November Med/Long Range Discussion

[Bob Chill]

@WxWatcher007

A neg ao with a well placed nao block can easily overcome a -pna. Squashes the SE ridge. Otoh- a +ao or nao with a +epo and or -pna is almost always ugly at our latitude. 

A flawed pac can still be servicable. Especially during the heart of the winter season with a west based -nao. West based nao's typically coincide with a -ao because of the shared domain space. 

A west based block is probably the most favorable feature we can ever ask for here. Seeing it on all guidance is pretty cool considering we haven't really had one since 10-11. Just gotta hope that we're seeing clues that higher heights west of GL will be favored on the means for at least a portion of DJF. My total wag is that it will be in Dec at least. Kinda has that feel right now. 

13-14 & 14-15 had a crap load of luck involved. I'd much prefer taking my chances with a -ao/nao on the means than only a -epo/+pna. This far south that type of winter is typically more rainy/icy followed by cold/dry. We probably experienced the 2 snowiest MA winters in history with a +ao and very +nao average. 

 

[mitchnick]

We have nothing to worry about.  It's "our time" in the MA this winter based on our 7-year cycle: 95/96, 02/03, 09/10, 16/17

[H2O]

9 hours ago, Bob Chill said:

@WxWatcher007

A neg ao with a well placed nao block can easily overcome a -pna. Squashes the SE ridge. Otoh- a +ao or nao with a +epo and or -pna is almost always ugly at our latitude. 

A flawed pac can still be servicable. Especially during the heart of the winter season with a west based -nao. West based nao's typically coincide with a -ao because of the shared domain space. 

A west based block is probably the most favorable feature we can ever ask for here. Seeing it on all guidance is pretty cool considering we haven't really had one since 10-11. Just gotta hope that we're seeing clues that higher heights west of GL will be favored on the means for at least a portion of DJF. My total wag is that it will be in Dec at least. Kinda has that feel right now. 

13-14 & 14-15 had a crap load of luck involved. I'd much prefer taking my chances with a -ao/nao on the means than only a -epo/+pna. This far south that type of winter is typically more rainy/icy followed by cold/dry. We probably experienced the 2 snowiest MA winters in history with a +ao and very +nao average. 

 

i'll always take the big 3 all in our favor to deliver the goods but agree that -ao/nao can overcome a crappy pna.  There are subtle combos that can make a huge difference tho.  I generally hope for a favorable Pac/nao than a Pac/ao as the latter isn't best for us specifically.

[WinterWxLuvr]

10 hours ago, Bob Chill said:

@WxWatcher007

A neg ao with a well placed nao block can easily overcome a -pna. Squashes the SE ridge. Otoh- a +ao or nao with a +epo and or -pna is almost always ugly at our latitude. 

A flawed pac can still be servicable. Especially during the heart of the winter season with a west based -nao. West based nao's typically coincide with a -ao because of the shared domain space. 

A west based block is probably the most favorable feature we can ever ask for here. Seeing it on all guidance is pretty cool considering we haven't really had one since 10-11. Just gotta hope that we're seeing clues that higher heights west of GL will be favored on the means for at least a portion of DJF. My total wag is that it will be in Dec at least. Kinda has that feel right now. 

13-14 & 14-15 had a crap load of luck involved. I'd much prefer taking my chances with a -ao/nao on the means than only a -epo/+pna. This far south that type of winter is typically more rainy/icy followed by cold/dry. We probably experienced the 2 snowiest MA winters in history with a +ao and very +nao average. 

 

I tend to think that the Pacific is more important because it is upstream of us.  Give me a cold Canada and I'll take my chances.  I much prefer the nickle and dime, consistently cold winter over the one that might spin up a giant storm.

If I can have at least a neutral Atlantic, then let's do it.

[Bob Chill]

28 minutes ago, WinterWxLuvr said:

I tend to think that the Pacific is more important because it is upstream of us.  Give me a cold Canada and I'll take my chances.  I much prefer the nickle and dime, consistently cold winter over the one that might spin up a giant storm.

If I can have at least a neutral Atlantic, then let's do it.

I wasn't trying to imply that the pac isn't important. It's very important. It's the whole see-saw thing. +ao/nao winters pretty much require a near perfect Pac or it's lights out. Having a stout -ao/nao can offset a less than perfect pac quite a bit though. There are cases like 12-13 when the Pac drove the bus and destroyed our hopes and dreams despite -AO/NAO on the means.

MA snowfall and the state of the AO is pretty strongly correlated through time. Wes did a great scatter plot showing this. That's our single most important feature year over year. The NAO is not as important for general snow chances but sure helps a lot for bigger events. I won't let the last couple years change my mind. Dominant +ao/nao winters rarely produce above normal snowfall. 

+AO nina winters can be particularly unfriendly.

