N. Pacific Warm Pool Effects On Fall/Winter 2014-15

[wildweatherman179]

Should it persist, the anomalous warmth in the North Pacific which had great effects on winter in the midwest, east central US, southern US, and the Northeast in winter 2013-14, could cause even more tremendous effects on winter in 2014-2015. I would like to know anyone's thoughts for or against this concept. I feel very strongly that when coupled with El Niño, regardless of strength, that the eastern 2/3 of the nation could be in for a crazy and extreme winter as far as snowfall and bitter cold are concerned. Possibly more so than last winter. I'd like to hear any thoughts whether in agreement or disagreement with what I think. Thanks!

[Kory]

Like you said, should it persist, repeated arctic cold shots along with an active subtropical jet across the Southern/Eastern U.S. should lead to some winter wonderland fun.  

 

But there's a caveat, the CFSv2 shows the North Pacific warm pool waning by the Dec/Jan/Feb period.  We shall see...

[wildweatherman179]

Right. I understood that there was some guidance suggesting that it would dissipate, however, there was also the same thought last season. That is definitely a wild card though. I have never found a year where the N pac is warm with a moderate el nino to look at as an analog. You know of any years off the top of your head?

[Kory]

I can only find SST anomaly maps that date back to 1996.  I looked at the 1997/1998, the 2002/2003, and 2009/2010 El Ninos.  Granted, the 1997 was a super Nino and the 2002/2009 were moderate Modoki Ninos.  With that being said, I'm only going to look at the data for the 2002 and 2009 Ninos, which are more in line with what we're experiencing this year.  2009 had a noticeable warm pool in the north Pacific, but 2002 didn't.  

 

 

 

But the warm pool had dissipated just a few months later.  

 

 

This is currently...looks very similar to 2009 at this time. 

 

[wildweatherman179]

Well, I may still be on to something because looking back at climate data, 2009-10 ranked as the 5th coldest winter in much of Northeast Oklahoma and probably much of the midwest/eastern US. I'll have to keep looking. Thanks for the info!

[EricHaley]

What effect, if any, does this have on the severe weather we've been experiencing lately?

[wildweatherman179]

What effect, if any, does this have on the severe weather we've been experiencing lately?

I would think mostly just causing amplification of the southern jet stream. Causing air pressure gradients, things like that unless someone can explain it more clearly than I can.

[wildweatherman179]

Is El Niño dying? The warm water in the NPAC is still holding strong. Looks like if we have el nino it may form too late to be of much value. Liking the warm waters off the west coast of Mexico but who knows if they'll last til fall or not. I still think a good to great winter is in the cards but basing a winter forecast completely on the presence of el nino or el nothing will cause a lot of busts this year in my opinion. Just my thoughts for the day. Now back to enjoying the rare July cold front. :-) Hard to have a cold front in July and not think of winter though. Lol

[wildweatherman179]

I guess now the general consensus is for the NPAC to remain anomalously warm throughout the winter of 2014-15. This serves as reinforcement of the thought that the north central, eastern, and south central parts of the US should remain in a cold (and in some cases extremely cold) state relative to average throughout the winter. Just thought I would add this as it is relevant to this topic. Numerous analogs are appearing that relate to some of the coldest winters recorded in nearly 100 years. (1917-18 and 1911-12) While in weather, nothing is guaranteed as we all know. However, it serves a person well to take notice of this distinct possibility.

As they say in Game of Thrones, "Winter is coming". :-)

[wildweatherman179]

A flip to cold neutral or Nina even is not out of the question yet as forecasters lower the chance of el nino to 50 percent. A late flip to either of the above states for the Pacific could cause forecasters some grief. Wasn't completely sold on there being a Nino anyway so my hopes aren't crushed yet. 1917-18 analog for winter is still holding.

[Quixotic1]

A flip to cold neutral or Nina even is not out of the question yet as forecasters lower the chance of el nino to 50 percent. A late flip to either of the above states for the Pacific could cause forecasters some grief. Wasn't completely sold on there being a Nino anyway so my hopes aren't crushed yet. 1917-18 analog for winter is still holding.

It's not done yet. MJO looks like it might be getting it's act together and another down welling KW seems imminent. Forecasts I've seen at the CPC still say 80% for winter.

[wildweatherman179]

It's not done yet. MJO looks like it might be getting it's act together and another down welling KW seems imminent. Forecasts I've seen at the CPC still say 80% for winter.

We'll see. I don't really get too excited about what the CPC has to say. Don't get me wrong, I do really hope a Nino develops but it's hard to see it happening at this time.

[Srain]

It's not done yet. MJO looks like it might be getting it's act together and another down welling KW seems imminent. Forecasts I've seen at the CPC still say 80% for winter.

