Where we're at, where we're going

[NinjaWarrior2]

Real -NAO/-PNA/-ENSO year temp

Makes much more sense to me, Pacific shows a stronger signal[ and a crappier one compared to the Atlantic] in these years. Had mainly a -NAO/-PNA/-EPO and -QBO influence, which meant West Coast Trough and East Coast Ridging with artic air trying to bulge in, but the PNA trough is too strong.

This yearmay be similar, except we will likely have a +QBO and a higher EPO value.

[Flying MXZ]

The wavelengths are absolutely perfect ~ Thanksgiving. A beautiful western ridge, strong -NAO and the motherload dropping down into southern Canada. Perhaps a Thanksgiving Buffalo massacre? You don't need me to say it again but the LES potential is just....wow.

Hope you don't mind, but I stole your quote to post it in the Upstate NY thread.

[usedtobe]

Wes, is there any site which tallies if the predominant nao state was east or west based? Also, if an east based neg nao is bad does that mean an east based pos nao is good? Because if we exclude neutral states, and no kind of pos nao is "good" for snow, that means that 75% of nao conditions are bad (if we assume there are equal chances of each kind.)

Snowgoose mentioned that in the past 5 years, we've seen a predominance of east based neg nao (when it is neg) and Im wondering if east based neg nao are more common..... and if its actually worse (for snow) then a pos nao?

Alex, Allan's site has what you want.

http://www.americanwx.com/raleighwx/index.php

I don't think last year's NAO was east based heck we had a record breaking negative AO which means the heights across the northern latitudes were pretty high across canada. That certainly was true during our snow storms.

[usedtobe]

But the NAO could do what it did in 2008 where it went sharply negative in early December and then again late Dec/early Jan. Then there was 2005 which went strongly negative late November and slowly climbed its way up through the first half of December. What you are worried about sounds a lot like 2000 where the NAO went negative late NOV/early DEC, went positive for a little bit and then came back negative from 12/20 onward.

I would be inclined to agree with a 2000-like NAO for December if it wasn't for the parameters we have in place this year. I hope you are right that it returns because it would make for some sick patterns.

I'm not arguing that it will necessarily be a cold dec throughout the winter, It could be a 1975-1976 type winter to start. I've been on the roller coaster idea for this winter sort of like 2007-2008 but probably a little colder overall with more snow than that year but admit I don't really have much feel for what's going to happen beyond the really warm days coming up sunday-tuesday and the cold weather coming around or just after turkey day. If the euro days 7-10 verifies, the great lakes sure should get a pretty good shot of snow with the cold coming across the open lakes.

[winterymix]

I don't really have much feel for what's going to happen beyond the really warm days coming up sunday-tuesday and the cold weather coming around or just after turkey day.

Wes: I quote you almost daily in my day job when people ask my opinion. I rattle off some comments and summarize with,

"Of course I could be completely wrong about all of that".

This strategy works beautifully and is terrific for stress reduction.

[usedtobe]

Wes: I quote you almost daily in my day job when people ask my opinion. I rattle off some comments and summarize with,

"Of course I could be completely wrong about all of that".

This strategy works beautifully and is terrific for stress reduction.

but it's true.

[Lee]

Real -NAO/-PNA/-ENSO year temp

Makes much more sense to me, Pacific shows a stronger signal[ and a crappier one compared to the Atlantic] in these years. Had mainly a -NAO/-PNA/-EPO and -QBO influence, which meant West Coast Trough and East Coast Ridging with artic air trying to bulge in, but the PNA trough is too strong.

This yearmay be similar, except we will likely have a +QBO and a higher EPO value.

Whoa now, wait a second here...very small sample size! If you break those "tons" of analogues down you can see that 71-72 is why your map looks that way. Here's the individual year links :

71-72:

http://climvis.ncdc.noaa.gov/tmp/StMap-Nov1811:31:535458374023.gif

55-56:

http://climvis.ncdc.noaa.gov/tmp/StMap-Nov1811:32:428258972167.gif

71-72 just looks typical Nina while 55-56 clearly looks altered by the -NAO..