DCA

71-78: 16.8" (14" fell during Feb when the AO trended negative. Disaster prior)

75-76: 2.2"

88-89: 5.7"

99-00: 15.4" (single storm winter...but it was a hellava storm)

07-08: 4.9"

[CAPE]

1 hour ago, WinterWxLuvr said:

I tend to think that the Pacific is more important because it is upstream of us.  Give me a cold Canada and I'll take my chances.  I much prefer the nickle and dime, consistently cold winter over the one that might spin up a giant storm.

If I can have at least a neutral Atlantic, then let's do it.

Hard to say if any one index is more important. A legit block that persists (more than a few days) parks the trough and places the mean storm track in a favorable position for the MA. I like the odds when we get the AO/NAO working in our favor.

[North Balti Zen]

Delayed, around here, often means denied. If this next "3 weeks out it looks great on the weeklies" gets pushed back, after the last one of these was pushed back, that may tell us what we need to know about how the winter will unfold.

[Bob Chill]

3 minutes ago, North Balti Zen said:

Delayed, around here, often means denied. If this next "3 weeks out it looks great on the weeklies" gets pushed back, after the last one of these was pushed back, that may tell us what we need to know about how the winter will unfold.

Last night's euro ens trended a good bit colder late in the run. Definitely changes in the EPac. The thing to watch if the weeklies have the right idea is a "final" trough digging into the west and higher heights building in the GOA/PNA/EPO region. That's when we can probably start to get at least a little excited that we're in the game. 

[CAPE]

7 minutes ago, Bob Chill said:

Last night's euro ens trended a good bit colder late in the run. Definitely changes in the EPac. The thing to watch if the weeklies have the right idea is a "final" trough digging into the west and higher heights building in the GOA/PNA/EPO region. That's when we can probably start to get at least a little excited that we're in the game. 

Fwiw the CFSv2 weeklies also show marked improvement in the EPac, starting around day 15 and getting better going forward.

[mitchnick]

10 minutes ago, Bob Chill said:

Last night's euro ens trended a good bit colder late in the run. Definitely changes in the EPac. The thing to watch if the weeklies have the right idea is a "final" trough digging into the west and higher heights building in the GOA/PNA/EPO region. That's when we can probably start to get at least a little excited that we're in the game. 

Bob, did you see how the 6z  GEFs have us under a persistent mean trough from around 228 hours through the end of the run? That's a stormy look with that Hudsons Bay block.

[Bob Chill]

5 minutes ago, C.A.P.E. said:

Fwiw the CFSv2 weeklies also show marked improvement in the EPac, starting around day 15 and getting better going forward.

 

5 minutes ago, mitchnick said:

Bob, did you see how the 6z  GEFs have us under a persistent mean trough from around 228 hours through the end of the run? That's a stormy look with that Hudsons Bay block.

 

EPS is only slightly different in the circles area (flatter) but caving towards the same kink in the isobars in western canada/ak. Mean 850 temps by d15 are actually below normal up through BC and part of AK. That's new. 

 

The overall height patterns on both ens looks pretty sweet with pac energy undercutting the block. Agree about a stormy look for sure. Hopefully we'll still be having this discussion in a week or 2. lol

 

 

[Bob Chill]

Just looked at the EPS member plots. Definitely trended cooler/wetter d10-15. .75" mean precip during the period. Mean snowfall over a half inch through the cities and 1" in mappytown. Less than half the members have snow on the panels so I'll stick with little chance until we get into Dec a piece....subject to change...lol

[mattie g]

36 minutes ago, North Balti Zen said:

Delayed, around here, often means denied. If this next "3 weeks out it looks great on the weeklies" gets pushed back, after the last one of these was pushed back, that may tell us what we need to know about how the winter will unfold.

I don't think that adage applies to weeklies in the middle of November, especially when there are plenty of indications that things (AO/NAO, in particular) will fall in our favor for at least some stretch this winter.

[WinterWxLuvr]

2 hours ago, Bob Chill said:

I wasn't trying to imply that the pac isn't important. It's very important. It's the whole see-saw thing. +ao/nao winters pretty much require a near perfect Pac or it's lights out. Having a stout -ao/nao can offset a less than perfect pac quite a bit though. There are cases like 12-13 when the Pac drove the bus and destroyed our hopes and dreams despite -AO/NAO on the means.

MA snowfall and the state of the AO is pretty strongly correlated through time. Wes did a great scatter plot showing this. That's our single most important feature year over year. The NAO is not as important for general snow chances but sure helps a lot for bigger events. I won't let the last couple years change my mind. Dominant +ao/nao winters rarely produce above normal snowfall. 

+AO nina winters can be particularly unfriendly.

