Late winter-early spring finale

[George001]

This thread will encompass the late winter to early spring window. The models have shifted away from a mild pattern for late Feb into early March to a much colder and potentially stormy pattern. My early thoughts for the late Feb period is that it does not favor an all snow event for SNE, due to the SE ridge in place and warming mid levels. However, there is a strong high to the north, so I do think there could be a significant (6+) front end before a changeover to sleet or ice. I’d favor north of Boston for the biggest snows, with Boston south getting a decent front end before a changeover. I do not think this will be a huge storm, 6-12 inches. Closer to 6 for the areas that mix and 12 for the areas that stay all snow. Although for the late Feb pattern there aren’t any signs of a huge storm, there is the possibly that if things break right we could get 2 or even 3 waves due to the energy out west ejecting in pieces, not all at once (if it does eject all at once, it would likely cut inland). We do not want a phase here). What once looked like a torch turned into a very interesting period with snow sleet and ice all on the table. 
 

Now the period that really interests me is early to mid March. I have read concerns about suppression and have seen comparisons to March 2014, but in my opinion this is unlikely. Why? In 2014, the vortex was over Maine. On the EPS, the vortex is east-central Canada, which is several hundred miles north of 2014. This argues that storms would have more room to come north than 2014. We also have an extremely amplified western ridge axis. The ridge axis is centered over Washington state and is poking up all the way to Alaska. Ideal for east coast cyclogenesis is over Montana, so if anything it’s a little west of ideal. This looks very similar to the Jan pattern but if anything, the western ridge is even more amplified. This suggests that any northern energy has room to dig very far south, enough to tap into gulf moisture and phase with any southern energy available.
 

The biggest and most important difference is it is early March, not early January climo. This is double edged, as the milder late winter waters clashing with the arctic airmass in place would encourage more explosive cyclogenesis, leading to a stronger low and farther NW low. However, if the track is too far NW it wouldn’t take as much to bring in warm air and flood the coast with rain (like the early Feb event last year, where Boston didn’t get much and interior areas got slammed). Rain snow lines are absolutely a concern, so I would like to see a Miller B or hybrid system more so than a Miller A for my area, but either way the potential for a big storm is there. In my opinion, this is the most explosive pattern I have seen since March 2018, and honestly has the potential to be even more explosive than that. We have an extremely amplified and western ridge displaced very far west combined with a piece of the polar vortex over central canada. We also have a weak east based La Niña currently in place. East based La Niña climo tends to be favorable in March, more so than western or central based events. 
 

my bold call: for many areas, there will be a storm in early-mid March that ends up being STRONGER than the January blizzard, and delivers even more snow. The question is, what happens in mid to late March? We are seeing signs that the polar vortex could finally start to rapidly weaken, which could lead to this favorable period being extended all the way to early April. If that happens, I believe we will get 2-3 big ones (12+) with possible a couple moderate (6+) ones mixed in as well. That is the upside with this pattern. Will it happen? It may not, but even if it doesn’t I am still convinced that the early-mid March period will deliver, and could even deliver 2 big ones, yes even with a positive NAO.
 

Then we have the mid March to early April period that could be interesting as well. The thing about the near record strong polar vortex we have right now is that when it does get disrupted and is displaced or even split (unlikely, I’m leaning displacement right now), all that cold air bottled up over the North Pole is going to come crashing south. This is an anomalous event, so we could see some crazy ass shit. A lot of you will probably think I’m going off the deep end here, but I’m just gonna say it. I think there will be a window in late March early April, with a much higher probability than normal for an April snowstorm this year. If I’m wrong I’m wrong, but when we combine the already colder than average Canadian airmass in place with a record strong vortex being possibly displaced or split, if it is displaced to this side of the globe, April 1997 becomes an analog (correct me if I am wrong, but I read that this was also a strong PV winter). This does not mean something as extreme, but a muted version of that? Hell yeah! Will the PV be displaced to this side of the globe? It may not, but I believe it will due to the polar vortex having a tendency to elongate and stretch toward this side of the globe this year, sunlike previous strong PV winters like 2020. 

[George001]

My original call was for 70-85 inches of snow in the Boston area for my first official winter forecast. I am sticking to my guns with this, although I do think it will be a “right for the wrong reasons” type deal as I expected the polar vortex to be weak. 