[usedtobe]

While the pattern looks like it will get colder, what it will look like during the weekend after thanksgiving is still a question mark. If you want a laugh compare the heights over the south on the GFS versus Euro.

One of them will be wrong well both will probably be wrong but how wrong? The euro looks stormtracker interesting except it's out in la la land.

[tacoman25]

Yeah I read that paper a long time ago and use the sun constantly when forecasting. The tropical forcing idea is not the only reason I am going warmer mid-month. And keep in mind, I said December would be best characterized in thirds for the mode of the pattern, so I am not describing the whole month as a blowtorch or even half. I think we see something like we saw in October again in December, potentially aiding in a very warm period. However, it could be an interesting look when this happens because a low anomaly may get left in the Southeast while the northern-tier warms up.

Do you remember a couple months ago when we were discussing the potential for a much colder/stormier pattern developing for the northern tier than has been seen in recent Novembers? Looks like it's coming to pass.

[HM]

LOL loaded pattern coming up, Manitoba Mauler to light the spark?

The ECMWF takes the MM out to sea, but a quicker/weaker Thanksgiving cyclone could allow more room for this thing to amplify. I am not holding my breath.

HM, if you could expand on this a little...

Down here, most of the gang is resigned to the fact that we're gonna have to chase to get good snow. We;ve settled on an epic LES chase. I'm anxious!

The delta T's over the lakes with this cold snap, even if you modify raw solutions, will be exceptional. The lake temperatures are what...50's? If you got -10C h85 temps coming in, at least, look out. The structure of the PV now may not have that southwesterly component to the deep layer winds, so I may have spoke to soon for Buffalo. But either way, the potential is there for a serious LES attack. I think Wes agrees. Just watch the trends in the low-mid level winds and where the PV sets up.

I'm not sure HM; the ridge axis around Thanksgiving looks like it's still a bit too far west and would lead to a storm being more of a cutter/redeveloper than a classic coastal. Heights over FL are still near 588dm which usually isn't a good sign for an I-95 event.

The pattern gets a little better after that, although we're losing the arctic connection due to the +EPO. It's still probably cold enough if we get the right s/w however, as the NAO blocking is through the roof.

Ji and I go way back and we just have fun. It is all good man. Plus, the events we are talking about are not what you are talking about here with this map. These would be after Thanksgiving.

[usedtobe]

The ECMWF takes the MM out to sea, but a quicker/weaker Thanksgiving cyclone could allow more room for this thing to amplify. I am not holding my breath.

The delta T's over the lakes with this cold snap, even if you modify raw solutions, will be exceptional. The lake temperatures are what...50's? If you got -10C h85 temps coming in, at least, look out. The structure of the PV now may not have that southwesterly component to the deep layer winds, so I may have spoke to soon for Buffalo. But either way, the potential is there for a serious LES attack. I think Wes agrees. Just watch the trends in the low-mid level winds and where the PV sets up.

Ji and I go way back and we just have fun. It is all good man. Plus, the events we are talking about are not what you are talking about here with this map. These would be after Thanksgiving.

[HM]

Do you remember a couple months ago when we were discussing the potential for a much colder/stormier pattern developing for the northern tier than has been seen in recent Novembers? Looks like it's coming to pass.

I do, I do. I am feeling good about late Nov into early Dec. My first half of November call matching 1954 went well. I am sure my streak will come to an end soon. Hopefully, it will be in December and the -NAO block doesn't go away mid-month.

[HM]

I'm not arguing that it will necessarily be a cold dec throughout the winter, It could be a 1975-1976 type winter to start. I've been on the roller coaster idea for this winter sort of like 2007-2008 but probably a little colder overall with more snow than that year but admit I don't really have much feel for what's going to happen beyond the really warm days coming up sunday-tuesday and the cold weather coming around or just after turkey day. If the euro days 7-10 verifies, the great lakes sure should get a pretty good shot of snow with the cold coming across the open lakes.

