Atlantic Hurricane Season – 2018
By Paul Homewood
Now that the Atlantic hurricane season has officially finished, it’s time to round up the data.
Despite a lot of media hype, the season has actually been pretty ordinary:
http://www.aoml.noaa.gov/hrd/tcfaq/E11.html
http://www.policlimate.com/tropical/
http://rammb.cira.colostate.edu/products/tc_realtime/
There were eight Atlantic hurricanes, of which only two were major, Florence and Michael. As both of these hit the US, there was inevitably more media coverage.
ACE was also at unremarkable levels, given the current warm phase of the AMO, when hurricanes tend to be stronger.
Globally, data for the 12 months up to the end of September shows 48 hurricanes, including 27 major.
http://www.policlimate.com/tropical/
ACE data is up to the end of October:
http://www.policlimate.com/tropical/
Neither metric shows anything out of the ordinary this year. Both indicate that hurricane activity peaked in the 1990s, and that over the last decade it has been at similar levels to the 1970s and 80s.
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NOT A LOT OF PEOPLE KNOW THAT 
Interesting – I see a bit of a correlation to global warming trends in the Atlantic basin hurricane plots (might also plot well against various ocean oscillation phases). An increasing trend with GW cycle between 1910-1945ish. Followed by a decreasing trend during global cooling from then but continuing past 1980 for another decade or so. Then an increase with the late 20th Century warming. Still warm out there – no recent major warming, nor cooling (yet) trend . . so it seems to stay rather active.
I’m not associating anthropogenic influence in that . . though perhaps there’s some in the past 40-50 yrs.
It’s almost possible to see a sine wave in the first three graphs.
Reblogged this on Climate Collections.
“Despite a lot of media hype, the season has actually been pretty ordinary
Surprise, surprise……..40 years of…….ordinary.
Not a go at you Paul.
Also this
https://tambonthongchai.com/2018/11/28/trends-in-tropical-cyclone-activity/
I suspect that we will see more in the coming years. For two years in a row we have seen an arc of cold water in the Atlantic in the NH and in those years we have seen above average seasons. I believe that we are at the beginning of a shift of the AMO to a negative phase and thus can expect to see more stormy weather in all of the seasons.
However I have no explanation for the dearth of active tornado seasons we have been experiencing here in N. America. This Hoosier sure isn’t complaining about that.
I was looking over the articles about the historic blizzard of 1978 we had when I was a young man. Now THAT was weather. Lowest barometric pressure ever recorded in the US not associated with a tropical system, 955.5 mb (28.22 inHg) . The only time in history a Governor of Indiana declared an emergency for the entire state. The only time in history the Indiana State Police declared all roads in the state closed to all but emergency vehicles. Trains couldn’t get through and the National Guard state wide was mobilized to bring out their heavy equipment to help clear the tracks and the roads. Indiana Bell telephone company only allowed emergency calls to go through. https://www.weather.gov/iln/19780126
Thanks for that RAH. The pictures in the link are wild; remember the news and photos of the storm quite well. I’ve looked off and on for a incredible color photo that was on the cover of some mag (thinking it was Life) following the storm. It was an aerial shot of a suburban area a day, or so after. Sunny, crystal clear blue sky, in the background. The snow is so deep not only are no cars visible, the houses were pretty much only identifiable by the pitch of the roofs buried under the snow. The whole area was simply buried.
I remember a snow plow trying to negotiate a street in Anderson, IN. It was taking the door handles off the buried parked cars on each side of the road. Indiana Highway nine had 4′ of snow covering it and the only way to get through was snowmobile. Twenty foot drifts in some places.
Some more facts about that blizzard.
https://www.wibc.com/blogs/wibc-blog/9-frosty-facts-about-blizzard-1978
No doubt if it happens again it will be blamed on Global Warming.
Off topic admittedly al beeb link but I couldn’t allow these quotes to go unnoticed with reference to, the
climatecultural Marxist loonies gabfest in Katowice.“not a political football” ?
(giggles in gales)
“not a political football” hmm but actually the whole shebang is erm “political”, how is it that these fixated eco lunatics – can she be so insouciantly unaware, or does dearest Camilla make play with us?
Before there was this:
so spake, “Yamide Dagnet from the World Resources Institute, and a former climate negotiator for the UK.”
Which begs the question, on who’s behalf and at who’s behest is Yamide Dagnet negotiating on, certainly not me and I would posit the same sentiments shared by some other 60 odd million Brits?
No doubt Yamide (quals?? a jejune yuman rites lawyer probably) was on some ridiculously grand stipend to do all this ‘negotiating’ on our behalf and on the say so of no one but our masters in the EU UK executive and in microcosm – ain’t it the problem. Democracy is it?? – you’re aving a larf – or they are and at our expense, paid for by you and me.
COPs? Climate conferences – to do what? other than a profligate, egregious and monumental waste of taxpayers money and time, without grand taxpayer subsidy – the great green scam just disappears up its own fundament and a dark place is where it needs to go.
Hurricanes form over warm ocean water. The water in the tropical Atlantic, the Caribbean Sea, and the Gulf of Mexico get hot enough to form hurricanes EVERY YEAR.
