Five Year Anniversary of Landfall of Superstorm Sandy

Five years ago today (October 29, 2012), the post-tropical remnants of what was Hurricane Sandy made landfall on the New Jersey coastline as a hurricane-force windstorm, causing destructive straight-line winds and historic, damaging surge from the North Atlantic extending from the Jersey coast north into the New York City Metro Area, with historic flooding of lower Manhattan.

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Image of extremely large Hurricane Sandy by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite on October 28, 2012. Sandy would become the largest tropical cyclone on record in the North Atlantic Basin.
Sandy produced widespread wind gusts of 75-90 mph across portions of New York and New Jersey with heavy rainfall totals of 7-10 inches across parts of New Jersey, Delaware, and Maryland. Storm surge was Sandy’s main cause of significant damage, with wind damage and flooding rainfall additional impacts. The post-tropical “superstorm” caused a 10-13 ft storm surge which damaged and destroyed homes and businesses along the Jersey Shore and Hudson Waterfront, with a record 13.88 ft water rise reported at Battery Park in Lower Manhattan.

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Damage by Super Storm Sandy in Brooklyn, NY (“Proud Novice” on Wikipedia).
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Super Storm Sandy damage in Mantoloking, NJ taken on October 30, 2012. (US Air Force).
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The flooded Brooklyn-Battery subway tunnel in NYC on October 30, 2012 (“vcohen” on Wikipedia).
Sandy’s expansive storm surge was more intense by multiple factors. As it came poleward, it grew significantly in size, a typical phenomenon for tropical cyclones moving into the mid-latitudes. However, Sandy’s weakening and mid-latitude interactions caused it become the largest North Atlantic tropical cyclone on record, producing a huge fetch (extensive wind over long stretch of open water). This fetch allowed for the building of significant ocean waves and piling up of water toward the shallow continental shelf of the Atlantic coast of the US. And although Sandy weakened somewhat and became “non-tropical”, this did not matter as the very large wind field remained and forward momentum of the very heavy ocean could not settle down in time before pounding the coastline with destructive surge.

In addition, Sandy made landfall at high tide, enhancing the storm’s ability to flood dry land areas and cause direct damage with battering waves. I will also note that this “flood reach” was even greater because of climate change-induced sea level rise. Global sea levels have risen 9 inches since 1880 and while the Intergovernmental Panel on Climate Change (UN) continues to indicate a likely sea level rise of up to 3.2 ft by 2100, many other reputable scientists have suggested the possibility of multi-foot sea level rise occurring this century as the result of exponential glacial melt feedbacks in Greenland and Antarctica. Perhaps as high as 6.5-16.5 feet by 2100 (see references #1-2 below). This, of course would be catastrophic for vulnerable coastal cities for both livability but initially for any places already exposed to storm surges. New York City is one most at risk.


Sea level rise has also been locally enhanced along the Northeast US Coast because of abnormally warm waters building offshore for years, leading to increased thermal expansion of the water surface upward. This may also be a result of climate change-induced weakening (#3) of the Atlantic Meridional Overturning Circulation (AMOC). While Superstorm Sandy wasn’t “caused” by climate change, it was part of an increasing regime of more extreme weather events (and events with with more extreme hazard variables) and a prelude to what will be far more frequent in the coming decades.

Sandy was retired after the 2012 Hurricane Season, causing 233 deaths from the Caribbean to the United States and producing an incredible $75 billion in damages (only 2nd to Hurricane Katrina). An incredible and devastating meteorological event which we can hope we continue to recover from and our country will be better prepared to mitigate against next time.

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Surface analysis at 5 pm EDT October 29, 2012 showing Superstorm Sandy just offshore the coast of New Jersey pounding the Mid-Atlantic to New England. The intense pressure gradient (shown by the isobars) caused areas of gale and storm force winds over the Great Lakes because of the expanse of the storm.
Scientific References (for the nerds like me!):

1- Hansen et al. 2016. (scientific technical)

2- New science suggests the ocean could rise more — and faster — than we thought (Washington Post/Oct 17)

3. Youtube video of conference presentation (2016) by Dr. Stefan Rahmstorf on weakening AMOC. Can also refer to (#1) on this issue as it relates to potential effect on ice sheet dynamics.

