2019 Hurricane season forecast: below average

Dr. Philip Klotzbach of Colorado State University writes on Twitter:

Seasonal #hurricane forecast from @ColoradoStateU predicts slightly below-average season: 13 named storms, 5 hurricanes & 2 major (Cat 3+, >=111 mph) hurricanes. Primary reason for slightly below-avg forecast is anticipated continuation of weak #ElNino.

We anticipate that the 2019 Atlantic basin hurricane season will have slightly belownormal activity. The current weak El Niño event appears likely to persist and perhaps even strengthen this summer/fall. Sea surface temperatures averaged across the tropical Atlantic are slightly below normal, and the far North Atlantic is anomalously cool.

Our Atlantic Multi-decadal Oscillation index is below its long-term average. We anticipate a slightly below-average probability for major hurricanes making landfall along the continental United States coastline and in the Caribbean. As is the case with all hurricane seasons, coastal residents are reminded that it only takes one hurricane making landfall to make it an active season for them. They should prepare the same for every season, regardless of how much activity is predicted.

PROBABILITIES FOR AT LEAST ONE MAJOR (CATEGORY 3-4-5) HURRICANE LANDFALL ON EACH OF THE FOLLOWING COASTAL AREAS:

1) Entire continental U.S. coastline – 48% (average for last century is 52%)

2) U.S. East Coast Including Peninsula Florida – 28% (average for last century is 31%)

3) Gulf Coast from the Florida Panhandle westward to Brownsville – 28% (average for last century is 30%)

PROBABILITY FOR AT LEAST ONE MAJOR (CATEGORY 3-4-5) HURRICANE TRACKING INTO THE CARIBBEAN

(10-20°N, 88-60°W) 1) 39% (average for last century is 42%)

Abstract:

Information obtained through March 2019 indicates that the 2019 Atlantic hurricane season will have activity slightly below the 1981-2010 average. We estimate that 2019 will have about 5 hurricanes (average is 6.4), 13 named storms (average is 12.1), 50 named storm days (average is 59.4), 16 hurricane days (average is 24.2), 2 major (Category 3-4-5) hurricanes (average is 2.7) and 4 major hurricane days (average is 6.2).

The probability of U.S. major hurricane landfall is estimated to be about 90 percent of the long-period average. We expect Atlantic basin Accumulated Cyclone Energy (ACE) and Net Tropical Cyclone (NTC) activity in 2019 to be approximately 75 percent of their long-term averages. This forecast is based on an extended-range early April statistical prediction scheme that was developed using 29 years of past data.

Analog predictors are also utilized. For the first time, we are also using a statistical/dynamical model based off of data from the ECMWF System 5 as an additional forecast guidance tool. The current weak El Niño event appears likely to maintain intensity or perhaps even strengthen during the summer/fall. The tropical Atlantic is slightly cooler than normal, while the subtropical Atlantic is quite warm, and the far North Atlantic is anomalously cool.

The anomalously cold sea surface temperatures in the far North Atlantic lead us to believe that the Atlantic Multi-decadal Oscillation is in its negative phase. There is considerable uncertainty as to what the configuration of Atlantic sea surface temperatures will look like for the peak of the Atlantic hurricane season.

Coastal residents are reminded that it only takes one hurricane making landfall to make it an active season for them, and they need to prepare the same for every season, regardless of how much activity is predicted. 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. The skill of CSU’s forecast updates increases as the peak of the Atlantic hurricane season approaches.


Source:
https://tropical.colostate.edu/media/sites/111/2019/04/2019-04.pdf

28 thoughts on “2019 Hurricane season forecast: below average

    • vukcevic
      Very nice charts.
      What is the measurement for Arctic atmospheric pressure – surface? What is the scale?
      Are your conclusions that it is the Arctic pressure that influences cyclone activity?
      If so what are the controlling factors of Arctic pressure?
      With regards

      • Are your conclusions that it is the Arctic pressure that influences cyclone activity?
        If so what are the controlling factors of Arctic pressure?

        … or maybe not
        My interpretation (to be taken with a large lump of the sea salt) is:
        The North Atlantic has complex system of surface and deep water currents created by the warm water current branching of the North Atlantic Drift Current (extension of the Gulf Stream) creating N. Atlantic leg of the global thermohaline circulation known as the ‘Global conveyor belt’. Greenland sea (Iceland, Greenland, Jan Mayen triangle) is an area of the intense ‘ocean – atmosphere’ interaction. Cold winds remove the surface heat at rates of several hundred watts per square meter, resulting in deep water convection / down-welling. There is a close relationship between atmospheric pressure and the temperature of the sinking thermohaline.
        Deep water ‘Global conveyor belt’ is a slow moving current, taking some 15-20 years to reach NW coast of Africa, where some of the cold current up-wells (Ekman pump) and by displacing warm equatorial surface water, creating another intense ‘ocean – atmosphere’ interaction, giving birth to the emerging hurricanes. The up-welling current temperature carries signature of the Greenland sea atmospheric pressure going back some 15-20 years during the previous down-welling.
        Hence, no butterfly flapping wings required, but I’m not inclined to dispute any of the opposing interpretations.