Let's forget about the winter and focus on this particular NAO block. I am trying to figure out if we pull a 2005 here or a 2000. It makes a pretty big deal if the Don S. rule goes into effect (that's right Don, I gave you a "rule") and the block reforms mid-late Dec. Now, I could see a late December reformation that battles a stealthy SE ridge/NW trough pattern. But during the relaxation period, the Pacific looks downright miserable. If there is nothing to fight the Pacific, why not go really warm...right?

[uncle W]

I do, I do. I am feeling good about late Nov into early Dec. My first half of November call matching 1954 went well. I am sure my streak will come to an end soon. Hopefully, it will be in December and the -NAO block doesn't go away mid-month.

lets hope 2010 does not continue like 1954...No heavy snow that year and less than a foot fell for the season...I don't think it will because there's more moisture on average...Doesn't mean much but the trend is there...I'm on the mild December cold February train...1973-74 or 1971-72 were my main analogs...If the nao stays mostly negative in December I'll probably be wrong...

[stormtracker]

While the pattern looks like it will get colder, what it will look like during the weekend after thanksgiving is still a question mark. If you want a laugh compare the heights over the south on the GFS versus Euro.

One of them will be wrong well both will probably be wrong but how wrong? The euro looks stormtracker interesting except it's out in la la land.

The bus is being detailed...

[HM]

lets hope 2010 does not continue like 1954...No heavy snow that year and less than a foot fell for the season...I don't think it will because there's more moisture on average...Doesn't mean much but the trend is there...I'm on the mild December cold February train...1973-74 or 1971-72 were my main analogs...If the nao stays mostly negative in December I'll probably be wrong...

Nah, I just was referencing 1954 for how my Nov1-15 map looked to clients. I am not so sure about February but I could see a nasty gradient set up between the Mid Atlantic and New England. Early indications kind of gave the impression of a rPNA signal in FEB.

[tacoman25]

Nah, I just was referencing 1954 for how my Nov1-15 map looked to clients. I am not so sure about February but I could see a nasty gradient set up between the Mid Atlantic and New England. Early indications kind of gave the impression of a rPNA signal in FEB.

Yeah, first half was very similar to 1954...taking a far different track now.

[Stebo]

Yeah the lake effect potential downwind of all the Great Lakes next weekend looks spectacular right now.

[HM]

If you do the roll-forward method and take nothing else into consideration, the analogs obliterate the cold pattern and favor some sort of torch for the northern 1/2 of the CONUS, outside of the NW. The GFS suite seems to be breaking the NAO block down a little faster than I thought on the latest runs. I think it is sniffing the warm shift a little early, but who knows.

[Road Runner]

Well Guys,

At this point...It looks like this upcoming nor'easter potential will being to form over the US on the 24th and eventually a second surface Low might develop on the 25th near the coast. The pattern after that looks good for a couple of days, but the "warm-up" does begin on the 27th for the East Coast. The 12z ECMWF and GFS do highlight on some warm-up moving into the South before spreading north. This kind of a pattern reminds me of the November 27th-December 11th,2008 cycle (with no "real warm-up" taking place!). I also noticed that the way a warm-up begins is a good indicator of how the nor'easter will behave. For example, the most recent warm-up stalled in the Plains region (using southerly winds as an indicator), and thus the nor'easter will begin in the Plains regions on the 24th before propagating eastward by the 25th. The idea here is that how the warm-up develops will shine a lot of light on the track of the nor'easter. I believe that with with the distant warm-up starting somewhere down South, it would mean that the storm system will propagate through a stalled boundary down South before moving north. A track displaced to the south and east would allow for more cold air to build down; I am also assuming a pattern similar to December '08 would take place for the upcoming period. I believe that sometime between December 10th-December 13th 2010, we might have a beautiful looking nor'easter on our hands. I am also in favor of a cold(er) period from November 25th to December 9th than what we are used to so far.

[NaoPos]

If you do the roll-forward method and take nothing else into consideration, the analogs obliterate the cold pattern and favor some sort of torch for the northern 1/2 of the CONUS, outside of the NW. The GFS suite seems to be breaking the NAO block down a little faster than I thought on the latest runs. I think it is sniffing the warm shift a little early, but who knows.

