Whether The Weather Deteriorates -- Possibly
"There's almost unanimous agreement that hurricanes will produce more rain in a warmer climate."
"There's agreement there will be increased coastal flood risk, at a minimum because of sea-level rise. Most people believe that hurricanes will get, on average, stronger. There's more debate about whether we can detect that already."
We used to think twenty years ago that in a warmer climate there would be more hurricanes."
"Then the computer models got better. Most of those started to show fewer hurricanes, not more. No one knew why Then some of the models started to show increases with warming. So I think we're back to where we don't know."
Adam Sobel, professor of applied physics, Columbia University
"If we had twice as many Category 5s -- at some point, several decades down the line -- if that seems to be the new norm, then yes, we'd want to have more partitioning at the upper part of the scale."
"At that point, a Category 6 would be a reasonable thing to do."
"The hurricane track has less guidance steering them, so are more prone to meanders and unusual turns."
"If the jet stream were a lot farther north, then you could imagine a situation where hurricane tracks could more easily hit the North American continent because they have more ability to continue in the direction of the continent from their tropical formation points."
Timothy Hall, senior scientist, NASA Goddard Institute for Space Studies
"We've tried to steer the focus toward the individual hazards, which include storm surge, wind, rainfall, tornadoes and rip currents, instead of the particular category of the storm, which only provides information about the hazard from wind."
"Category 5 on the Saffir-Simpson scale already captures 'catastrophic damages' from wind, so it's not clear that there would be a need for another category even if storms were to get stronger."
Dennis Feltgen, National Hurricane Center spokesperson
"Whether we're talking about a change in the number of storms or an increase in the most intense storms, the changes that are likely to come from global warming are not likely to be detectable until 50 years from now."
"There's so much natural variability in the system, the typical year-to-year variability in hurricane activity, that the signal really doesn't emerge from that background variability until the latter half of this century."
Brian Soden, professor of atmospheric sciences, University of Miami Rosentiel School of Marine and Atmospheric Science
Whew! All agreed? Climate change on the way? Um, hasn't climate change per se, always been a fact of weather variability on this planet? Little Ice Ages and that kind of thing? Sun spots affecting the degree of over-heated temperatures experienced in summer? Well, of course, too simplistic. The weather specialists know what's really happening. Don't they? Oh they don't really, after all, agree? Everyone busy out-experting the other, kind of thing. Well, it is a complicated matter, what nature in continual flux decides to impose on earthly existence. Not much given to consultation, either.
According to Dr. Hall, top wind speeds of up to 370 km/h by the end of this century could be commonplace during storms, should current trends continue in global warming. That windspeed comparable to the frenzy of a F-4 tornado capable of lofting cars and tossing them airbound. The question then is, whether five-category hurricane scale descriptives currently in use should be reflective of new wind speeds to include a Category 6, even 7?
Developed in the early 1970s the ranking of hurricanes from Category 1; winds of 119-152 kilometres an hour up to the most powerful, Category 5, covering winds of 250 kilometres an hour and over, have sufficed to the present, each covering a range of wind speeds. With wind speeds reaching 300 kilometres an hour latterly with more powerful storms with Irma reaching 289 kilometres and Hurricane Patricia off the Pacific coast of Mexico reaching a sustained wind speed of 346 km/hr, time to consider new categories?
Will naming and categorizing wind speeds actually accomplish anything in the science of forecasting? Apparently many of the experts simply shrug their shoulders in exasperation at the wasted effort in focusing on wind when so many other destructive issues should be factored into dangerous hurricane activity. As for predictions, there appears to be a good level of agreement that storms of the future will be activated in lower motion. The journal Nature published a new study finding tropical cyclones forward speed have been diminished by ten percent since 1949, so there's precedent aplenty.
What that means is not the expectation that winds diminish; rather hurricanes are in no hurry to move over a target area, they linger as did last year's Hurricane Harvey, settling over Texas, dropping over a metre of rain, to flood thousands of homes. A lot more rain is anticipated with slower future hurricanes as another study this year by researchers at the National Center for Atmospheric Research observed 20 Atlantic hurricanes to determine how they might be altered, taking place at century's end, linking them to global warming with the assurance that warm air retains more water than cold.
Hurricanes, according to the study conclusion, would generate on average more rain to the tune of 24 percent, representing a massive increase assured of producing catastrophic flooding. A study judging the amount of rain Harvey might have been responsible for had it occurred in the 1950s found rainfall had increased by up to 38 percent, attributed to global warming. Other studies view Harvey as an omen of what to expect in future.
Hurricanes are expected to follow more meandering and less predictable paths in the future resulting from climate change altering the jet stream, that high-altitude air current that streams hurricanes north and east. With warming oceans providing fuel for hurricanes, a hotter world might produce more frequent storms -- not necessarily -- feel some scientists -- more powerful storms.
Modelling for future climate events appear to indicate an increase in wind shear; criss-crossing high-altitude winds that rip apart incipient tropical cyclones. Showing as well less atmospheric instability required for the generation of thunderstorms.
So where were we now....?
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| A new analysis of global hurricane data since 1980 shows the number of storms with winds over 124 mph has doubled, and those with winds over 155 mph has tripled. Credit: NASA |
Labels: Climate Change, Global Warming, Nature, Storms, Weather
posted by Pieface @ Monday, July 16, 2018
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