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March 13-14, The Blizzard of 2017: Obs


Rtd208

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1 hour ago, UlsterCountySnowZ said:

IMG_2606.JPG

Great Map. Really shows how far inland the best snow were. At least 75 miles NW of 95. I was thinking the NW suburbs of NYC would have done better than they did. Really thought 2 foot line would be somewhere 20 miles to my north, not 50 or 75

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5 minutes ago, donsutherland1 said:

This has been an amazing storm, even if we have to watch it from the bleachers so to speak.

I agree. The storm never stopped coming west right up until storm time like many of of biggest events recently. The rising +AO along the +PNA seemed to enhance this storm trend. The good news is that while some models were better with the more west track, they all were indicating a high impact event for the Northeast for over a week now.

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5 minutes ago, mikem81 said:

Great Map. Really shows how far inland the best snow were. At least 75 miles NW of 95. I was thinking the NW suburbs of NYC would have done better than they did. Really thought 2 foot line would be somewhere 20 miles to my north, not 50 or 75

Typically the best snows fall about 75 miles NW give or take of the 850 low. I haven't actually done the in depth comparison against that map yet but my suspicion is this general rule of thumb worked out extremely well and has important forecast use viability.

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2 minutes ago, bluewave said:

I agree. The storm never stopped coming west right up until storm time like many of of biggest events recently. The rising +AO along the +PNA seemed to enhance this storm trend. The good news is that while some models were better with the more west track, they all were indicating a high impact event for the Northeast for over a week now.

Indeed 

The models actually handled this storm extremely well and anyone throwing up snowfall maps showing 24 inches for NYC to make an argument otherwise is mistaken. Even for NYC the liquid equivalent was spot on on most data, and the rain snow line should have been left to basic meteorology and applicable rules of thumb to derive from that, not crazy snow maps. 

Its quite obvious that our modeling has become a much more viable tool than even say ten years ago(perhaps less for that matter even), yet they struggle with thermal profiling at least as shown on snow maps which is why I like that the mods restrict those here because everyone gets that in their head that is what will occur when a simple look deeper into any of the models revealed the flood of mid level warmth and expectations could have been adjusted accordingly.

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16 minutes ago, JetsPens87 said:

Indeed 

The models actually handled this storm extremely well and anyone throwing up snowfall maps showing 24 inches for NYC to make an argument otherwise is mistaken. Even for NYC the liquid equivalent was spot on on most data, and the rain snow line should have been left to basic meteorology and applicable rules of thumb to derive from that, not crazy snow maps. 

Its quite obvious that our modeling has become a much more viable tool than even say ten years ago(perhaps less for that matter even), yet they struggle with thermal profiling at least as shown on snow maps which is why I like that the mods restrict those here because everyone gets that in their head that is what will occur when a simple look deeper into any of the models revealed the flood of mid level warmth and expectations could have been adjusted accordingly.

Absolutely, That's why I liked to pay more attention to trends in storm track and total precip amounts over the exact snowfall amounts. All the models were correct that the heaviest snows would be over the interior rather than right along the coast. 

Trying to pin down exact amounts for various locations was the biggest challenge with this event. With older modeling in the 70's and 80's, the errors in track and snow amounts were much greater. Several times there were complete misses in what the dominant precip type would be and whether there would even be any storm at all. The old DIFAX charts were also not the easiest to read with the cruder resolutions than we rely on today. 

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32 minutes ago, JetsPens87 said:

Indeed 

The models actually handled this storm extremely well and anyone throwing up snowfall maps showing 24 inches for NYC to make an argument otherwise is mistaken. Even for NYC the liquid equivalent was spot on on most data, and the rain snow line should have been left to basic meteorology and applicable rules of thumb to derive from that, not crazy snow maps. 

Its quite obvious that our modeling has become a much more viable tool than even say ten years ago(perhaps less for that matter even), yet they struggle with thermal profiling at least as shown on snow maps which is why I like that the mods restrict those here because everyone gets that in their head that is what will occur when a simple look deeper into any of the models revealed the flood of mid level warmth and expectations could have been adjusted accordingly.

