Wintry mix potential weekend of Jan 18-19, 2020

[Allsnow]

5 minutes ago, Enigma said:

Absolutely incorrect. Completely different setups. Coastal snow will breakout with isentropic lift from advancing warm front running into a very decent CAD signature. Chicago is none of that.

This isn't a SWFE or gradient type system. 

Yes, our snow is coming from the WAA precipitation. My reference to Chicago is that fact if they have precipitation problems that means the best WAA will be to the metros north. You can see that on the euro idv with a more amped up low. The WAA ends up moving more southwest to northeast. Perhaps why the eps mean has a tight gradient by the coast 

 

00z euro had the low in central Indiana with no Ptype issues for Chicago and better waa fo us.

[PB-99]

6 minutes ago, Enigma said:

Absolutely incorrect. Completely different setups. Coastal snow will breakout with isentropic lift from advancing warm front running into a very decent CAD signature. Chicago is none of that.

This isn't a SWFE or gradient type system. 

Doesn`t this originating out of the 4 corners and focusing it`s snow via WAA put it in that category ? 

 

I just don`t see a secondary, so I thought the flow through the OHV puts it in that category 

 

[Enigma]

3 minutes ago, PB-99 said:

Doesn`t this originating out of the 4 corners and focusing it`s snow via WAA put it in that category ? 

 

I just don`t see a secondary, so I thought the flow through the OHV puts it in that category 

 

SWFE are classically overrunning events with precipitation developing over the gradient/baroclinic zone. Very different than a warm front running  squarely into a CAD signature.

[Brian5671]

GFS slower-turning into a Sat night event

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looks like mainly rain epscially  city and south after a burst of snow up front

[Allsnow]

3 minutes ago, Brian5671 said:

GFS slower-turning into a Sat night event

Yep. More amped this run. Snowfall 2-4 along the coast a bit more inland. Pretty much what everyone expects 

[SnoSki14]

GFS more in line with Euro.

Does hint at a secondary developing east of the Delmarva, we'll have to see if that becomes a trend as it would likely allow cold air to linger longer. 

[MJO812]

16 minutes ago, Allsnow said:

Yep. More amped this run. Snowfall 2-4 along the coast a bit more inland. Pretty much what everyone expects 

Gfs is colder on the onset but it delayed the precip. Need the precip to come in faster but 2-4 is pretty good lol

[SnowGoose69]

2 hours ago, Enigma said:

Absolutely incorrect. Completely different setups. Coastal snow will breakout with isentropic lift from advancing warm front running into a very decent CAD signature. Chicago is none of that.

This isn't a SWFE or gradient type system. 

I have a pretty broad termination for SWFE.  I more or less would consider this to be one.  I’ve seen people call events like 12/5/02 SWFEs though and to me that is extending it too far.  

[Brasiluvsnow]

a little help guys,,,,,SWFE ??? Whats this mean or can you explain ? thanks in advance

[NYCweatherNOW]

7 minutes ago, Brasiluvsnow said:

a little help guys,,,,,SWFE ??? Whats this mean or can you explain ? thanks in advance

South west flow event 

[jm1220]

2 hours ago, SnoSki14 said:

GFS more in line with Euro.

Does hint at a secondary developing east of the Delmarva, we'll have to see if that becomes a trend as it would likely allow cold air to linger longer. 

The primary would have to die very fast in order to allow the coastal to keep the cold air in. Models have it lingering much too long to stop the warm air from coming in. And there really isn’t blocking or anything to stop a primary from surging up past a point where it wrecks our airmass. This one overall isn’t too tough to forecast IMO and we’ve seen numerous times. The question is how much cold is out front and snow we can get at the beginning vs it staying snow. That’s a question for I-90 not us. 

[weatherpruf]

24 minutes ago, jm1220 said:

The primary would have to die very fast in order to allow the coastal to keep the cold air in. Models have it lingering much too long to stop the warm air from coming in. And there really isn’t blocking or anything to stop a primary from surging up past a point where it wrecks our airmass. This one overall isn’t too tough to forecast IMO and we’ve seen numerous times. The question is how much cold is out front and snow we can get at the beginning vs it staying snow. That’s a question for I-90 not us. 

