks like some snow on Monday but nothing major. Temps are too warm.

[NEG NAO]

1 minute ago, MJO812 said:

Eps with the 1st wave north again. Looks like some snow on Monday but nothing major. Temps are too warm.

similar to the light snow earlier in the week MAYBE

 

[SnoSki14]

Wave 1 could trend more amped because blocking pattern hasn't set up and poor pacific favors it trending NW.

However by the time wave 2 happens you have strong blocking in place and it favors a hard stop to ENE track once the low is off the Delmarva. 

A whiff is more likely with wave 2 than it cutting.

[SnowGoose69]

1 minute ago, SnoSki14 said:

Wave 1 could trend more amped because blocking pattern hasn't set up and poor pacific favors it trending NW.

However by the time wave 2 happens you have strong blocking in place and it favors a hard stop to ENE track once the low is off the Delmarva. 

A whiff is more likely with wave 2 than it cutting.

Pattern is fairly progressive.  I don't see wave 1 really trending THAT much more NW

[rossi]

Although early I believe system will trend south.

Past years areas NYC and south have done well with coastal storms.

Rossi

[wdrag]

The 14th is a likely event I think, because there is not going to be much rain this weekend (less than a tenth or two) and we'll need a flushing of the mild air For Wednesday event).  Therefore an event Monday takes advantage of some WAA leftover low lvl moisture (dew point 30+) from this weekend and wrings it out as short wave passes by, which should result in decent BL CAA Tuesday.  (corrected PWAT reference at 822A to dewpoint).

[wdrag]

10 minutes ago, rossi said:

Although early I believe system will trend south.

Past years areas NYC and south have done well with coastal storms.

Rossi

If it does, we're going to have to see the 850 LOW's on both GEFS/EPS trend south.  Could happen. If the ensembles on this feature don't trend south in the future, then the winter action will be more n of I80 than s. I just don't know. 

[SnowGoose69]

Monday is too far out to iron out but if you were to take the 06Z Op Euro literally its probably an all snow event even at the coast.  

[MJO812]

2 minutes ago, SnowGoose69 said:

Monday is too far out to iron out but if you were to take the 06Z Op Euro literally its probably an all snow event even at the coast.  

Yep that event has trended north and stronger on the euro and eps.

[wdrag]

RMOP added for the GEFS. Lots of confidence on trough ne USA... and confluence to me appears across NNE.  fwiw..the 06z GEFS and 00z EPS are about the same on snowfall..nice ~6" SNE nw NJ and ne PA.  Plenty of time to move south, or north. 

[SnowGoose69]

1 minute ago, MJO812 said:

Yep that event has trended north and stronger on the euro and eps.

We've seen many of those types of events in recent years and they tend to look rainy at day 3-4 but as you get closer in models usually grasp the cold air bleeding in.  They always look scary when you're 45/35 6-12 hours out and everyone is screaming bust

[snowman19]

38 minutes ago, SnoSki14 said:

Wave 1 could trend more amped because blocking pattern hasn't set up and poor pacific favors it trending NW.

However by the time wave 2 happens you have strong blocking in place and it favors a hard stop to ENE track once the low is off the Delmarva. 

A whiff is more likely with wave 2 than it cutting.

If the PNA breaks down, it can absolutely cut 

[MJO812]

4 minutes ago, snowman19 said:

If the PNA breaks down, it can absolutely cut 

Absolutely 

[jm1220]

1 hour ago, SnoSki14 said:

Wave 1 could trend more amped because blocking pattern hasn't set up and poor pacific favors it trending NW.

However by the time wave 2 happens you have strong blocking in place and it favors a hard stop to ENE track once the low is off the Delmarva. 

A whiff is more likely with wave 2 than it cutting.

Also possible that a stronger Wave 1 could help suppress Wave 2 behind it? 

