December 2019

[the_other_guy]

17F this morning at 7am

[tim]

...KFOK got down to 10*..currently 12*

..i'm @ 15*.(actually 14.8*)

ideal radiational cooling last nite..heavy frost this morning.

[bluewave]

Longer range, it looks like convection migrating toward the Maritime Continent may weaken the -EPO. We’ll see how it goes.

EPO forecast courtesy of Bamwx on twitter from weathermodels.com

[MJO812]

1 hour ago, snowman19 said:

Once again, stop using the 10:1 ratio snowmaps, grossly, horribly inaccurate. Remember the last storm when people kept posting that the city was getting 6 inches of snow and it got one inch? That was thanks to using the 10:1 ratio maps. Here is the accurate one, compare: https://www.tropicaltidbits.com/analysis/models/?model=gfs&region=neus&pkg=asnowd&runtime=2019120806&fh=90

The maps weren't the reason why the city got less. Nice try though. 

[MJO812]

51 minutes ago, bluewave said:

It could be close to 40 when we have a changeover after midnight. Remember it will be in the low 60’s on Tuesday. Temperatures will need to fall to at least 33 or 34 for light accumulations on the grass to occur in NYC Central Park. Plus you need enough of a snowfall rate to get accumulation  the ball rolling in marginal temperarures.

The models tonight and tomorrow will be key to see how much of there will be.  I can see a few inches out of this for the city or even barely anything. 

Temps dont mean anything at all. Remember ,temps will crash once the precip begins 

[IrishRob17]

1 hour ago, Dan76 said:

A lot colder this morning than what was forecasted.

My forecasted low was 10, made it to 7. 

[HVSnowLover]

42 minutes ago, Snow88 said:

The models tonight and tomorrow will be key to see how much of there will be.  I can see a few inches out of this for the city or even barely anything. 

Temps dont mean anything at all. Remember ,temps will crash once the precip begins 

Temps do mean something if it's above freezing during the storm, we just saw the impact with the last event.

[MJO812]

2 minutes ago, HVSnowLover said:

Temps do mean something if it's above freezing during the storm, we just saw the impact with the last event.

Yes but the temps are crashing this time around. We need more precip.

[Brasiluvsnow]

8 hours ago, NYCweatherNOW said:

How much snow on the ground there?

NYSW , my buddy and I had to make a stop off by family up there before hitting the casino and I said to them " wow you still have quite a bit of snow here " and they told me that they got 15 inches the other day and as I said there was still a nice amount in the area. ps They live in Monticello 

[SnowGoose69]

1 hour ago, bluewave said:

Longer range, it looks like convection migrating toward the Maritime Continent may weaken the -EPO. We’ll see how it goes.

EPO forecast courtesy of Bamwx on twitter from weathermodels.com

I think the window for it to matter though is quickly closing.  The analogs mostly suggest the pattern would likely become progressively favorable as we progress into January so if something bad doesn’t happen soon out there I’m not sure we would see more than just a brief 2 week period where the pattern is a shutout 

[uofmiami]

17.5 in Muttontown & 18.2 in Syosset for the low.

[bluewave]

33 minutes ago, SnowGoose69 said:

I think the window for it to matter though is quickly closing.  The analogs mostly suggest the pattern would likely become progressively favorable as we progress into January so if something bad doesn’t happen soon out there I’m not sure we would see more than just a brief 2 week period where the pattern is a shutout 

The timing for any potential weakening of the -EPO may begin just before the solstice. We have seen this temperature moderation period often during the last decade. Even the MJO remaining in the weaker circle portion of phases 4-5 could produce a temperature moderation. Not really speculating on what things look like all the way out to January yet.

[MJO812]

Nam looks better than past runs

Cold front comes through faster

[MJO812]

Few inches for the city and several for inland areas

[purduewx80]

The battle between Tuesday's near-record warmth and the influx of Arctic air from the Lakes Wednesday will lead to an impressive jet streak across the Northeast. This kind of jet structure can lead to a band of moderate-heavy precipitation that would be our best bet for a few inches of wet snow Wednesday morning. NAM and GFS both showing a 170-190KT wind max between 200-300mb:

Most of the forecast soundings suggest we go from rain to a wintry mix (IP and FZRA) over to snow, but we may not know exactly what transpires for another day or two.

[NYCweatherNOW]

Nam crushes the area but temps are a bit warm for the city but you never know sometimes models underestimate dynamic and wetbulbing cooling if you will.

[frd]

2 hours ago, bluewave said:

Longer range, it looks like convection migrating toward the Maritime Continent may weaken the -EPO. We’ll see how it goes.

Bluewave, any thoughts regarding progression of the +IOD /  standing wave this month?

In the short-term, as in this month, do you envision any weakening of the standing wave and a weakening in the general record +IOD.  Eric Webb mentioned maybe later this month it starts to weaken.  I believe it is typical as well to see the seasonal change over there and the eventual decline in the +IOD as we go through Jan and Feb. 

[MJO812]

2 minutes ago, NYCweatherNOW said:

Nam crushes the area but temps are a bit warm for the city but you never know sometimes models underestimate dynamic and wetbulbing cooling if you will.

Need it slightly more east with the heavy precip.  Nice event unfolding.

[EasternLI]

Hopefully this trend continues....