I tend to agree. We will need to wait until September/October to see how things actually develop. The 2009 analog that Kory posted is interesting, but I suspect we could look a bit further back into the 80's and even the 60's to see some similarities. That said the Gulf of Alaska warm pool has certainly played a big role in the recent rains across the Rockies into the Plains and on E. If that trend continues into the Fall and Winter months, our friends in California and the Desert SW may be in a world of hurt unless we start seeing re-curving  EPAC TC's that would assist with the long term drought across Southern California into Arizona. The Monsoon season has been a bit further E across Eastern Arizona into New Mexico this summer.

[Quixotic1]

Unfortunately for the west the recent tendency towards Modoki or West-Based El Ninos means less chance of the old fire hose or Pineapple Express.  In the words of HM, they may need a "La Nina that acts like an El Nino" (a la December 2010) to get some relief. 

 

It appears that the eastern fringes of the drought region appears to be heading back west.

[wildweatherman179]

The waters in the GOA/NPAC are getting warmer by the day. I think they will hold. Looks as good as last year. :-)

[wildweatherman179]

http://www.ospo.noaa.gov/data/sst/anomaly/2014/anomp.8.18.2014.gif

Doesn't get much more beautiful than this.

[Kory]

http://www.ospo.noaa.gov/data/sst/anomaly/2014/anomp.8.18.2014.gif

Doesn't get much more beautiful than this.

Don't forget about the warmer SST up by Greenland.  May help enforce a -NAO.

 

[nzucker]

Don't forget about the warmer SST up by Greenland.  May help enforce a -NAO.

 

 

The SST pattern is about as favorable as it gets for winter weather lovers in the East and Midwest. We've got an extremely warm Gulf of Alaska, cooler waters near the Aleutians, and a weak El Nino. You'd think the predominant pattern would be a prevailing Aleutian low, with a +PNA/EPO and a trough east of the Mississippi. Just as Bastardi said, this should place the core of the cold further east than last winter, when the greatest negative anomalies were over Minnesota and the Upper Great Lakes, and less extreme cold given a warmer Canada and globe. 

 

On the Atlantic side, warm waters near Greenland are favorable, and we have a near tripole configuration with some remnant of the Newfoundland cold pool essentially to maintaining a -NAO and favorable storm track. I'd like to see a bit more pronounced cold anomaly in the north-central Atlantic to exaggerate the tripoler/-AMO, but it's not terrible right now.

 

However, SST are just one factor among many. We have to wait to see the autumn snow cover and NAO state. And how much snow can you get in Tuscaloosa anyway?

[wildweatherman179]

The SST pattern is about as favorable as it gets for winter weather lovers in the East and Midwest. We've got an extremely warm Gulf of Alaska, cooler waters near the Aleutians, and a weak El Nino. You'd think the predominant pattern would be a prevailing Aleutian low, with a +PNA/EPO and a trough east of the Mississippi. Just as Bastardi said, this should place the core of the cold further east than last winter, when the greatest negative anomalies were over Minnesota and the Upper Great Lakes, and less extreme cold given a warmer Canada and globe.

On the Atlantic side, warm waters near Greenland are favorable, and we have a near tripole configuration with some remnant of the Newfoundland cold pool essentially to maintaining a -NAO and favorable storm track. I'd like to see a bit more pronounced cold anomaly in the north-central Atlantic to exaggerate the tripoler/-AMO, but it's not terrible right now.

However, SST are just one factor among many. We have to wait to see the autumn snow cover and NAO state. And how much snow can you get in Tuscaloosa anyway?

I don't really care much about Tuscaloosa personally. Pretty much just the Ozark Plateau. Personally I think the southeast gets ridged out of a lot of the fun this winter except for maybe a front or 2 in hard winter that can break it down. That shifts the southernmost parts of the cold air south and west of where some think it will be. With a Greenland block in place it would be almost a guarantee to shift it west in my opinion. The next 40 days is incredibly important as far as patterning and ssts go but I'm seeing a probability of ridging the southeast now quite a bit. Just a thought.

[nzucker]

I don't really care much about Tuscaloosa personally. Pretty much just the Ozark Plateau. Personally I think the southeast gets ridged out of a lot of the fun this winter except for maybe a front or 2 in hard winter that can break it down. That shifts the southernmost parts of the cold air south and west of where some think it will be. With a Greenland block in place it would be almost a guarantee to shift it west in my opinion. The next 40 days is incredibly important as far as patterning and ssts go but I'm seeing a probability of ridging the southeast now quite a bit. Just a thought.

If you look at Bastardi's maps, he does indeed have the deepest cold air from the Southern Lakes towards the Mississippi/Tennessee Valley, with anomalies of -4F for the winter...most of the Southeast and Lower Mid-Atlantic is in the -2F anomaly area. This would indicate a storm track that's not purely El Nino...more of a hybrid with some Colorado Lows and Lakes Cutters that can favor areas like Arkansas, Missouri, etc while the SE Ridge keeps Dixie as rain. 

