On WHY the pattern resembles La Nina winter 1950

[wxguy25]

The reason why the pattern resembles 1950 is b/c of the Position of the PAC warm pool. IF you go back and review the SSTA data from JAN 1950 you will notice that the CORE of the warm pool was between 140W and 180 DEG longitude.

http://www.wxguy.storm2k.org/temp/1950SSTA.bmp

Right now it’s centered near 150 W. this means that the ridge develops near the warm pool and forces the trough to pull back into the west. In highly amplified pattern when you have a trough in the west – basic wave physics tells you that you must have a strong ridge downstream of it over the EUS. UNLESS the NAO is negative.

A –NAO changes the game completely since it would act to suppress the height field along the east coast and keep the SE ridge from reaching extreme amplitude and prevent it from becoming a major factor. JAN 1969 was GREAT example. It was a SEVERE winter in the PAC NW w/ strong RNA pattern MOST of the winter. The PNA index averaged -2.1 in JAN 1969. BUT the NAO saved it for the east. Recall FEB had the Lindsay storm (20” in NYC) and a longer duration event along the New England coast.

http://www.wxguy.storm2k.org/temp/jan1969.bmp
http://www.wxguy.storm2k.org/temp/jan1969_2.bmp

Overall however 1968-69 was a strange winter given the fact that we had weak to moderate EL NINO going BUT the Pattern was more reminiscent of LA NINA w/ Anomalously weak Aleutian low and strong RNA pattern (Most likely the result of the NPAC SSTA configuration and PDO cycle).

http://www.wxguy.storm2k.org/temp/1969ssta.gif

The warm pool in JAN 1969 was much further west between JAPAN and 180 degrees longitude w/ pronounced cold pool in the GOA…like 2001-02 BUT notice the Atlantic SSTA configuration. CLEARLY inverted SSTA tripole supporting a –NAO. Although the warm pool in the central Atlantic is breaking down, we DO NOT have that inverted SSTA tripole right now. And until we get rid of the warm pool and develop the tripole, we will not have a predisposition toward a –NAO. JAN 1950 had a warm Atlantic but again, no defined tripole.

In other words we had the –NAO fending off the effects of the PAC SSTA configuration in 1969 we did not in 1950, and probably will not until the last week of JAN this year.

While some prefer 1950 as an analog to this JAN I have another year in mind which I used in my January outlook that IMO fits the pattern just as well if not better.

Wild card for the middle of the month is the new MJO which is heating up near 120 E.

[wxguy25]

And if -NAO does NOT develop by JAN 20-25 my outlook for JAN 15-30 will BUST.

[yoda]

And if -NAO does NOT develop by JAN 20-25 my outlook for JAN 15-30 will BUST.

I hope a -NAO does develop... I am looking for a good snow here... LOL.

[wxguy25]

And if -NAO does NOT develop by JAN 20-25 my outlook for JAN 15-30 will BUST.

I hope a -NAO does develop... I am looking for a good snow here... LOL.

It will, we just have to give it time. Don't worry though-- FEB should be MUCH better in the EUS.

You know I get the impression that a lot of folks are disappointed IF the winter does not start off strong and continue that way right to the end…LIKE 1986-87, 1995-96, 2002-03 etc. Fact of the matter is NOT EVERY WINTER can be or will be like those particular years. There are several GREAT winters in the EUS that started off crappy like this year, and had spectacular or in some cases HISTORIC finishes. 1957-58, (Nor easter in FEB, end of the winter event in MAR), 1992-93 (superstorm), 1993-94, 1996-97 (APR blizzard in SNE) just to name a few.

Everyone just needs to sit back and relax. Its only JAN 2. Not MAR 31!!!

[yoda]

And if -NAO does NOT develop by JAN 20-25 my outlook for JAN 15-30 will BUST.

I hope a -NAO does develop... I am looking for a good snow here... LOL.

It will, we just have to give it time. Don't worry though-- FEB should be MUCH better in the EUS.

You know I get the impression that a lot of folks are disappointed IF the winter does not start off strong and continue that way right to the end…LIKE 1986-87, 1995-96, 2002-03 etc. Fact of the matter is NOT EVERY WINTER can be or will be like those particular years. There are several GREAT winters in the EUS that started off crappy like this year, and had spectacular or in some cases HISTORIC finishes. 1957-58, (Nor easter in FEB, end of the winter event in MAR), 1992-93 (superstorm), 1993-94, 1996-97 (APR blizzard in SNE) just to name a few.

