This year, two tropical cyclones have sprung up in the Western Arabian Sea. A region where, according to our understanding of climate, “storms do not form.” Well, the climate has clearly changed. Because a storm is raging there now. And for Oman today, these changes bring with them serious threats to life and property.
(Discussion of how climate change has altered tropical cyclone formation and intensity dynamics in the Western Arabian Sea during 2018.)
About five days ago, tropical storm Sagar formed east of Somalia in the Western Arabian Sea near the Gulf of Yemen. The storm was notable due to the fact that it was the furthest west a storm had ever formed in this region, according to records. The storm then dumped copious amounts of rainfall over Somalia — resulting in the loss of 34 lives.
Just a few days later, a second storm, Mekunu formed in about the same region. Tracking north, it is now threatening Oman with the potential to hit category 2 intensity. Unlike Sagar, Mekunu poses a triple threat due to expected very heavy rainfall, large waves, and storm surge.
(Mekunu rages south of Oman and Yemen after forming in the Western Arabian Sea. Image source: NASA.)
The region near Salalah Oman that the storm is barreling toward — typically receives just five inches of rainfall per year. But Mekunu could deliver two to five times that amount (or more) in just a few days. Moreover, the flat coastal plain is backed by mountainous terrain to the north. The higher land produces lift that will intensify expected rainfall. And current models predict that more than two feet of water (24 inches) could fall on up-sloping regions facing Mekunu’s advance. What’s notable is that these totals keep rising and that peak local totals for the storm in the NOAA NCEP model show some ridiculous amounts — up to 74 inches (see below).
Why are peaks in this model so high? First, sea surface temperatures are very extreme throughout the region. In the immediate vicinity of Mekunu, ocean surfaces range from 30 to 32 degrees Celsius. The waters are about 1 to 2 C above normal and are thus providing Mekunu with a lot more moisture than is typical. However, the larger environment that Mekunu is feeding off of also has much higher than typical moisture loads. For one, sea surfaces east of Somalia have spiked to as much as 5 C above average recently — pumping out great loads of evaporation. Further, moisture levels over the Arabian Peninsula are high due to moisture streaming in along a rather intense subtropical Jet Stream moving over the also much warmer than normal sea surfaces in the Med. The result is a much higher than normal rainfall potential.
(Mekunu presents a very severe rainfall risk for Oman in addition to a predicted strong storm surge and very high waves. Image source: NOAA NCEP.)
The significant wave height leads me to think coastal flood potential is a real threat. At some point the water from waves crashing onshore does not have time to drain before the next wave hits. My gut feeling is that we could see a noticeable storm surge that is quite dynamic, with a lot of wave action and rapidly moving water. Expect wave heights to be tremendous.
(Much warmer than normal sea surface temperatures in the Mediterranean and Arabian Seas are helping cyclones to form in atypical regions even as they are lending fuel to their intensification. Image source: Earth Nullschool.)
Mekunu’s intensity is certainly quite high. And it is one of a recent spate of storms to impact the region. With research showing that the intensity of storms in the Arabian Sea has increased during the past 20 year period. However, the far western formation of Mekunu and Sagar add a new twist to the story. For it appears that the zone of storm formation is also shifting westward as sea surface temperatures rise and, apparently, Jet Stream changes have the potential to deliver higher levels of atmospheric moisture to the Arabian Peninsula. All of these factors feed both storm formation and intensity potentials.
Too close to home. That’s the sentence that best describes hurricane Matthew’s impacts — at least for this particular observer. And it’s one that I think we will be saying more and more often over the coming years as sea levels rise and peak storm intensities continue to increase due to a human-forced warming of the world’s atmosphere and oceans.
(Hurricane Matthew interacted with a trough to dump 1 in 1000 year rains over North Carolina and Virginia on October 8th even as its powerful storm surge continued to flood coastal communities. Image source: LANCE MODIS.)
Severe Damage To Florida Coastline Communities — But it Could Have Been Worse
On Thursday, October 6th, as the storm was barreling in toward the Florida coastline, I was on the phone with numerous Florida relatives — somewhat frantically asking if they’d heeded evacuation orders and gotten away from low-lying areas near the ocean. One uncle had decided to hunker down in an inlet-side New Smyrna Beach home about 6 feet above sea level, but the rest had headed inland. Thankfully, Matthew passed just off shore of New Smyrna at low tide — only giving my uncle a bit of a scare by flooding his neighborhood but not completely inundating his house (as would have happened if Matthew had made landfall in that community as a category 4 storm rather than remaining at sea).
