Novie is near, the first un-official month of SNE winter!

[CoastalWx]

The AO has been mostly + over the last several years. It doesn't seem to care much about ice.

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/month_ao_index.shtml

[Sugarloaf1989]

28 minutes ago, Damage In Tolland said:

I think he was talking about one of the regions great screaming sou easters though when he referred to the big Nov event 

Yes, but he was talking about cold weather for mid-November-mid-December as well as the November storm and that got me thinking about how that winter played out. No real relation to what he was saying, just recalling memories of that fantastic winter. I recall skiing at Plattekill in March with snow nearly waist deep.

[qr7121]

3 hours ago, CoastalWx said:

The AO has been mostly + over the last several years. It doesn't seem to care much about ice.

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/month_ao_index.shtml

...again, an arbitrary index calculated from an arbitrary box. the "AO" may be negative or positive -- I don't really care -- nor does mother nature. the practical impact of having significantly less sea ice vs previous years will result in an extraordinary amount of high latitude blocking this winter (so whether your arbitrary box counts that as -AO or +AO is ultimately irrelevant). 

[OceanStWx]

7 minutes ago, qr7121 said:

...again, an arbitrary index calculated from an arbitrary box. the "AO" may be negative or positive -- I don't really care -- nor does mother nature. the practical impact of having significantly less sea ice vs previous years will result in an extraordinary amount of high latitude blocking this winter (so whether your arbitrary box counts that as -AO or +AO is ultimately irrelevant). 

Really? I feel the need to respond just for others who may hear about and are curious about these indices. 

A +AO describes stronger than normal counterclockwise winds around the Arctic (i.e. zonal flow). This keeps cold air bottle up under the PV. So high latitude blocking will result in more meridional flow and a weaker than normal counterclockwise flow around the Arctic (-AO). So the "box" it looks at is just as arbitrary as the area you look at for sea ice. 

[qr7121]

5 minutes ago, OceanStWx said:

Really? I feel the need to respond just for others who may hear about and are curious about these indices. 

A +AO describes stronger than normal counterclockwise winds around the Arctic (i.e. zonal flow). This keeps cold air bottle up under the PV. So high latitude blocking will result in more meridional flow and a weaker than normal counterclockwise flow around the Arctic (-AO). So the "box" it looks at is just as arbitrary as the area you look at for sea ice. 

in an ice-free Arctic there may be a PV over the open/nearly-open ocean but there certainly won't be any cold air underneath (since it is over the ocean...)... at that point whatever cold is left will be over Greenland or the continents *regardless* of the index's arbitrary state... maybe the "AO" had usefulness as an index prior to our new normal, but in the absence of a cohesive Arctic ice pack, i think it is useless... the PV continually spills its guts over the continents, and has been doing this for yrs now, which is why the sea ice is at a catastrophic low right now...

whether +AO or -AO this has been the ongoing case, which shows why the index is now meaningless

[CoastalWx]

3 minutes ago, qr7121 said:

in an ice-free Arctic there may be a PV over the open/nearly-open ocean but there certainly won't be any cold air underneath (since it is over the ocean...)... because what remains it will be over Greenland or the continents at that point... maybe the "AO" had usefulness as an index prior to our new normal, but in the absence of a cohesive Arctic ice pack, i think it is useless... the PV continually spills its guts over the continents, and has been doing this for yrs now, which is why the sea ice is at a catastrophic low right now... whether +AO or -AO this has been the case, which shows why the index is now meaningless

SO under the PV there is no cold, it just escapes somewhere else? You don't understand meteorology at all.

[qr7121]

Just now, CoastalWx said:

SO under the PV there is no cold, it just excapes somewhere else? You don't understand meteorology at all.

pretty much...

[qr7121]

Just now, CoastalWx said:

Those are anomalies, not temperatures. Go back to your parents basement.

ad hominem attacks are fine, the Arctic is literally 40-50F warmer than normal in spots, i have maps and data to back up every assertion i make... and yes, the Arctic continues to spill its guts across the continents over and over again. that is why it is way colder in Siberia and Northern N America than all but about 1M KM2 of the Arctic Ocean.

[CoastalWx]

It's called the Siberian high. 

[CoastalWx]

This is a November thread, not a CC thread. 

[qr7121]

Just now, CoastalWx said:

This is a November thread, not a CC thread. 

ok so obviously the above maps showing the Arctic at +40-50F vs normal will have no relevance to our sensible november weather... really? REALLY?????

