Back on March 26th I posted my thoughts on how the hurricane season looked to unfold. Looking at everything, I really haven't changed my mind. As far as I can see, I was the first or just about the first to post numbers on the 2017 hurricane season. I wanted to post before the Annual National Tropical Weather Conference was held this year. I also wanted to beat Colorado State University's April outlook. Why? Because I wanted to make it clear that my ideas are sound, and lay the groundwork , by getting my predictions out there first.
The Atlantic hurricane season runs from June 1st until November 30th. But that doesn't mean tropical cyclones can't form before or after those dates.
Back in March, I said my analog years were, 1951,1953,,1957,1972,1997,2015. Since then I looked at and added 1965, 1976, and 2002. All of these years had some similarities to 2017.
The North Atlantic Osculation as primarily been positive since January. So the North Atlantic Sea Surface Temperature (SST) anomalies have been cold. The cooling off of the SST increased in March. So now we have cool SST in the North Atlantic, cool tropical SST off the West Coast of Africa, with warm SST off the East Coast of the United States. This places the Atlantic Multidecadal Oscillation (AMO) in a basically negative phase.
The El Nino-Southern Oscillation (ENSO) is currently neutral. I've been posting on My Facebook weather pages, and I also talked about it in my March 26th blog post. So I won't go into a lot of detail on that. But, the ENSO looks to head for El Nino conditions. During the 2016 hurricane season we were experiencing a strong El Nino. Then late in the fall we transitioned into La Nina. During winter 2016-2017 the La Nina stayed very weak. This is one of many reasons why the winter turned out the way it did.
This year I don't think we will see the return of a strong El Nino. Instead I think it will be weak to moderate. I don't think we will see a El Nino until at least mid-summer. Right now, the atmosphere is still acting like we have a weak La Nina; it will take awhile for the atmosphere to catch up. So, there wouldn't be Atlantic influence until we get into the hurricane season.
Predictions from other major weather outlets.
Colorado State University (CSU):
They issued there outlook on the 6th of April, 2017. The team from CSU said they expect 11 named storms, 4 hurricanes, 2 of them major Cat3 or higher.
Issued their hurricane forecast April 5th, 2017. They say 10 named storms will form, 5 will become hurricanes, 3 will become major.
Tropical Storm Risk, INC (TSR):
TSR a prestigious private hurricane forecasting company in Britain, issued their hurricane outlook on April 5th, 2017. They say they expect, 12 named storms, 6 hurricanes, 2 of them major.
They released their thoughts on numbers for the 2017 season, on 31 March, 2017. They have listed, 10-12 named storms, 4-6 hurricanes, 1-2 of them major.
The numbers I released on the 26th of March, 2017:
I said, my early thoughts were, 10-12 named storms, 3-4 hurricanes, with 1 major.
Last season's tropical cyclone numbers:
In 2016, there were 15 named storms, 7 of them became hurricanes, with 4 major hurricanes.
The bottom line:
The combination of a positive AMO and El Nino will increased trades winds over the Main Development Zone (MDZ) of the tropical Atlantic. We also have those cool SSTs, in the eastern Atlantic. All of this will severely curtail tropical development in the MDZ. So the odds of Cape Verde tropical storms will be much lower than average. This same thing happened in 2016.
Those warm SSTs off the East Coast of the U.S., and the warm waters in the Gulf of Mexico and Caribbean will set the stage, for tropical cyclone development in the western Atlantic Basin. As was the case last year, most of the tropical development should develop closer to the U.S. main land. The warm SSTs also, increased the odds of stronger hurricanes coming up the East Coast.
My Call based on right now, is 10-12 named storms, 4-5 hurricanes, with 1-2 of them major.
If I have to adjust anything, I will release an updated outlook, during the last half of May.