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Hurricane Florence Catch all Thread

Brian5671

By Brian5671,
in New York City Metro

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LibertyBell

LibertyBell

Posted
Posted
5 hours ago, bluewave said:

I just found a great presentation on the 1821 hurricane.

https://ams.confex.com/ams/95Annual/webprogram/Paper257982.html

Tuesday, 6 January 2015: 2:30 PM
128AB (Phoenix Convention Center - West and North Buildings)
Megan E. Linkin, Swiss Re America Holding Corporation, Armonk, NY
 
Hurricane Sandy, with its unique track, 1,000 mile wide wind field and low central pressure, pushed record breaking storm surge into the New York and New Jersey coasts, destroying businesses, homes and lives in a short 24 hour period. But for all the devastation and damage that Hurricane Sandy brought, its intensity at landfall, measured by 1-minute maximum sustained winds, was equivalent to a minimal Category 1 hurricane. Other events in recent years (Irene, Isabel, Gloria, Bob), while significant, weakened prior to landfall, coming onshore as either Category 1 or Category 2 hurricanes, and not the major hurricanes originally anticipated and feared. 

History, however, shows us that we may not always be as fortunate. The 1821 hurricane, commonly referred to as the Norfolk � Long Island hurricane, roared through the Mid-Atlantic and Northeastern United States in early September, passing over or near major cities and tourism regions such as the Outer Banks, Norfolk, Cape May and New York City. Coastal communities in North Carolina were washed away, ships in Norfolk, VA were pushed ashore and the Delaware Bay flooded Cape May, NJ. On eastern Long Island, the aftermath was described as, "the most awful and desolating ever experienced." The hurricane was a devastating event for the expanse of Northeast United States, with communities, farms and churches laid in ruins from North Carolina to New Hampshire. The hurricane is notable not only for its strength, but its contribution to science; it is the storm that led to the discovery that in the Northern Hemisphere, these weather systems rotate in a counterclockwise direction. 

With all existing documentation around the 1821 hurricane referring to a catastrophic, devastating event, and with today's models we can reconstruct a track for this hurricane to understand how it moved up coast, along with its wind field and storm surge field to determine what the loss potential is if the 1821 hurricane recurred today. 

Using Swiss Re's proprietary tropical cyclone model, a deterministic wind field and storm surge analogs are developed for the 1821 hurricane. The wind footprint calculated for the 1821 hurricane results in a large area of the Eastern Seaboard being affected by powerful winds and wind gusts; in parts of coastal North Carolina, the wind gusts are in excess of 150 mph, with wind gusts up to 130 mph reaching as far north as Connecticut. Storm surge values for the analog hurricanes range from 11 � 13 feet at The Battery, and up to 25 feet in Atlantic City, NJ. 

With trillions of dollars of residential, commercial and automotive exposure currently in the path of such a storm, the loss potential of the 1821 Norfolk-Long Island hurricane exceeds economic losses from other notable East Coast storms, including the 1938 Long Island Express and Hurricane Sandy. Physical economic losses are calculated to be in the range of USD 100 billion; actual economic losses, which include the intangibles, such as lost tax revenue and changes in asset values, are closer to USD 150 billion. 

It is imperative that we, as a nation and a society, look into the past to plan for the future, especially peering through the veil of climate change. Hurricanes Irene and Sandy served as harsh reminders that the Eastern Seaboard, particularly the Northeast US, is not immune to hurricane strikes. A recurrence of the 1821 Norfolk Long Island hurricane would be a paradigm shifter, severely and negatively impacting the economy and altering the culture of the oldest part of the United States going forward. Comprehending the potential consequences of historical storms today will help both improve our understanding of the "worst case event," and motivate those in coastal areas to take the necessary steps to prepare for all storms which are possible, even those beyond our current generations' memories.

 

 

Wow 25 feet at Atlantic City rivals Katrina.  Hailstorm's modeling showed a worst case scenario delivering a 33 foot storm surge to Southern Queens which would exceed Katrina by a few feet.

 

With all these stalling hurricanes we've had recently due to anomalous blocking I wonder if we might need to revise our idea of a worst case scenario- what if a powerful Cat 3/4 came close to landfall in Central NJ and just stalled there, a la Dec 1992 noreaster or Ash Wednesday 1962 storm or Harvey or what Florence might do?  It would slowly weaken but the surge and wind over many high tide cycles would be truly catastrophic and the feet of rainfall!

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LibertyBell

LibertyBell

Posted
Posted
On 9/9/2018 at 6:08 PM, Hailstorm said:

I definitely agree with this. According to the SLOSH models I have just run, parts of Brooklyn and Queens could get slammed with up to a 32-foot storm tide in a Cat. 4, assuming the impact coincides with high tide. Sandy, by comparison, "only" produced a storm tide of 11 feet in Manhattan. This would make Sandy appear to be "child's play" if that scenario came into fruition; as the surge would penetrate at least 3 miles further inland along the south-facing shorelines of Brooklyn, Queens and Long Island.

image.thumb.png.493d873330735bd8c8e29d94691a608f.png

 

Wow almost 34 ft near Southern Queens, I wonder why it's less in Southern Nassau?  Was this from a track modeled into Sandy Hook of a 145 mph hurricane?  It would be interesting to see the same track modeled with different intensity hurricanes from 1-4.  Also with the new climate regime of stalling hurricanes I wonder how much worse it would be to have a Cat 3/4 stall right along the coast, similar to what the Dec 1992 noreaster or the Ash Wednesday 1962 storm or what Harvey did or what Florence might do.