[George001]

For the Friday system the question is, is this a run off the mill SWFE, front end snow to mix then drizzle and dry slot, or is it something more? I was originally thinking it was just a run of the mill SWFE, but the models have trended towards more secondary redevelopment (Miller B) over the past couple of days. This is seen on the 12Z EPS.

 

The GEPS is even more aggressive with the secondary redevelopment and has an absurd amount of moisture involved, shown in the pics below. 
 

 

that’s a widespread .75+ inches of QPF with over 1 inch in the mid Atlantic, and that’s a mean 7 days out. There is also a strong high to the north on all guidance, 1038 mb in an ideal location. That’s arctic airmass to the north combined with the clash of well above normal temps to the south, has me convinced that this system will have significantly more moisture than a run of the mill 4-8 inches of snow SWFE. This type of setup we will see above normal temps south of the boundary and below normal north of it, but the temp contrast with this system is much more pronounced than normal. We have a near 1040 mb high clashing with a mild southern airmass bringing near record high temps to the area on Wednesday when the first storm passes to our north. My area is forecast to reach 60 degrees on Wednesday, this is the average temperature for mid April, not late Feb. We are going to have arctic cold ramming into that unseasonably warm airmass to the south. Due to these factors, in my opinion this has room to juice up even more.  

[mahk_webstah]

On 2/17/2022 at 5:58 PM, George001 said:

This thread will encompass the late winter to early spring window. The models have shifted away from a mild pattern for late Feb into early March to a much colder and potentially stormy pattern. My early thoughts for the late Feb period is that it does not favor an all snow event for SNE, due to the SE ridge in place and warming mid levels. However, there is a strong high to the north, so I do think there could be a significant (6+) front end before a changeover to sleet or ice. I’d favor north of Boston for the biggest snows, with Boston south getting a decent front end before a changeover. I do not think this will be a huge storm, 6-12 inches. Closer to 6 for the areas that mix and 12 for the areas that stay all snow. Although for the late Feb pattern there aren’t any signs of a huge storm, there is the possibly that if things break right we could get 2 or even 3 waves due to the energy out west ejecting in pieces, not all at once (if it does eject all at once, it would likely cut inland). We do not want a phase here). What once looked like a torch turned into a very interesting period with snow sleet and ice all on the table. 
 

Now the period that really interests me is early to mid March. I have read concerns about suppression and have seen comparisons to March 2014, but in my opinion this is unlikely. Why? In 2014, the vortex was over Maine. On the EPS, the vortex is east-central Canada, which is several hundred miles north of 2014. This argues that storms would have more room to come north than 2014. We also have an extremely amplified western ridge axis. The ridge axis is centered over Washington state and is poking up all the way to Alaska. Ideal for east coast cyclogenesis is over Montana, so if anything it’s a little west of ideal. This looks very similar to the Jan pattern but if anything, the western ridge is even more amplified. This suggests that any northern energy has room to dig very far south, enough to tap into gulf moisture and phase with any southern energy available.
 

The biggest and most important difference is it is early March, not early January climo. This is double edged, as the milder late winter waters clashing with the arctic airmass in place would encourage more explosive cyclogenesis, leading to a stronger low and farther NW low. However, if the track is too far NW it wouldn’t take as much to bring in warm air and flood the coast with rain (like the early Feb event last year, where Boston didn’t get much and interior areas got slammed). Rain snow lines are absolutely a concern, so I would like to see a Miller B or hybrid system more so than a Miller A for my area, but either way the potential for a big storm is there. In my opinion, this is the most explosive pattern I have seen since March 2018, and honestly has the potential to be even more explosive than that. We have an extremely amplified and western ridge displaced very far west combined with a piece of the polar vortex over central canada. We also have a weak east based La Niña currently in place. East based La Niña climo tends to be favorable in March, more so than western or central based events. 
 

my bold call: for many areas, there will be a storm in early-mid March that ends up being STRONGER than the January blizzard, and delivers even more snow. The question is, what happens in mid to late March? We are seeing signs that the polar vortex could finally start to rapidly weaken, which could lead to this favorable period being extended all the way to early April. If that happens, I believe we will get 2-3 big ones (12+) with possible a couple moderate (6+) ones mixed in as well. That is the upside with this pattern. Will it happen? It may not, but even if it doesn’t I am still convinced that the early-mid March period will deliver, and could even deliver 2 big ones, yes even with a positive NAO.
 