Further north, my college town of St. Augustine, FL did not fair quite so well. Downtown St. Augustine, which borders the Matanzas River — an estuary of the Atlantic Ocean — saw Matthew sweeping by at high tide. As a result, severe storm surge flooding rose up over the sea wall and put the city’s streets under 3-4 feet of water. Local businesses flooded, a 17th Century Fort that is a tourist attraction saw its moat fill and then overtop, and Flagler College, which I attended during the 1990s, had its grounds soaked. Nearby, parts of Route A1A on Flagler Beach were swept out into the Atlantic Ocean even as the dune line at Jacksonville Beach was breached — precipitating significant tidal flooding through parts of that seaside city. But as with New Smyrna Beach, the situation would have been far worse for St. Augustine and Jacksonville if Matthew had made landfall and not remained off shore.
Matthew Delivers Severe Flooding to Georgia, South Carolina, North Carolina and Virginia
As the storm passed just to the east of North Florida on October 7th, consensus model guidance at the time suggested that Matthew would re-curve out to sea after battering Florida, Georgia, South Carolina and North Carolina, returning for a possible second hit to Florida by about the 13th as a much weakened system. However, Matthew instead took a more northerly track — hugging the coastline. As a result, moderate to severe coastal flooding impacted beach after beach from Georgia and on through South Carolina, North Carolina and Virginia even as heavy rains inundated the region.
(Matthew pushes storm surge flooding into Murrells Inlet — inundating local communities and swamping this marina. Video source: Huge Storm Surge Follows Hurricane Matthew.)
At Murrells Inlet — a late-summer and early fall reunion and beach-going spot for my family — over-wash from the ocean and tidal flooding from the local inlet pushed 1-2 feet of water into numerous neighborhoods. A local marina from which family members have enjoyed both the scenic view of the inlet and such water activities as kayaking through the teeming waterways to experience close-up encounters with local fish and wildlife was completely flooded out on the 8th of October as Matthew passed (see video above).
Meanwhile, severe flooding rains were just starting to sweep into North Carolina on the 8th and 9th — presenting a serious problem even as coastal communities along the Outer Banks received a significant battering. A large swath of the state saw up to 16 inches of rain fall. These rains hit regions already saturated by previous extreme rainfall events. As a result, water-logged grounds could not take in any more precipitation and rainfall runoff swiftly flooded streets and streams. The flooding has, by early Tuesday afternoon, left 14 people dead, three people missing, and thousands of homes inundated by rising waters. A severe flood situation that is still ongoing as of October 12th. North Carolina Governor Pat McCrory stated earlier today that: “Too many people have died, and we don’t want anymore to die. Yet there are going to be conditions during the next 72 hours which will be extremely dangerous.”
(Hundreds of vehicles, homes and businesses were flooded across Hampton Roads as a result of Matthew’s severe storm surge and heavy rainfall. The region has grown particularly vulnerable during recent years due to sea level rise — which has added about 1.5 feet of water rise over the past 100 years and could add another 2-3 feet or more by mid-Century under a business as usual fossil fuel burning emissions path. Image source: Hurricane Matthew Causes Widespread Flooding, Power Outages.)
On the 8th and 9th Matthew also began to hurl its flooding rains and storm surge at my parents’, grandparents’, and sister’s homes in the Hampton Roads cities of Norfolk, Chesapeake, Virginia Beach and Portsmouth. A local river backing up to the Albermarle and Pamlico sounds rapidly filled with storm surge flooding — inundating my parents’ neighborhood and leaving them stranded. Flooding in Chesapeake also stranded my sister in her home. Flooding from heavy rains and a significant storm surge swept into houses on Atlantic Avenue in Virginia Beach near my grandmother’s residence. Downtown Norfolk was shut down by storm flooding (see Granby street image above) and the heavy rains of Matthew combined with a previous severe rainfall event just two weeks ago to produce more than 30 inches of accumulated rainfall over the past 30 days for some parts of Hampton Roads. The result of Matthew’s combined heavy rains and storm surge for the region was never-before seen flooding for many areas — including my parents’ neighborhood.