Everyone just needs to sit back and relax. Its only JAN 2. Not MAR 31!!!

Correct and good post Wxguy.

[Chris the Weather Man]

And if -NAO does NOT develop by JAN 20-25 my outlook for JAN 15-30 will BUST.

I hope a -NAO does develop... I am looking for a good snow here... LOL.

It will, we just have to give it time. Don't worry though-- FEB should be MUCH better in the EUS.

You know I get the impression that a lot of folks are disappointed IF the winter does not start off strong and continue that way right to the end…LIKE 1986-87, 1995-96, 2002-03 etc. Fact of the matter is NOT EVERY WINTER can be or will be like those particular years. There are several GREAT winters in the EUS that started off crappy like this year, and had spectacular or in some cases HISTORIC finishes. 1957-58, (Nor easter in FEB, end of the winter event in MAR), 1992-93 (superstorm), 1993-94, 1996-97 (APR blizzard in SNE) just to name a few.

Everyone just needs to sit back and relax. Its only JAN 2. Not MAR 31!!!

Yep..... Agreed 100%..... A little history here, March 31-April 1st 1997, Mass got over 30" of snow....... By the way, you won't bust, you are too good..............

[dvdweatherwizard]

For reference, here is the map for the mean 500 mb heights during January 1950. Right off the bat, you can see at least some similarities with the big ridge in the Alaska vicinity, the rather large Polar Vortex in northern part of Canada, and the ridge in the vicinity of the southeastern states.



The 12Z January 2nd map from this year is posted below.




Of course, the match is far from precise, and it never will be precise in an analog, but after looking at these two maps, I can sort of see why people keep bringing up January 1950 as a POSSIBLE analog at least. Also, keep in mind that the top map is a MEAN of an ENTIRE month, and the map below that is a snapshot from a single time.

[wxguy25]

AND its the ensemble mean.

[dvdweatherwizard]

AND its the ensemble mean.

Yeah, that's true. The bottom is the ensemble mean at the 00 hr initialization time of 12Z on January 2nd. Should I not have picked the ensemble mean to show? I didn't think it really mattered much whether I picked the real model or the ensemble mean since it was at the initialization time. I wasn't really even paying attention to which one I was picking at the time. I was trying to find a map that showed the entire Pacific, Atlantic, and U.S. mainland like the top map did.

[wxguy25]

AND its the ensemble mean.

Yeah, that's true. The bottom is the ensemble mean at the 00 hr initialization time of 12Z on January 2nd. Should I not have picked the ensemble mean to show? I didn't think it really mattered much whether I picked the real model or the ensemble mean since it was at the initialization time. I wasn't really even paying attention to which one I was picking at the time. I was trying to find a map that showed the entire Pacific, Atlantic, and U.S. mainland like the top map did.

thats alright it really doesn't matter. its just that one or two of the ensemble members can skew the mean. But thats another issue for another time.

Here is the 12z ECMWF initial -- GLOBAL view.

[dvdweatherwizard]

Ah, I like your image much better because it's color filled, which is consistent with my top image, and I think it's easier to read than my bottom image. Plus, I have heard rumblings that the ECMWF produces a better initialization dataset anyway, and I completely forgot about that when I posted my maps.

[wxguy25]

Ah, I like your image much better because it's color filled, which is consistent with my top image, and I think it's easier to read than my bottom image. Plus, I have heard rumblings that the ECMWF produces a better initialization dataset anyway, and I completely forgot about that when I posted my maps.

Better...that is a GROSS understatement. And beats the OP GFS. Especially tonight when the GFS had NO Mexican raobs in for the run. anytime that happens w/ the NCEP models I would toss the run. Wait til 12z.

[dvdweatherwizard]

Ah, I like your image much better because it's color filled, which is consistent with my top image, and I think it's easier to read than my bottom image. Plus, I have heard rumblings that the ECMWF produces a better initialization dataset anyway, and I completely forgot about that when I posted my maps.

Better...that is a GROSS understatement. And beats the OP GFS. Especially tonight when the GFS had NO Mexican raobs in for the run. anytime that happens w/ the NCEP models I would toss the run. Wait til 12z.

Haha, yeah you're right.