Whether hurricanes form and how they track is dependent on WEATHER conditions, not ocean waters. The ocean waters are ALWAYS available in season to support hurricanes.
“…to support [sic] hurricanes…”
The hurricane phenomenon is merely one of unstable air masses – it has very little to do with the heat energy in the water, except in so far as a higher temperature in summer can increase the water vapour above the sea’s surface, and START a vigorous convection. * The actual core of high wind results from CONCENTRATION of ‘curl’ (measure of vorticity) that is already in the atmosphere. ** It is like a skater pulling in her arms and spinning faster.
Only a tiny amount of the energy conveyed into the atmosphere by evaporation and subsequent condensation goes into increasing the vorticity. The idea that slightly warmer water and air somehow has more energy which must manifest in the kinetic energy of high wind, is simply silly.
* Air that receives water vapour immediately becomes less dense.
As a matter of interest, even on clear days at sea it is sometimes observed that sound does not travel far. That is when the sun has driven water vapour into the air; for it is well known that a cloud of invisible water vapour will block sound waves as effectually as a visible cloud will block light rays. It is one of the subjects Tyndall investigated, with a view to improving the warning bells operating on light-houses.
**The atmosphere as a whole has almost no net curl – there are areas of cyclonic and anti-cyclonic tendencies, which largely balance out.
Then call me silly.
‘Development of a tropical depression into a mature hurricane requires heat energy from the ocean surface. For this reason, hurricanes do not usually develop over land or outside of the warm tropical oceans where the sea surface temperature (SST) is colder than ~26.5°C (~80°F).’
The ‘tropical depression’ has almost as much wind energy in it as the ‘mature hurricane.’ It is just that the ‘run-away’ convection in the hurricane has drawn the winds into a tighter spiral and concentrated the energy into a small area of high winds. The run-away is a spontaneous, random, threshold, phenomenon, which depends on the sea temperature (an intensive physical measure) and not on heat energy per se (an extensive physical measure).
The stylized picture of Atlantic hurricanes is that they start as little whorls thrown off from Africa which drift across and somehow ‘feed’ on the hot water SO THAT the stolen heat increases the speed of the wind. But is better to think of them as diffuse, BIG whorls; the angular momentum is simply conserved, if by chance a hurricane develops.
If the top of an incipient hurricane is torn up by local wind-shear it does not develop; and this is not really consistent with the view that it is essentially a monster feeding on the heat in the water, is it?
The hurricane immediately dies when it goes over land because there is not enough water vapour there, evaporating from the the surface, to keep the central air column light and rising. The energy of the wind partly spreads out again and partly is lost by friction with the surface.
In general, about 1/200 th of the heat transferred from the ocean to the atmosphere during a hurricane is converted into kinetic energy.
If the entire annual cycle of surface temperature of the sea in the Caribbean shifted up a little, this might increase the LENGTH of the hurricane season,but not change individual hurricanes which will always be variable.
As I remember correctly the first half of the Atlantic season was dominated by heavy dust coming off Africa inhibiting formation in the main development region. It not for that, the 2018 season could have been much worse.
The kick start to get the convective energy engine of a hurricane to begin takes energy from another source. The energy of contrasts in pressure.
And Dave, though hurricanes generally degenerate rather quickly as they come over land they can still be deadly. The great hurricane that hit Galveston, TX in 1900 killed far more people inland than it did at the shore.
This truck driver drove through the remnants of TS Gordon this year coming up Interstate 57 in Southern Illinois and it was no fun. Driving north just south of Marion, IL I hit a wall of horizontal rain just south of Marion, IL. The wind and rain was coming directly out of the west. So it was 4 or 5 miles of flashers on moving at 15 mph and thanking my lucky stars I had some weight in the 53 ft trailer I was pulling. Most of the smaller vehicles pulled to the shoulders to wait it out. After I drove out of it and went about 10 miles of clear driving I hit a blast of wind and air coming out of the east. This northern part of what was left of the storm was far less powerful. But the fact is what had been TS Gordon still had it’s cyclonic rotation 1,000 miles after it came ashore.
“The [potential] energy of contrasts in pressure.”
That is what “lighter air” means – sort of. Over land, the lighter air comes about when the sun heats the surface, which warms the lowest air by conduction whilst the upper air is always cooling by means of net radiation to space. Over water, it comes from the statistical properties of the phase changes of water molecules at the interface between liquid and gas and the way in which dry air and water vapour mix.
Because air rising in one place is always matched by air descending in another place, the net amount of energy needed for atmospheric convection is small. This is just like a moving elevator in a building, where the car and the counter-weight simply exchange potential energy and only a small amount of electrical power is needed to move the people and overcome frictional losses.
Viewed as a heat engine (in which the load or useful output is kinetic energy of air moving in bulk) the sea/air system is extremely inefficient. That is lucky for us. Imagine if, say, a hurricane was 50% efficient. That would translate into gusts of 2,000 mph.!
“Still had its cyclonic rotation.”
Exactly. When I said hurricanes immediately die, I meant as hurricanes. They still have a punch and they can make a lot of rain.
Once inland mountains are the fastest killer of hurricanes.