Above-average Atlantic hurricane activity again expected in 2021

Posted: April 23, 2021 by oldbrew in ENSO, predictions, Temperature, weather
Tags: ,
TypicalLaNina

Typical influence of La Niña on Pacific and Atlantic seasonal hurricane activity. Map by NOAA Climate.gov, based on originals by Gerry Bell.

Prediction time as the 2021 season approaches. The expected impacts of El Niño and La Niña on hurricane seasons in both the Atlantic and Pacific ocean areas are discussed by NOAA here. Hurricane detection has improved over time, so what is considered ‘average’ now is unlikely to be the same as it used to be.
– – –
The year 2020 saw the most active hurricane season on record and marked the fifth consecutive year for above-average activity, says Phys.org.

A University of Arizona-led hurricane forecasting team predicts another year of above-average hurricane activity over the Atlantic Ocean in 2021.

The team predicts 18 named storms, including eight hurricanes, throughout the 2021 North Atlantic hurricane season, which runs from June 1 to Nov. 30.

In comparison, the 30-year average is 13 named storms and seven hurricanes annually.

Four storms are expected to produce major hurricanes, which are defined as category 3, 4 or 5.

If the predictions are realized, 2021 will be the sixth-consecutive year for above-average activity.

“The past decade has been very active for hurricanes,” said forecast creator Xubin Zeng, director of the university’s Climate Dynamics and Hydrometeorology Center and a professor of atmospheric sciences.

“We need to ask ourselves if this is part of the natural variability of the system, or if we are already seeing impacts of global warming,” said Zeng, who is also the Agnes N. Haury Endowed Chair in Environment in the Department of Hydrology and Atmospheric Sciences. “If this is part of the natural variability, then after some overactive seasons, we’d expect activity to quiet down, but every year is kind of crazy in the past few years.”

While Zeng expects that a warming world is translating to warmer ocean waters that fuel hurricane development, that can’t yet be confirmed through modeling.

“In climate modeling, every model resolution (similar to a single pixel or grid box on the Earth’s surface) is about 50 miles by 50 miles. In contrast, for global weather forecasting models, the resolution is more like five miles by five miles,” Zeng said. “If we really want to simulate the impact of global warming on hurricanes, it’s preferable we have the smaller model grid box, and we just don’t have the computing power for that yet for decade-long simulations.”

Zeng predicts, however, that in another 10 years, he will have the data and confidence to say for sure that the increase in hurricane activity was outside of the natural variability of the climate.

While this season is expected to bring above-average activity, it isn’t expected to be as dramatic as last year, partly due to average climate patterns in the Pacific Ocean driven by sea surface temperatures.

When eastern tropical Pacific sea surface temperatures are below average—a weather phenomenon known as La Niña—it drives up easterly wind speeds over the Atlantic that exacerbate hurricanes.

When Pacific sea surface temperatures are above average—a weather pattern referred to as El Niño—it weakens easterly winds and weakens hurricane activity over the Atlantic.

Full article here.

Comments
  1. pameladragon says:

    More disinformation! Really, just because they fudged the numbers last year and named a lot of storms that were not really hurricanes doesn’t mean that the numbers of storms are increasing, only that they are naming stuff that in years past would not have been designated with an official name. Improved methods of storm detection does not mean more storms forming only that more storms are noticed. These people need to study some hurricane history, prior to their dates of birth! After all, it is not the total number of storms that matters but the number of storms that make landfall and cause enormous damage.

  2. Gamecock says:

    ‘While Zeng expects that a warming world is translating to warmer ocean waters that fuel hurricane development, that can’t yet be confirmed through modeling.’

    Climate computer clown.

  3. Chaswarnertoo says:

    There was no ‘above average’ activity last year.

  4. Gamecock says:

    Guessing the number of hurricanes is a fun game that all can play.

    How many hurricanes can dance on the head of a pin?

    Should I begin boarding my windows? Of course not. Their prediction is of no value whatsoever; it is completely esoteric. Even if it were exactly correct, it would still be of no value.

