Reviewing the processes behind this winter's snowstorms

[Momza]

Thanks Earthlight ! Will copy paste and save forever

also

Probably my favorite and best quote on this board came early Christmas eve morning from a poster(can't quite remember who) who posted"the first thing I'll do when I get my degree, is take a bat to the models".

What a Christmas gift we were given!

[Isotherm]

Great write up dude. Helluva winter, and although most of our snow has probably fallen, March still has potential to bring the goods.

Boxing Day blizzard was probably the most exciting storm I've witnessed in my life, between the insane, long duration hvy snowfall rates, strong wind gusts, cold temperatures, and deep snow, plus a delayed but much appreciated Christmas present. Yeah we didn't get the white Christmas but I'd take a day after blizzard any time.

What's also remarkable is the persistent cold we've seen since Thanksgiving. Barring a couple days here and there, we've been below normal for 8-10 weeks. As a result of this, snow cover has been on the ground longer than I ever remember. Most years, even in our bigger snow seasons, we have difficulty keeping snow on the ground more than 15 consecutive days, and rarely have snow on top of an already deep snow base. Just insane that the bottom layer of snow outside right now is from late December. I feel like I've been living in Vermont the past couple years and I love it.

[Isotherm]

frenzy that this would be our only opportunity. Come January we would be torched ... Anyhow, Xmas eve morning I was writing this article saying how the storm would be a miss with maybe some light snow if westward trends occurred, just as I glanced at the 12z gfs..Hmm, WTF is the gfs trying to do here?! Every other model in that suite held steady to out to sea, so i was perplexed as all hell, not believeing it but looking for an explanation. When HPC came out with the "bad initialization" and the euro remained east, that was enough for me to disregard the 12z gfs. Being the "prepare for the worst" type when it comes to forecasting, I was smart enough to at least

Yeah and I hope the past couple of winters have confirmed to some people that ENSO state does not necessarily govern our snow potential in the Northeast. We had a huge snow season in a strong El Nino last winter, and a huge snow season this year in a strong La Nina. The common denominator in those 2 winters -- obviously the historic arctic and north atlantic blocking. With a -NAO and -AO in place, we can usually do pretty well in our neck of the woods.

Another factor I didn't see mentioned by anyone is the stronger than normal sub-tropical jet this winter, possibly hang-over from the strong el nino regime last year. So in effect we had another perfect storm of ingredients -- strong NAO, AO blocking, a colder global regime due to the La Nina (more arctic air available) and residual juice in the southern stream to help phase w/ the nern short waves for our big snows.

[Chris L]

To me, the ENSO state is a LITTLE bit overrated if you got the right upper air pattern in place.

BUT, I would take a Nino just for the STJ and the cutoff low(s) it can form SE and the tons of QPF amounts we would be getting.

Trade off? Arctic air.

[ORH_wxman]

Nice writeup, I haven't had the time to read it fully but scanned it. But I'll go back and read it more fully later.

I'll say this about the 1/26-27 event...its setup in the longwave pattern was not ideal, but it happened to work out perfectly in a flawed long wave pattern. The other storms had a more classic long wave pattern

[A-L-E-X]

To me, the ENSO state is a LITTLE bit overrated if you got the right upper air pattern in place.

BUT, I would take a Nino just for the STJ and the cutoff low(s) it can form SE and the tons of QPF amounts we would be getting.

Trade off? Arctic air.

I agree, if you look at NYC top ten snowstorms, you have all sorts of ENSO in there, and even various NAO states. The MJO also has to be factored in, as well as the direction the NAO is moving and if it crossed the critical threshold (Archembault Event.)

[Allsnow]

The boxing day storm was the worse blizzard i been through...and somthing i will prob never forget. The pictures of chicago from there storm was quite similiar to the drifitng we had here.(they had stronger winds and bigger drifts) After 24 hrs straight of plowing driving home for a nap the express lane on the parkway was still one big drift with cars abandon from holmdel-red bank. Counted atleast a 100 that morning.....also the drifts by the loading docks was crazy...we needed to use loaders...When i talk to john and greg that night i believe i told them the only thing you could see is the plow in front of the truck. The rest of time you where just aiming the truck....and hope you dont hit anything. I would say that storm was one of the biggest bust since march 2000.......to go from weather men on radio saying sunday no snow...storm going ots on xmass eve....to 12-18 xmass night was crazy...it was a recipe for failure and it def did not dissapoint in that aspect.

