Hurricane Dorian: Just weather, not climate change

Posted: September 7, 2019 by oldbrew in alarmism, atmosphere, Critique, Temperature, weather, wind
Tags: ,

Hurricane Dorian

As the peak of the Atlantic hurricane season arrives, weather forecaster Chris Martz tries to inject some sanity into the clamour around the latest weather event to hit the headlines. This is an extract from the full article, which as you might expect offers a more in-depth view.

We’ve made it three weeks without extreme weather and/or climate change hysteria making rounds on social media. Unfortunately, that streak has come to an end, making the lives of most weather forecasters like me a lot more difficult.

We are quickly approaching climatological peak of the Atlantic hurricane season¹ (September 10th) (Figure 1), thus it should be NO surprise to anyone that we have seen an uptick in tropical activity. However, I stand corrected - people are losing their minds about it.
– – –
Debunking the SST myth

I want to debunk the popular myth that has been circulating around the internet. Warmer sea surface temperatures (SST) does not guarantee that hurricanes will become more frequent or more intense.

While warm water temperatures extending from the surface down to around 150 feet (45.72 meters) below the ocean surface are required to be warmer than 80°F (26.67°C) for “fuel” for a tropical cyclone to develop,⁴ there are many other factors that govern hurricane activity not only on short-term time scales, but also decadal and millennial time scales, the latter of which I’m not going to explore in this article.

Warmer sea surface temperatures do not spontaneously spawn hurricanes. It just doesn’t work that way. Most of the time, there has to be a pre-existing atmospheric disturbance, preferably an area of low pressure where thunderstorms can form around (as that’s essentially what a hurricane is).

Low atmospheric pressure is caused by the convergence (meeting) of winds in the low levels of the atmosphere. Where these winds meet, they are forced to rise.

In the Northern Hemisphere, low pressure systems spin counterclockwise as a result of the Coriolis Force. The Coriolis Force in and of itself initiates vorticity in the atmosphere whereby winds can converge at the surface.

In addition to low-level convergence, the atmosphere in the lower to mid-levels of the troposphere must be fairly saturated in order for tropical cyclogenesis.⁴ The air becomes more humid if there is more evaporation occurring, which is a function of warm sea surface temperatures.⁴

Once the atmosphere in the low and mid-levels of the atmosphere is saturated, that means clouds will form as the air reaches the dew point temperature whereby water vapor must condensate out into liquid water droplets.⁴

If there is very high thermodynamic instability, or a sharp decrease in temperature with altitude, then more condensation will occur. The more condensation that occurs releases latent heat into the atmosphere, causing it to warm up (Figure 3).⁴

As the warmer air rises and expands, it’s forced to diverge once it reaches the tropopause and flow clockwise, thereby decreasing the air pressure at the surface.⁴

If the outflow of winds high in the troposphere is outpacing the converging winds at the surface, the air pressure will decrease around the center of the storm.⁴ If the central air pressure in the eye decreases, the storm will strengthen.⁴

Read more here.
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Note: for full text, graphics and numbered links – see original article.

  1. ivan says:

    So all rather a damp squib rather than a full blown problem just like all of the global warming/climate change/climate emergency/latest buzzword garbage that is being used to scare the public.

  2. oldbrew says:

    After-the-fact claims about ‘human fingerprints’ of climate change tend to fail the smell test IMO.

  3. oldbrew says:

    After-the-fact claims about ‘human fingerprints’ of climate change tend to fail the smell test IMO.

    Martz: La Niña years conversely tend to produce more hurricanes in the Atlantic basin due to lesser wind shear. It is for this reason for why I think that the Atlantic basin was very quiet between 2005 and 2017. Keep in mind, hyperactive seasons like 2005, 2017, and even 2018 (not hyperactive, but bad) were La Niña years.⁷

  4. oldbrew says:

    UK weather forecast: Hurricane Dorian remnants to hit Britain with gale force winds after glorious sunshine this weekend

    Forecasters say the tail end of the storm will hit Scotland and northwest England on Tuesday.

    Strong gusts and torrential showers will then move towards the southeast the next day.

  5. Gamecock says:

    Dr. Martz is correct that warm water to depth is required for hurricanes to form. What may not be obvious – and EVERYONE SHOULD KNOW – is that the tropical north Atlantic/Caribbean/Gulf of Mexico get hot enough to form hurricanes EVERY YEAR. It is ALWAYS THERE, summer to mid-autumn.

    “Global warming” can’t have an effect on hurricane formation, as it is already warm enough.

  6. oldbrew says:

    The claim now is that hurricanes will, or do now, dump more water than they used to. But even if turns out to be true, it would not have to mean any human causation was at work.

    Martz: ‘There are other theories that suggest that while hurricanes will NOT become more frequent or intense due to climate change, they may become wetter. By wetter, they mean increased rainfall. This is an interesting and plausible theory. NOAA has suggested it. But, until we start to see increases in hurricane rainfall, this theory doesn’t hold water.’

