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AlaskaETC

Winter 2016-2017 Speculation and Discussion

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9 hours ago, Bob Chill said:

The last time DC had 4+ winters with above climo snow in a row was in the 60's. It was actually 6 in a row from 62-63 through 67-68. IAD had 5 in a row in the 60's and Baltimore hasn't had 4 in a row since the early 40's. Considering the obvious change in climo since the 60's it would be VERY impressive to hit a 4th in a row this winter at the airports.  

While it would be impressive to hit 4 in a row I don't really see it as meaningful. IMHO- it's more of a byproduct of chaos. Our snow luck is more random than typical unlike areas further north and west. 

Sure would be nice to string the 4th because our next chance at doing it may be longer than I'm alive. 

Out of curiosity, what was climo for this area in the '60s?  

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15 hours ago, nw baltimore wx said:

Man, that's a good read! I'd love an early cold winter for the holidays. 

Yeah...good read just from the writing/ease of comprehension perspective.

Cold for Christmastime would be money, especially if we have a shot at some white flying in the run up. Thanksgiving? I don't mind having the windows wide open!

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2 hours ago, Bob Chill said:

Still a little early to get excited for this threat but once we get under 1,000 hours someone can start a thread

frontloaded.JPG

 

2 hours ago, Bob Chill said:

I'm hoping once the vort gets onshore the models will speed this up a day. The WD index is high for a white christmas. 

 

boxingday.JPG

Look at the dates....very 12/02'ish!  :weenie:

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On ‎10‎/‎24‎/‎2016 at 1:24 PM, Bob Chill said:

...Baltimore hasn't had 4 in a row since the early 40's. Considering the obvious change in climo since the 60's it would be VERY impressive to hit a 4th in a row this winter at the airports.  

I believe we only need 32" this season to have the highest avg for any of those 4 year periods. I'm using Balto. (Neither DC site is acceptable for long term snow climo)

Additional....

Avg for 2013-15 is 34.3".

Highest 4 in a row is 1932-35 at 33.75"

Total 4 in a rows are: 1908-11; 1932-36; 1939-43 (3 total, with the last 2 being actually 5 in a row)

This doesn't address the little issue of the average (20.1 per NOAA) not quite being average over the whole period. But that's not too bad.

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15 hours ago, Bob Chill said:

Still a little early to get excited for this threat but once we get under 1,000 hours someone can start a thread

frontloaded.JPG

 

I'll be in South Carolina that week. Typical!

 

15 hours ago, Bob Chill said:

I'm hoping once the vort gets onshore the models will speed this up a day. The WD index is high for a white christmas. 

 

boxingday.JPG

I think we can speed this up, but that High needs to speed up along with it or else it's going to roast given the GL low.

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44 minutes ago, nw baltimore wx said:

Didn't we do this last year, Woody?

Haha. If we're thinking of the blizzard, I was in Newport Beach.

I do recall being down there for one really cold powder event a few years ago (late January 2014?). I was disappointed, but if I recall that ushered in our late-season cold, snowy period, so it didn't feel like I missed out too badly.

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On 10/24/2016 at 10:39 PM, mfastx said:

Out of curiosity, what was climo for this area in the '60s?  

I missed this post. The 60's were an exceptionally snowy and cold period for our area. I used a bad choice of words by saying "since the 60's". It's more since the mid 80's but the 60's and 70's marked the end of bitter protracted cold in the mid atlantic. . Since our latitude is often on the fringe with temps during winter events, the general warming we've had since the 60's makes it harder to snow in general. The huge increase in UHI doesn't help the airports either.  Some of that is being offset by a larger frequency of bigger storms but overall in general our winters are milder now than 30 years ago. It doesn't rule out cold ones like 13-14 but the frequency of below normal DJF has declined significantly since the 70's. 

Using the 1950-95 climo, the decade was -2 for DJF in the MA. You can take another degree or 2 off using the 1981-2010 climo

Snowfall in DC:

 60s snow dc.JPG

 

Temps using 1950-95 climo:

60s temp.JPG

The reasons are hotly debated and not a good place to discuss here. 

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19 minutes ago, Bob Chill said:

I missed this post. The 60's were an exceptionally snowy and cold period for our area. I used a bad choice of words by saying "since the 60's". It's more since the mid 80's but the 60's and 70's marked the end of bitter protracted cold in the mid atlantic. . Since our latitude is often on the fringe with temps during winter events, the general warming we've had since the 60's makes it harder to snow in general. The huge increase in UHI doesn't help the airports either.  Some of that is being offset by a larger frequency of bigger storms but overall in general our winters are milder now than 30 years ago. It doesn't rule out cold ones like 13-14 but the frequency of below normal DJF has declined significantly since the 70's. 

Using the 1950-95 climo, the decade was -2 for DJF in the MA. You can take another degree or 2 off using the 1981-2010 climo

Snowfall in DC:

 60s snow dc.JPG

 

Temps using 1950-95 climo:

60s temp.JPG

The reasons are hotly debated and not a good place to discuss here. 

Where's Tenman when you need him?

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^ It doesn't mean much at this stage in the game at all. The strat pv will almost surely consolidate again. 

 

In the longer term picture it's good to see that the strat PV is having a hard time becoming strong. That in general will favor higher chances blocking in the the high latitudes this winter. The AO has already been negative since the beginning of Oct and is forecast to stay that way for the next 2 weeks and probably beyond.

There's a natural barrier between the strat and trop most of the time. There's always chatter about SSWs in the winter propagating into the trop though. That can have significant impacts when they occur. But we don't need one to have favorable heights in the arctic. We mostly just don't want a big consolidated beast spinning around the strat the entire winter. We seem to be off to a good start but it's pretty early.  

