El Nino's Impact on the Coming Chase Season

[Bob Hartig]

The CPC's December 21 update of their ENSO report makes it clear that the present El Nino is intensifying, with sea surface temperatures now averaging 1.2 C above normal in the eastern Pacific.

Now, I am no climatologist, but I do take an interest in the potential impact of this El Nino on the upcoming storm season. So the charts depicting projected sea surface temperatures caught my eye.

I've tried copying those charts here, but my skills with Photoshop are lame, and having screwed around with it a bit, I'm afraid that by the time I finished reducing the graphics to the point where they meet ST filesize regulations, the images would be meaningless. So instead, I'll steer you to page 28 of the above link.

In a nutshell:
* Panels 3 and 4 (March-May and April-June) show above-average SSTs in the eastern Pacific, pooling significantly off of Baja.
* Slightly lower-than-average temps preside in most of the GOM.
* Panel 5 (May-July) shows warmer temperatures finally moving toward the coast of the GOM.
* With the June-August map, the GOM seems to be in good shape, and the SSTs off of Baja appear to be breaking down.

What I make of this picture is that subtropical moisture from the southwest (i.e. the subtropical jet) may play a bigger-than-usual role in the springtime weather, while Gulf moisture return may be delayed. That's not a very promising scenario for this coming storm season.

Again, I am NOT a climatologist, and all of the above is just my clumsy attempt to piece together stuff I'm aware of but don't really understand. I was initially excited to think that this present El Nino would remove drought from the moisture fetch equation this spring, but now I'm not sure that we may not wind up with other concerns on our hands.

More knowledgeable heads than mine are free to correct me. I'm not attempting to make a long-term prognosis here so much as I'm looking to understand the big picture. Believe me, I won't mind in the least being shown why I'm wrong.

 

[Matt Gingery]

I am neither an expert in climatology nor meteorology but I did sleep at a Holiday Inn last night and this is my 2 cents worth. Looking at the line graph it shows the position we were in during this past spring, as well as looking into the future at the projections for this spring. It would seem to me that we have hit a peak on the current El Nino with a downswing in SST's progged for the prime time chase period. There is a +1-1.5 C swing in temp from last year to the forecast for this coming spring. Moisture return last year was one for the books. It was non-existent for much of May. May 15 it seemed the Death Ridge settled in and it was over until the first of June. NW UA flow was the norm. That being said, I can not imagine this season being worse than last. It should play out as a typical El Nino year, "Very Unpredictable". Looking at the trend towards SST cooling would lead me to believe that the subtropical jet would be more of a player this season "Glass Half Full". I did a student write up on the effects of El Nino/La Nina on our MSU website http://msustormchase.ning.com/profiles/blogs/variations-in-active-tornado. If you compare with the NOV 1997 El NIno, and the FEB 1999 La Nina it could be a hint of things to come. Large swings, i.e. extremes can have a + and - effect on our climate. We could be trending towards a strong La Nina with 2010 being a transition year. 1998 was a transition year and a record year for Tornadoes. Should turn out to be much more successful this coming spring. Great thread discussion. We need some climatoligists to chime in on this.

 

[Adam Lucio]

2003 was an el nino spring and it was very active for the midwest area. Just because the plains wont be in the hot spot doesn't mean the season will be a wash. I agree nothing can be worse than last year. If we look at what el nino has done recently it has spun up some very intense and moist storms systems. 3 total in the month of December.

I would certainly be in favor of one of these monsters spinning up in the spring time. My un-expert opinion would think that with the more intense southern stream we certainly won't have issues with shear profiles, although this means probably allot of rocket storm motions as well.

Its fun to speculate...but I doubt anyone can say with any degree of certainty. If anything it will be another year in which we continue to study the correlation between el nino and the weather patterns.

 

[Greg McLaughlin]

2003 was an el nino spring and it was very active for the midwest area. Just because the plains wont be in the hot spot doesn't mean the season will be a wash.

I think every chaser out there would take another Ten Days of May like what we saw in 2003. Of course it would be nice to not have the fires in South America this time around.

 

[Mike Smith]

This is germane to the discussion: http://meteorologicalmusings.blogspot.com/2009/12/above-normal-early-winter-snow-cover.html

Mike

 

[Andrew Pritchard]

This is germane to the discussion: http://meteorologicalmusings.blogspot.com/2009/12/above-normal-early-winter-snow-cover.html

Mike

It's funny to note the above normal snow cover, as two weeks ago me and a few others were just discussing the overall LACK of a snow cover in North America. How quickly things change, shows how little I want to try guessing what things will be like in May.

 

[Chris Hayes]

Someone made mention of how 2003 was a great year for the midwest. Anyone have info on the drought situation in 2003? How bad was the drought in OK, KS, and TX? If things continue like this theres no way there'll be a drough situation in those states during our favorite time of year. That would keep the dry ling pulled back a lot further west than in 2003.

 

[Mike Smith]

Here is the December, 2002, Palmer Drought Index: www.ncdc.noaa.gov/img/climate/research/2002/dec/phd200212_pg.gif

Here is the May, 2003, Palmer Drought Index:
www.ncdc.noaa.gov/img/climate/research/2003/may/zin200305_pg.gif

As you can see, it is far wetter now than than it was seven years ago at this time. That would indicate that storms will develop farther west in 2010 if this pattern continues.

