Discussion-OBS Weekend Feb 8-9 Another mainly 12 hour snow-ice event possibly changing to rain before ending Sunday. NYC-LI-S of I78 on the edge?

[psv88]

  On 2/7/2025 at 3:21 AM, RU848789 said:

0Z NAM and ICON, fwiw...still think the NAM map with the "hole" in CNJ is improbable (I get a bigger early thump SW of CNJ and more N of CNJ with the later coastal, but not sure I've ever seen this before).  

Also, kind of curious if folks in this forum like seeing the zoomed in Pivotal maps or the regional mid-Atlantic or NEUS maps.  

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Whichever map shows me getting the most snow works for me

[RU848789]

0Z GFS zoomed in; nice improvements over 18Z for most, although those weird cutoffs/discontinuities persist - there's just no way Allentown gets 0.8" and Easton gets 3+".

[LVblizzard]

  On 2/7/2025 at 4:07 AM, RU848789 said:

0Z GFS zoomed in; nice improvements over 18Z for most, although those weird cutoffs/discontinuities persist - there's just no way Allentown gets 0.8" and Easton gets 3+".

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It’s because of the low resolution of the model. It always does this around the mix/snow line.

[MJO812]

Cmc is nice

[MJO812]

Ukie

[NEG NAO]

Upton is going all in on this weekend event -  posted there is still a chance of warning level 6 inch snows in NYC

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[RU848789]

  On 2/7/2025 at 4:13 AM, MJO812 said:

Cmc is nice

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I think something is wrong with the Kuchera calculation for that CMC map.  The algorithm is liquid equivalent ratio (RAT) is 12.0 + 2.0*(271.16-MaxT) and looking at Philly, for example, the 10:1 ratio is 4.0", whereas the Kuchera for Philly is essentially 0.0, which makes no physical sense at all, especially given the algorithm.  For the SLR to be 0 means that the max column temp in the column would have to be 277.16K (6C or 42.8F), so the equation would be SLR = 12.0 + 2.0(271.16-277.16) = 0.  It just makes no sense.  It's another reason I almost always use 10:1 ratio maps, so I know how much QPF is falling as 10:1 snow and then one can still adjust.  

https://www.facebook.com/hopwrf/posts/562550350492139

[CPcantmeasuresnow]

  On 2/7/2025 at 3:21 AM, RU848789 said:

0Z NAM and ICON, fwiw...still think the NAM map with the "hole" in CNJ is improbable (I get a bigger early thump SW of CNJ and more N of CNJ with the later coastal, but not sure I've ever seen this before).  

Also, kind of curious if folks in this forum like seeing the zoomed in Pivotal maps or the regional mid-Atlantic or NEUS maps.  

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I cant stand the Mid Atlantic maps, what's happening in Delaware, Maryland and Cape May is of no interest. There's 2 other forums for those regions.

[RU848789]

0Z Euro is nice...a bit more for folks south of 78 and south of 276/195, but a little less for folks north of 80 (but still 5-6")...

[HeadInTheClouds]

  On 2/7/2025 at 5:41 AM, RU848789 said:

0Z Euro is nice...a bit more for folks south of 78 and south of 276/195, but a little less for folks north of 80 (but still 5-6")...

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That's 10:1. It should be higher than that N and W. 

[jm1220]

  On 2/7/2025 at 5:46 AM, HeadInTheClouds said:

That's 10:1. It should be higher than that N and W. 

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SWFE usually have low snow ratios because the warming air aloft often makes the snow making/max lift region in the cloud above the ideal temp for dendrites which form at -12 to -18C. So ratios are more like 10-1 or even less in some cases. Snow ratios are mostly determined by the cloud conditions where the snow forms. If the max lift is in the -12 to -18C region, ratios are maximized. 

[HeadInTheClouds]

  On 2/7/2025 at 5:58 AM, jm1220 said:

SWFE usually have low snow ratios because the warming air aloft often makes the snow making/max lift region in the cloud above the ideal temp for dendrites which form at -12 to -18C. So ratios are more like 10-1 or even less in some cases. Snow ratios are mostly determined by the cloud conditions where the snow forms. If the max lift is in the -12 to -18C region, ratios are maximized. 

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NWS Albany is expecting higher ratios north of 84 where I am. This makes sense with possibility of DGZ being tapped and lows in mid 20's. Most models give this area .6 or so QPF and NWS has Poughkeepsie area expected snowfall around 8 inches. 