I agree with this, not that it matters. Great analysis.

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1 minute ago, donsutherland1 said:

I agree with this, not that it matters. Great analysis.

Thank you

And,

It matters very much to me.

I have always found your insight invaluable and respect your thoughts and opinions and have for many years of posting and reading on weather forums. You are an irreplaceable member of this community. 

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6 minutes ago, JetsPens87 said:

Thank you

And,

It matters very much to me.

I have always found your insight invaluable and respect your thoughts and opinions and have for many years of posting and reading on weather forums. You are an irreplaceable member of this community. 

Thank you for the very kind words. I greatly appreciate them.

 

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1 hour ago, mikem81 said:

Great Map. Really shows how far inland the best snow were. At least 75 miles NW of 95. I was thinking the NW suburbs of NYC would have done better than they did. Really thought 2 foot line would be somewhere 20 miles to my north, not 50 or 75

More like 40 miles NW of 95.. Im just over 50 miles NW of 95 and received 23.5"

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Albany has issued a WWA up here additional 1-3"

 

 

 

National Weather Service in Albany has issued a Winter
Weather Advisory for snow and blowing snow, which is in effect
until 8 PM EDT this evening. The Blizzard Warning has been
cancelled.


* HAZARD TYPES...Blowing snow and occasional falling snow.

* Additional Snow Accumulations...A coating to one inch in
  valleys, and 1 to 3 inches across higher elevations.

* TIMING...Gusty winds will produce frequent blowing and drifting
  snow through the day. Occasional snow showers will also develop
  this morning and continue into this afternoon.

* IMPACTS...Slippery travel conditions and reduced
  visibilities due to frequent blowing and drifting snow, and
  occasional falling snow.

* Winds...West to northwest at 10 to 20 mph, with gusts of 30 to
  40 mph.

* Visibilities...Occasionally under one mile in areas of blowing
  and drifting snow.
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32 minutes ago, jm1220 said:

Many streets in Queens are still a mess. Nice big piles and bulletproof snowpack. The one plus about sleet is that it doesn't compress further and when it freezes up it turns impenetrable. It feels more like 12+ fell up here. 

We had about 10" up on the 120th. 5" was sleet so the piles are very very impressive. Looks more like 18" of powder fell. If it were January this pack would last for weeks 

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2 hours ago, JetsPens87 said:

Indeed 

The models actually handled this storm extremely well and anyone throwing up snowfall maps showing 24 inches for NYC to make an argument otherwise is mistaken. Even for NYC the liquid equivalent was spot on on most data, and the rain snow line should have been left to basic meteorology and applicable rules of thumb to derive from that, not crazy snow maps. 

Its quite obvious that our modeling has become a much more viable tool than even say ten years ago(perhaps less for that matter even), yet they struggle with thermal profiling at least as shown on snow maps which is why I like that the mods restrict those here because everyone gets that in their head that is what will occur when a simple look deeper into any of the models revealed the flood of mid level warmth and expectations could have been adjusted accordingly.

 

1 hour ago, bluewave said:

Absolutely, That's why I liked to pay more attention to trends in storm track and total precip amounts over the exact snowfall amounts. All the models were correct that the heaviest snows would be over the interior rather than right along the coast. 

Trying to pin down exact amounts for various locations was the biggest challenge with this event. With older modeling in the 70's and 80's, the errors in track and snow amounts were much greater. Several times there were complete misses in what the dominant precip type would be and whether there would even be any storm at all. The old DIFAX charts were also not the easiest to read with the cruder resolutions than we rely on today. 

