Lorenzo’s Ominous Climate Message

October 1, 2019

Washington Post:

Here are some remarkable facts about Lorenzo and recent Category 5 activity in the Atlantic:

  • It became a Category 5 over 600 miles east-northeast of the previously farthest east Category 5s on record – Isabel and Hugo.
  • It became the sixth Category 5 since 2016 (after Matthew, Irma, Maria, Michael, and Dorian). There have only been 26 Category 5 since 1960.
  • 2019 becomes just the seventh year with more than one Category 5 in the Atlantic, joining 1932, 1933, 1961, 2005, 2007, and 2017.
  • Its pressure of 925 millibars Saturday night was the lowest on record east of 50 degrees west longitude. The lower the pressure, the stronger the storm.

Abnormally warm waters in the Atlantic, likely boosted by climate change, aided Lorenzo in attaining such strength. “The water under Lorenzo when it was a Category 5 hurricane is about 28°C (82.4), which is about 1°C (1.8°F) warmer than average… just enough to give it that extra jolt,” wrote Brian McNoldy, Capital Weather Gang’s tropical weather expert.

As Tropical Storm Karen withers away, Hurricane Lorenzo has become “one of the largest and most powerful hurricanes of record for the tropical central Atlantic,” according to the National Hurricane Center.

Now packing 140 mph winds, Lorenzo became a Category 4 storm Thursday farther east than any other previous storm on record, save for Julia in 2010. While far from any populous land masses at the moment, Lorenzo could be having an impact on the Azores in less than a week’s time — all the while marking a potentially ominous climate signal.

The Category 4’s sprawling cloud shield spans more than 1,000 miles — roughly the distance from Washington, D.C., to Miami; including its outflow, it would be large enough to cover the entire East Coast beneath overcast.

Lorenzo is enormous. Its hurricane-force winds extend up to 45 miles from the center, with tropical storm-force winds reaching out 265 miles. The storm would be large enough to bring tropical storm-force winds to a region as large as the distance between the Delmarva Peninsula and Toronto.


For the time being, Lorenzo’s dance is just a show for meteorologists. But beneath the surface, it is the latest overachieving storm to fit into a pattern ripe with overachieving storms.

Lorenzo’s central air pressure was lower than that of any other hurricane on record this far east. It also became the strongest hurricane east of 45 degrees west longitude on record. Lorenzo is very much out of bounds.

It’s also only the 10th major hurricane on record east of the 40 degrees west marker. Five of those have occurred in the past decade, a number that National Hurricane Center forecaster Eric Blake called “probably no coincidence.” Ocean water temperatures in the corridor swept over by Lorenzo are up to a few degrees warmer than their former average baseline, making the lower atmosphere replete with fuel to spin up a beastly storm.

Hurricanes are the atmospheric equivalent of large heat engines; with more thermal heat input by the ocean as seas continue to warm, scientists have concluded that more of these higher-end storms are likely in the future.

A summary of available research from NOAA’s Geophysical Fluid Dynamics Laboratory notes that “tropical cyclone intensities globally will likely increase.” An increase in the most intense tropical cyclones, Category 4s and 5s, may already be underway. Each of the past four Atlantic hurricane seasons has featured at least one Category 5.

Hurricanes are the atmospheric equivalent of large heat engines; with more thermal heat input by the ocean as seas continue to warm, scientists have concluded that more of these higher-end storms are likely in the future.

A summary of available research from NOAA’s Geophysical Fluid Dynamics Laboratory notes that “tropical cyclone intensities globally will likely increase.” An increase in the most intense tropical cyclones, Category 4s and 5s, may already be underway. Each of the past four Atlantic hurricane seasons has featured at least one Category 5.

It’s not just the intensity of the storms we are seeing, it is the tracking behavior – which will be explored in the new video, stay tuned.

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2 Responses to “Lorenzo’s Ominous Climate Message”

  1. rhymeswithgoalie Says:

    We broke the arctic, which broke the jet stream. My bet in the office pool is that, with increasingly blobby formation of highs and lows, steering currents for tropical cyclones will increase the range of speeds for movements, both faster-moving and slower-moving storms than we usually see.

    It’s already clear that rain events—rather than wind speed—and the resulting inland flooding are becoming a more common source of damage.

  2. redskylite Says:

    Irish Times – Thu, Oct 3, 2019

    Ocean warming may be behind remnants of hurricanes hitting Ireland more often

    “We can expect more Storm Lorenzos. Ocean warming is leading to these storms travelling further. Storms will track this direction more often. This is a sign of things to come. Ireland is not ready for the future – we need to start planning now. Our coastal areas are at substantial risk.”

    https://www.irishtimes.com/news/environment/ocean-warming-may-be-behind-remnants-of-hurricanes-hitting-ireland-more-often-1.4038216


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