Matthew and the Continuing Erosion of Normalcy
Thankfully, everyone I know is OK. But the same cannot be said for six people living in Florida and Georgia, 14 (and possibly more) people living in North Carolina, and over 1,000 people who are now thought to have lost their lives as Matthew made its first catastrophic landfall in Haiti. There, tens of thousands are estimated to be homeless as a result of the storm which leveled entire forests and towns as it roared ashore packing 130 mph sustained winds. Now, aid agencies are struggling to reach the survivors even as tropical diseases such as cholera threaten to spread in the unsanitary conditions following in the storm’s wake.
(Hurricane Matthew maintained strength as a major hurricane for the longest period of time on record for any October storm in the North Atlantic. Near record warm surface waters and a record warm and moist global atmosphere helped to enable Matthew to remain strong for such a long period of time — producing severe damage along a swath stretching for about 1,500 miles. Image source: WLXT.)
As a family, my relatives have suffered dislocation and some property damage from the storm. But we are among the fortunate ones. We did not experience the devastating material losses and loss of life that has impacted some in Haiti or North Carolina. However, what we have experienced is a loss of security. We’ve seen floods that have never happened before in the neighborhoods we occupy and in the places we have grown to love and cherish. And we find ourselves wondering what the next Matthew will bring — or the next, or the next.
Conditions in Context — Climate Change is Making Storms Like Matthew More Powerful and Devastating
Matthew was an extraordinarily powerful storm whose devastating toll will continue to be counted during the coming weeks and months along its broad and wide-ranging swath. But as we pick up the pieces, respond to the still ongoing disasters in North Carolina and Haiti, begin to rebuild, and try return to semi-normalcy, we should also seriously consider the conditions that helped to spawn Matthew and to bring about its record October intensity. For Matthew emerged over near-record hot waters, formed in a record hot world, and produced its damaging storm surges out of seas that are rising due to human-forced climate change.
(Rising sea levels spurred by global warming is an enabler of worsening coastal flooding during storms. In addition, added atmospheric moisture and ocean heat due to global warming increases peak potential storm intensity. Image source: Dr. James Hansen Warns Seas Could Rise by Several Meters This Century.)
Matthew’s heavy rains were unarguably pumped up by near record atmospheric moisture levels due to conditions related to climate change. And Matthew’s long, strong intensity was fed by all that climate change related heat and moisture. Like Sandy and Katrina, Matthew was a fore-runner to the worse storms that are now on the way. Storms made worse by our continued burning of fossil fuels and what is a wholesale global dumping of carbon into the Earth’s atmosphere. Until that stops and the Earth starts to cool — freak events like Matthew and Sandy will continue to occur. To grow worse and to have their peak wind intensities pumped higher, their rains intensified, and their storms surges compounded by rising sea levels, larger storm circulations, and stronger wind fields.
(Matthew is predicted to track along the Eastern Seaboard from Central Florida through Georgia as a major hurricane on Friday and Saturday. After this first predicted strike as a major hurricane, long range model guidance is indicating that Matthew could re-curve. Such a path would bring Matthew repeatedly over the near record warm waters of the Gulf Stream and possibly produce a second landfall in Florida by Wednesday of next week. Image source: The National Hurricane Center.)
Matthew — A Record-Breaking Storm in a Record Hot World
This powerful hurricane has consistently fed on sea surface temperatures in the range of 29 to 30 degrees Celsius (84 to 86 Fahrenheit). These waters are 1-3 degrees Celsius above 20th Century averages and are at or near record hot levels. Furthermore, added heat at the ocean surface has led to greater evaporation which has contributed to 75 percent relative humidity readings at the middle levels of the atmosphere.
Such high levels of heat and atmospheric moisture are not normal. They provide an excessive amount of fuel for powering intense hurricanes like Matthew. And all this heat and moisture is now made more readily available by a record hot global environment resulting from the ever-rising levels of greenhouse gasses in the Earth’s atmosphere due to fossil fuel burning.
Maintaining Major Hurricane Intensity Despite Making Landfall Twice
Yesterday this heat-fueled storm vented its fury first on Haiti and then on Cuba. But as the rains fell at rates of up to 5 inches per hour and as the winds howled in at 145 mph, the mountainous terrain of these two islands took its toll on Matthew’s circulation. According to Dr. Jeff Masters, Matthew’s eye wall was disrupted and partially collapsed as the storm tracked over rugged eastern Cuba. As a result, its peak intensity dropped off from 145 mph early Tuesday to around 115 mph or a minimal category 3 storm during the morning on Wednesday.