Not sure if you saw my kind of long-winded analysis, earlier in the thread, of why I thought the storm wasn't as much of a bust as many have said, so in case you haven't, I'll do the short version here, as I think we're in agreement that from a forecasting perspective, it was far more important to get the total mass of frozen precip correct than it was to get the snow/sleet breakdown perfect, which is very hard to do, as you've noted, given the challenges with modeling thermal profiles.  Sure, their predictions were for snow, not snow + sleet as mass equivalent, so that's clearly a miss, but that's a minor point to me.  

For me, for yesterday's storm, the prediction from the NWS for Edison (northern Middlesex County) was 18-24" on the map and 12-18" in the blizzard warning (not sure why the discrepancy, but it doesn't matter much for this) and was about 12-20", on average from the various local media.  So, I got 5" of snow, then 1/2" of mixed snow/sleet, then 2.5" of 90% snow (those amazing 4" diameter mini-pancakes), then 2.5" of 90% sleet and it was a total of 8" on the ground, due to compaction.  I know the 2.5" sleet number because I shoveled right after the snow changed fully to sleet and almost all that fell afterwards was sleet and that was 2.5" on my driveway.  

So, if I assume my roughly 7.5" of ~90% snow that fell had a typical 10:1 ratio of snow to liquid that would be 0.75" of liquid equivalent. And then if I assume the roughly 3" of ~90% sleet that fell had a typical ratio of 3:1, that would be 1.0" of liquid equivalent, making a sum total of 1.75" of liquid equivalent. Converting that back to all snow, assuming a typical 10:1 ratio, that would be 17.5" of snow equivalent that fell. Pretty close to the estimated LE from most of the models and vs. the roughly 18" of snowfall forecast (if I took an average). And I would say the impact of this mass of snow equivalent is essentially the same as 17" of actual snow would've been - just ask anyone who shoveled, plowed or drove around in this stuff - and just the fact that it was a snowy/sleety mess on NYC streets tells me the impact was there (unlike last Friday's storm which all melted on roads). 

https://www.americanwx.com/bb/topic/49828-march-13-14-the-blizzard-of-2017-obs/?do=findComment&comment=4522637

 

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6 minutes ago, RU848789 said:

 

Not sure if you saw my kind of long-winded analysis, earlier in the thread, of why I thought the storm wasn't as much of a bust as many have said, so in case you haven't, I'll do the short version here, as I think we're in agreement that from a forecasting perspective, it was far more important to get the total mass of frozen precip correct than it was to get the snow/sleet breakdown perfect, which is very hard to do, as you've noted, given the challenges with modeling thermal profiles.  Sure, their predictions were for snow, not snow + sleet as mass equivalent, so that's clearly a miss, but that's a minor point to me.  

For me, for yesterday's storm, the prediction from the NWS for Edison (northern Middlesex County) was 18-24" on the map and 12-18" in the blizzard warning (not sure why the discrepancy, but it doesn't matter much for this) and was about 12-20", on average from the various local media.  So, I got 5" of snow, then 1/2" of mixed snow/sleet, then 2.5" of 90% snow (those amazing 4" diameter mini-pancakes), then 2.5" of 90% sleet and it was a total of 8" on the ground, due to compaction.  I know the 2.5" sleet number because I shoveled right after the snow changed fully to sleet and almost all that fell afterwards was sleet and that was 2.5" on my driveway.  

So, if I assume my roughly 7.5" of ~90% snow that fell had a typical 10:1 ratio of snow to liquid that would be 0.75" of liquid equivalent. And then if I assume the roughly 3" of ~90% sleet that fell had a typical ratio of 3:1, that would be 1.0" of liquid equivalent, making a sum total of 1.75" of liquid equivalent. Converting that back to all snow, assuming a typical 10:1 ratio, that would be 17.5" of snow equivalent that fell. Pretty close to the estimated LE from most of the models and vs. the roughly 18" of snowfall forecast (if I took an average). And I would say the impact of this mass of snow equivalent is essentially the same as 17" of actual snow would've been - just ask anyone who shoveled, plowed or drove around in this stuff - and just the fact that it was a snowy/sleety mess on NYC streets tells me the impact was there (unlike last Friday's storm which all melted on roads). 