[CoastalWx]

Anyways, would be nice for a GEFS look. That's pretty sweet looking. I still have my doubts on that amplitude with the -EPO.

[qr7121]

GEFS agree

[Ginx snewx]

https://weather.gc.ca/city/pages/nu-10_metric_e.html

[jbenedet]

28 minutes ago, CoastalWx said:

Anyways, would be nice for a GEFS look. That's pretty sweet looking. I still have my doubts on that amplitude with the -EPO.

I dunno--is that really a sweet look?

The position of the PNA ridge is too far west. That kind of setup with a -NAO would likely keep us on the warm side of a potent cutter. 

[Typhoon Tip]

-NAO doesn't correlate well with Lakes storm tracks. The correlation is suppression of latitude over eastern N/A. 

[CoastalWx]

31 minutes ago, jbenedet said:

I dunno--is that really a sweet look?

The position of the PNA ridge is too far west. That kind of setup with a -NAO would likely keep us on the warm side of a potent cutter. 

Well I don't want to get too specific with the details, but I like that overall look for New England. Trough axis is in a good spot, and you potentially have a decent airmass to work with. I suppose if you have a crazy amped up s/w it could cut...but I don't think too many people in New England would scoff at that look. 

 

Of course climo needs to be considered.  It's hard with any pattern in November on the coast, unless it's an icebox of an airmass.

[OceanStWx]

Wtf happened in here today? 

I've been off long term for a few days, but I know when I left that desk the look wasn't terrible. I'm skeptical that we'll get our end of tea golf tourney in on the 13th.

On another note, NROW should have some good presentations tomorrow. A whole session on ensemble forecast tools.

[jbenedet]

57 minutes ago, CoastalWx said:

Well I don't want to get too specific with the details, but I like that overall look for New England. Trough axis is in a good spot, and you potentially have a decent airmass to work with. I suppose if you have a crazy amped up s/w it could cut...but I don't think too many people in New England would scoff at that look. 

 

Of course climo needs to be considered.  It's hard with any pattern in November on the coast, unless it's an icebox of an airmass.

Yea. I guess the point I'm trying to make is IF you have that setup--and as you said: a good air mass is in place--what's going to keep a shortwave--any shortwave--from really amping up as it hits the base of that trough? 

I completely understand not wanting to look at details this far out, and I also understand that that setup is certainly improved from the current one and is getting closer to something we can *maybe* get excited about. I guess I'm just pointing out a potential caveat to what should be an improving UL pattern, beginning in the latter half of the month.

Tip mentions suppression with -NAO and may have the data to support that, which I'd be interested in seeing, but my experience is contrary to that, absent blocking. With a good ridge out west you can see deepening shortwaves move nearly meridional as they round the bend of a deep-long-wave trough with a -NAO.

 

[qr7121]

43 minutes ago, CoastalWx said:

Well I don't want to get too specific with the details, but I like that overall look for New England. Trough axis is in a good spot, and you potentially have a decent airmass to work with. I suppose if you have a crazy amped up s/w it could cut...but I don't think too many people in New England would scoff at that look. 

 

Of course climo needs to be considered.  It's hard with any pattern in November on the coast, unless it's an icebox of an airmass.

crazy amped up SW will lay down needed snowpack over interior NE/Ontario/QC ~11/15... then next event = we cash in (IMO ~one week-10 days later)

maybe a clipper in between w snow as well

[CoastalWx]

11 minutes ago, jbenedet said:

Yea. I guess the point I'm trying to make is IF you have that setup--and as you said: a good air mass is in place--what's going to keep a shortwave--any shortwave--from really amping up as it hits the base of that trough? 

I completely understand not wanting to look at details this far out, and I also understand that that setup is certainly improved from the current one and is getting closer to something we can *maybe* get excited about. I guess I'm just pointing out a potential caveat to what should be an improving UL pattern, beginning in the latter half of the month.

Tip mentions suppression with -NAO and may have the data to support that, which I'd be interested in seeing, but my experience is contrary to that, absent blocking. With a good ridge out west you can see deepening shortwaves move nearly meridional as they round the bend of a deep-long-wave trough with a -NAO.