(Near record warm surface waters in the Caribbean Sea and in the Atlantic Ocean off the US East Coast in the range of 1-3 degrees Celsius above average combined with very high atmospheric moisture levels to fuel Matthew’s unprecedented intensity. Such conditions are consistent with those produced by human-caused climate change. Factors that provide more energy for storms to feed on when they do form. Note that the readings depicted in the map are departures from average — with red through orange, yellow and white representing above-normal temperatures. Image source: Earth Nullschool.)
Matthew Restrengthening
But Matthew has since re-emerged as a major hurricane over very warm waters near the Bahamas and it is again drawing on a nearly unprecedented supply of ocean heat and atmospheric moisture. As a result, the storm is rapidly re-strengthening. Thunderstorms around the center are rising again to towering heights. Pressures are dropping and peak wind speeds are starting to pick up. By tomorrow morning, it’s entirely possible that Matthew will have returned to Category 4 status — boasting a very large circulation and sustained winds in excess of 130 mph as it starts to threaten the Florida coast.
As of 5 PM EST on Wednesday the storm had already regained some intensity — hitting 120 mph maximum sustained winds. Model guidance puts the storm near or over the Coast of Central and Northern Florida by Friday morning with some models (ECMWF) showing a minimum central pressure near 940 to 945 mb by that time — representing a very powerful storm with winds possibly again exceeding 145 mph.
(Rapid bombification? Matthew re-intensifies as it tracks toward the Bahamas and Florida. Very dangerous situation emerging with swift, significant increases in strength possible. Image source: the National Hurricane Center.)
Matthew’s Predicted Track Could Bring Major Hurricane Conditions to Numerous East Coast Communities
Matthew is predicted to run parallel to the coast, with part of its circulation remaining over water. As a result, the storm could maintain intensity even as it drives hurricane force winds and strong storm surges into multiple cities and towns along the coast.
The subtropical ridge over the western Atlantic is still strong, and the flow pattern around this ridge should continue to steer the hurricane toward the northwest during the next day or two with no significant change in forward speed. After that time, the ridge will shift eastward, allowing Matthew to move northward very near or over the north Florida east coast, and then near or to the east of the Georgia and South Carolina coasts.
Such a path would tend to keep Matthew strong for a longer period of time. In addition, movement along the coastline could result in severe impacts ranging over a very large region — not just focusing on a particular section of the shore, but running along the oceanfront for hundreds of miles. In the worst case scenario for Matthew, diverse regions from Cape Canaveral to Jacksonville to Savannah all experience significant hurricane impacts including major hurricane winds and severe storm surge flooding.
(Hurricane Matthew has the potential to put multiple communities from Florida through Georgia under severe storm surge flooding. The above map shows a worst case scenario (1 in 10 probability) where most of St. Augustine, FL — a city of about 120,000 people — is under 1-9 feet of water. This potential is repeated in the NHS model on up and down the Florida and Georgia coastlines. Image source: The National Hurricane Center.)
Matthew Could Hit Florida Twice
But if the current forecast isn’t rough enough, the long range looks even worse. Model guidance is now starting to form a consensus that Matthew may not immediately head out to sea following its first encounter with the US East Coast. In fact, models like GFS, ECMWF and CMC are indicating that Matthew may loop back, possibly even striking Florida a second time by Wednesday (GFS). Though highly uncertain, the possibility of Matthew returning to the warm water environment that so greatly added to its strength initially, before hitting Florida a second time, was enough to draw some pretty strong words from experts like Dr. Jeff Masters over at Weather Underground earlier today.
Dr. Masters noted:
Thanks to my advancing years and a low-stress lifestyle that features daily meditation, there’s not much that can move me to profanity—except the occasional low-skill driver who endangers my life on the road. But this morning while looking at the latest weather model runs, multiple very bad words escaped my lips. I’ve been a meteorologist for 35 years, and am not easily startled by a fresh set of model results: situations in 2005 and 1992 are the only ones that come to mind. However, this morning’s depiction by our top models—the GFS, European, and UKMET—of Matthew missing getting picked up by the trough to its north this weekend and looping back to potentially punish The Bahamas and Florida next week was worthy of profuse profanity.
Such a loop back and second hit to Florida and the Bahamas is highly uncertain at this time. However, given all the heat and moisture available, there’s a possibility that Matthew could re-strengthen along such a path after the significant wind shear predicted Sunday and Monday subsides — bringing forward the possibility, however unlikely, of the same storm striking Florida and the Bahamas twice as a major hurricane over the course of 5-7 days.