Seen many of these; sometimes we eke out 3 inches before it turns over to rain. I usually clean the driveway just for the heck of it, but in truth it is all almost always gone by the time the storm exits, depending on how much rain and warm air there is.

[LongBeachSurfFreak]

28 minutes ago, jm1220 said:

The primary would have to die very fast in order to allow the coastal to keep the cold air in. Models have it lingering much too long to stop the warm air from coming in. And there really isn’t blocking or anything to stop a primary from surging up past a point where it wrecks our airmass. This one overall isn’t too tough to forecast IMO and we’ve seen numerous times. The question is how much cold is out front and snow we can get at the beginning vs it staying snow. That’s a question for I-90 not us. 

This screams last March to me right along the coast.  (I’m talking immediate south shore and jersey shore) where East winds are the kiss of death and you scratch an inch of slush and 10 miles inland it’s another world. We really need to speed things up. 

[SnowGoose69]

12 minutes ago, weatherpruf said:

Seen many of these; sometimes we eke out 3 inches before it turns over to rain. I usually clean the driveway just for the heck of it, but in truth it is all almost always gone by the time the storm exits, depending on how much rain and warm air there is.

The upper ceiling for the metro on events like this is usually 6-7 inches and that accounts for a small percentage of them. Most fall between 1-4 

[uncle W]

25 minutes ago, SnowGoose69 said:

The upper ceiling for the metro on events like this is usually 6-7 inches and that accounts for a small percentage of them. Most fall between 1-4 

Feb 2008 had a 6" one and Feb 1993 a 4" one...they came a month later when the Ocean is colder...I remember 1972 being a nothing winter until the last week in January...then all hell broke loose but we missed out on the KU that came later in February...

[Brian5671]

6 minutes ago, uncle W said:

Feb 2008 had a 6" one and Feb 1993 a 4" one...they came a month later when the Ocean is colder...I remember 1972 being a nothing winter until the last week in January...then all hell broke loose but we missed out on the KU that came later in February...

sounds like Feb 89...although there was absolutely nothing before this storm-garbage winter and then a bust on a KU to end it....

[jm1220]

52 minutes ago, LongBeachSurfFreak said:

This screams last March to me right along the coast.  (I’m talking immediate south shore and jersey shore) where East winds are the kiss of death and you scratch an inch of slush and 10 miles inland it’s another world. We really need to speed things up. 

IIRC, the preceding airmass for those was pretty stale and there wasn’t much preceding to change things over when the wind shifted. We’ve had some where we lucked out like 12/15/03 where we had 6” even in Long Beach before rain. This will at least have a fairly strong high to trap cold air in for the start. Definitely though, inland areas will have a better shot at keeping it from raining at least. Just inland over CT, NJ and Hudson Valley would likely go to ice vs rain for the coast. Maybe the north shore and northern NYC can grab another inch or two vs the south shore. I haven’t really looked at how strong the mid level warmth might come in-a strong WAA push and heavy snow to start usually means faster warm mid level air too. 

[weatherpruf]

32 minutes ago, uncle W said:

Feb 2008 had a 6" one and Feb 1993 a 4" one...they came a month later when the Ocean is colder...I remember 1972 being a nothing winter until the last week in January...then all hell broke loose but we missed out on the KU that came later in February...

That Feb one actually delivered for us out my way...the big show was in March though. 

[qg_omega]

4 hours ago, Enigma said:

SWFE are classically overrunning events with precipitation developing over the gradient/baroclinic zone. Very different than a warm front running  squarely into a CAD signature.

This is a SWFE there is no CAD signature the high is slipping off the coast 

[uncle W]

38 minutes ago, Brian5671 said:

sounds like Feb 89...although there was absolutely nothing before this storm-garbage winter and then a bust on a KU to end it....

the 1972 storm changed to rain in NYC...1989 missed completely...