Then we have the mid March to early April period that could be interesting as well. The thing about the near record strong polar vortex we have right now is that when it does get disrupted and is displaced or even split (unlikely, I’m leaning displacement right now), all that cold air bottled up over the North Pole is going to come crashing south. This is an anomalous event, so we could see some crazy ass shit. A lot of you will probably think I’m going off the deep end here, but I’m just gonna say it. I think there will be a window in late March early April, with a much higher probability than normal for an April snowstorm this year. If I’m wrong I’m wrong, but when we combine the already colder than average Canadian airmass in place with a record strong vortex being possibly displaced or split, if it is displaced to this side of the globe, April 1997 becomes an analog (correct me if I am wrong, but I read that this was also a strong PV winter). This does not mean something as extreme, but a muted version of that? Hell yeah! Will the PV be displaced to this side of the globe? It may not, but I believe it will due to the polar vortex having a tendency to elongate and stretch toward this side of the globe this year, sunlike previous strong PV winters like 2020. 

that is so meridional.  a sw diving n to s from almost the north pole straight down into the mid south?  that would have to produce a big storm, but woulds the vortex in NQuebec move it along quickly?  I believe that would be a manitoba mauler, yes?

[George001]

30 minutes ago, mahk_webstah said:

that is so meridional.  a sw diving n to s from almost the north pole straight down into the mid south?  that would have to produce a big storm, but woulds the vortex in NQuebec move it along quickly?  I believe that would be a manitoba mauler, yes?

Yeah that looks like it would be. Late Jan 2015 I believe was one of those, hopefully we can get the pieces to align for something similar. Pattern looks great.

[George001]

I like how far north the vortex is, that should help us avoid suppression like March 2014.

[CoastalWx]

[bristolri_wx]

1 hour ago, CoastalWx said:

 

[Great Snow 1717]

1 hour ago, bristolri_wx said:

 

George did say perhaps as much as 18 so he is correct because there is close to 18 weenies on the grill...

[George001]

Eps has a low offshore for this time period now. Look how amplified and far west that western ridge is, this threat has big potential. Then we could have another threat March 5-6th or so.

[George001]

I was excited for a big threat mid Feb as well, and while it was a respectable storm (ended up with 7-8 inches) it didn’t quite pan out the way I originally thought with the big late Jan type phase. This setup is significantly better than that one. 

What the late Feb threat has going for it that the mid month didnt is a significantly more poleward western ridge. The pattern was just a bit too progressive for a big phase mid month, but even so we saw that northern energy trend more aggressive like the pattern argued it would. With this threat similar to the last one, the ridge axis is over Idaho, which is slightly west of ideal but very good. It argues that a storm would have plenty of room to trend NW. The main difference is for this threat, we have the ridge out west extending to the north pole, where as the mid month threat only had it extending to NW Canada. This would support a more amplified pattern, giving the northern energy more room to strengthen and dig more SW, likely enough to tap gulf moisture. If this idea is correct, the northern stream would be able to do it on its own. There would be plenty of room for the trough to go negative early enough to bring the storm up the coast (Miller B cyclogenesis). With a northern vort digging that far SW and then strengthening rapidly as it taps gulf moisture, as the trough goes negative there is a decent chance we could see the upper low close off. In my opinion, this threat has a good chance at working out because are less at the mercy of timing since we wouldn’t really need a full phase with a strong piece of southern energy. If we get that it would up the ante even more, but it wouldn’t be necessary. I like this threat even more than I like the Friday storm. Friday is a legitimate threat and I like what I saw from the models tonight. However, it is more thread the needle for a bigger solution and even if everything goes right, the upside is capped somewhat compared to what the ceiling is with the Feb 28 threat. 

[George001]

Looks like we got another threat to track end of Feb after the Friday one.

[George001]

NAVY ON BOARD!

[George001]

Canadian close for the 3rd

[Cold Miser]

...Congrats @George001 for having the most posts within your own thread.  It's almost like you are talking to yourself.