2020: CSU Predicts Busier Than Average Atlantic Hurricane Season

The upcoming hurricane season is likely to be more active than usual, according to the April outlook from a team at Colorado State University that has been issuing seasonal hurricane predictions for decades. In its outlook issued Thursday, the CSU group is calling for a total of 16 named storms, 8 hurricanes, and 4 major hurricanes, compared to the long-term average (1981-2010) of 12.1 named storms, 6.4 hurricanes, and 2.7 major hurricanes. The group is also projecting an accumulated cyclone energy (ACE) index of 150, compared to the long-term average of 106.

This is only the fifth time in the 26-year history of CSU’s April forecasts that the team has called for at least 16 named storms. Of those four other years, all but one ended up producing at least 14 named storms.

Unusually warm sea surface temperatures (SSTs) during the first quarter of this year, in two distinct parts of the globe, are among the main factors that pushed CSU’s forecast toward the high side.

—Warm SSTs across the eastern Atlantic, from the tropics to latitude 50°N, are associated with weaker trade winds, lower surface pressures, and warmer SSTs over the tropical Atlantic during the subsequent hurricane season.

—Warm SSTs in the Coral Sea, northeast of Australia, tend to inhibit the development of El Niño, which typically acts to suppress hurricane development in the Atlantic.

Seasonal forecast models—especially those from NASA, NOAA, and the Australian Bureau of Meteorology—have leaned increasingly toward the development of a La Niña event later this year. The long-range outlook from the European Centre for Medium-Range Weather Forecasts (ECMWF) is calling for neutral conditions.

A cautionary note: “The early April forecast is the earliest seasonal forecast issued by Colorado State University and has modest long-term skill when evaluated in hindcast mode,” notes the outlook, which is produced by CSU’s Phil Klotzbach, Michael Bell, and Jhordanne Jones.

For this year’s April outlook, the CSU team debuted a more sophisticated (and more complex!) version of its forecast strategy. The CSU outlooks originated as a statistical product, correlating observed features with characteristics of the hurricane season to come. Last year the team added a statistical-dynamical component, based on output from the ECMWF’s SEAS5 seasonal modeling system and developed with the Barcelona Supercomputing Centre. Like other statistical-dynamical models, SEAS5 incorporates the state of the oceans and sea ice to produce longer-range outlooks than would be possible using the atmosphere alone.

This year CSU has added a second statistical-dynamical scheme, this one based on the UK Met Office's GloSea5 seasonal prediction system. When evaluated in hindcast mode (predicting past events as if they were occurring in real time), the SEAS5 and GloSea5 models show measurable skill as soon as March in predicting surface winds for July over the Main Development Region of the Atlantic (see graphic below). In turn, July wind shear is a useful index to the amount of tropical cyclone activity one might expect in the Atlantic over the following months.

Jeff Masters weighs in

WU co-founder and Cat 6 founder Dr. Jeff Masters had this to say about today’s release:

“I think the April 2020 CSU forecast has an above-average chance of success, given strong model agreement and very warm Atlantic SSTs currently in place. However, April forecasts of hurricane season activity have had little or no skill in the past, primarily since they must deal with the so-called ‘spring predictability barrier’. April is the time of year when the El Niño/La Niña phenomenon commonly undergoes a rapid change from one state to another, making it difficult to predict whether we will have El Niño, La Niña, or neutral conditions in place for the coming hurricane season.

“Last year’s CSU April forecast called for a slightly below-average 2019 Atlantic hurricane season, with 13 named storms, 5 hurricanes, 2 intense hurricanes, and an Accumulated Cyclone Energy (ACE) of 92. This forecast ended up being below the mark, as the season actually had 18 named storms, 6 hurricanes, 3 major hurricanes, and an ACE of 130.

“The next CSU forecast, due on June 4, is worth paying more attention to. Their late May/early June forecasts have shown considerable skill over the years.”

Wunderground

You can read the forecast from Colorado State University at https://tropical.colostate.edu/media/sites/111/2020/04/2020-04.pdf

MET office advises Belize to prepare for a busy hurricane season

The 2020 Atlantic Hurricane Season is anticipated to have an above-average probability for major hurricanes along the United States coastline and in the Caribbean. According to a report from the Colorado State University Tropical Meteorological Project, current warm conditions appear to transition to cool conditions by this summer/fall. These are perfect conditions for hurricanes to be formed. In speaking with the Deputy Chief Meteorologist at the National Meteorological Service, Ronald Gordon this means that Belize must plan ahead and be prepared if any of these hurricanes decide to come our way.

Ronald Gordon, Climatologist, National Meteorological Service: “Well indications from most of the reliable institutions that do predictions are indicating that the hurricane season will be slightly above normal. I don’t have the exact numbers in front of me but the indications are that they should be above normal and an above normal hurricane season indeed. For Belize it doesn’t really mean anything except that you need to be prepared and we also educate that whether the season is forecasted to be below or above normal it only takes on storm to make a difference so we repeat the same thing have your hurricane plan and be prepared for any eventuality as would be the case with any other year.”

The official hurricane season for the Atlantic Basin which includes the Atlantic Ocean, the Caribbean Sea, and the Gulf of Mexico is from June 1 to November 30.

LoveFM

The 2020 Atlantic Hurricane Season

It's that time of the year when we have to begin to prepare for the 2020 Atlantic hurricane season. This year is especially challenging because we are also battling a global pandemic that will change the way we respond to a threat. We invited our guest to share some information about the 2020 season. He talked about the factors that determine how active a season will be and the predictions for this year as a above average season.
Carlos Fuller - International and Regional Liaison Officer, Caribbean Community Climate Change Center

Opening of 2020 Atlantic Basin Hurricane Season

Monday 1st June marks the beginning of the 2020 hurricane season for the Atlantic Basin. The season runs from 1stJune to 30th November each year. However, the formation of tropical cyclones is possible at any time of the year, as shown by the formation of tropical storm Arthur on May 16 and tropical storm Bertha on May 27. The formation of these systems marks the sixth consecutive year a storm has developed before the official start of the season.

The 2020 forecast is suggesting that tropical cyclone activity will be above normal in the Atlantic Basin (North Atlantic Ocean, Caribbean Sea and the Gulf of Mexico). The prediction is for there to be thirteen to nineteen (13 to 19) named storms, of those six to ten (6 to 10) are expected to become hurricanes and three to six (3 to 6) are expected to become major hurricanes (Category 3 or stronger). An average season in the Atlantic Basin consists of twelve (12) named storms, six (6) hurricanes, and two (2) major hurricanes.

The main factors that were used to forecast an active 2020 Atlantic hurricane season are:

(1) No El Nino is expected this year therefore this factor will not contribute to the suppression of tropical cyclone activity in the Atlantic basin.

(2)Warmer than average sea surface temperatures in the tropical Atlantic Ocean and Caribbean Sea, which tends to favour hurricane development.

(3) Weaker vertical wind shear

(4) Weaker tropical Atlantic trade winds

(5) An active west African monsoon

What Does this Mean for Belize?

There is no strong correlation between the number of storms or hurricanes that form in any given season to the number of storms that make landfall in Belize. One or more of the 13 to 19 named storms forecast to develop this season could hit the country, or none at all. Therefore history teaches us, as a nation located in such a vulnerable area, we should be prepared each year no matter what is the forecast is.

So Belizeans be prepared , stay safe and heed to all advice and warnings coming from the National Meteorological Service and National Emergency Management Organization during the 2020 Hurricane Season.


2020 Hurricane - Preparedness