hurricane patricia, which is threatening the coast of western mexico with a catastrophic impact, intensified at rates that were among the fastest scientists have seen anywhere on earth. the storm went from 60 mph winds to 200 mph in just 30 hours.  by early friday morning, the storm was the most intense hurricane ever recorded in either the eastern pacific or entire north atlantic basin, which also includes the gulf of mexico and caribbean.  it's no coincidence that this storm exploded in an area of near-record warm sea surface temperatures that had not yet been tapped by any other recent storms. it's also an area where atmospheric conditions were favorable for such a storm to strengthen.  consider this: as of 5 a.m. et on thursday, the storm had 85 mile-per-hour winds and a minimum central air pressure of 980 millibars. by 5 a.m. et on friday, the winds increased to 200 miles per hour, with an air pressure of 880 millibars.  that's an astonishing 100 millibar drop in air pressure in a 24-hour period, which is virtually unheard of. the intensification rate looked like a steep staircase when graphed using a satellite-based computer algorithm that tracks storm intensity.  chart indicates the rapid intensification rate of hurricane patricia. image: university of wisconsin  a period of rapid intensification was forecast by most hurricane prediction models, though none foresaw the sheer ferocity that the storm would eventually achieve.  while scientists have made great strides in recent years in understanding what factors cause hurricanes and typhoons to rapidly intensify, there remain some mysteries about this process.  based on email conversations mashable had with a half dozen tropical cyclone experts on friday morning, here's what we know so far.  warm water served as fuel  the storm exploded over an area of exceptional ocean warmth, with waters of 1 to 2 degrees celsius above average for this time of year. in addition, the atmospheric conditions in this area were ideally suited for a rapidly strengthening storm, with what is known as "thermodynamic potential intensity" readings at a maximum. this occurred right in the area where patricia spun its way into the record books on friday morning.  the ocean warmth is largely due to a near-record strong el niño event, which has not only raised ocean temperatures in the eastern tropical pacific, but has also caused those warm waters to extend deeper below the surface than is usually the case, which also helps storms to intensify.  sea surface temperature anomaly in the area where hurricane patricia intensified. image: weatherbell analytics  in addition, most of the storms that have formed so far this year — and there have been a record number in the eastern tropical pacific — have formed well west of where patricia spun up. these left plenty of undisturbed warm water, which is fuel for a storm like this.  "basically that area closer to mexico usually has a lot more tropical cyclones nearby," said eric blake, a hurricane specialist at the national hurricane center in miami. "since they were all much farther west, patricia ended up moving over very warm, untapped waters with the rest of the conditions quite ripe."  cooperative atmosphere  ryan maue, a meteorologist for the private weather firm weatherbell analytics, said "alarm bells" were ringing on thursday based on computer model indications that the storm would intensify quickly.  tc ocean heat content anomaly. eastern pac beneath #patricia is extremely warm & deep @afreedma #elnino signature pic.twitter.com/la3a7uiuqq — ryan maue (@ryanmaue) october 23, 2015  these signals showed an "optimal/perfect atmosphere and ocean conditions for explosive intensification," maue wrote. he said the fact that patricia is a small storm, with a compact inner core of intense thunderstorms, helped it to "deepen pressure within a tiny radius of maximum wind." (the storm is smaller, in area, than super typhoon haiyan and hurricane katrina.)  maue also noted that the ocean temperatures the storm is tapping into are the warmest left in the entire northern hemisphere at this date, at about 31 degrees celsius, or 88 degrees fahrenheit.  but is this intensification rate an indication of how global warming is altering the characteristics and behavior of nature's most powerful storms? that's a harder question to answer at this point, scientists told mashable.  tropical cyclone potential intensity as of oct. 19, 2015, showing the highest value near where hurricane patricia intensified. image: kerry emanuel  kerry emanuel, a hurricane expert at mit, said the lack of a consistent record of eastern pacific storms using hurricane hunter flights makes it difficult to determine if there is a global warming-related trend in such storms. such flights are typically flown in the atlantic and only occasionally in the eastern pacific, so this was an exceptional case.  "there is no question that this is an exceptionally intense tropical cyclone," he wrote. "but i wonder whether we really know that prior storms in the region have not been equally intense and we are just lucky to have measured this one."  global warming considerations  maue, for his part, said hurricanes tend to respond to more localized conditions when intensifying or weakening, rather than global trends.  "hurricanes respond locally, and rapid/explosive intensification changes due to climate change could be a result but hard to say with just one storm during a strong el niño," he wrote.  kevin trenberth, a senior climate researcher at the national center for atmospheric research in boulder, colorado, said the unusually mild ocean temperatures are allowing more moisture to flow into the storm, which adds fuel to the fire.  trenberth's research has shown that global warming has increased the available water vapor for storms around the world, which plays a role in everything from more intense local downpours to hurricanes.  "the moisture flowing into the storm, that provides its primary fuel, must be higher than it has ever been before," he wrote. "it still requires the right setup to convert that into an intense storm, but the environment is surely ripe. that consists, of course, of a substantial el niño-related component, but also the background global warming that has a memory through the ocean heat content."  according to trenberth, el niño has redistributed ocean heat across the tropical pacific, putting a bullseye of heat right underneath hurricane patricia.  "this is the warmest large-scale spot in the hemisphere," trenberth said. this causes moisture to rush toward that area from relatively cooler ocean waters around it.  sea levels off the coast of mexico are about 8 inches above average because of the warm bulge of water (water expands as it is heated). "the subsurface ocean is exceptionally warm as well as the sea surface," he said.  it's not just el niño that's boosting ocean temperatures in the eastern pacific, either. other natural climate cycles are contributing too, according to hurricane researcher gabriel vecchi of the geophysical fluid dynamics laboratory in princeton, new jersey.  "to answer which factors was dominant, and by how much, would take a systematic analysis — so i don't think i'm willing to shoot for the hip to tell you which ones are important this year, much less for this particular storm," he said. "but it's my opinion that there will be time, and there are ways, to assess the impacts of these factors in the future."  according to vecchi, projections do show that global warming will increase ocean temperatures in the eastern tropical pacific, which could bring more hurricanes like this one.  tom knutson, who works in princeton with vecchi, told mashable that a new study shows that the northeast pacific basin, where hurricane patricia is located, will have the largest future increase in the frequency of category 4 and 5 storms of anywhere on earth, which he says is "probably just a coincidence."  he said computer modeling studies that he and his colleagues have published show that manmade warming will increase storm intensities in the future, and that this trend may already have begun to a "small" extent in the northeast pacific.  knutson cautioned that observations of northeast pacific storms do not show such a trend yet, at least for the period from 1982 to 2009.
how hurricane patricia became the strongest hurricane so quickly