Hard to believe, but hurricane season is less than 100 days away. So, it’s time to start talking about the Tropics. Based on data from 1991 to 2020, an average season typically sees 14 named storms, seven hurricanes, and three major hurricanes. Before we get into the 2024 season, let’s take a quick look at the 2023 Atlantic season.
A look
back at the 2023 Atlantic hurricane season...
In 2023 the
tropical Pacific experienced El Nino. Typically, El Nino suppresses tropical
cyclone development in the Atlantic Basin, due to increased atmospheric
stability and increased vertical wind shear. But last season, in spite of it being a strong
El Nino; The season was very active. In fact, the 2023 Atlantic hurricane
season ranks 4th for most-named storms in a year. Looking at the numbers, there
were 20 named storms (including an unnamed subtropical storm that formed on
January 16), seven of which were hurricanes, three of them became major
hurricanes (Cat 3+), and the season had an overall Accumulated Cyclone Energy (ACE) of
146. In total there were 3 landfalling tropical cyclones on the U.S. main land.
The numbers show 2023 saw the most named storms in the Atlantic basin of any El
Nino influenced year in the official record. Another thing that is generally
true with El Nino impact on the Atlantic tropical season, is that the upper-level
wind pattern is more supportive of storms recurving north before they reach the
U.S.
When I
released part three of the hurricane outlook back in May, my final numbers were
14-20 named storms, 8-12 hurricanes, 3-5 major hurricanes. The CONUS would see
2-4 landfalls with one of them possibility being major. The ACE would be
100-150. So, my outlook ended up as close to perfect as you can get.
I did a post
on why the season was so active, you can find it here.
OK let start
talking about the 2024 tropical season in the Atlantic…
My outlooks
are based on yearly weather patterns. During the preseason, I look at that
overall pattern and how major teleconnections and things like Sea Surface
Temperatures (SST) will play into all of that.
The Atlantic
Hurricane Season officially starts on June 1st.
Teleconnections…
EL Nino is
fading, and looks to be quickly replaced by La Nina
La Nina,
increases the odds for tropical cyclones. Because there is generally increased
atmospheric instability and decreased vertical wind shear. Also, since La Nina has by and large the opposite El Nino impact on the Atlantic tropical season, so
tropical systems have a greater chance to come farther west, into the western
Atlantic, Caribbean, and Gulf of Mexico.
The SSTs in
the Atlantic Main Development Region (the area where most of the hurricane’s form)
between the West Coast of Africa and the Lesser Antilles are well above average.
Right now, SSTs in the North Atlantic Basin
are running 2°F above the 1990-2020 average, and around 3°F above the average
SST back in the 1980’s.
Here is a
chart make by Brian McNoldy (University of Miami’s Rosenstiel School, Senior Research
Associate) that shows just how dramatic these temperatures are.
This warm
water provides developing tropical cyclones the fuel they need to develop and
become more intense.
General
thoughts for the 2024 season…
The combination
of La Nina and well above average SST means, 2024 has a good chance to be as
active or even more active than 2023 was.
The current trend
of the La Nina, looks to be in place for June and July. If this happens, the
middle and end of this hurricane season could be very active, maybe even
hyperactive.
When we look
at the projected Atlantic rainfall anomalies, we see where the highest anomalies
(the green swath) are located, pointing into the Caribbean and along the
Southeast Coast. While this doesn’t show tropical cyclones, it does show where
thunderstorms are more likely to form and track. With all that warm water, La
Nina potentially lowering wind shear, this would make sense. As it would
support hurricane development in this part of the Atlantic.
Hot
Spots…
Based on the
pattern that looks to be setting up, these are the areas I think are at the
greatest risk of seeing a landfalling tropical cyclone this season.
The models
are generally pointing to the Caribbean, the eastern and central Gulf Coast and along the
Southeast Coast. So, hurricane impacts are particularly concerning for these
two areas.
That doesn’t
mean the Middle Atlantic and Northeast can relax this season. The areas away
from these hot spots are at a lesser risk, but that risk isn’t zero. New England is long overdue for a hurricane
impact. Last season New England dodged a couple of bullets. With the odds
favoring tropical cyclones making it farther west this season, New England has a
better shot at seeing a direct impact.
The official
list of tropical cyclone names in the Atlantic basin for 2024 includes…
Alberto, Beryl,
Chris, Debby, Ernesto, Francine, Gordon, Helene, Isaac, Joyce, Kirk, Leslie, Milton,
Nadine, Oscar, Patty, Rafael, Sara, Tony, Valeria, William.
Final
Thoughts…
This is the
time to get prepared for the upcoming hurricane season, develop a plan for you
and your family that will keep you safe, also make sure that a hurricane kit is ready to go, just in case.
It’s too
early to try and figure out the possible numbers of hurricanes this season. So that
detail will be covered over the next couple of months.
This is an
early outlook that is calling for an above average active hurricane season, due
to the record warm SST in the tropical Atlantic and El Nino likely switching to
La Nina at the peak of season. But if La Nina doesn’t form or takes longer to
develop that could change things. Still,
plenty of time to watch how things trend and evolve.
The Climate
Prediction Center (CPC) will release NOAAs seasonal hurricane outlook around
May 23rd. Other major weather outlets will be releasing outlooks
during April into May.
I will release
part two sometime in April and then part three in May.
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