[nzucker]

Yeah and I hope the past couple of winters have confirmed to some people that ENSO state does not necessarily govern our snow potential in the Northeast. We had a huge snow season in a strong El Nino last winter, and a huge snow season this year in a strong La Nina. The common denominator in those 2 winters -- obviously the historic arctic and north atlantic blocking. With a -NAO and -AO in place, we can usually do pretty well in our neck of the woods.

Another factor I didn't see mentioned by anyone is the stronger than normal sub-tropical jet this winter, possibly hang-over from the strong el nino regime last year. So in effect we had another perfect storm of ingredients -- strong NAO, AO blocking, a colder global regime due to the La Nina (more arctic air available) and residual juice in the southern stream to help phase w/ the nern short waves for our big snows.

I find it quite incredible that we managed such a snowy year in a strong La Niña, just amazing when you consider how the Pacific pattern was stacked against us and the lack of a sub-tropical jet. However, the historic blocking in December and early January managed to force the jet well south of its normal position during a powerful Niña, giving us plenty of phasing potential. Having a +QBO and cold Pacific enhanced the polar vortex, which brought bitter cold to parts of the United States given the blocking regime. It's interesting how these teleconnections can turn on their head when anomalous blocking is present. Without a doubt, this winter had the most snow cover I've seen in NYC metro, as well as a very stormy January which led to many sleepless nights.

The blocking does seem to be loosening its grip now...I wonder if this is just a temporary break given how extreme the solar minimum has gotten; NASA has once again revised downward its predictions for maximum sunspots at the peak of Cycle 24 due to the lack of activity in recent months. I wouldn't be surprised if we return to a -NAO regime in late February and March, and then again next winter, especially if the ENSO state is weak Niña, which is probably favored right now.

[simpsonsbuff]

I'll be honest... I really did think we were too close to Jupiter to allow Boxing Day to happen...

[A-L-E-X]

I find it quite incredible that we managed such a snowy year in a strong La Niña, just amazing when you consider how the Pacific pattern was stacked against us and the lack of a sub-tropical jet. However, the historic blocking in December and early January managed to force the jet well south of its normal position during a powerful Niña, giving us plenty of phasing potential. Having a +QBO and cold Pacific enhanced the polar vortex, which brought bitter cold to parts of the United States given the blocking regime. It's interesting how these teleconnections can turn on their head when anomalous blocking is present. Without a doubt, this winter had the most snow cover I've seen in NYC metro, as well as a very stormy January which led to many sleepless nights.

The blocking does seem to be loosening its grip now...I wonder if this is just a temporary break given how extreme the solar minimum has gotten; NASA has once again revised downward its predictions for maximum sunspots at the peak of Cycle 24 due to the lack of activity in recent months. I wouldn't be surprised if we return to a -NAO regime in late February and March, and then again next winter, especially if the ENSO state is weak Niña, which is probably favored right now.

This is some great news--- weak ensos are big snow producers here with neg nao (well the second part is the key.) Three of our strongest la ninas featured high snowfall totals and cold weather, but the solar and ao/nao was the key.

[Isotherm]

This is some great news--- weak ensos are big snow producers here with neg nao (well the second part is the key.) Three of our strongest la ninas featured high snowfall totals and cold weather, but the solar and ao/nao was the key.

I can't even imagine three consecutive winters of 50"+ in the area, basically would be a repeat of 2002-2005 except much snowier.

[nzucker]

I can't even imagine three consecutive winters of 50"+ in the area, basically would be a repeat of 2002-2005 except much snowier.

I don't think you'll need to imagine it, it's probably going to happen. A weaker Niña or weak Niño following a strong Niña is a great signal for a cold/snowy winter. This year's cold ENSO event has significantly lowered global temperatures and should allow the arctic to stay more intact this summer, which will have a small impact on the following winter. I also think we see a trend towards high-latitude blocking when we have a weak ENSO event following a strong ENSO event....thinking about 76-77, a frigid weak Niño after a strong La Niña in 75-76; 00-01 which was a weak Niña after two moderate Niñas; and 08-09 which was a weak Niña after a moderate Niña. Given that we're in the decadal -NAO phase with low solar activity continuing (NASA has once again lowered its forecast), we should see a favorable pattern next year for snow in the I-95.