DCA

71-78: 16.8" (14" fell during Feb when the AO trended negative. Disaster prior)

75-76: 2.2"

88-89: 5.7"

99-00: 15.4" (single storm winter...but it was a hellava storm)

07-08: 4.9"

I remember it well.  I also remember that the combination of both being positive is better than you would think.  Maybe you could post it.  I have it somewhere, but no idea where.

[WinterWxLuvr]

I feel strongly that we see accumulating snow BEFORE the first of December.

Lots of action precip wise, lower than normal heights most of the time...... I think it has a good chance.

[mappy]

10 minutes ago, WinterWxLuvr said:

I feel strongly that we see accumulating snow BEFORE the first of December.

Lots of action precip wise, lower than normal heights most of the time...... I think it has a good chance.

quoting so i can either laugh, or applaud you.  

[Bob Chill]

10 minutes ago, WinterWxLuvr said:

I remember it well.  I also remember that the combination of both being positive is better than you would think.  Maybe you could post it.  I have it somewhere, but no idea where.

I found the one I was thinking of. It's the correlation to the state of the AO&PNA. I don't remember if Wes did one with the NAO. I don't think he did but he might have. 

 

 

 

Once the AO gets above +1 SDs things start getting pretty bleak. 

[Bob Chill]

I think the 12z gfs/gefs is a good example of how things may go down. Progressive/active flow before a big cold dump dives into the rockies/plains. That could be the harbinger of a shift to more persistent cold in the eastern 2/3rds of the CONUS. 

[Bob Chill]

23 minutes ago, WinterWxLuvr said:

I feel strongly that we see accumulating snow BEFORE the first of December.

Lots of action precip wise, lower than normal heights most of the time...... I think it has a good chance.

12/6/03 has been the top or near the top CPC D8&11+ analog for a few days now. 

[WxUSAF]

GEFS advertised for the end of November/early December is certainly workable with a big ol' west-based -NAO.  Pattern at least looks entertaining for the next 2 weeks following coldfrontzilla tomorrow.  

[WinterWxLuvr]

1 hour ago, Bob Chill said:

I found the one I was thinking of. It's the correlation to the state of the AO&PNA. I don't remember if Wes did one with the NAO. I don't think he did but he might have. 

 

 

 

Once the AO gets above +1 SDs things start getting pretty bleak. 

He did.  I just need to find it.

[mattie g]

7 minutes ago, WinterWxLuvr said:

He did.  I just need to find it.

I've seen it quite a few times, but never saved it. I'm sure it's floating around here somewhere.

[WinterWxLuvr]

6 minutes ago, WinterWxLuvr said:

He did.  I just need to find it.

Maybe Wes will stumble in here and post that plot of NAO/AO

[mattie g]

Just did a simple Google search and came up with this one, but I can't find one that has AO and NAO. I'm thinking I may have gotten Nino and NAO mixed up.

https://www.washingtonpost.com/blogs/capital-weather-gang/post/january-weather-outlook-warmer-than-average-below-average-snow/2011/12/28/gIQAjjLoMP_blog.html

 

[mattie g]

[WinterWxLuvr]

3 hours ago, mattie g said:

That's the one.  You want a neg AO, but if you're stuck with a pos AO you want the pos NAO to go with it.

[Bob Chill]

I think the lack of storms in a +AO/-NAO background state has more to do with the rarity of it and not that it is overly hostile. Any -nao during a +ao state is going to be quick and transient and most likely east based. A stable -NAO during a +AO state is probably impossible to maintain for anything but a very brief period. 

 

A +AO/NAO is fairly common so you can rack up thread the needles over time. 

[WinterWxLuvr]

22 minutes ago, Bob Chill said:

I think the lack of storms in a +AO/-NAO background state has more to do with the rarity of it and not that it is overly hostile. Any -nao during a +ao state is going to be quick and transient and most likely east based. A stable -NAO during a +AO state is probably impossible to maintain for anything but a very brief period. 

 

A +AO/NAO is fairly common so you can rack up thread the needles over time. 

This could easily be a valid theory.

14-15 tho ...

[CAPE]

Broke down and did the Weather Bell subscription today. Euro Weeklies look pretty nice going into December, and especially towards mid month.  CFSv2 weeklies seem to be in decent agreement as well. No guarantees obviously, but I have much better feeling as we head towards Dec than I had the past 2 years. Would be nice to get some legit wintry weather before Xmas for a change.

[WinterWxLuvr]

15 minutes ago, C.A.P.E. said:

Broke down and did the Weather Bell subscription today. Euro Weeklies look pretty nice going into December, and especially towards mid month.  CFSv2 weeklies seem to be in decent agreement as well. No guarantees obviously, but I have much better feeling as we head towards Dec than I had the past 2 years. Would be nice to get some legit wintry weather before Xmas for a change.

I'm finding it hard to wait until Dec 1 but I think I can do it.

3 months.  By March I don't care.