  7. craigm350 says:

    Dr Roy Spencer also looked at this:

    In the news reporting of major Hurricane Dorian which devastated the NW Bahamas, it is commonly assumed that hurricanes in this region have become stronger due to warming sea surface temperatures (SSTs), which in turn are assumed to be caused by human-caused greenhouse gas emissions.

    Here I will use observational data since the 1870s to address the question: Have landfalling major hurricanes on the east coast of Florida increased in intensity from warming sea surface temperatures?
    What surprised me is that the SST warming in this region during peak hurricane season (August/September) has been very weak: +0.02 C/decade since 1871, and +0.03 C/decade since 1950.

  8. oldbrew says:

    Re: craigm350 says…
    – – –
    No difference between the number of major hurricanes above and below the dashed line.
    Ergo: no trend. In fact only 3 of the last 10 are above the line.


  9. oldbrew says:

    SEPTEMBER 7, 2019

    NASA finds classic comma-shape in tropical storm Faxai
    by NASA’s Goddard Space Flight Center

    Faxai is on the right here…

    – – –
    Fibonacci spiral

  10. Gamecock says:

    ‘What surprised me is that the SST warming in this region during peak hurricane season (August/September) has been very weak: +0.02 C/decade since 1871, and +0.03 C/decade since 1950.’

    That we have SST data from 1871. Or 1881. Or 1891. Etc. Ridiculous. WTF is he talking about ???

    He uses a decimal point to show that he has a sense of humor.

  11. Gamecock says:

    Addendum: as Dr Martz says, SST has not a damn thing to do with it. It is temperature at depth that matters.

  12. oldbrew says:

    They are being led up the garden path by ridiculous climate model ‘projections’, based on the absurd assumption that minor trace gases dominate the planetary climate system.
    – – –
    Storm Dorian makes landfall in Canada
    6 hours ago

    Storm Dorian has made landfall in the Canadian province of Nova Scotia as a post-tropical cyclone.

    The powerful storm hit Halifax on Saturday with winds of 100mph (160km/h), toppling trees and cutting power to more than 450,000 homes.

    Canada’s Public Safety Minister Ralph Goodale said the military would be deployed to help recovery efforts.

  13. oldbrew says:

    Cries of ‘unethical’…

    ‘Alarmism enforcement’ on hurricanes and global warming
    Posted on September 7, 2019
    by Judith Curry

    I used to be concerned about ‘consensus enforcement’ on the topic of climate change. Now I am concerned about ‘alarmism enforcement.’

    Ever since Hurricane Katrina in 2005, any hurricane causing catastrophic damage has been seized upon by climate alarmists as evidence of the horrors of global warming.

    As if the record-holding hurricanes from the 1920’s through the 1950’s never happened.

    The catastrophic damage to the Bahamas from Hurricane Dorian is no different.
    . . .
    JC message to the ‘alarmism enforcers’

    Well there’s probably a better chance of President Trump listening to me than there is of the climate scientists who are alarmism enforcers listening to me, but here goes anyways.

    Your behavior is violating the norms of science, and in my opinion is unethical:

    — failure to acknowledge uncertainty and low levels of confidence in much of the research surrounding hurricanes and climate change.

    — cherry picking research that supports your personal narrative of alarm, without acknowledging disagreement among scientists and other research and assessment reports that do not support your narrative of alarm.

    — misleading the public and policy makers as a result of the above two practices

    — and last but not least, bullying other respected scientists who have different perspectives on evaluating the evidence.

    The above is what happens when scientists become political activists. [bold added]
    – – –
    Not sure alarmists are worried about being called ‘unethical’ :/
    As long as their employers are not worried, then hey-ho.

  14. oldbrew says:

    Worth a look…

    Surprising Parallels Found Between Solar Activity And Hurricane Development
    By P Gosselin on 7. September 2019

    Cat 5 Hurricane “Dorian” showed a development parallel to a solar storm lasting several days, which reached the earth from 27 August to 4 September 2019
    – – –
    Can’t rely on data from one event, but if a similar pattern from several events turned up they could be on to something.

  15. hunterson7 says:

    Please delete my post
    September 7, 2019 at 11:31 pm
    I posted it without review and allowed too many typos and spell check errors.
    Thank you

  16. Tom Williams says:

    The 1900 Hurricane that destroyed Galveston, TX and left 5,000 dead is just one of many severe storms that preceded the “human induced” climate change. The hyper activists will draw on any event to use as “proof” of their theory. No snow = climate change: Tons of snow = climate change.

  17. […] Posted: September 7, 2019 by oldbrew in alarmism, atmosphere, Critique, Temperature, weather, wind Tags: climate change, hurricanes 18 […]