El Niño and Its Possible Effects On This Upcoming Winter

El Niño Forecast

There continues to be a lot of speculation about the El Niño that will likely develop later this year. As most of you read earlier this year, the majority of meteorologists/climatologists were leaning towards a stronger El Niño developing by this winter, which would have had major influences on the weather around the globe particularly this upcoming winter. Most of them had valid reasons for these predictions, and while most models agreed with these predictions earlier this year, I did point out a couple of reasons why I didn’t think we would go into a super El Niño. Please understand that predicting when an El Niño will develop and how strong it will be can be extremely difficult. 

The reason I care so much about El Niño is because it can influence the weather in a major way, particularly during the winter months. Strength and placement of the warmer waters across the equatorial Pacific play a big role on how much El Niño influences the temperatures and precipitation across the United States. 

For most of this year, the atmosphere has not reacted in a way that would favor the development of an El Niño, although that has begun to change in recent weeks. The atmosphere MUST react to the warmer waters across the equatorial Pacific to further reinforce the buildup of warmer waters across the central and eastern Pacific. Without the help of the atmosphere pushing El Niño along, it simply cannot develop, which is why cooler waters started to re-emerge back over the region that dramatically warmed up earlier this year. This entire process is a ocean-atmosphere system, and when the warmer waters across the equatorial Pacific drive the atmosphere to induce even additional warming of these waters, this is what is referred to as a positive feedback, which is what you need. 

SOI Index

When the SOI index is more negative, this typically means that an El Niño is developing or has already developed

Now that the atmosphere is starting to react to a developing El Niño, the warmer waters will likely begin to emerge to the surface, so it’ll be interesting to watch what takes place over these next several weeks. Typically, winds blow from east to west across the equatorial Pacific, which is referred to as trade winds, but this completely reverses during El Niño events. If you look at the graphic below, you can see that above-average temperatures are beginning to re-develop and re-surface. The top part of the graphic is the ocean surface and the further you go down on the graphic, the deeper the ocean. Notice the darker oranges, and how they’re starting to surface back to the top.

El Nino sea surface temperatures

From everything that I’m seeing, I still believe that we are going to be dealing with an El Niño Modoki event, meaning the warmer waters will be more focused across the central Pacific instead of the eastern Pacific. If you look at previous years that had similar setups, the temperatures during the winter were warmer out West particularly in the Northwest, while it was really cold out East. As I mentioned in my winter forecast, there are other factors that could influence this winter, just because this El Niño will likely stay weak to moderate. If this El Niño were to be stronger than I am anticipating, then I’d have to make some changes to my winter forecast, but I find that to be unlikely at this point. 

El Niño Forecast

Several climate models continue to indicate a developing El Niño.

An El Niño Modoki event would most likely bring wetter conditions to southern California and across most of the Southern Plains and Southeast. Due to the colder-than-average temperatures that I’m expecting further east this winter, this would bring above-average snowfall for many regions across the Southern Plains and Southeast, even in areas that may not see snow too often. The Mid-Atlantic and most of the Northeast will also be very cold with the Mid-Atlantic and parts of the Northeast being impacted by several larger storms this winter. Please read my 2014-15 winter forecast to see what I’m expecting for your area this winter. 

Preliminary 2014-15 Winter Forecast

Firsthand Weather’s Preliminary 2014-15 Winter Forecast

I’m still going to continue to keep a watch on everything. Depending on how everything plays out over the next couple of months will determine how our fall will end up being, and then of course, my main focus will shift to winter. Always remember that things can change, meaning my forecasts are subject-to-change. 

Please continue to follow Firsthand Weather on Facebook, and be sure to like the page if you haven’t already. I always try to keep the Facebook page updated as much as possible. 

Hurricane Iselle Heading Straight For Hawaii

Projected Path of Hurricane Iselle

I just wanted to put out a brief update on Hurricane Iselle, which is still a category 1 hurricane and is heading for Hawaii. It’s not unheard of for Hawaii to be impacted by tropical cyclones, however, it is very rare. Hurricane Iselle currently has sustained winds of 90 mph with gusts up to 115 and is moving west northwest at 16 mph. It is expected to make landfall sometime Thursday evening. A few hours ago, Iselle began to re-strengthen with convection wrapping symmetrically around its eye, however, some weakening seems to have occurred over the last couple of hours.

Projected Path of Hurricane Iselle

Projected Path of Hurricane Iselle

Hurricane Iselle has taken on the characteristics of what is known as an annular tropical cyclone. These types of tropical systems feature a large, symmetric eye with intense convection wrapping around the eye. These rare types of tropical systems are not influenced as much by poor environmental conditions and often weaken much slower than typical hurricanes. That’s why forecasting the intensity of these types of systems can be tricky. However, it does look like Iselle has lost the typical structure of an annular tropical cyclone over the last couple of hours, which means it could be weakening. 

Hurricane Iselle is currently moving over some cooler waters, but wind shear overall has been weak, which is likely what has allowed Iselle to strengthen some today. Iselle will move over slightly warmer waters as it moves closer to Hawaii; however, wind shear will most likely increase as it makes its way further west.

Hurricane warnings have been issued for the Big Island, so expect hurricane force winds in that region. Heavy rains and flooding will also be a big threat with this system. Historically, Hawaii has never been hit by a hurricane coming from the east, so if Iselle were to maintain its hurricane status upon landfall, this would make history. Since 1949, the Hawaiian Islands have only been directly hit by a hurricane twice, one in 1959 and 1992. 

I’ll continue to keep a close watch on everything tonight. Please continue to follow Firsthand Weather on Facebook, where plenty of updates will be put out on Iselle throughout tonight and tomorrow.

Tropical Storm Bertha Likely To Recurve and Miss the United States

Tropical Storm Bertha Model Track Guidance

I’ve been keeping a close eye on Tropical Storm Bertha over the last couple of days. As I mentioned on Facebook a few days back, Bertha was going to likely struggle and would have to fight off dry air, which ended up being one of the main factors that kept the system from really strengthening. As of 8 pm ET on August 1st, Bertha’s winds are sustained at 50 mph, and it’s moving west-northwest towards Puerto Rico at 24 mph. The system overall hasn’t really looked too healthy, but tonight, I have noticed that convection is really starting to fire around the center.

The track is going to be key as to whether or not this system will be able to survive by the time it moves into those waters near the Bahamas and off the East Coast. The mountains of the Dominican Republic can really tear a system like this up, but if it only brushes the island, then it should be able to maintain enough of its strength to see some pretty quick strengthening in the warm waters off the East Coast.

That is the region that we are going to have to keep a close watch on all season. Luckily, the trough over the eastern United States and the ridge over the Atlantic will most likely create an upper-level flow that steers this storm out to sea, causing it to miss the East Coast and recurve northeast out to sea.

Tropical Storm Bertha Model Track Guidance

Tropical Storm Bertha Model Track Guidance

Remember, those waters off the East Coast are very warm and as this system moves into that region, it’s going to also be in an environment with lighter wind shear. Like I said, if it does miss most of the Dominican Republic, then we may end up seeing Bertha rapidly intensify. In fact, I wouldn’t be surprised if we end up getting a hurricane out of this if that’s the case.

Again, I do not expect Bertha to hit the United States, but I do plan to keep a close eye on this. It’s good to watch this because it will again confirm that this is the region in the Atlantic to watch this year. It only takes one storm in the season to cause a lot of damage along the East Coast.

Please like Firsthand Weather for the latest updates on Tropical Storm Bertha.