 

The effects of a -ao/nao are most profound starting in mid-late Nov through winter. In October even with blocking it's uncommon for the polar jet to consistently punch this far south. That changes with the seasons as the wavelengths shorten. 

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16 minutes ago, Bob Chill said:

^ It doesn't mean much at this stage in the game at all. The strat pv will almost surely consolidate again. 

 

In the longer term picture it's good to see that the strat PV is having a hard time becoming strong. That in general will favor higher chances blocking in the the high latitudes this winter. The AO has already been negative since the beginning of Oct and is forecast to stay that way for the next 2 weeks and probably beyond.

There's a natural barrier between the strat and trop most of the time. There's always chatter about SSWs in the winter propagating into the trop though. That can have significant impacts when they occur. But we don't need one to have favorable heights in the arctic. We mostly just don't want a big consolidated beast spinning around the strat the entire winter. We seem to be off to a good start but it's pretty early.  

 

The effects of a -ao/nao are most profound starting in mid-late Nov through winter. In October even with blocking it's uncommon for the polar jet to consistently punch this far south. That changes with the seasons as the wavelengths shorten. 

Thanks for the explanation! Didn't that happen during one of the cooler summer patterns we had a couple years ago (plus or minus)?

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3 hours ago, Bob Chill said:

I missed this post. The 60's were an exceptionally snowy and cold period for our area. I used a bad choice of words by saying "since the 60's". It's more since the mid 80's but the 60's and 70's marked the end of bitter protracted cold in the mid atlantic. . Since our latitude is often on the fringe with temps during winter events, the general warming we've had since the 60's makes it harder to snow in general. The huge increase in UHI doesn't help the airports either.  Some of that is being offset by a larger frequency of bigger storms but overall in general our winters are milder now than 30 years ago. It doesn't rule out cold ones like 13-14 but the frequency of below normal DJF has declined significantly since the 70's. 

Using the 1950-95 climo, the decade was -2 for DJF in the MA. You can take another degree or 2 off using the 1981-2010 climo

Snowfall in DC:

 image

Temps using 1950-95 climo:

image

The reasons are hotly debated and not a good place to discuss here. 

Thanks for the info, I'm a total n00b with respect to meteorological history and have only been here a year, so much appreciated.  

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Good forecast Matt. I don't spend a lot of time on seasonal because you put in all the work to weight 20 variables and how they will play off each other then one factor changes or an unforeseen variable becomes dominant and the whole thing was a waste of time. I'm not saying seasonal is not valuable and I have much respect for those that do it. Some years it's definitely easier to see a clear signal then others. This is not one of those years. But my from my very limited ability to read the tea leaves I would agree with that forecast. I definitely see way more variables lining up in favor of a cold first 1/2 of winter then warm. I also think some who are expecting a warm or snowless winter are leaning too much on La Niña when I see it as being too weak to exert that much influence. 

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Also so many of our years snowfall is based on luck. The worst years and best like 2002 or 2010 were going to be good or bad no matter but for the rest getting lucky a couple times is the difference between getting 15" or 30" on the year.  No way to predict luck on the specific track of a few synoptic systems from months in advance. 

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On 10/27/2016 at 9:47 PM, Deck Pic said:

Yup, good comments in there.  I think most everyone here would take the preliminary DJF monthlies that you posted in here a little while back (-2/-2/+2 temps), with normal to somewhat above normal snow, and gladly call that a winter.  Even +2 for February isn't totally awful, if that occurs...doesn't necessarily mean a very early spring, and it would still allow for some cold (and snow) to sneak in here or there.

I've perused this thread now and then, and I guess from what several others have said, getting some decent NA blocking will be a big key, of course.  Haven't seen the very latest ENSO stuff, but I gather it's still sort of in the weakish Nina territory going by what I read earlier.  I'm not expecting another big HECS-level storm this year, but I'd definitely take the opportunity to have more (realistic) events to follow and get a couple or so solid moderate storms along with some cold periods.  An early period of cold with snow possibilities in December would be a nice change!  We seem to have lost December as a winter month the past few years.

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On 10/19/2016 at 8:33 AM, mattie g said:

I know that the SAI has taken a beating the last couple years, but it's still interesting to follow. I just posted this in the "And we begin" thread (which is hopping spectacularly, by the way!). Just a talking point:

Sorry for all the pictures, but here are the last few days of the month (minus today). The rate of increase wasn't terribly high in the past week, and then yesterday happened. Virtually all of Russia is snow covered right now. With a weak ENSO signal and no index looking like it might overwhelm other indices, you may have to take SAI a little more seriously this year.

ims2016299.gif

ims2016300.gif

ims2016301.gif

ims2016303.gif

ims2016304.gif

 

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8 minutes ago, mattie g said:

 

Sorry for all the pictures, but here are the last few days of the month (minus today). The rate of increase wasn't terribly high in the past week, and then yesterday happened. Virtually all of Russia is snow covered right now. With a weak ENSO signal and no index looking like it might overwhelm other indices, you may have to take SAI a little more seriously this year.

ims2016299.gif

ims2016300.gif

ims2016301.gif

ims2016303.gif

ims2016304.gif

 

Snow cover, and the SAI are ending on a high note this last day of October, also of interest is the recent Eastern Canada snowfall , it is above normal at this time.   

Have to see about the effects of a possible recurving Typhoon  in the 6 to 10 period as well as the robust signal for a positive PNA.   

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Saw this in the SNE thread:

34 minutes ago, OceanStWx said:

Euro upgrade coming our way 11/22. I know there has been some angst about its performance recently, but it is still tops.

Looks like most changes are fairly cosmetic (better data assimilation, cloud models, some aviation fields etc) but they are updating snowfall output by using radar analysis. Biggest news is the EPS is going down to 0.25 degree and 75 levels. Basically the EPS will be comparable to the GFS op. 

 

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