 

One thing that matters is the exact placement of the PNA/western ridge. If the ridge is placed further west towards Alaska/BC then you have the pattern of last winter where the GoA ridge teleconnects to a Midwest trough and then a bit of a West Atlantic ridge, limiting the penetration of the cold air into the Southeast and Lower Mid Atlantic. A 2013-14 winter was great for NYC, great for Chicago, but not as great for Atlanta as say 2009-2010 or the beginning parts of 10-11 when we had the giant block in December 2010. 

 

Opposite to what you say, a classic Greenland block (-NAO) brings the lowest heights into the Southeast or off the Southeast coast in the West Atlantic. That's how the NAO is defined at the surface: it's a reduction of the gradient between the Azores High and the Icelandic Low, meaning that 500mb heights over the Atlantic Ocean are lower than normal whereas heights over Greenland and Iceland are higher than normal, reversal the normal pattern. You can see in December 2010 that a powerful Greenland block leads to deep troughing over the Southeast:

[wildweatherman179]

I understand where I was wrong on the Greenland blocking/-NAO stuff. I guess the problem for me is there doesn't seem to be a concrete correlation in my mind as to exactly what it does. I've learned to watch the indexes but the correlation to what does what is not really as important here as it is on the east coast in my opinion.

[Kory]

The SST pattern is about as favorable as it gets for winter weather lovers in the East and Midwest. We've got an extremely warm Gulf of Alaska, cooler waters near the Aleutians, and a weak El Nino. You'd think the predominant pattern would be a prevailing Aleutian low, with a +PNA/EPO and a trough east of the Mississippi. Just as Bastardi said, this should place the core of the cold further east than last winter, when the greatest negative anomalies were over Minnesota and the Upper Great Lakes, and less extreme cold given a warmer Canada and globe. 

 

On the Atlantic side, warm waters near Greenland are favorable, and we have a near tripole configuration with some remnant of the Newfoundland cold pool essentially to maintaining a -NAO and favorable storm track. I'd like to see a bit more pronounced cold anomaly in the north-central Atlantic to exaggerate the tripoler/-AMO, but it's not terrible right now.

 

However, SST are just one factor among many. We have to wait to see the autumn snow cover and NAO state. And how much snow can you get in Tuscaloosa anyway?

It ain't much and when it does fall, it usually melts a few hours later.  The one thing about 2013/2014 was the number of events we had and the duration.  The Snowmageddon in late January dropped about 2" but it stuck around for about 36-48 hours.  Same with the mid February event.  We had an overrunning event that dropped freezing rain, a switch to rain, back to freezing rain, and then finally to all snow in about a 36 hour event.  It was certainly the most snow I've seen there.  

 

If you look at Bastardi's maps, he does indeed have the deepest cold air from the Southern Lakes towards the Mississippi/Tennessee Valley, with anomalies of -4F for the winter...most of the Southeast and Lower Mid-Atlantic is in the -2F anomaly area. This would indicate a storm track that's not purely El Nino...more of a hybrid with some Colorado Lows and Lakes Cutters that can favor areas like Arkansas, Missouri, etc while the SE Ridge keeps Dixie as rain. 

 

One thing that matters is the exact placement of the PNA/western ridge. If the ridge is placed further west towards Alaska/BC then you have the pattern of last winter where the GoA ridge teleconnects to a Midwest trough and then a bit of a West Atlantic ridge, limiting the penetration of the cold air into the Southeast and Lower Mid Atlantic. A 2013-14 winter was great for NYC, great for Chicago, but not as great for Atlanta as say 2009-2010 or the beginning parts of 10-11 when we had the giant block in December 2010. 

 

Opposite to what you say, a classic Greenland block (-NAO) brings the lowest heights into the Southeast or off the Southeast coast in the West Atlantic. That's how the NAO is defined at the surface: it's a reduction of the gradient between the Azores High and the Icelandic Low, meaning that 500mb heights over the Atlantic Ocean are lower than normal whereas heights over Greenland and Iceland are higher than normal, reversal the normal pattern. You can see in December 2010 that a powerful Greenland block leads to deep troughing over the Southeast:

 

Bingo!  Last year the pattern was very progressive.  The cold was rarely locked in.  We'd get frigid (by Southern standards) for about 2-3 days then a moderation.  We were missing the Greenland block.  The highlight of last winter was how cold it got, but not the duration.  

[Quixotic1]

I understand where I was wrong on the Greenland blocking/-NAO stuff. I guess the problem for me is there doesn't seem to be a concrete correlation in my mind as to exactly what it does. I've learned to watch the indexes but the correlation to what does what is not really as important here as it is on the east coast in my opinion.

It helps even as far west as our part of the country.  It's just not as essential. 

 

That said, I think a tendency towards a -NAO is likely if the sun stays quiet.