https://www.americanwx.com/bb/topic/49828-march-13-14-the-blizzard-of-2017-obs/?do=findComment&comment=4522637

 

Very True. That stuff was hard to remove, roads were a mess this morning and many schools canceled or at least had a delayed opening. I assume the discrepancy is Mt Holly doesn't split your county so the northern part was forecast to get more than the southern half but they just went with a general 12 to 18 as a whole. Upton changed Western Union to 12 to 16 but had the eastern half only 6 to 10. Meanwhile there ended up being very small differences within the county and nobody saw more than 10". In fact Elizabeth had the highest amount in the county, probably I'm assuming due to more pure snow and slightly less mixing. I saw a 15" report in Irvington which seems very suspect considering its less than 5 miles from the airport which had half that amount and they have no elevation.

The bigger bust may have been further south which ended up with little frozen despite being under blizzard or WSW

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4 minutes ago, RU848789 said:

 

Not sure if you saw my kind of long-winded analysis, earlier in the thread, of why I thought the storm wasn't as much of a bust.

 

Yeah, several models like the UKMET and NAM did very well with the more tucked in track. The difficulty was guessing which model to rely on more heavily before the event unfolded. Luckily, we still haven't seen a model error of the magnitude that was experienced back in January 2000 for about 17 years now.

 

http://www4.ncsu.edu/~nwsfo/storage/cases/20000125/

In general, forecast models preformed very poorly during this event. An example of this is shown in the image below which compares the 48 hour, observed liquid equivalent precipitation with the Eta model 48 hour forecast valid at the same time (click on the image to enlarge, image provided by Michael Brennan, NC State University). The model failed to capture the significant precipitation over the Carolinas and Virginia; in fact the Eta forecast had no precipitation over Raleigh and Richmond where over an inch of liquid equivalent was observed. 

As forecasters scrambled to adjust forecasts to reflect the unfolding snowstorm, there was little time to analyze the full reason why the forecast had gone bad. In the wake of the storm, many were left wondering how nearly two feet of snow could have fallen in less than 24 hours with very little warning. Was there something that could have been analyzed ahead of time that would have lead to questioning of model precipitation forecasts? Or was there a physical mechanism that was misunderstood, or missed by the models? Below is a brief summary of some of the forecast errors and research topics that arose from this case. 

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Just now, bluewave said:

Yeah, several models like the UKMET and NAM did very well with the more tucked in track. The difficulty was guessing which model to rely on more heavily before the event unfolded. Luckily, we still haven't seen a model error of the magnitude that was experienced back in January 2000 for about 17 years now.

 

 

But the warm air coming in during the height of the storm would've been very hard to nail down. If you stayed all snow you got 18", if you flipped you got 6 or anywhere in between. So it was very tricky, and the NWS didn't do a good job illustrating this IMO. They were slow to even mention mixing and took a long time to reduce amounts (I saw the posted article explaining the reasoning)

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10 minutes ago, Stormlover74 said:

Very True. That stuff was hard to remove, roads were a mess this morning and many schools canceled or at least had a delayed opening. I assume the discrepancy is Mt Holly doesn't split your county so the northern part was forecast to get more than the southern half but they just went with a general 12 to 18 as a whole. Upton changed Western Union to 12 to 16 but had the eastern half only 6 to 10. Meanwhile there ended up being very small differences within the county and nobody saw more than 10". In fact Elizabeth had the highest amount in the county, probably I'm assuming due to more pure snow and slightly less mixing. I saw a 15" report in Irvington which seems very suspect considering its less than 5 miles from the airport which had half that amount and they have no elevation.

The bigger bust may have been further south which ended up with little frozen despite being under blizzard or WSW

Thanks.  Definitely agree the bigger bust is where mostly/all rain fell instead of several inches of snow, like Ocean/Monmouth Counties, where some coastal folks got almost all rain.  Rain vs. frozen is a much bigger difference than sleet vs. snow. 

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