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13 minutes ago, MJO812 said:

Eps

sfcmslp-meanmem.conus.png

sfcmslp-meanmem.conus (1).png

No cold. Funny how you don’t show the EPS snow mean. I wonder why that is?

 

@NEG NAO Top weenie statement: “There’s no cold at the surface but it will ‘make its own cold’ and pull it down from aloft!!” “Dynamic cooling!!”

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So question for all the people that prefer rain over snow this time of year.  What can you do with this absolute garbage weather. This is literally the most depressing type of weather and why I wish I could be in Phoenix from March to mid-May. Too warm to snow to enjoy snow sports and too cold to enjoy being outside and then just wet. Days like today even with the heat in just feel damp and raw. 

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Just now, snowman19 said:

No cold. Funny how you don’t show the EPS snow mean. I wonder why that is?

there is cold air aloft but the surface and mid levels need to cool down and they would with heavier precip

 

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13 minutes ago, JustinRP37 said:

So question for all the people that prefer rain over snow this time of year.  What can you do with this absolute garbage weather. This is literally the most depressing type of weather and why I wish I could be in Phoenix from March to mid-May. Too warm to snow to enjoy snow sports and too cold to enjoy being outside and then just wet. Days like today even with the heat in just feel damp and raw. 

March is the worst month around here IMO.    Still winter but not spring, generally too warm for snow but too early for things to green up.

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1 hour ago, donsutherland1 said:

Some points about the 12z GFS's Day 8-9 Storm:

1. The GFS is in a timeframe where skill is low
2. The GFS lacks support from other global models and the ensembles
3. The GFS's soundings show readings remaining above freezing throughout the storm

New York City's Above Freezing Snowfalls:

 

In short, unless there is more than a marginal air mass and strong support from the other guidance, one should be skeptical of the snowfall amount (7.8") shown on the GFS. Ratios for any snow would be far lower than 10:1.

Agreed on all your points. However, I was under the impression that NCEP doesn't disseminate forecasted snowfall amounts. I could be wrong, maybe it's an experimental parameter...? But obviously 3rd party snowfall accumulation algorithms should be ignored at this range, particularly with a marginal wintry setup.

The only point that I partially disagree with is the temperatures. The low level temps are actually pretty cold - and with a continued LL cold drain - particularly just outside NYC. I think the scenario as modeled (12z GFS), with a thick cloud cover or nighttime precipitation, could support accumulating snow outside of high-impervious %, urban areas.

I consider a snow threat a very low likelyhood outcome right now for the immediate NYC metro area.

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On 2/29/2024 at 3:25 PM, Fresh cold air said:

Jan 2008 opened with an impressive cold shot but thereafter any cold that followed was ordinary cold.  Mif feb 2008 had another strong arctic dump and that was able to squeeze out about 3 inches before torrential rains took over and washed it all away overnight and the next day.  We did get a surprise 6 inch snow in later feb 2008 thanks to a rare overperformance for a change.

Yes I loved that late February 2008 event it was 6-8 inches here on the south shore and it's when the waters are coldest too.

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1 hour ago, donsutherland1 said:

The heaviest precipitation is finished by 204 hours, even as it's cold enough for snow. Hours 204-210 might be sufficient for 1"-2", if the model output is right. But at this point in time, it's speculative given the lack of other support and timeframe involved. My point is that the 7.8" total is unlikely without dramatic changes.

I don't agree with this summation. 8" is unlikely just based on typical snowfall frequencies in NYC and the low model skill at this range. But the GFS depiction - as is - shows a very wintry scenario.

We would absolutely not need dramatic changes from what the 12z GFS shows to get significant snowfall near our region. As shown it's actually quite close to a long duration, region-wide snowstorm. But a snowy outcome is still very unlikely for the other reasons that you've mentioned.

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On 2/29/2024 at 3:21 PM, Fresh cold air said:

Yes, thats exactly what happened.  Even worse in december before the waters had time to chill down.  Ive seen the deepest of arctic air get scoured out real fast many times.  Itd very deptessing when that occurs!  It stayed in the 20s all day that friday in dec 1989 but when precip arrived about 8-9pm, temps shot up like a rocket straight to 40 and leveled off there.  Of course the deep arctic air was reinforced after the storm departed.  Manhattan somehow managed to squeeze out close to an inch before the changeover.  Brooklyn didnt stand a chance

I heard the Bronx might have had up to 3 inches but zero here on the south shore and they were still calling for 6-8 inches for everyone while it was raining lol.

Just like in February 1989 they were still calling for 6-8 inches when it was eminently clear that would be a virga storm for us and ACY got close to 20 inches of snow.

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54 minutes ago, JustinRP37 said:

So question for all the people that prefer rain over snow this time of year.  What can you do with this absolute garbage weather. This is literally the most depressing type of weather and why I wish I could be in Phoenix from March to mid-May. Too warm to snow to enjoy snow sports and too cold to enjoy being outside and then just wet. Days like today even with the heat in just feel damp and raw. 

No one likes rain unless it's a drought, no matter the time of year

It should only ever AT MOST rain once a week.

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2 minutes ago, Fresh cold air said:

I remember the late feb 1989 miss.  Similar to the jan 2010 miss.  For the 1989 one, it looked,felt, and smelled like snow all day and mid 20s arctic cold was locked in place right on the coastline.  Clouds lowered and thickened and it was very depressing when it didnt occur.  Jan 2010 was even closer.  Parts of staten island got at least 6 inches but that Verrazano bridge was literally like a brick wall that day woth one of the sharpest cutoffs you'll ever see!