  5. Phoenix44 says:

    I’m not following his argument re: models. Why does he need to model the entire globe to model hurricanes in part of the globe?

  6. RE: “named a lot of storms that were not really hurricanes”
    When a tropical depression reaches wind speeds of 39 MPH, it is then classified a tropical storm, and it receives a name. It does not have to become a hurricane to receive a name.

  7. oldbrew says:

    Rare subtropical storm takes shape in Atlantic Ocean
    By Brian Lada, AccuWeather meteorologist and staff writer

    Updated Apr. 22, 2021

    Only a handful of tropical systems have ever been recorded over the Atlantic Ocean south of the equator, although the frequency of this phenomenon has been trending upward in recent years.

    Before Potira developed, there had only been 14 named tropical systems in the southern Atlantic Ocean, a majority of which were subtropical storms. This means that they have meteorological characteristics of both a tropical storm and a non-tropical storm.

    https://www.accuweather.com/en/hurricane/subtropical-storm-potira-near-brazil/935912
    – – –
    ‘trending upward in recent years’ – as have weaker solar cycles 🤔

  8. stpaulchuck says:

    mid ocean tropical storms did not get fully detected for the last couple hundred years but now we have satellites and radars all over the place so – AMAZINGLY – we see more of them. What a shocker! I only care about the ones that make landfall. Of course you then have to take in the massive shore building of homes and businesses over the last fifty years in particular which skews the ‘damage’ number considerably. Not that the alarmists would tell the public of course.

  9. Gamecock says:

    ‘Only a handful of tropical systems have ever been recorded over the Atlantic Ocean south of the equator’

    Do they spin clockwise?

  10. oldbrew says:

    Chinese scientists: Most climate models fail to reproduce global warming slowdown
    Date: 24/04/21 Meng Wei et al. (2021, Science China Earth Sciences, 15 April 2021

    A new study by a team of Chinese climate scientists and published by Science China Earth Sciences, a journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China, reveals the failure of most of the latest climate models to reproduce the global warming slowdown during 1998–2013.

    https://www.thegwpf.com/chinese-scientists-most-climate-models-fail-to-reproduce-global-warming-slowdown/
    – – –
    Failure? How dare they!

  11. oldbrew says:

    Bastardi forecasts dangerous 2021 hurricane season
    By Craig Rucker | April 23rd, 2021

    When the man who first accurately projected the impact of Hurricane Sandy tells us we’re in for a big Atlantic hurricane season, preparation must be made.
    . . .
    Pay special attention if you live on the Gulf Coast from Texas to the Florida Panhandle, in Southern Florida, the Bahamas, or the Atlantic Coast from the Carolinas to Southern New England. We recommend you evaluate your risk and be ready.

    https://www.cfact.org/2021/04/23/bastardi-forecasts-dangerous-2021-hurricane-season/
    . . .
    Big Joe has spoken 😯

  12. Gamecock says:

    ‘When the man who first accurately projected the impact of Hurricane Sandy tells us we’re in for a big Atlantic hurricane season, preparation must be made.’

    Argumentum ad verecundiam.

    Cirrusly, oldbrew, the CFACT article is junk.

    ‘Joe posted his incredibly detailed 2021 hurricane forecast to CFACT.org.’

    Incredible details? Hurricanes. 2021.

    Bastardi – a good guy – says we are going to have hurricanes this year.

    That’s it. There is no other useful information in his message.

    Since we already figured there would be hurricanes this year, his message is useless.

    ‘Joe Bastardi forecasts that 3-6 hurricanes will make landfall in the United States during the 2021 season and that 2-4 will be major.’

    INCREDIBLE DETAIL!

    ‘Pay special attention if you live on the Gulf Coast from Texas to the Florida Panhandle, in Southern Florida, the Bahamas, or the Atlantic Coast from the Carolinas to Southern New England. We recommend you evaluate your risk and be ready.’

    OMG. Just like any other year.

  13. ren says:

    Solar wind may now have periods of growth. If the circulation changes to zonal, there could be several hurricanes in the Atlantic.

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