[SnowGoose69]

55 minutes ago, jm1220 said:

IIRC, the preceding airmass for those was pretty stale and there wasn’t much preceding to change things over when the wind shifted. We’ve had some where we lucked out like 12/15/03 where we had 6” even in Long Beach before rain. This will at least have a fairly strong high to trap cold air in for the start. Definitely though, inland areas will have a better shot at keeping it from raining at least. Just inland over CT, NJ and Hudson Valley would likely go to ice vs rain for the coast. Maybe the north shore and northern NYC can grab another inch or two vs the south shore. I haven’t really looked at how strong the mid level warmth might come in-a strong WAA push and heavy snow to start usually means faster warm mid level air too. 

12/15/03 was similar to 11/2018.  It came straight up from the south or south southwest 

[Allsnow]

18z eps even more amped with less snow along the coast. Let’s hope this levels out soon. 

[NorthShoreWx]

20 minutes ago, uncle W said:

the 1972 storm changed to rain in NYC...

I was a bit young then, but I recall a storm that I think was the same February storm where we had about 6" of snow in the morning, then most of it washed away in the afternoon, then it flipped back and we had another 6" in the evening.  I'm pretty sure it was on a Saturday because I remember dad taking us sledding the next day (Sunday).  Could be a different time, but I also recall another 5 or 6" overnight a few days later from what a radio met (Gordon Barnes?) described as an "upper air disturbance". 

[uncle W]

Just now, NorthShoreWx said:

I was a bit young then, but I recall a storm that I think was the same February storm where we had about 6" of snow in the morning, then most of it washed away in the afternoon, then it flipped back and we had another 6" in the evening.  I'm pretty sure it was on a Saturday because I remember dad taking us sledding the next day (Sunday).  Could be a different time, but I also recall another 5 or 6" overnight a few days later from what a radio met (Gordon Barnes?) described as an "upper air disturbance". 

that was the KU on 2/19/72...5" of very wet snow changed to heavy rain in the city then ended as an inch of snow...that month had a wet storm that started as snow on the 2nd...5" of snow on the 6th...heavy rain on the 13th...2" of snow on the 17th..the 5.7" on the 19th...another 5" of unexpected snow on the 23rd...

[HVSnowLover]

1 hour ago, qg_omega said:

This is a SWFE there is no CAD signature the high is slipping off the coast 

There is a major CAD signature, the 850 line is down in the Central MA. NYC is just such a horrible location for snow in these setups, the boundary layer warms up so fast at the immediate coast (of course there have been some exceptions to this)

[HVSnowLover]

4 minutes ago, sferic said:

If every NYC winter was like 1995-96 you wouldn't be saying that LOL

It was actually a really good run for the coast in the early 2010s but lately everything has returned to normal

[HVSnowLover]

The GFS is likely overdoing the warming of the boundary layer, 850s are really cold. The setup on the GFS is a 2-5 inch snowstorm easily for the city with more to the NW despite what the verbatim maps may show.

[HVSnowLover]

The best forcing on the GFS is over NJ and NYC, I really doubt heavy precip is going to flip to rain in the middle of the night with 850s and 925 temps below freezing  but I could be wrong.  

[weatherpruf]

20 minutes ago, WestBabylonWeather said:

50% of the last two decades have had winters yielding 50” per snow or more as per upton

nyc doesn’t suck for winter weather

 

we just have runs of snowless winters here and there 

I question some of those numbers; I am just west of SI. No way we had 43 in 2009; 2013 was just about average. 2015, 2017 and 2018 are also off. These seem like LI numbers maybe?

[weatherpruf]

2 minutes ago, HVSnowLover said:

The best forcing on the GFS is over NJ and NYC, I really doubt heavy precip is going to flip to rain in the middle of the night with 850s well below freezing  but I could be wrong.  

I'd go with the most knowledgeable posters here; this is likely 1-3 and then rain. I can only remember one of these that delivered close to 8, and that was in 2008 during a two winter snow drought....these storms often flip over fast.