I think you mean Feb 6, 2010..... we got 1.5" of snow here near JFK but it should have been a lot more!  Toms River got 20"!  In January there was another storm that gave them 6" but we got nothing but some clouds in that one.

 

 

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36 minutes ago, eduggs said:

Agreed on all your points. However, I was under the impression that NCEP doesn't disseminate forecasted snowfall amounts. I could be wrong, maybe it's an experimental parameter...? But obviously 3rd party snowfall accumulation algorithms should be ignored at this range, particularly with a marginal wintry setup.

The only point that I partially disagree with is the temperatures. The low level temps are actually pretty cold - and with a continued LL cold drain - particularly just outside NYC. I think the scenario as modeled (12z GFS), with a thick cloud cover or nighttime precipitation, could support accumulating snow outside of high-impervious %, urban areas.

I consider a snow threat a very low likelyhood outcome right now for the immediate NYC metro area.

The GFS figure is from 10:1 vendor maps, not the NOAA.

Soundings show sleet during the height of the precipitation in NYC with a warm layer at 850 mb +/- 25 or so mb. Just as other model output is low skill at the timeframe involved, the same applies to the soundings. However, the other guidance is warmer. Until there is consensus toward the GFS idea, I'm reluctant to embrace the GFS's outlier solution.

The temperature chart merely illustrates the range for past storms with specified temperatures. The point is that typically storms with above freezing temperatures tend to have lower snowfall amounts. Only a few have been moderate or larger. North and west of NYC, things would be more favorable. But we'll have to see where things stand in a few days when model skill begins to improve and when the synoptic picture itself becomes clearer.

It's premature for the posting of operational model maps showing a snowy outcome for NYC. Indeed, just one member of the GEFS and not a single EPS member shows anything like the GFS did. There are many arguments for caution, not to mention that such events have been infrequent for NYC following winters as warm as the one the region just had.

In sum, the base case is against the 12z GFS's significant snowfall for NYC (not necessarily well north and west of it). Something lighter is currently in play for NYC, JFK, and LGA. Until much changes (synoptic details, model/ensemble support, deeper cold farther south, etc.), there's little reason to depart from the base case.

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11 minutes ago, donsutherland1 said:

The GFS figure is from 10:1 vendor maps, not the NOAA.

Soundings show sleet during the height of the precipitation in NYC with a warm layer at 850 mb +/- 25 or so mb. Just as other model output is low skill at the timeframe involved, the same applies to the soundings. However, the other guidance is warmer. Until there is consensus toward the GFS idea, I'm reluctant to embrace the GFS's outlier solution.

The temperature chart merely illustrates the range for past storms with specified temperatures. The point is that typically storms with above freezing temperatures tend to have lower snowfall amounts. Only a few have been moderate or larger. North and west of NYC, things would be more favorable. But we'll have to see where things stand in a few days when model skill begins to improve and when the synoptic picture itself becomes clearer.

It's premature for the posting of operational model maps showing a snowy outcome for NYC. Indeed, just one member of the GEFS and not a single EPS member shows anything like the GFS did. There are many arguments for caution, not to mention that such events have been infrequent for NYC following winters as warm as the one the region just had.

In sum, the base case is against the 12z GFS's significant snowfall for NYC (not necessarily well north and west of it). Something lighter is currently in play for NYC, JFK, and LGA. Until much changes (synoptic details, model/ensemble support, deeper cold farther south, etc.), there's little reason to depart from the base case.

But would you say that the chances of NYC reaching 10" by the end of the season is at least 30% Don?

 

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12 minutes ago, donsutherland1 said:

The GFS figure is from 10:1 vendor maps, not the NOAA.

Soundings show sleet during the height of the precipitation in NYC with a warm layer at 850 mb +/- 25 or so mb. Just as other model output is low skill at the timeframe involved, the same applies to the soundings. However, the other guidance is warmer. Until there is consensus toward the GFS idea, I'm reluctant to embrace the GFS's outlier solution.

The temperature chart merely illustrates the range for past storms with specified temperatures. The point is that typically storms with above freezing temperatures tend to have lower snowfall amounts. Only a few have been moderate or larger. North and west of NYC, things would be more favorable. But we'll have to see where things stand in a few days when model skill begins to improve and when the synoptic picture itself becomes clearer.

It's premature for the posting of operational model maps showing a snowy outcome for NYC. Indeed, just one member of the GEFS and not a single EPS member shows anything like the GFS did. There are many arguments for caution, not to mention that such events have been infrequent for NYC following winters as warm as the one the region just had.

In sum, the base case is against the 12z GFS's significant snowfall for NYC (not necessarily well north and west of it). Something lighter is currently in play for NYC, JFK, and LGA. Until much changes (synoptic details, model/ensemble support, deeper cold farther south, etc.), there's little reason to depart from the base case.

I am also largely discounting the 12z GFS solution locally. I think there could be snow somewhere in the northeast next weekend, but I think it's a longshot for NYC and the immediate suburbs. That said, there is some decent in situ cold on the GFS run specifically.

I also want to try to dispel the myth that the GFS produces snowfall maps. A model output can be perfectly accurate and seem completely wrong in terms of forecasted snowfall if 3rd party vendors are used. So we should usually just ignore them and use model output and forecast soundings.

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