  1. There is a 50% chance that half of the info provided will be off one way or the other.

    • I would say there’s a nearly 100% chance your forcecast will be off one way or the other… if your forecast includes no margin of error. 😀

    • How did their 2018 forecast do at the same time as last year?

      I would imagine insurance companies would be very interested in the accuracy of these predictions.

  2. When you have no real idea, the best prediction is that the future will be much like the past (or the average of the past).

  3. These forecasts for some reason never mention the WAMI (west African monsoon index).

    The actual ENSO forecast shows decreasing chances for El Nino as the summer progresses.

  4. “2019 Hurricane season forecast: below average”

    Oh no! Why can’t you find a historical data manipulator when you need one?

  5. Klotzbach is the real deal on Hurricanes. His mentor was Dr. William Gray and he has been doing this work since the turn of the century.

    When we lived in the Caribbean on our venerable old catamaran, the Golden Dawn, we anxiously awaited the Gray/Klotzbach forecasts and made our hurricane season plans accordingly.

  6. > 2019 Atlantic hurricane season will have activity slightly below the 1981-2010 average.

    What’s wrong with the 1979-2018 average?

    • It is greater than 30 years??
      Climate Scientists LLLLLOVE to base their prognostications against 30 year averages.

  7. I see where AOC was quoting that bogus “3,000 hurricane deaths in Puerto Rico” computer model the other day. The number was determined by a computer model that estimated the body count, not an actual body count. Someone ought to call AOC on this unsubstantiated speculation.

    https://www.americanthinker.com/blog/2018/09/trump_is_right_about_the_exaggerated_puerto_rico_hurricane_death_count.html

    “Using a study from a team of independent researchers, officials in Puerto Rico said they’re raising the official death toll from Hurricane Maria to 2,975 from 64.

    Researchers have determined that an estimated 2,975 people died from September 2017 through the end of February 2018. The independent study, from George Washington University’s (GWU) Milken School of Public Health, was commissioned by the Puerto Rican government.

    The estimate of 2,975 was determined using a mathematical model based on historical patterns, with adjustments made for age and sex, researchers said. That sum is more than 4,500 percent higher than the original estimate of 64.”

    end excerpt

    Modern-day climate science is just one lie after another.

  8. Can I complain about the use of the word ‘anomaly’ in these climate discussions and announcements, as in “the far North Atlantic is anomalously cool.”? Do they expect NA temperatures to remain constant and not vary about a mean?

    Anomalous definition: deviating from or inconsistent with the common order, form, or rule; irregular; abnormal

    Averages should not be expected to be ‘normal’ or expected conditions. The media like to make it sound abnormal for any climate measurement if it is anything but average, but averages are a calculation (not raw data) from the variations (the so-called anomalies), so should not be expected as the norm.

    Lay persons hearing the word ‘anomaly’ may be fooled into thinking that a reported value is unusual when it is not

    (disclaimer – I am not a scientist/mathematician)

  9. So, the real question is ‘how is a below average hurricane season a bad thing?’

    Not even farce – during the nearly twelve year hurricane drought there were literally articles in the mainstream press explaining why – the gist apparently being that Mother Nature was just loading it all up for a big one.

    • “So, the real question is ‘how is a below average hurricane season a bad thing?’”

      Bad if you want the weather wet in the southern US wet…

      On average, five North Atlantic hurricanes or their remnants lead to rainfall across the contiguous United States each year, contributing between a tenth and a quarter of the annual rainfall to the southern United States. While many of these storms form in the Atlantic basin, some systems or their remnants move through Mexico from the Eastern Pacific basin. Tropical cyclones from the eastern Pacific bring nearly 20 percent of the average annual rainfall to southern California. [from Wikipedia]

  10. Clueless Holthaus seems to be unaware about the unprecedented 12-year break from major hurricanes that ended less than 2 years ago in 2017. He needs to give the world a break from his hand-wringing hyperbole.

    The first look at Hurricane Season 2019 is here: 12 to 14 named storms 5 to 7 hurricanes 2 or 3 major hurricanes That’s a roughly “normal” season, but given the devastation of recent years — we really need a break.

    https://twitter.com/EricHolthaus/status/1113853983515398146

  11. According to science I thought the numbers should be down but individuals storms should record-breakers.

  12. I have been wondering, just from my memory of past seasons, if below average storm years have stronger storms, or stronger storms making landfall? Was discussing this season with some friends who are heading to Florida to relocate, moving to the area east of Naples, and it of course turned to “the worst storm” topic. Got me to thinking about which seasons are worse, high number of storms or low number, and is there any correlational between how many storms occur in a season and their strength, or lack thereof.

    • 2hotel9 – we look at the specific sources of energy and their strengths – and the coincidental surroundings in the region around the hurricane and where it’s moving. The synoptic pattern is rarely the same because there are different influential layers from surface to 35,000 feet.

      The correlation that climatologists talk about involves the strength of windshear and the warmth of the waters at different latitudes for each path of each season’s hurricanes. The paths are the result of the steering flow at 20,000 feet and it varies widely across the hurricane regions.

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