What Does That Mean In Terms Of Everyday Weather & The 2015 Atlantic Hurricane Season?
The Climate Prediction Center (CPC) has finally declared the Pacific is now in a weak El Niño state, more than a year after the prospect of a El Niño event first surfaced. Based on all of the analysis that I have done, it seems that we have been in a weak/borderline El Niño state since about last spring (Spring of 2014), but just now been declared an official El Niño. My analysis is supported by the fact that the summer of 2014 was generally cool across the United States and this is generally a El Niño weather pattern.
It appears that we will be at borderline El Niño conditions through about April with the possibility of a strengthening El Niño by this summer into this fall, based on the ENSO prediction models. Should this El Niño persist into the fall of 2015, then 2015 could become one of those rare years that sees a continuous El Niño from January to December. Going back to the start of NOAA records in 1950, the only other such years are 1953, 1969, and 1987.
ENSO Probability Forecast:
What sort of effects could this El Niño have on the overall weather pattern across North America: Weak El Niño events are much less likely to produce significant weather pattern changes across North America than what we might see with a moderate or strong El Niño.
With that said, we could see some enhanced rainfall across the Gulf states this spring into the summer. In addition, unlike a moderate or strong El Niño, a weak El Niño has little or no effect on the rainfall across the western United States; so, unfortunately, a very dry summer seems likely across the western United States.
Madoki Weak El Niño Rainfall Pattern:
Looks Similar To The Spring, 2015 Seasonal Forecast From The CFS Model:
And how could this weak El Niño impact the 2015 Atlantic Hurricane Season: The correlation between a weak El Niño and how active the Hurricane season in the Atlantic is not very strong. There have been years in the past, such as 2004, 1969 and 1953 that had weak El Niño conditions with busy to very busy Atlantic hurricane seasons. On the other hand, there have been years, such as 1987, which also had weak El Niño conditions which were fairly quiet in the hurricane department.
One thing that should be noted is that right now we have a Modoki weak El Niño as all of the warm waters are in the central Pacific. A Madoki El Niño is different than a conventional El Niño. A conventional El Niño features the warmest waters across the eastern Pacific. Whereas, a Madoki El Niño is associated with strong warming waters over the central tropical Pacific and cooling in the eastern and western tropical Pacific.
In terms of hurricanes, a Madoki (central Pacific centered) El Niño are different from those of the traditional Eastern Pacific El Niño. During a Madoki El Niño, like we have right now, there tends to be more hurricane landfalls on the United States and Caribbean than what we would see during a traditional El Niño.
As I just mentioned, the correlation between weak El Niño conditions and Atlantic hurricane activity is weak. With that said, 1953, 1958, 1969 and 1994 are all showing up as potential analog years right now. All are weak El Niño years with a Madoki type setup. The amount of activity/impact during those 4 analog years are split right down the middle with 1953 and 1969 being quite active and impactful while 1958 and 1994 were much less active and impactful.
Here are my latest thoughts given the latest information in regarding to the 2015 Atlantic Hurricane Season:
Eastern Atlantic: It appears that the eastern Atlantic east of 50 West Longitude may be quiet this year with below average activity. The ocean water temperatures across the eastern Atlantic are colder than average and it appears that it may remain that way right into much of the Hurricane season.
Caribbean: The Caribbean is a “wild card” as we could see two types of development this Hurricane season in the Caribbean. The first is from disturbances tracking into the Caribbean from the east and second from homegrown development from frontal boundaries sinking southward. If the current Madoki El Niño translates into a eastern Pacific centered traditional El Niño, then the Caribbean could be shut down due to strong wind shear caused by the weather patterns resulting from the traditional El Niño conditions.
US Southeast Coast & The Bahamas: Ocean water temperatures off of the US Southeast coast and in the Bahamas are forecast to be warmer than average this hurricane season. I think that we will see a fair amount of tropical activity in the subtropics this hurricane season rather than across the tropical latitudes. This would potentially open up the US Southeast Coast, the Bahamas and potentially the entire US East Coast to impacts from tropical storms/hurricanes. I think that we will need to watch close to home for those homebrew type systems that form at the end of fronts or from upper level low pressure systems.
Gulf Of Mexico: I think that the Gulf of Mexico could also be open to tropical cyclone development this hurricane season as it is extremely unusual to have two straight hurricane seasons in a row with no more than one weak tropical storm. In addition, ocean water temperatures in the Gulf of Mexico are expected to be above average this summer into the fall and any homegrown type systems coming off of fronts would be able to feed off of these warm waters. Even if there are some traditional eastern Pacific centered El Niño conditions, the Gulf of Mexico is normally not affected as much by shear and will be an area that will need close watching.
With all of this said, I want to remind you that it’s only March 6th and a lot can and probably will change between now and June 1st, and as always, all it takes is one.