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Bob Chill

November Long Range Disco

848 posts in this topic

The 0z euro op last night caught my eye:

ecmwf_z500a_nhem_11.png

12z gfs long range caught my eye again. Not so much as that I think it's accurate but it did present an interesting long range solution that is pretty similar to where the Euro was going last night. 

Major squeeze play between HP in the N Pac and N Atl. The panel is d16 but the pattern starts setting up around d9-10. The entire country except for the desert SW is cold:

 

gfs_z500a_nhem_53.png

 

My first thought when I saw it is that the ensembles would show something much different. But they didn't...

 

D12-16 mean 5h is one of the more interesting looks I've seen in a while:

gfs-ens_z500aMean_nhem_12.png

 

The most important thing we need to come out of Nov with is a weak and/or displaced PV. We don't want a big blue ball destroying our hopes and dreams. Looks like we might kick off Nov with something favorable to consider as we creep along towards Dec. 

 

 

 

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Excellent post as usual Bob.  I have been looking to see when was the last time we had snow in November.  Since the 2006-2007 winter, DCA has recorded a T in 5 of the 10 past winters.  However, if you want accumulating snow (greater than 0.1") at DCA, one pretty much has to go back to the winter of 1995-1996 -- 0.5" of snow.  November snow of greater than a T has been pretty rare once the 90s started

http://www.weather.gov/media/lwx/climate/dcasnow.pdf
 

 

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1 hour ago, WxUSAF said:

If blank, model image not available

EPS not quite as strong with the high-latitude blocking in early Nov, but same general idea.  

The longer Greenland blocking is delayed (but not denied), the better!

eta: What I mean by that is the existence of blocking is so important later on when considering its effect with climo.  If blocking were to form today, would it be able to last long enough when we need it later in the winter?  Imo, the last thing we want for winter as a whole is having blocking develop and fade before winter can even get going.

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22 minutes ago, BTRWx said:

The longer Greenland blocking is delayed (but not denied), the better!

With respect to the AO/NAO state, I just want to see indications in the guidance, as Bob has talked about. And so far, we are. Pacific has looked decent too. We aren't getting anything wintery in the next month or so in the lowlands regardless. If things pan out, could be a nice early snow season for places like Canaan though.

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48 minutes ago, BTRWx said:

The longer Greenland blocking is delayed (but not denied), the better!

During Nov/Dec the last thing we want is a delay because the state of the AO going into Dec can tell a large part of the story for how our winter is going to play out in the blocking dept. We want disruption and displacement as much as possible from now on. We've seen what a strong PV in Nov and Dec can do 3 years in a row. We need the opposite. 

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58 minutes ago, WxUSAF said:

 

EPS not quite as strong with the high-latitude blocking in early Nov, but same general idea.  

Hey, that looks pretty good to me. Spread is obviously smoothing things way out on that panel but nothing scary showing up. 

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4 minutes ago, Bob Chill said:

During Nov/Dec the last thing we want is a delay because the state of the AO going into Dec can tell a large part of the story for how our winter is going to play out in the blocking dept. We want disruption and displacement as much as possible from now on. We've seen what a strong PV in Nov and Dec can do 3 years in a row. We need the opposite. 

What about early November?

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3 minutes ago, BTRWx said:

What about early November?

The behavior of the PV (strat and trop) during all of fall is an important indicator as to how strong it will be and also predominant location during winter. We've had multiple years of a pretty strong strat and trop PV during fall and blocking has been completely absent for the most part for all of those years. Any panel that shows a weakened PV or above normal heights in the AO/NAO domain space is a welcome sight at any time. 

The last year we had year blocking early in winter was 2010. This is the November h5 anomaly panel:

8Mlxwik.jpg

 

 

November isn't as important as December. December is the most important when it comes to anomalies in the AO/NAO regions. 

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20 minutes ago, Bob Chill said:

During Nov/Dec the last thing we want is a delay because the state of the AO going into Dec can tell a large part of the story for how our winter is going to play out in the blocking dept. We want disruption and displacement as much as possible from now on. We've seen what a strong PV in Nov and Dec can do 3 years in a row. We need the opposite. 

Weeklies out tonight. :weenie:

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1 minute ago, Bob Chill said:

The behavior of the PV (strat and trop) during all of fall is an important indicator as to how strong it will be and also predominant location during winter. We've had multiple years of a pretty strong strat and trop PV during fall and blocking has been completely absent for the most part for all of those years. Any panel that shows a weakened PV or above normal heights in the AO/NAO domain space is a welcome sight at any time. 