It would be a very odd and unfortunate event if it did happen. One that would have been fueled by all the climate change related hot water and near record moisture readings sitting at the ocean surface and rising on up into the middle levels of the atmosphere. But given the storm now blowing up over the Bahamas this evening, a possible first strike is already looking rough enough.
UPDATES TO FOLLOW
Links/Statements:
Note: This is a potentially highly dangerous developing weather situation. Coastal interests from the Bahamas through Florida, Georgia and the Carolinas should stay abreast of forecasts provided by the National Hurricane Center and stay tuned to local weather statements and/or possible evacuation/emergency storm shelter information.
These crippling snowfall totals were hitting very close to home in Gaithersburg, MD — where I took this video of still heavy snows over an already amazing 21 inch accumulation (unofficial).
The video was taken during a lull in an area that’s been experiencing accumulations at faster than 1 inch per hour rates since late last night. Sporadic reports of thundersnow were also starting to trickle in — especially in areas closer to the Chesapeake Bay like Baltimore.
Severe Coastal Flooding Threat Grows
Along the coast, Jonas’s impacts began to look more like those of Superstorm Sandy than of a typical winter snowmaker. Winds on the Eastern Shore of Virginia hit a peak hurricane force gust of 85 miles per hour earlier this morning as Jonas gorged on record warm Atlantic Ocean waters and intensified. These strong winds combined with astronomical high tides and a climate change related pile up of Gulf Stream waters off the US East Coast to push tides to the second highest level on record for Delaware beaches.
On Saturday morning, the water level at Lewes, Delaware, rose to 9.27 feet, a storm surge of more than 4 feet. This is the highest level on record at that gauge, beating 9.20 feet on March 6, 1962. Record flooding has also been observed in at least three New Jersey locations (Great Channel at Stone Harbor, Cape May Harbor, Delaware Bay at Cape May).
Cindy Nevitt in Cape May, New Jersey sent along this photo of ocean floodwaters and ice floes surging around her coastal home this morning as Jonas mercilessly drove its surge inland:
(Severe coastal flooding surges into Cape May New Jersey as hurricane force gusts drive a storm surge into the Northeast Coast on Saturday morning. Image source: Cindy Nevitt.)
Reports are beginning to come in of ongoing emergency evacuations of coastal homes flooded by surging waters in this region. Given the 9 foot above normal tides combined with hurricane force wind gusts and 30 foot waves slamming into beaches, sand dunes and sea walls, it’s a situation that is, sadly, likely to worsen as the day progresses.
Many of the Worst Impacts Still to Come
To this point, it’s important to note that, with Jonas still centered off the Delmarva Peninsula, this major tidal flooding that regions are now currently experiencing is just the start. The head of water should continue to build on into late Saturday as it moves up the coastline and into New York City, Long Island, Coastal Connecticut, Rhode Island and Massachusetts. Furthermore, impacts to New Jersey and Delaware should remain dangerous or worsen over the coming hours as winds pile waves and waters on top of already record high tides.
Meanwhile, Jonas will continue to generate heavy snowfall over hundreds of miles on into Saturday evening. The situation, therefore, remains quite dangerous and all residents in the affected areas should keep tuned to local emergency officials for instruction. In other words, this climate change enhanced monster winter storm isn’t done yet. Not by a long shot.
UPDATE: 330 PM, 25-26 Inches, Everything is Getting Buried
The locals are calling this thing Snowzilla. And for the past 36 hours it feels like I’ve had the darn thing by the tail. It’s been a rough ride but now things are honestly starting to get weird. Howling winds and heavy snows at the rate of 1 inch or more per hour continue. And we’re just sitting here as all that moisture feeding in off the Atlantic hits that cold air and condenses out in the form of a merciless fall of snow.
In our most recent set of homebrew storm videos, filmed at 3:30, the world is taking on the features of an alien landscape. Everything familiar is being covered in massive piles that dwarf people, cars, trees and even make the buildings seem to blend into a blank background of mounded white. Snowfall accumulation, in our unofficial estimate, has now reached between 25 and 26 inches. But everywhere 3, 4, 5, 6 foot and larger piles and drifts can be found (if you want to view my complete video essay of this storm, now composing 10 live films of events as they unfolded in Gaithersbur, MD, it’s available here).
