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

[ChineseFood4Snow]

5 minutes ago, Ericjcrash said:

That's your prerogative and maybe plays out that way but beware of the tuck.

[SnowGoose69]

27 minutes ago, wdrag said:

I've heard that but Im not sure if there is science to that effect. 

It definitely hurt ratios in the 12/26/10 event.  The thermals indicated should have been 12-14 to 1 and it was only about 9-10

[bluewave]

The other thing to watch for is coastal flooding. The astronomical tides will be the highest of December this week with the new moon. Unfortunately, The solar eclipse will only be visible in the Southern Hemisphere. All that is needed for moderate coastal flooding is a 2 foot surge. The big high to the north can make this possible creating a gale to possible storm force gradient. A slower track in later runs would also help to pile up the water.

https://www.space.com/total-solar-eclipse-2020-preview

 

[Rjay]

12 minutes ago, Allsnow said:

Closer look. IMO i80 would have no issues with any of those tracks 

Good catch bud

[Allsnow]

ICON is stronger with the confluence at 12z 

 

8-10 for the metro and 6-12 north and west 

[Rjay]

46 minutes ago, wdrag said:

I've heard that but Im not sure if there is science to that effect. 

There is.   Even Upton has mentioned it in our windier snow storms.   I hate using TWC as a source but the other links have PDFs that are just too long for most people to read.

"High winds can also result in lower snow ratios since snowflakes can break apart in that situation, says NOAA."

https://weather.com/storms/winter/news/2018-02-08-snow-forecast-ratios-united-states-climatology

[Rjay]

@wdrag.  Here's more info on the effect of wind on snow ratio.  I hope this is useful info for you.

 

Influence of surface wind speed on snow ratio

"Surface wind speed can affect the snow ratio. Surface winds exceeding approximately 9 m s⁻¹ can move ice crystals at the surface, fracturing the crystal during saltation and increasing the snow density (e.g., Gray and Male 1981, 345–350). Therefore, only snow events occurring at wind speeds below 9 m s⁻¹ were considered. Classifying the snow events by snow-ratio bin and plotting the fraction of events as a function of wind speed results in Fig. 6. Although the fraction of average snow ratios is constant with wind speed, the fraction of heavy snow ratios increases with wind speed from about 10% at low wind speeds to about 20% at 9 m s⁻¹ (correlation coefficient of 0.572). In addition, the fraction of light snow ratios decreases with wind speed from about 53% at low wind speeds to 40% at 9 m s⁻¹ (correlation coefficient of −0.507). These relationships are statistically significant at the 98% level. If considered in isolation, the wind speed plays a small, but significant, role in determining the snow ratio by shifting the distribution of snow ratio toward lower values at higher wind speeds (Fig. 6). This minor role for wind speed may be due partly to the way Roebber et al. (2003) compiled their data, using 6-h observations to minimize effects of prolonged wind compaction on snow ratio. However, Roebber et al. (2003) also showed that wind speed can be quite important when combined with other parameters. In addition, accounting for the gauge undercatch (e.g., Goodison 1978; Yang et al. 1998) may also lead to a stronger relationship between snow density and wind speed."

 

https://journals.ametsoc.org/view/journals/wefo/21/1/waf903_1.xml?tab_body=fulltext-display

 

[SI Mailman]

GFS has a 987 low just east of the benchmark for Monday evening.  Lets see how this impacts Wednesday.

[jm1220]

58 minutes ago, Rjay said:

 

Those super tucked solutions would be crush jobs for @Juliancolton and crew while I cry snow weenie tears and @forkyfork laughs.

Yeah... this is going to try to hug the coast and tuck as much as it can. We need that confluence to be in place to force it east. 

[bluewave]

2 hours ago, JoshSnow said:

I love where we stand right now obviously it can change. We’ll see by tomorrow

We’ll be good to go if these solutions hold once within the NAM’s best range. The NAM has been our go to model for snowfall with the numerous Euro misses in recent years. I can still remember the NAM bringing home the goods on the January 2016 blizzard while the Euro was too suppressed.

[MJO812]

More confluence so far on the gfs

[Sn0waddict]

1 minute ago, bluewave said:

We’ll be good to go if these solutions hold once within the NAM’s best range. The NAM has been our go to model for snowfall with the numerous Euro misses in recent years. I can still remember the NAM bringing home the goods on the January 2016 blizzard while the Euro was too suppressed.

Any difference with accuracy between the 12 k and 3 k NAM?

[Rjay]

Holy crap gfs lol

[snowman19]

4 minutes ago, MJO812 said:

More confluence so far on the gfs

GFS is going to show a massive hit. Look at 500mb

[Franklin0529]

Looks like lot of rain for the coast

[Rjay]

Just now, Rjay said:

Holy crap gfs lol

 

Just now, snowman19 said:

GFS is going to show a massive hit. Look at 500mb

Wow.  

[MJO812]

Omg what a crushing snowstorm  on the gfs

[MJO812]

Gfs is really cold

[Rjay]

Just now, Franklin0529 said:

Looks like lot of rain for the coast

Idk what you're looking at 

[Rjay]

Now that was quite a run 

[Allsnow]

Mother of god!!!!

[Franklin0529]

Just now, MJO812 said:

Gfs is really cold

Even for the coast? Looked like lot mixing along coastal plains

[Rjay]

So so sick and area-wide too. 

[MJO812]

2 minutes ago, Franklin0529 said:

Even for the coast? Looked like lot mixing along coastal plains

Yes very cold

[SI Mailman]

Yay, I'm gonna have a snow day on Thursday!!  No way those mail trucks are getting over the Verrazzano according to the GFS.  

[Brian5671]

[Allsnow]

Omg 

[David-LI]

Just now, SI Mailman said:

Yay, I'm gonna have a snow day on Thursday!!  No way those mail trucks are getting over the Verrazzano according to the GFS.  

Well deserved day off

[Rjay]

Just your average 15-30" blizzard

[Brian5671]

wow.   Still have to worry about a possible shift north though....always seems to happen 24-48 hrs (like it is with Monday's event-that was nothing 2 days ago b/c it was OTS)