The last year we had year blocking early in winter was 2010. This is the November h5 anomaly panel:

8Mlxwik.jpg

 

 

November isn't as important as December. December is the most important when it comes to anomalies in the AO/NAO regions. 

It is possible I am just thinking about my region but  wasn’t 2010-2011 winter the winter where we had a lot of nickel and dime events and we ended up above average snowfall.

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5 minutes ago, Philadelphia Snow said:

It is possible I am just thinking about my region but  wasn’t 2010-2011 winter the winter where we had a lot of nickel and dime events and we ended up above average snowfall.

No, you guys had a big one at the end of January that was a real wet snow, plus you had Boxer Day.

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10 minutes ago, mitchnick said:

No, you guys had a big one at the end of January that was a real wet snow, plus you had Boxer Day.

without much more than that unfortunately

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13 minutes ago, mitchnick said:

No, you guys had a big one at the end of January that was a real wet snow, plus you had Boxer Day.

Btw it looks like I was thinking about 2013-2014 winter. Apparently it was phillys 2nd snowiest winter. I think that was the winter with the nickel and dime events. Seems like DC did well that winter too.

https://www.washingtonpost.com/news/capital-weather-gang/wp/2014/03/27/the-long-white-2013-2014-winter-bringing-snowy-back-to-the-d-c-region-season-statistics/?utm_term=.73f4a0b466af

 

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11 minutes ago, mitchnick said:

No, you guys had a big one at the end of January that was a real wet snow, plus you had Boxer Day.

That year really only missed with the boxing day debacle. I think we got screwed in Feb too but I try hard to forget that year. The one good storm we had I had the legit flu and was laying in bed wondering why god was punishing me. lol

I certainly wasn't comparing the years or using 10-11 as an analog. My post was strictly about blocking in general (as I'm sure most understood). 

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29 minutes ago, Bob Chill said:

The behavior of the PV (strat and trop) during all of fall is an important indicator as to how strong it will be and also predominant location during winter. We've had multiple years of a pretty strong strat and trop PV during fall and blocking has been completely absent for the most part for all of those years. Any panel that shows a weakened PV or above normal heights in the AO/NAO domain space is a welcome sight at any time. 

The last year we had year blocking early in winter was 2010. This is the November h5 anomaly panel:

8Mlxwik.jpg

 

 

November isn't as important as December. December is the most important when it comes to anomalies in the AO/NAO regions. 

I definitely agree that November and December patterns are key to most winter setups.  That 2010 November scenario leading into December and winter may have looked quite different if the time period of the torch over Greenland was earlier.

Blocking impacts for this region in November, December, and January are very different.

November 2010 500 mb first week.gif

 

November 2010 500 mb second week.gif

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19 minutes ago, Bob Chill said:

18z gefs still holding the look. I haven't picked up wxbell for the year yet so hopefully someone can recap the weeklies tonight. 

 

gfs-ens_z500aMean_nhem_12.png

Weather.us you wouldn't need wxbell

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8 hours ago, Bob Chill said:

 

The most important thing we need to come out of Nov with is a weak and/or displaced PV. We don't want a big blue ball destroying our hopes and dreams

 

Blue balls are the worst.

 

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You can already tell how much Weatherbell is falling apart without Ryan Maue. I went to check the weeklies and they aren't loaded right. Been seeing this with more and more maps on their site.

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6 hours ago, Bob Chill said:

18z gefs still holding the look. I haven't picked up wxbell for the year yet so hopefully someone can recap the weeklies tonight. 

 

 

As someone else has mentioned Wxbell has been somewhat rough so far. As far as the weeklies the only thing up at this point is temps. For the first 30 days it has a non-Nina look in the east with below temps through the gulf states into the southeast. Also has below temps in the Pac northwest for those 30 days. Last 15 days sees all of N America get flooded with warmth with the cold locked on the other side of the globe. Notable in the final two weeks is Greenland cools suggestive of a weakening of the -NAO to possibly a neutral state. Alaska and the Bering straits torch, ridging? We also see a warming and expansion over the polar regions throughout the 46 day period probably indicative of increasing heights. Overall look in the polar regions is probably indicative of a weakened PV displaced onto the other side of the globe. 

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GEFS didn't take long to flip to a warm look in the LR. lol. Model war opened up last night. GEFS buries a trough in the west with down stream ridge in the east d10. EPS is the opposite.

