The Winter 2010-11 NYC/PHL Medium Range Thread

[phlwx]

12z euro at day 10 is better than 0z. Brings some cold air in, but no where near to the level as the gfs does. the t giving storm or weekend threat on the euro is a lake cutter, cold air follows behind. Euro Has an east and semi west based nao. Se ridge is still around but is squashed a little. Also has a GOA low, which to means what ever cold that comes east will be pretty transient. The pna looks neutral.

Cold air is just ten days away (again) on the Euro. Really winds things up with the 2nd storm for Friday into Saturday.

Not a good look to the pattern...looks like cold continues to remain west/central while the southeast has ridging.

The troughing is not very deep...north Pacific tends to blast any troughiness away in the East that tries to pop up.

Continues to support the "transient" and "variable" pattern I've been talking about.

[Guest Kramer]

Don't forget, there was a time when the GFS was indicating that EXACT setup for 11/17 and then for 11/23 and look where the trough IS/WILL ultimately wind up for those two dates.

Two ways to look at that

1) GFS rushing the pattern

2) GFS model bias/noise

I am sure most of us hope its #1

[phlwx]

Two ways to look at that

1) GFS rushing the pattern

2) GFS model bias/noise

I am sure most of us hope its #1

3) GFS s/e cold bias (a classic DT talking point).

[Guest Kramer]

Cold air is just ten days away (again) on the Euro. Really winds things up with the 2nd storm for Friday into Saturday.

Not a good look to the pattern...looks like cold continues to remain west/central while the east has ridging.

The troughing is not very deep...north Pacific tends to blast any troughiness away in the East.

Continues to support the "transient" and "variable" pattern I've been talking about.

Euro is starting to become a lone ranger, especially against its own ensembles, I would be careful of that.

In regards to the troughing not being deep, nope, not gonna get that with a -PNA, but look very carefully as the PNA begins to slide neural +, as that can be a good ingredient for storms in the east, especially with big swings from deeply neg.

Lastly, if the -NAO sets in and gets west, I don't think the pattern is a transient as you make it out to be. Iit should be plenty cold and stormy for a siginificant amount of time.

Of coruse, this is assuming the NAO is real and gets west based. That is the fun of it all thought, right?

[Guest Kramer]

3) GFS s/e cold bias (a classic DT talking point).

well, isn't that #2? bias?

Yes, DT has lots of talking points, some good, some bad.

[tombo82685]

whats killing us is the pna, and anytime you have goa lows, the pna is not going to go pos.

[SnowGoose69]

Two ways to look at that

1) GFS rushing the pattern

2) GFS model bias/noise

I am sure most of us hope its #1

Its likely a combination of both....there is going to be some sort of colder period in the East if these NAO and especially AO number predictions are correct but it may be short lived.

[tombo82685]

Anyone have a verification score for the gfs compared to the euro in the 8-10 day range?

[MJO812]

12z Euro

Timberrrrrrrrrrrrrrrrrr

[jrodd321]

12z Euro

Timberrrrrrrrrrrrrrrrrr

Yea, but from what Tom is saying it sounds like it doesn't even matter that the NAO is severely negative. Still no cold.

[tombo82685]

12z Euro

Timberrrrrrrrrrrrrrrrrr

Is this sht euro or the ens? If its the euro it looks nice, but what you really need to determine is is west vs east. Im pretty sure all the forecasts don't decipher that, and what looks like an insane nao could be an insane east based nao.

[Guest Kramer]

Euro ensembles look A LOT like GFS OP and Ensembles. Could be EURO suffering from model bias or having trouble with the abrupt pattern change.

So nice to have winter and model tracking back!

[MJO812]

Yea, but from what Tom is saying it sounds like it doesn't even matter that the NAO is severely negative. Still no cold.

looks nice, but what you really need to determine is is west vs east. Im pretty sure all the forecasts don't decipher that, and what looks like an insane nao could be an insane east based nao.

West based Nino would be good.

Anyway, the Euro ensembles are a lot colder than the op. They look like the GFS.

[phlwx]

Anyone have a verification score for the gfs compared to the euro in the 8-10 day range?

Last I saw Euro wins day 8, GFS edges the Euro on Day 10 but both models are scoring less than .500 at day 10.

[tombo82685]

Yea, but from what Tom is saying it sounds like it doesn't even matter that the NAO is severely negative. Still no cold.

John, the 12z euro's nao is mainly east based. Highest heights are over greenland. For west based you need that back towards baffin island. Secondly, the pacific on the euro just looks blah, no pos pna to really dig the trof down stream. Its pretty much flat.

[tombo82685]

Just for shats and giggles to show the difference between the euro and gfs on the cold. Lowest hgt anomaly in the US is 520, on the gfs at the same time period is 506. Gfs has the lowest hgts over the great lakes, while the euro is over the north central US. Gfs has 514 hgts over phl at hr 240, while euro is 550.... Doesn't the euro also have a bias of holding trofs to long in southwest? Another pretty good difference between the euro and gfs is the gfs has a pretty decent ridge out west, while the euro is flat.

[earthlight]

John, the 12z euro's nao is mainly east based. Highest heights are over greenland. For west based you need that back towards baffin island. Secondly, the pacific on the euro just looks blah, no pos pna to really dig the trof down stream. Its pretty much flat.

12z ECMWF Ensembles are pretty encouraging especially towards the 26-27th with a robust block over Greenland. The PV drops into SE Canada with a trough over the Aleutians and some higher heights over the Western US.

[Chris L]

A West Based Negative -NAO IS more ideal than an East based -NAO, to allow the heights over Northern Canada, rather direcetly on Greenland.

Several examples (February '10) had a west based -NAO (Right?)

