El Niño years vs. La Niña years

[Brian R]

Good evening, and happy holidays to everyone!

I have been talking to a few people and I am not sure but from what I am hearing is we are headed into an El Nino year for 2015 and from what people are saying that should equal a much more active severe storm season than 2014 was. Wondering if there is any truth to these comments or not..... is an El Nino year known for having a more active spring and summer for severe weather or not. Hopefully 2015 will be more active than2014 was.

 

[Marcus Diaz]

The last El Niño year was 2010, which was active further south. 2011 was La Niña yeah, which had very high numbers of tornadoes, but the southern parts of the Plains lacked in setups. If you want to know if 2015 is going to be active in the southern High Plains, keep an eye on how much rain northern Mexico gets this winter.

 

[Mark Blue]

It has been really slow to develop this year, so if it eventually does get its act together it will be a weak event at best. There are studies that suggest a correlation between past El Niño events and increased severe weather in the Gulf states, but there are others with different outcomes as well. Seems to me there's still a lot to try and understand with global climate and events such as these.

 

[Brian R]

I have to agree, it sure seems like the pattern changes from year to year and it makes it really difficult to figure out if we are going to have an active spring or another boring one like this year was.

 

[Jeff Duda]

I'm pretty sure there is little to no predictive value in the ENSO phase on its own. That's because ENSO is not the only element impacting planetary and synoptic scale weather. Other factors must also be considered. These include other low frequency oscillations like AO, NAO, PDO, and PNA. Drought and soil moisture conditions must also be considered. Additionally, lee-cyclogenesis frequency and intensity must also be considered. While ENSO does impact these other features, it doesn't control them, meaning drought and lack of mid-latitude cyclones across the central US can occur in all three phases of ENSO.

EDIT: Ooh, now that I remember, I should mention there was a paper in BAMS earlier this year that mentioned tornado numbers may increase a little with certain phases of the MJO. I think it was phases 2 and 8 or something like that.

 

[Mark Blue]

Increased tornado activity really is dependent on a variety of global climate factors, just as Jeff suggested. I believe this study was the one I recalled as having seen before. There are probably several newer studies that exist out there as well, it's just a matter of digging them up for the sake of some light reading. Attempting to determine what kind of severe weather season we will have is very complex and difficult to ascertain based on my limited experience and is one of those million dollar questions we see each year here on ST.