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5 hours ago, showmethesnow said:

As someone else has mentioned Wxbell has been somewhat rough so far. As far as the weeklies the only thing up at this point is temps. For the first 30 days it has a non-Nina look in the east with below temps through the gulf states into the southeast. Also has below temps in the Pac northwest for those 30 days. Last 15 days sees all of N America get flooded with warmth with the cold locked on the other side of the globe. Notable in the final two weeks is Greenland cools suggestive of a weakening of the -NAO to possibly a neutral state. Alaska and the Bering straits torch, ridging? We also see a warming and expansion over the polar regions throughout the 46 day period probably indicative of increasing heights. Overall look in the polar regions is probably indicative of a weakened PV displaced onto the other side of the globe. 

500 mb on the weeklies is finally out. Day 0-14 is pretty much on par with what we see with current guidance.

Day 14-21 Shows higher heights through southern Canada and most of the US except for the Pacific Northwest. Possible east based -NAO. Northern based +PNA through Canada into Alaska. Pretty much a zonal flow through the US with a slight hint of a trough setting up in the mid section of the country. Low to neutral heights are seen over the polar region for the most part.

Day 21-28 shows higher heights in the northeast. Higher heights dominate the upper latitudes for the most part on our side of the globe with what looks to also we a west based -NAO. A weak trough looks to setup in the midwest. There is a +PNA in Canada into Alaska undercut by bagginess in the southwest maybe indicative of a potential split flow/sub tropical jet.

Day 28-35 shows a trough setting up towards the southwest. Again a northern based +PNA, strong at that, being undercut by a -PNA. We also see high heights off the Atlantic coast suggestive of WAR (western Atlantic ridging). No sign of blocking to be seen central Canada eastward through Greenland with low heights seen east of Greenland. 

Day 35-46 sees once again a northern based +PNA undercut by a -PNA. Trough extending into the southwest. Higher heights on the east coast extending into the Atlantic. Some higher latitude higher heights but little sign of blocking. 

Day 39-46 sees a repeat on the west coast with the PNA. Also trough looks to extend towards the southwest again. We see higher heights dominate all of N America. We also have what looks to be a +NAO setting up.

The PV looks to stay disturbed/weak/elongated throughout with a slow shifting north to where we finally see it set up shop just this side of the pole extended down into eastern Russia.

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9 minutes ago, Powderboy413 said:

so basically weeklies looked garbonzo in the sense of high latitude blocking and ridging in eastern us

It isn't what I call awe inspiring that's for sure . :)

I am not sure I really buy what it is trying to sell us though  As early as day 11-18 the 500 mb mean is already showing a very flat and zonal pattern through the CONUS. This look would be indicative of a strong, straight as an arrow from Russia, Pac jet entering the west coast.  But when looking at the Euro at day 10 it shows another disruption and weakening of the jet creating huge waves in the flow in the central Pacific which should continue for some time. Not only that but to my eye it looks as if another disruption would probably occur several days after that as well. This can be seen on the GFS op runs that have been continually showing this follow up disruption. One other point is that a strong straight PAC  jet is normally a feature we see with a strong PV and at this point in time we have anything but. Now huge undulations impacting the west coast will normally not result in a zonal flow across the CONUS as seen in the weeklies but should instead produce pronounced waves in the flow (Troughs, ridges). 

I think what we may actually be seeing in the day 11-18 period of time is smoothing of all the different member solutions, canceling out each other to give the false impression of a flat flow. This can be seen quite well on the EPS on the progression from day 10 to 15 as the spread between members increases the flow increasingly takes on a flatter look. We also see the same thing occurring on the GEFS though not quite as pronounced. 

If in fact the day 10 Pac jet disruption occurs, and especially the follow up, I would not be surprised to see the flat zonal flow in the CONUS verify as something completely different for day 11-18. And of course that would more then likely effect the rest of the weeklies forecast.

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22 minutes ago, yoda said:

12z GFS at the end of its run is bringing in a huge arctic blast Day 15-16 into the Northern Plains

Your not kidding. Well below zero if correct. .lol

gfs_T850a_namer_53.png

The whole run is interesting...day 8-9 has a trough interacting with tropical moisture. Check this 700mb rh feed out.

700rh.conus.png

700rh.conus.png

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26 minutes ago, yoda said:

12z GFS at the end of its run is bringing in a huge arctic blast Day 15-16 into the Northern Plains

PV does some wild gyrating on this run and eventually drops an extension of the PV down into N Dakota and Minnesota. 

Edit. we see a ridge bridge from the Aleutians through the pole into Europe.

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