[Chris L]

Let's not all get bent out of shape about it now.

I do think December will be a good month for snow...

Now Joe Bastardi on the other hand.....

[SnowGoose69]

A West Based Negative -NAO IS more ideal than an East based -NAO, to allow the heights over Northern Canada, rather direcetly on Greenland.

Several examples (February '10) had a west based -NAO (Right?)

For whatever reason the last 5 years or so the NAO when its been negative has had a pronounced tendency to be east based vs. west....I'm not sure why this has been occurring but its been a notable trend for sure.

[Guest Kramer]

A West Based Negative -NAO IS more ideal than an East based -NAO, to allow the heights over Northern Canada, rather direcetly on Greenland.

Several examples (February '10) had a west based -NAO (Right?)

East based /west based is the hot topic right now so lets talk objectively about it. First all of, I think we would do best with putting down the cute blue maps from Raleigh weather. Take the time to look at 500MB charts themselves from the actual model runs. Just because you have more +height anomolies east of greenland doesnt mean you the NAO is east based and thus non productive. Look at the GFS 12zOP today. The block actually is quite expansive. Just because the highest of heights arent west of greenland doesnt mean its not a west based block. Sure, it can be MORE west based, but that is a nice block showing up and will do just fine. You can clearly see the + heigh anomolies from the davis strait back to the east of greenland and even out in the western atlantic. That is more than sufficient. The big problems come with a western atlantic ridge or truly east based block which never gets onto and past greenland in anyway and instead is centered to the right back up towards iceland and europe.

Now, in regards to Feb 2010, it started out VERY east based and then did eventually come west, so it was a hodge podge.

[NJwinter23]

I posted this in the obs thread but it was probably more fitting here. I wanted to know what you guys think about the way this article is layed out. I'm trying to make it understandible for the non-meteorologists (friends and family) that have been reading my articles and not take away too much from the more scientific way we discuss things around here. Would appreciate any feedback.

http://www.examiner.com/weather-in-newark/cool-conditions-friday-through-sunday-give-way-to-warm-beginning-to-turkey-week

main link to all articles is in my sig.

[tombo82685]

East based /west based is the hot topic right now so lets talk objectively about it. First all of, I think we would do best with putting down the cute blue maps from Raleigh weather. Take the time to look at 500MB charts themselves from the actual model runs. Just because you have more +height anomolies east of greenland doesnt mean you the NAO is east based and thus non productive. Look at the GFS 12zOP today. The block actually is quite expansive. Just because the highest of heights arent west of greenland doesnt mean its not a west based block. Sure, it can be MORE west based, but that is a nice block showing up and will do just fine. You can clearly see the + heigh anomolies from the davis strait back to the east of greenland and even out in the western atlantic. That is more than sufficient. The big problems come with a western atlantic ridge or truly east based block which never gets onto and past greenland in anyway and instead is centered to the right back up towards iceland and europe.

Now, in regards to Feb 2010, it started out VERY east based and then did eventually come west, so it was a hodge podge.

according to will, you want the highest height anomalies around the baffin island region/davis straights and even back towards hudson bay. East based is eastern greenland to iceland.

[Guest Kramer]

according to will, you want the highest height anomalies around the baffin island region/davis straights and even back towards hudson bay. East based is eastern greenland to iceland.

that is IDEAL for the nyc area, but that is often the END of a block (typical KU setup where one of the indexes goes + to - or vice versa). What I am saying is that a west based block doesn't have to be what you are describing, which is basically the ideal block, or a straits block.

Agree as to the eastern description, and is what I describe above.

[phlwx]

http://www.meteo.psu.edu/~gadomski/ECMWF_12z/test8.gif

One of the big differences is the trough alignment near Newfoundland. The depth of the trough in Newfoundland and in the Western US is forcing a SE ridge to pop in between the two troughs on the EURO. The GFS solution is a broader based trough.

IF the Euro is holding back energy in the SW then the GFS may be more correct. We also have to factor the GFS bias of suppression, which means the EURO may be a bit more right.

Splitting the difference between the two means the pattern won't be "ideal" for cold and snow...it's a total needle thread, which it normally is around here.

[tombo82685]

that is IDEAL for the nyc area, but that is often the END of a block (typical KU setup where one of the indexes goes + to - or vice versa). What I am saying is that a west based block doesn't have to be what you are describing, which is basically the ideal block, or a straits block.

Agree as to the eastern description, and is what I describe above.

well aren't we talking about that, an ideal setup? We want something that is going to be favorable for a snowstorm to lock in the cold from nyc south....

[Guest Kramer]

well aren't we talking about that, an ideal setup? We want something that is going to be favorable for a snowstorm from nyc south....

IDEAL is rare, I think the point I was trying to make is we don't need ideal to get snow, even at the end of November.

Certainly as you get deeper into the winter less than ideal works more times than not, a good example, Feb 06. NAO just got enough west based with a just barely good enough 50/50. Most certainly that setup would NOT work earlier in the winter.

I am NAO'ed out....LOL.

[tombo82685]

IDEAL is rare, I think the point I was trying to make is we don't need ideal to get snow, even at the end of November.

Certainly as you get deeper into the winter less than ideal works more times than not, a good example, Feb 06. NAO just got enough west based with a just barely good enough 50/50. Most certainly that setup would NOT work earlier in the winter.

I am NAO'ed out....LOL.

hahahaha yea i see what your saying...

[tombo82685]

timberrrr on both indices. Something tells me its going to be like pulling teeth to get that pna pos this winter.

[Manny]

From the basis of this discussion, we need a west based -NAO for some pronounced cold, and hopefully a good setup for some early snows, as the GFS OP, Ens, and Euro Ens is showing.