Offshore, Jonas is still strengthening, still hurling more snow our way. Now, forecasts are indicating the merciless accumulation won’t stop until around 8 PM this evening. National Weather Service radar analysis puts our region firmly under the pivot point of the storm and very heavy bands just keep spiraling in. Given the slow motion of the storm and the current visible conditions, I’m starting to think that the early forecasts were optimistic. We’re just getting socked here.
From 1923 to 1970, ‘Katrina’ class storm surges only occurred about once every other decade. By 2010, that number had doubled.
Now, a new study from the Niels Bohr Institute shows that temperature increase of about .4 degree C over that period drove a doubling of extreme storms. According to the paper, now half of all ‘Katrinas’ can be attributed to human caused climate change.
The study used measurements from tide gauges along the US East Coast from Texas to Maine in order to determine the frequency of major storm surge events. And they found that as temperature increased, storm surges steadily rose. Now major storm surge events on the order of Katrina are twice as frequent.
But the study didn’t stop there. It used a new form of global ocean heat modeling to predict how frequent Katrina size events would become as world temperatures increase to 2 degrees C above the 20th century average by 2050. And what they found was stunning. Major storm surge events steadily increase along with global temperature until they occur once every other year when temperature increase exceeds the 2 degree mark.
In such a world, 9 out of ten ‘Katrinas’ could be attributed to human caused warming.
Hard work needed to prevent major storms
In order to keep global temperature increases below the 2 degree Celsius mark, only 1/3 of current world fossil fuel reserves can be burned. Unfortunately, massive efforts are still underway to extract and burn fossil fuels as rapidly as possible. The Ryan Budget contains numerous proposals that would increase US coal, oil, and gas burning while increasing production of high-carbon unconventional fossil fuels like fracked oil and tar sands from Canada.
Even top democrats like President Obama appear to be ready to offer up increasing carbon emissions in the form of the Keystone XL Pipeline as a ‘compromise’ to Republicans. Such compromises would set us on a path not just to 2 degree warming, but to 3, 4, 5, or more. And with 2 degree warming, at the very least, seeing a ten-fold increase in powerful storms the likes of Katrina, shouldn’t we be seriously reticent about any ‘compromise’ that future damages US cities and coastlines?
It is doubtful if coastal towns and cities could withstand the onslaught of one Katrina every other year. Places that include the names New York, New Orleans, Houston, Ocean City, Atlantic City, Boston, Charleston, Miami, Jacksonville, St. Augustine, Daytona, Wilmington, and even Washington DC would fall under the gun with increasing frequency. But this crazy new pace of powerful storms isn’t the only problem 2 degrees of warming serves up. That’s right, an ever-greater number of storms would rush to shore atop a rising world Ocean.
Rising seas would further complicate the impacts of increasingly frequent and powerful storms by providing a higher launching pad from which major storm surges would drive to shore. In such cases, one would expect to see greater impacts to coastlines and even to locations far inland — especially in flat regions like Florida, Louisiana and coastal Virginia.
In light of clear dangers coming from new science on how global warming impacts powerful storm frequency and storm surge it becomes just a little crazy to even consider bad policy choices like building more coal plants, relying more on fracked oil, or shackling America to tar sands via the Keystone XL pipeline. And the new, proven, technologies of wind, solar, and vehicle to grid look all the more appealing.
Though some future damage is already in store due to the greenhouse gasses we have already emitted, why would we even consider making the problem worse? This new study is yet one more warning. And the burning question is — will we listen?
The above video, taken about three hours before high tide, shows how Sandy’s storm surge was already having a strong impact on Union City, New Jersey. The video serves as a nice counterpoint to evidence uncovered by Grinsted et al in a new study entitled Homogeneous record of Atlantic hurricane surge threat since 1923 showing that hurricanes and other severe ocean storms are growing more intense.
Traditionally, wind speed has been used to gauge the force of storms. But since wind evidence has been less accurate until recent years, it has been difficult to provide a record of storm intensity over time. To avoid this problem, Grinsted turns to another, more reliable, measure — tidal gauges.
In his study, Grinsted used six tidal gauges at different locations along the US Gulf and East Coast to track storm surges from major events occurring from 1923 to the present. And what Grinsted found was evidence for increasingly powerful storms.
