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.
Teleconnections:
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 neutral. I don't think we
will see what could be a El Nino Modoki (Central Based) 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.
Accuweather:
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.
Weatherbell:
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 for much of the season.
So the odds of Cape Verde tropical storms will be much lower than
average through at least mid August. This same thing happened in
2016. But once we get closer to September we could see the season kick in and become quite active. We could see a few Cape Verde systems during that time.
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. I said last season, we would have a major hurricane impact the East Coast. But I was wrong, major Hurricane Matthew scraped the coast of eastern Florida, missing a direct landfall by just a few miles. This year will be different. I'm going back out on that limb and saying we will have a major hurricane strike the US in 2017.
My Call
based on right now, is 14-18 named storms, 6-10 hurricanes, with 4-6 of them
major. So something similar to last season.
If I have to
adjust anything, I will release an updated outlook, during the last half of
May.