[gravitylover]

  On 2/7/2025 at 4:13 AM, MJO812 said:

Cmc is nice

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  On 2/7/2025 at 4:47 AM, MJO812 said:

Ukie

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The Champlain Valley gets skunked in both of these. 

[MJO812]

1-3 is a good call for NYC. Can always go higher if needed. 

[qg_omega]

  On 2/7/2025 at 11:24 AM, MJO812 said:

1-3 is a good call for NYC. Can always go higher if needed. 

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Beer? 

[SRRTA22]

NWS will likely go with a WWA for NYC metro for 3-5" locally 6" later unless models trend upwards with amounts.

Also 6z RGEM hinting at 2 areas of banding, one just north of NYC and one in central NJ with a subsidence zone in between. Gotta watch that. If that comes to fruition I could see the southern band being a bit more north. 

 

[allgame830]

  On 2/7/2025 at 11:24 AM, MJO812 said:

1-3 is a good call for NYC. Can always go higher if needed. 

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I’d say 1-3 is good for the southern portion of the boroughs with 3-5 for northern parts including a good portion of northern LI. 5-8 locally 10 NW 

[weatherpruf]

  On 2/7/2025 at 11:39 AM, SRRTA22 said:

NWS will likely go with a WWA for NYC metro for 3-5" locally 6" later unless models trend upwards with amounts.

Also 6z RGEM hinting at 2 areas of banding, one just north of NYC and one in central NJ with a subsidence zone in between. Gotta watch that. If that comes to fruition I could see the southern band being a bit more north. 

 

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The subsidence zone will always be the border of Middlesex and Union counties, right around Colonia/Rahway. Book it. Seen it so many times people think I'm lying; have had 3 inches when New Brunswick had a foot...

[jm1220]

  On 2/7/2025 at 11:39 AM, SRRTA22 said:

NWS will likely go with a WWA for NYC metro for 3-5" locally 6" later unless models trend upwards with amounts.

Also 6z RGEM hinting at 2 areas of banding, one just north of NYC and one in central NJ with a subsidence zone in between. Gotta watch that. If that comes to fruition I could see the southern band being a bit more north. 

 

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It’s the same rule as before, if snow comes in like a wall there’s a shot at the higher end accums. If shredded up the warm air will have an easier time advancing and changeover is sooner. 

[lee59]

Looks like there has been a steady increase of snowfall amounts for my area by the NWS. Good call right now looks to be around 4 inches.

[allgame830]

  On 2/7/2025 at 11:56 AM, jm1220 said:

It’s the same rule as before, if snow comes in like a wall there’s a shot at the higher end accums. If shredded up the warm air will have an easier time advancing and changeover is sooner. 

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This storm is more organized than yesterday. 

[Allsnow]

Congrats north west crew 

this is slop for the metro 

[dmillz25]

  On 2/7/2025 at 11:24 AM, MJO812 said:

1-3 is a good call for NYC. Can always go higher if needed. 

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Tony being conservative is actually a good thing lol

[allgame830]

  On 2/7/2025 at 12:05 PM, Allsnow said:

Congrats north west crew 

this is slop for the metro 

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Well thanks for the congrats! However I see more than just stop for the metro especially northern parts of the metro. 

[EastonSN+]

  On 2/7/2025 at 12:05 PM, Allsnow said:

Congrats north west crew 

this is slop for the metro 

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Yup, though will be the highest snowfall totals for Central Park this season and likely putting it over 10 inches for the season.

[winterwarlock]

  On 2/7/2025 at 12:05 PM, Allsnow said:

Congrats north west crew 

this is slop for the metro 

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Yep the nams want no part again..maybe a bit more snow than the last one but still disappointing 

[CPcantmeasuresnow]

  On 2/7/2025 at 6:34 AM, gravitylover said:

 

The Champlain Valley gets skunked in both of these. 

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Thoughts and prayers for Burlington and Plattsburgh. 

[EastonSN+]

Both names are remarkably close with snowfall totals for Central Park 3K 2.5 12K 3.5 inches. 

[EastonSN+]

GFS 3.5 as well for Central Park.

Only EURO and CMC are a bit higher.

2 to 4 is a good call right now for Central Park.

[EastonSN+]

  On 2/7/2025 at 12:15 PM, winterwarlock said:

Yep the nams want no part again..maybe a bit more snow than the last one but still disappointing 

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Not sure why this would be disappointing, would likely be Central Park's largest snowfall total for the year and was always supposed to be a mix event.