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Post-Tropical Cyclone Ophelia advancing on Ireland

Post-Tropical Cyclone Ophelia is quickly approaching Ireland with hurricane-force strength. It’s a fully non-tropical frontal system, but powerful one. Gusts of 45-55 mph are already occurring over the south coast of the country. My forecast for Ireland is HERE at the bottom, no significant changes since 24 hrs ago. Lots of wind and of course high surf. Stay safe if you’re located in Ireland or Scotland.

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Hurricane Ophelia Undergoing Extratropical Transition as it races for Ireland and the UK

Update at 6:50 pm CDT Sunday:

Ophelia appears to have nearly completed the process to Post-Tropical based on satellite imagery, with the whole arrangement of frontal boundaries and more asymmetric wind field and lack of any significant tropical characteristics outside of some convection (thunderstorm activity) northeast of the center. Ophelia is still a hurricane-force cyclone (likely top sustained winds 75-85 mph) and impacts still expected to quickly increase over Ireland Monday morning with rain, damaging winds and dangerous surf and coastal flooding.

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Hurricane Ophelia…at least it was still considered one at 11 am AST…is quickly transitioning to a hybrid post-tropical cyclone. I made up a schematic using current infrared satellite imagery. You can clearly see the transitioning hurricane becoming surrounded by cold, dry air on its’ back side, with its own warm, moist tropical air mass contributing to warm air advection ahead of it. And you can the developing frontal structure…cold front developing offshore Portugal and warm frontal cloud structure fanning out far to the north of the low center and offshore Ireland. The cyclone itself should be fully post-tropical in the next few hours, if it can’t be considered so already. Impacts (moderate to heavy rain and damaging winds) begin their arrival  Monday morning. My forecast for Ireland (written last night) can be found HERE.

Surreal view…a major hurricane near Western Europe.

Incredible views today…

Hurricane Ophelia set two records: 1) The highest latitude major hurricane on record in the North Atlantic Basin, set beginning at 35.9 N and 2) the most easterly major hurricane on record in the basin, set beginning at 26.6W. It will likely weaken below major hurricane force by Sunday morning as it begins to undergo transition into a frontal cyclone from its interaction with the jet stream and further reduction of sea surface temperatures below 72 degrees F/22 degrees C. However, it will be one for the record books.

Fortunately, Ireland and the United Kingdom will not need to worry about a major hurricane hitting them. They will need to worry about a likely damaging windstorm from a post-tropical hybrid cyclone. The post-tropical incarnation will develop frontal characteristics as it initially weakens, but its strong inner warm-core will continue to release some heat into the system, re-intensifying it as it becomes fully embedded in the mid-latitude westerlies and races into Ireland and the UK Monday afternoon and evening. My updated forecast for Ireland is below. Still expecting winds capable of downing trees and causing major power disruptions. The forecast for intense winds is high in confidence as computer models hone in on the center of the storm either coming ashore the southern tip of Ireland or just grazing the western shore. This is favorable for a “big blow” over the entire island. Residents need to be prepared to stay indoors and stay safe during the day Monday.

Ireland Forecast for Post-Tropical Cyclone Ophelia:

 

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Forecast zones (North and South) used for my forecast.

 

Monday Morning (After 7 am local time): For the southern half of the island, wind gusts of 40-50 mph (64-80 km/h) will develop during the morning, increasing to 60-85 mph (97-137 km/h) by mid to late morning from the coast, northward. The strongest gusts will be along the coastal areas, especially the south shores where isolated gusts may approach 100 mph (161 km/h). For the northern half of the island, wind gusts to 40 mph will develop mid morning , increasing to 50-60 mph late morning, from south to north.

Monday Afternoon (After noon): For the south, wind gusts of 60-85 mph (97-137 km/h) early afternoon with isolated to 100 mph/161 km/h along the south/southeast shores). For the north, wind gusts of 50-60 mph (80-97 km/h) early afternoon will increase to 60-85 mph by mid afternoon with isolated gusts to 100 mph along the northeast shores, spreading from south to north into the late afternoon.

Monday Night (after 5 pm local time): For the south, wind gusts will gradually decrease to 40-55 mph (64-89 km/h) during the early evening from south to north. For the north, wind gusts will gradually decrease to 40-55 mph during the mid to late evening (after 7 pm) from south to north.