The above graph illustrates the number of major storm surges in any given year. Averages in 1923 steadily climbed from about 4 per year then, to nearly 7 per year now. This new, higher rate of powerful storm surges is also occurring in areas where ocean levels are 1 foot higher than they were during the 1920s and were development has encroached the shoreline boundary like never before. This combination of rising seas, increasingly powerful and more frequent storms, and runaway development has put a vast coastal region on a precipice. In coming years, this region will face at least a 1 meter rise in sea level, and, if the rate of increase illustrated in Grinsted’s study bears out, as many as ten major storm surge events per year on the East and Gulf Coasts by 2100.
(My personal opinion is that the 1 meter sea level rise predictions under business as usual fossil fuel emissions is a highly optimistic notion. More likely, unless emissions are reigned in, we will probably see at least 3 meters in sea level rise as first Greenland, then West Antarctic enter periods of rapid melt. In my view, the 1 meter range may be achieved only through rapid reductions in greenhouse gas emissions.)
Grinsted notes:
We find that warm years in general were more active in all cyclone size ranges than cold years. The largest cyclones are most affected by warmer conditions and we detect a statistically significant trend in the frequency of large surge events (roughly corresponding to tropical storm size) since 1923. In particular, we estimate that Katrina-magnitude events have been twice as frequent in warm years compared with cold years.
In this statement, Grinsted establishes a direct link between storm intensity and human caused global warming. This statement also corresponds with a meteorological theory called heat engine theory, which shows that storms grow stronger as more heat energy becomes available.
Links:
Aslak Grinsted, John C. Moore, and Svetlana Jevrejeva (2012), Homogeneous record of Atlantic hurricane surge threat since 1923, PNAS, http://www.pnas.org/content/109/48/19601.
(Sandy’s powerful swell surges into Atlantic City. Image credit: here.)
Yesterday, a hurricane that had combined with a nor’easter and then tapped into both the powerful energies of an over-heated Atlantic Ocean and cold Arctic air seeping out through regions once encased in sea ice vented its fury on the New Jersey coastline. All up and down the Jersey Shore, community after community faced a historic storm surge born of a storm made far worse by climate change. A storm whose effects were the worst seen in this region of the US East Coast in 300 years.
Atlantic City seemed to bear the brunt of Sandy’s wrath. As early as Monday morning, the city’s coastal defenses were breached, its sea wall overwhelmed, its boardwalk washed away and its streets and homes subject to the pounding force and rush of storm waves. Residents of the barrier island community found themselves stranded as the rising tide cut off access to their community. Many fled to community storm shelters only to find the rising tide flooding these structures as well. Homes were ripped off their foundations and floated down the street or were swept into the raging Atlantic. At one point, a National Guard unit made a valiant effort to save some of those stranded by the storm. The effort was partly successful, but resulted in the loss and flooding of a number of pieces of military equipment. Overnight, the storm worsened, preventing any access to the storm-ravaged town and forcing its terrified residents to spend a water logged and fearful night alone and without public aid.
Just to the south of Atlantic City, Ocean City also faced Sandy’s terrible wrath. A seven foot water rise inundated the town and flooded its streets. As the water rose, 231 residents made emergency calls for help after refusing to heed evacuation orders. Though 50 persons were moved to escape the raging seas, miraculously no lives were lost. Almost as an after-thought Sandy parted with a 100 foot section of the Ocean City Pier.
Further north along the coast, Point Pleasant waged a valiant battle against rising seas all throughout the day. High waves and pressing tides battered the city’s beleaguered dune line. Finally, as the storm rushed in with the astronomical high tide, the dunes gave way and torrents of water rushed into the town’s streets. The city’s boardwalk was torn to shreds as boats were ripped from their moorings to float into the city where they were finally laid to rest on streets, lawns, or railroad tracks. In some places, water rushed nearly a mile inland. One home, three quarters of a mile from the shore, flooded with more than a foot of ocean water in the first floor driven in by Sandy and the 8 PM high tide.
“I kept asking him [my husband], ‘Should we go on the roof?’ I was really scared,” said Rosemary, as their house flooded. “The force and the speed that the water was pouring down and pouring over, it was scary. It rose so fast. It just kept coming and coming.”
In another part of town, firemen bravely faced the rising waters, slogging through the chest-deep flood to reach stranded residents.
The word New Jersey governor Chris Christie used to describe the wide-spread and far-ranging devastation all up and down the Jersey coast was “unthinkable.”
“The idea … that you see homes in the middle of Route 35 southbound and northbound is just unfathomable,” Christie told reporters at a morning briefing.
A deadly and devastating storm, one that set records not seen in 300 years, dealt a terrible blow to New York’s coastal regions Monday.