 

[Bob Hartig]

Its fun to speculate...but I doubt anyone can say with any degree of certainty. If anything it will be another year in which we continue to study the correlation between el nino and the weather patterns.

I agree that about all we can do is speculate, and I think it's helpful that you've mentioned this up front, Adam, due to the nature of this thread. It's the kind that invites comments about such speculation being pointless because, ultimately, we'll find out what's going to happen when it happens, and not until then.

True enough if we're talking about nothing more than crystal ball gazing, and I think most folks who've been on ST for any length of time understand that. But if the purpose is to better understand the atmosphere--specifically, as Adam put it, "the correlation between El Nino and the weather patterns"--then what we're really talking about is observing, and processing, seeing which of our personal reasonings bear out and which fall flat, and hopefully learning a little bit more.

Besides, it's human nature to speculate, particularly when the snow's flying. It sure as heck beats shoveling.

 

[Richard Dickson]

This is germane to the discussion: http://meteorologicalmusings.blogspot.com/2009/12/above-normal-early-winter-snow-cover.html

Mike

"However, there is some good news here: There is no widespread severe drought anywhere in the contiguous United States."

I find the last paragraph of the article to be interesting. I suppose the optimum word is 'widespread', but according to the NWS in Tucson, almost all of Arizona is covered by a severe drought as shown on this link. However, one of the charts within the link is predicting a significant improvement prior to the end of March, 2010.
http://www.wrh.noaa.gov/twc/climate/seazDM.php

 

[Mike Smith]

Here is more information on the topic. Scroll down to see the correlation between El Ninos of the current intensity and ICT spring rainfall:

http://meteorologicalmusings.blogspot.com/2009/12/above-normal-early-winter-snow-cover.html

Mike

 

[Jonathan Behle]

I've always thought El Nino and La Nina are a bit over hyped in terms of severe weather. Yes they do influence the overall pattern, but in terms of something as complicated as very micro or localized super cells and chasing, I just cant blame or praise El Nino..

With that said, some interesting trends I am noticing this winter so far are that storms are really increasing in intensity as they get into Eastern areas of the Plains and Midwest. Areas like Iowa have seen some very impressive and deep Low Pressures and amazing gradients. If this repeats as we go late into spring, I could see a few major outbreaks in areas like Iowa and Illinois, along with more localized smaller setups to the SW a day before these major outbreaks.

I think moisture will by default have to be better then it was throughout alot of 2009 and the trends of this winter are encouraging for no major drought to develop as we go into spring. The one worry I have is sometimes El Ninos tend to cool down the waters in the Gulf of Mexico though..

 

[Chris C Sanner]

I've always thought El Nino and La Nina are a bit over hyped in terms of severe weather. Yes they do influence the overall pattern, but in terms of something as complicated as very micro or localized super cells and chasing, I just cant blame or praise El Nino..

With that said, some interesting trends I am noticing this winter so far are that storms are really increasing in intensity as they get into Eastern areas of the Plains and Midwest. Areas like Iowa have seen some very impressive and deep Low Pressures and amazing gradients. If this repeats as we go late into spring, I could see a few major outbreaks in areas like Iowa and Illinois, along with more localized smaller setups to the SW a day before these major outbreaks.

I think moisture will by default have to be better then it was throughout alot of 2009 and the trends of this winter are encouraging for no major drought to develop as we go into spring. The one worry I have is sometimes El Ninos tend to cool down the waters in the Gulf of Mexico though..

If anything, if we keep up a wet winter then the early season setups might be better than year's past if moisture isn't an issue. Usually on early season setups, you have all the shear you need, just instability/moisture seems to be the issue. I'm not sure as to the exact extent of what effect it would be, but it can't hurt to not have any major drought areas and moist soils heading into spring if that's what ends up happening.

 

[Greg Campbell]

"However, there is some good news here: There is no widespread severe drought anywhere in the contiguous United States."

I find the last paragraph of the article to be interesting. I suppose the optimum word is 'widespread', but according to the NWS in Tucson, almost all of Arizona is covered by a severe drought as shown on this link. However, one of the charts within the link is predicting a significant improvement prior to the end of March, 2010.
http://www.wrh.noaa.gov/twc/climate/seazDM.php

Indeed.
For the last few months, CPC has been promising Southern Aridzona plentiful winter rain. Unfortunately, the clouds don't seem to have received the memo. Several storm systems have come and gone, but most have focused their energy well to the north.

Likewise, most mid-range models consistently overestimate the southern extent of precipitation, and correct their forecast only a day or so before the system's arrival. This has been the case for the last few years, it seems.

In short, El Nino may produce more precipitation for someone, somehwere, but I don't know if we'll see any of it.

 

[David Hodges]

El Nino And La NINO..... Just Speculation

The talk about El Nino and La Nino .The truth is nobody can predict until the season is upon us if it will be an above average year for severe wx in the southern plains. Past events are not a indicator of future happenings. Long term forecasts are not a reliable tool.