Sea conditions will be hazardous all around Ireland with wind gusts in excess of 100 mph (161 km/h) likely in the south coastal waters and in the Irish Sea.

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High-resolution Swiss model showing the tightly-packed circulation of then Post-Tropical Cyclone Ophelia reaching coastal Ireland midday Monday. Damaging winds will be spreading throughout the Irish Republic and Northern Ireland by this time. Shown for illustration of the overall forecast scenario.

Hurricane Ophelia now a very rare Category 3 storm south of Azores

Hurricane Ophelia has strengthened into a Category 3 hurricane with maximum sustained winds of 115 mph as it moves south of the Azores. It is moving over prime atmospheric conditions, even as it overcomes waters of only 25 degrees C/77 degrees F. In normal tropical environments, tropical cyclones need water temperatures of 26 degrees C/79 degrees F to maintain themselves and warmer to significantly strengthen. However, the colder temperatures in the upper-atmosphere associated with the mid-latitude troposphere is providing Ophelia with ample atmospheric instability (warm, moist air rising into cold air aloft intensifying thunderstorm activity). In addition, mid-latitude dynamics are playing a role…the approaching frontal system and associated upper-level trough of low pressure approaching Ophelia is giving the system a “poleward outflow jet” to pull air away from the system and allow the surface low to strengthen.

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Meteorological Analysis of Category 3 Hurricane Ophelia. Favorable dynamic and thermodynamic set up allowing system to strengthen at high latitude, over cooler waters for hurricane maintenance. With that said, water temps under Ophelia are running 2-3 degrees C above normal, also allowing it to have its unusual intensity near Western Europe.

See my previous post from late last night for my wind forecast for Ireland. Strong winds should begin to impact the island midday Monday (local time), with stormy conditions lasting into Monday night. The southeastern Azores will see some gusty winds and 1-3 inches of rain as it passes by this evening and night.

–Meteorologist Nick Humphrey

Analysis and Forecast Impacts of Post-Tropical Ophelia in Ireland Monday

Hurricane Ophelia is a high-latitude hurricane by tropical standards…a Category 2 storm with maximum sustained winds of 100 mph as of 11 pm AST…moving south of Azores at 20 mph.

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Analysis of meteorological state around Hurricane Ophelia at 2 am AST. The hurricane is moving south of the Azores island chain and will pass between the Azores and Portugal Sunday morning.

This hurricane, is on track to take its already unusual path northward toward a collision course with Ireland and the United Kingdom Monday and Tuesday!

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National Hurricane Center advisory on Ophelia and it’s path. It’s expected to reach Ireland as a “post-tropical” cyclone…a hybrid frontal system…on Monday. VERY rarely are tropical cyclones, particularly any stronger than Category 1 located in the Northeast Atlantic Ocean.

Not to worry, however. Ophelia will NOT be a tropical cyclone when it arrives in the British Isles Monday. Sunday, the hurricane will begin to pass over much cooler waters between the Azores and Portugal (and note, the hurricane is currently over waters 2-3 degrees C/~3.5-5.5 degrees F above normal). At the same time, if you look at the previous satellite analysis, the hurricane will begin to interact with the existing frontal zone and ingest air from an approaching cold air mass moving in from the North Atlantic. This will begin the process of extratropcial transition where Ophelia becomes a mid-latitude frontal system. However, because of its old, warm tropical air mass, it will continue to retain some of its internal energy, enabling it to be a powerful hurricane-force windstorm.

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European “Euro” Model showing Post-Tropical Cyclone Ophelia approaching Ireland Monday morning (AST). Other global computer models vary the center of circulation either just offshore the west shore of Ireland or make landfall over southern Ireland Monday morning.
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Euro Model showing damaging wind gusts overspreading Ireland from south to north Monday. Models generally agree with bringing damaging wind gusts of 75-85 mph (~120-135 km/h) to the south and southwest coast of Ireland Monday afternoon (local time) with isolated gusts over 100 mph (~160 km/h). Gusts to 60-65 mph (97-105 km/h) with isolated higher gusts to 75 mph (120 km/hr) in the south of the island will be possible across much of the rest of the country into Northern Island Monday evening and night. All surrounding coastal waters will be hazardous for marine interests.