 

 Are you saying a -NAO helps storms amplify and cut west? Sometimes the extreme west based -NAO setups  an do that as a piece of the PV in Ontario phases when an incoming s/W. But more often than not, I think a -NAO would help keep storms at bay off the east coast. Usually a more classic -NAO will have ridging in the Davis Straits area and an ULL near Newfoundland. This helps keep the flow across Quebec more westerly. This in turn would try and prevent a low from cutting west.

Now getting back to ridge placements out west, that does mean something. You can have a sharp ridge poking into AK that dumps the cold right in the Plains. Sometimes that setup can cause some sort of cutter or mixed precip event here. 

 

[jbenedet]

32 minutes ago, CoastalWx said:

 Are you saying a -NAO helps storms amplify and cut west? Sometimes the extreme west based -NAO setups  an do that as a piece of the PV in Ontario phases when an incoming s/W. But more often than not, I think a -NAO would help keep storms at bay off the east coast. Usually a more classic -NAO will have ridging in the Davis Straits area and an ULL near Newfoundland. This helps keep the flow across Quebec more westerly. This in turn would try and prevent a low from cutting west.

Now getting back to ridge placements out west, that does mean something. You can have a sharp ridge poking into AK that dumps the cold right in the Plains. Sometimes that setup can cause some sort of cutter or mixed precip event here. 

 

Yes. The flow is also slower relative to +NAO which allows for a an earlier bend-back, i.e. the storm doesn't outrun the increasing barcolincity at our latitude.

It seems the distinction is in what you call a "classic" -NAO. The ULL near Newfoundland is absolutely critical to suppression in a setup like this. My point was based on this feature not being present.

 

[CoastalWx]

5 hours ago, jbenedet said:

Yes. The flow is also slower relative to +NAO which allows for a an earlier bend-back, i.e. the storm doesn't outrun the increasing barcolincity at our latitude.

It seems the distinction is in what you call a "classic" -NAO. The ULL near Newfoundland is absolutely critical to suppression in a setup like this. My point was based on this feature not being present.

 

Usually some form of convergence zone is though. That's part of the -NAO and why they better for the most part vs a +NAO. A +NAO actually encourages storms to amplify and cut west as usually some sort of Hudson bay vortex gets involved and usually features ridging off the coast. we really lucked out for two years with a great Pacific, but 13-14 also showed you how even with a great Pacific, you can get cutters. The 60s had a lot of Ninas, but also a -NAO too. That helped keep the se ridge down and allow for good winters. 

[Rtd208]

16 minutes ago, CoastalWx said:

Usually some form of convergence zone is though. That's part of the -NAO and why they better for the most part vs a +NAO. A +NAO actually encourages storms to amplify and cut west as usually some sort of Hudson bay vortex gets involved and usually features ridging off the coast. we really lucked out for two years with a great Pacific, but 13-14 also showed you how even with a great Pacific, you can get cutters. The 60s had a lot of Ninas, but also a -NAO too. That helped keep the se ridge down and allow for good winters. 

Coastal,

Do you see the pacific jet overwhelming the pattern this winter which would keep most of the conus warm??

[CoastalWx]

Looks like more warmth possible later next week. Setting up for another +month I think.

[CoastalWx]

Just now, Rtd208 said:

Coastal,

Do you see the pacific jet overwhelming the pattern this winter which would keep most of the conus warm??

I have no idea. If I knew that, I'd be rich...lol. You tend to get a lot of GOAK lows this time of year. I don't really see an issue, just because we have one now.

[Rtd208]

4 minutes ago, CoastalWx said:

I have no idea. If I knew that, I'd be rich...lol. You tend to get a lot of GOAK lows this time of year. I don't really see an issue, just because we have one now.

I am really hoping we get a major pattern change to colder/stormier by the last 10 days of the month, I am really not expecting much before that.

[CoastalWx]

17 minutes ago, Rtd208 said:

I am really hoping we get a major pattern change to colder/stormier by the last 10 days of the month, I am really not expecting much before that.

The models have had too much troughing in the east. The pacific is killing everything. This month is inferno for most of conus and into Canada.  

[Rtd208]

1 minute ago, CoastalWx said:

The models have had too much troughing in the east. The pacific is killing everything. This month is inferno for most of conus and into Canada.  

If this continues on into the winter I think we are toast, but hopefully not. Its only early November so I am not overly concerned at the moment.

[Damage In Tolland]

What a disaster the promises of a pattern change this month has turned into. Nothing but a torch it seems based on what's being discussed