The 940 millibar storm, the most intense for this region on record, pulled a 14 foot storm surge up Long Island Sound and into Naragansett Bay Monday evening. This intense pulse of water overwhelmed New York’s flood defenses, filling the great city’s subways, overwhelming the Battery area, and soaking New York City neighborhoods. Construction at the new World Trade Center site was inundated, underground subways; parking lots and shopping centers were flooded out.
Massive surges of water assaulted the US’s largest city from all sides. Naragansett, to the north spilled water into the city’s back side. Long Island Sound, to the south, funneled an amplifying pulse of water directly into the city’s heart. The massive storm surge rushed in through storm drains, sending water gushing up through sewers, fountaining out of man hole covers, until neighborhood after neighborhood looked out over flooded streets.
Above the city, the storm left the twisted wreckage of a crane dangling from a high rise apartment complex built for the affluent. Billionaires, who occupied the top four floors of the complex, were treated to a front row view of the wreckage — twisting and swaying in Sandy’s 90 mph winds. Transformer fires and electrical equipment explosions whelmed the night before leaving much of the city dark late Monday. Large sections of the city remained without power as first responders began to pick over the damage this morning.
Though New York City was assaulted by a host of troubles, much of Long Island and coastal New York also fell under the heavy blow of this monster storm. Storm surges left section after section of the coast assaulted by battering waves. In places, the dune lines or sea walls were breached, leaving communities vulnerable to the ravages of an angry sea.
Sandy’s fury inundated Breezy Point. The force of the storm was enough to flood first floors and foundations, ripping off debris and sloshing it together in a twisted, shambling mound of wreckage at the mercy of an angry tide. But the worst came in the form of an unexpected fire that leapt from house to house even as the flood waters swirled about. Fire fighters dragged hoses through the heaving water or piled into inflatable boats in a desperate attempt to combat the spreading inferno. NYPD personnel took to the water in scuba equipment to reach victims trapped in flooded, burning homes. As the water began to trickle out, homes burned to their foundations. In all, the fire claimed about a hundred structures. By sunrise, all that remained of a large swath of town was a pile of wet and smoldering debris. A scene that might remind one of last year’s Japan Tsunami or of Dante’s Inferno, depending on predilection.
At 943 mb lowest central pressure, Sandy will be the most powerful storm ever to make landfall in the Northeastern US. Described as a hurricane wrapped in a Nor’easter, the beating heart of this monster storm is now growing more powerful.
Sandy’s maximum winds have intensified to 90 mph, a rapid intensification from 75 mph just 12 hours ago. It is rapidly approaching the New Jersey shore and will likely make landfall there between 8 and 11 PM this evening. Water temperatures in the region are 5 degrees Fahrenheit higher than normal and a powerful dip in the jet stream is lending energy to this immensely powerful storm.
It is difficult to underestimate the potential coastal effects of this storm, particularly to the right of the center as it comes ashore. First, the storm is coming in at or near the time of high tide, an abnormally high tide amplified by the moon. So storm surges of 4-11 feet or more will pile up on top of an abnormally high tide of 2-4 feet above mean low water. In addition, water rises of around 4 feet or more are already being recorded along the coast. This water rise is being pushed against the coast by the wind and by the force of the approaching storm. The result is that many places may see water rises of 10 feet or more above normal. Given the intensity of this storm and the fact that it is continuing to intensify as it approaches the coast, these values may be underestimated.
Maryland, Delaware, New Jersey, New York City, Rhode Island, Connecticut, and Massachusetts may all experience the highest water rise values ever seen. Already, significant flooding has occurred along the Outer Banks and into the Hampton Roads area. Below is a picture of Chicks, a popular VA Beach restaurant being flooded out by Sandy.
After two days of battering, scenes like these have become commonplace in North Carolina and Virginia Beach. But what has happened there is just a prelude to what will likely unfold over the next few hours as Sandy comes ashore.
UPDATE
Reports are coming in that Atlantic City New Jersey is now under water (11:35 Oct 29).
UPDATE:
Some locations in New Jersey are reporting 9 feet water rises. Record rise for the region are 10 feet. The below image shows Ocean City flooding.
UPDATE:
Reports are coming in that the Point Pleasant, NJ dunes have been breached and sea water is rushing through city streets like a river (7:53 PM).
UPDATE:
Some locations in New York City are reporting storm surge flooding above 9 feet (7:53 PM).
robertscribbler 