 

[Michael Riedl]

This is not your normal El Nino. It is West based opposed to some recent El Ninos which have been East Based and if I remember right it is predicted to cool down as 2010 progresses. In general the Southern Jet will be stronger because of this,

 

[Bob Hartig]

The talk about El Nino and La Nino .The truth is nobody can predict until the season is upon us if it will be an above average year for severe wx in the southern plains. Past events are not a indicator of future happenings. Long term forecasts are not a reliable tool.

David, it's understood that this discussion is highly speculative. See my previous post in which I addressed your comment before you ever made it.

 

[Will Wilkens]

Indeed.
For the last few months, CPC has been promising Southern Aridzona plentiful winter rain. Unfortunately, the clouds don't seem to have received the memo. Several storm systems have come and gone, but most have focused their energy well to the north.
Likewise, most mid-range models consistently overestimate the southern extent of precipitation, and correct their forecast only a day or so before the system's arrival. This has been the case for the last few years, it seems.

In short, El Nino may produce more precipitation for someone, somehwere, but I don't know if we'll see any of it.

Greg, it's still December. Most of the previous El Nino's didn't even begin to impact Southern California and Arizona until January. I've been logging (in detail) rain events in Southern California since I was a kid, back during the El Nino of '77-'78 (gawd now I'm dating myself). It wasn't until after Christmas '77 when the first El Nino enhanced systems started arriving. The following 3 months, Jan-March of '78, were epic around Southern California. As I thumb through all my log sheets in front of me right now, the same applied to the subsequent El Ninos of the early 80's, early 90's, and the epic El Nino of '97-'98. I do not remember in any detail how Arizona was affected during each of these events, but I do remember seeing on the news the Salt River through Phoenix flooded several times during some of those El Nino years.

While it is true what David says that past events are not an indicator of future happenings, there is sufficient climate data over a period of time to draw reasonable conclusions for the possibilities "in general".

We still have 3 months ahead of us.

 

[Greg Campbell]

Greg, it's still December. Most of the previous El Nino's didn't even begin to impact Southern California and Arizona until January. I've been logging (in detail) rain events in Southern California since I was a kid, back during the El Nino of '77-78 (gawd now I'm dating myself). It wasn't until after Christmas '77 when the first El Nino enhanced systems started arriving. The following 3 months, Jan-March of '78, were epic around Southern California. As I thumb through all my log sheets in front of me right now, the same applied to the subsequent El Ninos of the early 80's, early 90's, and the epic El Nino of '97-'98. I do not remember in any detail how Arizona was affected during each of these events, but I do remember seeing on the news the Salt River through Phoenix flooded several times during some of those El Nino years.

While it is true what David says that past events are not an indicator of future happenings, there is sufficient climate data over a period of time to draw reasonable conclusions for the possibilities "in general".

We still have 3 months ahead of us.

Thanks for offering hope!

-Greg

 

[Jason Boggs]

I'm going to go ahead and say it...2010 will be a great year for tornadoes in the southern plains! Our weather pattern right now has been pretty active since El Nino kicked in. If this pattern stay together, and I think it will, were in for a great season!

Get your camera gear dusted off now!!!

 

[Chris C Sanner]

I'm going to go ahead and say it...2010 will be a great year for tornadoes in the southern plains! Our weather pattern right now has been pretty active since El Nino kicked in. If this pattern stay together, and I think it will, were in for a great season!

Get your camera gear dusted off now!!!

I like the optimism Jason. I'm going to go ahead and endorse this plan for the 2010 chase season.

Happy New Year all!

 

[Jason Boggs]

From living here since 1978, I have seen a lot of weather patterns play out. When we have a wet and snowy winter, you can almost guarantee an above average storm season. Now, that doesn't happen all the time, but it can be a good predictor.

 

[Mike Smith]

It is interesting that much of southeast and south central Kansas have had the wettest three years in history. Missouri has experienced the wettest two years in its history ( http://climate.missouri.edu/ ). New Orleans, its wettest month ever.

Given the amazingly wet Palmer Drought Index ( http://meteorologicalmusings.blogspot.com/2009/12/updated-palmer-drought-index.html ) all the way to the Gulf, it seems likely that early to mid-season dynamic systems will have more moisture than average to work with.

If I had to guess, I'd say 'above normal' storm season.

 

[Jason Boggs]

I agree with you Mike. 2 things may make this year an above average season. First, there may be wave after wave of energy moving into the southern plains when spring arrives. Second, with the current wet pattern, evapotranspiration will keep the dryline further west, instead of the dryline hauling east due to very shallow moisture in the PBL.

 

[Bob Hartig]

... with the current wet pattern, evapotranspiration will keep the dryline further west, instead of the dryline hauling east due to very shallow moisture in the PBL.

That's what I was initially thinking, too, and it makes a whole lot of sense. Just that other pieces of the El Nino puzzle made me wonder. A cooler-than-average GOM and hyperactive subtropical jet could be a concern. Frankly, though, my gut tells me that you and Mike are right. I sure hope so. I'd like to see 2010 be as good as 2009 was lousy.