[EastonSN+]

3 hours ago, bluewave said:

The Euro begins mixing when NYC is 37 degrees. Temps fall to 33 when the snow ends early Wednesday. So it has 2.8 falling from the sky as snow or mix. Figure on a C-2 on the colder surfaces like then grass in Central Park since a portion of that will melt.

Agreed for city and se burbs.

NW as always can squeeze an extra inch or two.

As long as it's an inch or so it's gravy, keep stacking the small accumulations to get us a bit closer to average.

[MJO812]

27 minutes ago, purduewx80 said:

The battle between Tuesday's near-record warmth and the influx of Arctic air from the Lakes Wednesday will lead to an impressive jet streak across the Northeast. This kind of jet structure can lead to a band of moderate-heavy precipitation that would be our best bet for a few inches of wet snow Wednesday morning. NAM and GFS both showing a 170-190KT wind max between 200-300mb:

Most of the forecast soundings suggest we go from rain to a wintry mix (IP and FZRA) over to snow, but we may not know exactly what transpires for another day or two.

This is an impressive jet . This is what happen with the last few  anafronts. City turned to snow and received a few inches after being in the upper 30s.

I can see the same but the front has to come through quick while the low is riding it on the  backside. Nam was a step in the right direction.

[MJO812]

3 minutes ago, EastonSN+ said:

Agreed for city and se burbs.

NW as always can squeeze an extra inch or two.

As long as it's an inch or so it's gravy, keep stacking the small accumulations to get us a bit closer to average.

It depends on the speed and the position of the trough. It's funny how people think it's  only going to be a coating. This can see a few inches . It all depends on timing.

[Doorman]

18 minutes ago, NYCweatherNOW said:

Nam crushes the area but temps are a bit warm for the city but you never know sometimes models underestimate dynamic and wetbulbing cooling if you will.

more brush than crush atm

 

[purduewx80]

1 minute ago, Snow88 said:

I can see the same but the front has to come through quick while the low is riding it on the  backside. Nam was a step in the right direction.

There is consensus on the surface front passing by 8-9PM Tuesday evening, but the 925-850-700 fronts lag well behind (i.e. anafront), hence the rain to mix to snow scenario. The high placement and shallow nature of the Arctic air mass is not supportive of the cold air plowing over the Appalachians, so we'll have to rely on dynamic cooling from the jet max and stretched 500 vort to get anything that will stick. 

[NYCweatherNOW]

This reminds me of the event a day after the super bowl a few years ago. It was in the 60’s the day before on that Sunday, it became cloudy it rained for a few hours, turned into heavy snow Monday morning and Central Park got 8 inches. At least it’s trending snowier... anyone know the year ?

 

edit: it was in 2014 I just looked it up!

[frd]

2 minutes ago, bluewave said:

That would line up with our annual temperature moderation around the solstice.

Really interesting how this post 12/20 warm up seems to happen more frequently the last several years. Maybe this year will be a exception, but as you mention, the MJO progression increases the odds that it might occur yet again. 

[EastonSN+]

1 minute ago, bluewave said:

Right now we have the low frequency forcing in MJO 6 along with the +IOD standing wave. The low frequency forcing has produced the colder -EPO pattern in November into December. But they all show some forcing moving over closer to MJO 4-5 Just before the solstice. Even weaker MJO 4-5 forcing in the circle can flip the +EPO to more neutral or positive. That would line up with our annual temperature moderation around the solstice. That bubble high near the open water in the Chuckchi Sea may persist. While this could eventually drop the AO a bit, the NAO looks to stay positive. So any slight improvement in the AO could be countered by a less favorable +EPO and -NAO. 

The positive EPO is showing up here with a negative PNA.

However, not the worst pattern we have seen as the NAO heads to almost neutral and the AO heads to slightly below neutral. Cold air would be lacking however if we can get a storm to cut underneath and strengthen like the last storm, with it being later in the year perhaps a bit of a better result.

[Zelocita Weather]

Separate thread for this event....

[SnowGoose69]

2 minutes ago, purduewx80 said:

There is consensus on the surface front passing by 8-9PM Tuesday evening, but the 925-850-700 fronts lag well behind (i.e. anafront), hence the rain to mix to snow scenario. The high placement and shallow nature of the Arctic air mass is not supportive of the cold air plowing over the Appalachians, so we'll have to rely on dynamic cooling from the jet max and stretched 500 vort to get anything that will stick. 

It seems there is rarely an issue with these events as far as getting snow.  Either they end up all snow once the FROPA occurs or the wave never develops at all and it’s all rain.  There’s always a scare in the few hours preceding it where places like SWF/HPN/FWN are like 34/24 and the city is still 42/34 but inevitably the cold air makes it in.  I always find these things to be all similar like most SWFEs are.  If they happen it’s generally a good 2-6 inch type event with only a small percentage of them falling below or above that range 

[SnowGoose69]

10 minutes ago, NYCweatherNOW said:

This reminds me of the event a day after the super bowl a few years ago. It was in the 60’s the day before on that Sunday, it became cloudy it rained for a few hours, turned into heavy snow Monday morning and Central Park got 8 inches. At least it’s trending snowier... anyone know the year ?

 

edit: it was in 2014 I just looked it up!

It was similar.  I want to say that one may have had a strong surface reflection develop on the front than we see with this one now.  Someone on Twitter was comparing it to 2/2-2/3 1996.  There is no comparison to that.  That was an entrenched arctic air mass with a boundary that had stalled nearby and had multiple waves move along it