[jm1220]

55 minutes ago, bluewave said:

The EPS 500mb forecast doesn’t match the NYC 6”+ composite for December yet. Notice how the 5 events since 1995 had a stronger +PNA pattern. The upper low was also usually a little further south instead of over the Great Lakes. But we do have very strong blocking over the North Pole and Greenland and a 50/50 low.  We have seen unlikely looking 500 mb patterns produce major snows here since 2010. So while these 500 mb composites can act as a guide, the are not always definitive with several new extremes we have seen recently. I have also included a 14 storm December composite going back to 1948 which is similar.

 

 

5 storm December composite since 1995

 

 

14 storm composite since 1948

 

 

Yep, with the PNA not cooperating so well this could end up trying to run inland. Time for that to improve still though 

[White Gorilla]

22 minutes ago, jm1220 said:

Also possible that a stronger Wave 1 could help suppress Wave 2 behind it? 

How 2020 it would be if wave 1 goes all rain and wave 2 completely misses. 

[White Gorilla]

18 minutes ago, JoshSnow said:

Wave 1 isn’t going to be all rain it looks to be a miss entirely

Well, what will be will be... 

[MJO812]

13 minutes ago, jm1220 said:

Yep, with the PNA not cooperating so well this could end up trying to run inland. Time for that to improve still though 

The NAO might be the saving grace here 

[HeadInTheClouds]

9 minutes ago, JoshSnow said:

I’m more worried about this out to sea to be honest but if I were to guess this could be a big hit

Me too, especially where I am a little north of 84. Ultimately I still think we get a decent event. 

[wdrag]

Tentatively, based on 12z/11 and 00z/12 model cycles,, I'll update-rewrite the topic for the 14th and 16th-17th events (saving the original at the end) and drop the 18th. This could be a nice pair of events around parts of our area. No changes for me though, prior to 5P or possibly not til 6A Saturday. 

[SnoSki14]

41 minutes ago, snowman19 said:

If the PNA breaks down, it can absolutely cut 

Not if there's a strong block in place. Large 50/50 low is allowing the high to hold to our north. 

A strong high like that will stop the low from cutting. We see it time and time again with SWFEs. 

[romba]

1 hour ago, NEG NAO said:

Good Luckas for 12/16 event I would be concerned about much accumulating snow south of I78 - unless the EURO starts trending south - still a wide range of solutions from the wound up warm 0Z EURO OP to the 0Z very cold Canadian OP............

A blend would be really nice...

[MJO812]

7 minutes ago, SnoSki14 said:

Not if there's a strong block in place. Large 50/50 low is allowing the high to hold to our north. 

A strong high like that will stop the low from cutting. We see it time and time again with SWFEs. 

The fear here is a sheared mess with a 50/50 low.

[rclab]

11 hours ago, nycwinter said:

field is 97 still alive....

That is wonderful. I also remember Storm Field. That would be a great name for a forum members child. Although, my lost love would have made sure I was gelded if I tried. As always......

[wdrag]

One model I've not heard much about... the IBM model that is supposed to be much better than the available models that we all look at.  This model made some news a year or two ago about picking up on some storms sooner.  Has it been implemented? Any public guidance available? 

[Neblizzard]

24 minutes ago, rclab said:

That is wonderful. I also remember Storm Field. That would be a great name for a forum members child. Although, my lost love would have made sure I was gelded if I tried. As always......

My brother and I met storm field several times when we used to visit Larry Cosgrove at UPN 9.  Two class acts 

[wdrag]

Also for those who like to hunt these comparisons down... the last time we've seen a modeled surface pattern similar to Wednesday's projected (early this mornings WPC guidance)???... I think its' been at least back to March 2018, if not before?

[snowman19]

48 minutes ago, SnoSki14 said:

Not if there's a strong block in place. Large 50/50 low is allowing the high to hold to our north. 

A strong high like that will stop the low from cutting. We see it time and time again with SWFEs. 

This is not a SWFE setup. This is like the argument that it’s “impossible” for a low to cut over deep snowcover. If a shortwave is amped enough in the wrong spot, it will cut

[SnoSki14]

Wave 1 could be a sneaky snow event.

Models continue ticking north and there's a surprisingly high amount of precip with it despite it being a fast mover.