If the pattern has been delayed by a week or 2( GFS bringing in the cold way early), then the pattern that exits should be looked at as too quick of a break down in it. That would make sense right?

by the way, nice job to all disco's in here. A lot of info being thrown around by all. Makes the thread enjoyable to read.

[usedtobe]

It does look like after thanksgiving we do get a nice cold shot. The 6-10 mean forecast patterns are showing that the ridge in the pacific did reform west which let a trough replace the strong ridge that was poking in AK. That trough in term built a ridge over the western U.S. Not a great ridge or one that would tap lots of cold but one that will force the initial cold air eastward and under the block that has set up over Greenland. This block is forecast to retrograde. The big down side is that once the cold air gets to us, this pattern looks more like a chilly, dry one than one that will produce that much snow except initially over the lakes with cold air flowing across them and the west slopes of some of the mountains providing the trajectories are decent.

The 06Z GFS ensembles did have one member out of 12 with a look that could give a snowstorm around the 2nd or so. I like the block but not the lack of any southern stream which makes me think any snow for the mid atlantic region east of the mountains would have to come from northwest flow flurries. With time, the flow seems to want to go zonal across the u.s. but that could be a function of the uncertainty of timing of shortwave and the effect of meaning them out. As to how long the cold and blocking will last. Usually in our area, it's time span is limited. My guess is within two weeks of getting the cold, we go into a warm period before the next cold shot. The big fly in the ointment remains the NOA which does become quite negative on the progs. That often leads to another negative nao period down the line. Hopefully, Don Sutherland can provide some stats.

[Gibbsfreeenergy]

If you do the roll-forward method and take nothing else into consideration, the analogs obliterate the cold pattern and favor some sort of torch for the northern 1/2 of the CONUS, outside of the NW. The GFS suite seems to be breaking the NAO block down a little faster than I thought on the latest runs. I think it is sniffing the warm shift a little early, but who knows.

Nothing new here right...models too fast with pattern changes and to fast in weakening of blocks.

[BlizzardWx]

Speaking of too fast on model changes, thats why us in the west have been waiting for the cold intrusion for over two weeks. GFS saw it a long time and and kept it, but kept pushing it back...again and again...but at least its finally here.

[Gibbsfreeenergy]

Black Friday=Black Friday b/c of high frost bite risk nationally

[Ginx snewx]

Black Friday=Black Friday b/c of high frost bite risk nationally

LOL black toes and black noses will great those who stand in line for cheap clotheses. Ha

[bluehens]

Need to start shorting retail stocks now as the cold will keep shoppers out of the malls and hurt retail stocks. <BR><BR>Just kidding....<BR><BR>

Black Friday=Black Friday b/c of high frost bite risk nationally

[HM]

Nothing new here right...models too fast with pattern changes and to fast in weakening of blocks.

Speaking of too fast on model changes, thats why us in the west have been waiting for the cold intrusion for over two weeks. GFS saw it a long time and and kept it, but kept pushing it back...again and again...but at least its finally here.

Exactly. December is going to look interesting when the temp anomalies take on a brief El Niño look.

[usedtobe]

I decided to look at the ncep superensemble mean to see what analogs it spits out. It is a centered mean that covers 5 days and today's prog is centered on November 30th. One of the advantages at looking at a centered mean is that it damps out the shorter less predictable waves and the larger scale waves show up giving and idea of what overall pattern might be in terms of temps, etc but it can't tell you which days will be the coldest or even whether there might be a warm day sandwiched into the period. Last year the product really helped identify possible "windows of opportunity" for snow and really suggestIed that the pattern was one in which the odds of a major snowstorm/s was way above climo. Last night's dates only came up with one storm in the space covering the period around the centered mean and it was a light snow. I guess that's not surprising based on the time of year. Not sure what that means except that the pattern is not a good one for getting any sizeable snowstorm and that there is only a small chance of getting an inch based on the pattern providing the mean has the basic idea right. It does look like there is potential for flurries or snow showers in the cold air behind Thanksgiving front but the 18Z ensemble guidance even at 156 hrs shows lots of spread so it's not something to get excited about.

[Ji]

2 major snowstorms showing up on the 12z GFS for Mid Atlantic