I have moderate confidence in my forecast…some uncertainty deals with the track of the low pressure system. A track farther offshore to the west would limit significant winds to the south and west shores and coastal communities. A track very close or even onshore the south coast would send very high winds deeper inland into Ireland. Regardless, those in the country should expect widespread downed trees, power outages, and difficult driving conditions for high-profile vehicles during the afternoon into late evening Monday.


Here is the climatological history of all known tropical cyclones in the North Atlantic just to show the rarity of systems such as Ophelia. Although some cyclones may have been missed prior to the satellite area, it is possible that such cyclones were less likely to survive in the distant past because of cooler waters where Ophelia is located now. Sea surface temperatures have warmed on Earth because of climate change.

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All hurricane tracks in the North Atlantic (1851-2012). Note, tracks heading to near the British Isles were likely as extratropical systems. Hurricane Vince, however, made a historic landfall as a tropical depression in southern Spain in October 2005.
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Ophelia is over waters 2-3 degrees C above normal. The hurricane will move away from waters favorable for hurricane maintenance during the day Saturday.

–Meteorologist Nick Humphrey

Hurricane Nate and Dangerous Storm Surge Heading for the Northern Gulf Coast Saturday (Updated at 2 pm CDT)

Update at 2 pm CDT:

Hurricane Nate is likely to be a Cat 1 or 2 at landfall (thinking NHC forecast of 2 as high-end). It is leveling off based on current satellite presentation as well as air force reconnaissance observations. STORM SURGE REMAINS THE GREATEST HAZARD. The asymmetric structure…a product of Nate’s forward motion, may intensify/focus surge/battering waves from Mouth of Mississippi River to the MS/AL border. 9-11 ft surge with battering waves expected Mouth of Miss. River to MS/AL border as center passes nearby. 6-9 ft east to AL/FL border. Dangerous. High tide along Gulf Coast of MS around midnight, passage of center may be 8-10 pm CDT…partial enhancement could exacerbate flooding.

Probability of Cat 1 at initial landfall: 90%

Probability of Cat 2 at initial landfall: 10%

Landfall should be between 5-7 pm in far Southwest Louisiana.

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Hurricane Nate is headed for a likely landfall with the northern Gulf Coast of the US this evening. The hurricane is blasting north-northwestward very fast for a tropical cyclone…26 mph at the moment. This is under the influence of an approaching upper-level trough of low pressure which will eventually turn it northeastward after landfall. The system has continued to organize as expected over the warm waters (83-84 degrees F) and favorable low wind shear. The storm (at 10 CDT) is a Category 1 hurricane with maximum sustained winds of 90 mph with gusts to 110 mph.

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Visible imagery of Nate showing its rapid forward motion toward the coast.

The waters atmospheric and oceanic conditions should remain favorable for intensification up until landfall. Landfall is likely between 6-8 pm in far southwest Louisiana. My assessment based on this on trends, is that Nate is likely (65%) to make landfall as Category 2 (100-110 mph sustained) with a moderate chance (10%) to make landfall as a Category 3 (115 mph+), if more rapid intensification occurs during the next 7-8 hrs. There is also a 25% chance of a landfall as a Category 1.

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National Hurricane Center track forecast at 10 am CDT Saturday.

Heavy rainfall (lessened by the storm’s forward speed) is most likely over southern Mississippi into Alabama. Much of Louisiana will miss the worst of the storm, including New Orleans, however points east will face potentially significant surge. Surge may reach 7-11 ft along the mouth of the Mississippi River to the Mississippi/Alabama border; 6-9 ft from the MS/AL border to the AL/FL border, including Mobile Bay.

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Potential Storm Surge Flooding by Nate Saturday night. Orange and Red colors represent potential for 6-9+ feet of surge.

If you know anyone in these areas, please tell them to evacuate NOW!! This storm is moving FAST and storm surge will, BY FAR be the greatest danger from Nate. Far more than the wind or even inland flooding. I do have some concern that the combination of the relatively recent development of this system, its fast forward movement, and resulting shorter lead time, in addition to the system being relatively weaker in terms of maximum sustained winds that people may not leave or leave fast enough. People need to leave and be safe.

I will have updates when possible this afternoon and evening.