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NJwx85

NJwx85

Posted
Posted

Still too early to determine if we will receive any impacts up here at all except for beach erosion, however the remnants should eventually merge with a trough which will swing through here early next week. Unless of course Florence ends up taking a wild track and ends up further Southwest than forecasted.

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tdp146

tdp146

Posted
Posted
On 9/9/2018 at 6:08 PM, Hailstorm said:

I definitely agree with this. According to the SLOSH models I have just run, parts of Brooklyn and Queens could get slammed with up to a 32-foot storm tide in a Cat. 4, assuming the impact coincides with high tide. Sandy, by comparison, "only" produced a storm tide of 11 feet in Manhattan. This would make Sandy appear to be "child's play" if that scenario came into fruition; as the surge would penetrate at least 3 miles further inland along the south-facing shorelines of Brooklyn, Queens and Long Island.

image.thumb.png.493d873330735bd8c8e29d94691a608f.png

 

Did you send the NWS your email address via this page in order to get access to run that model? https://slosh.nws.noaa.gov/sloshPub/disclaim.php

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bluewave

bluewave

Posted
Posted
5 hours ago, gravitylover said:

In the latest visible shot this really is a beautiful storm. Knowing (approximately) what's going to happen over the next few days I hate appreciating it but I can't help it.

Someone on the north side of the Chesapeake area-MD/DEL/NJ coast is getting a heckuva surf day today.

 

Decent surfing conditions today along the South Shore. A 5-6 foot hurricane swell with light winds. 

https://nysea.com/live-cam/

142618034_Screenshot2018-09-12at4_38_14PM.png.ffcbcda81ffd679921c9981883636681.png

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Hailstorm

Hailstorm

Posted
Posted
20 hours ago, LibertyBell said:

Wow almost 34 ft near Southern Queens, I wonder why it's less in Southern Nassau?  Was this from a track modeled into Sandy Hook of a 145 mph hurricane?  It would be interesting to see the same track modeled with different intensity hurricanes from 1-4.  Also with the new climate regime of stalling hurricanes I wonder how much worse it would be to have a Cat 3/4 stall right along the coast, similar to what the Dec 1992 noreaster or the Ash Wednesday 1962 storm or what Harvey did or what Florence might do.

I would assume the proximity to another large body of water (Jamaica Bay) would account for the extra surge in Southern Queens. For reference, this was assuming the worst-case scenario track, direction and speed in which a hypothetical hurricane would take up here. The exact factors that make up this scenario were a mid-range Cat 4 hurricane (so I assume around 145 MPH) that was racing NW at 60 MPH (very possible, aka the 1938 one) at normal high tide before making landfall in Monmouth County. I assume a stalling hurricane would enhance the surge, as long as upwelling is not a large issue and the hurricane-force wind field has a huge diameter.

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LongBeachSurfFreak

LongBeachSurfFreak

Posted
Posted
6 hours ago, bluewave said:

Decent surfing conditions today along the South Shore. A 5-6 foot hurricane swell with light winds. 

https://nysea.com/live-cam/

142618034_Screenshot2018-09-12at4_38_14PM.png.ffcbcda81ffd679921c9981883636681.png

One of the positives of hurricane season. There has been hurricane surf (above 3’) on 16 of the last 17 9/11s. Pretty remarkably consistent for a place that doesn’t average much surf the rest of the year. 

I’m waiting for our local buoys to start showing the mega swell associated with the captured fetch of the last couple days. Some of the buoys down south are seeing swell periods of 16 seconds now which are very rare on the east coast. It’s those very periods and the tremendous energy and speed of those wave trains that will lead to beach washovers and flooding of beach front locations when it arrives. Surf wise today was a blast, tomorrow will be at least double the size and challenging!

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uncle W

uncle W

Posted
Posted

next week Florence will be effecting us...How much rain will we get?...will it make this list?...

rainfall in NYC from a tropical storm/hurricane...

date.................amount........

Sept 1882.......10.63"

Sept 1944.........7.76" great Atlantic hurricane

Aug 2011..........6.87" Irene

Aug 1955..........6.32" Connie

Aug 1971..........5.96" Doria

Sept 1938.........5.74"

Sept 1934.........5.48"

Sept 1999.........5.44" Floyd

June 2013.........4.77" Andrea

Aug 1879..........4.59"

Aug 1976..........4.28" Belle

Oct 1877...........4.07"

Aug 1893..........3.94"

Sept 1904.........3.85"

Aug 1991..........3.72" Bob

Sept 1985.........3.58" Gloria

July 1960...........3.56"

Sept 1954.........3.30" Carol

Sept 1960.........2.42" Donna

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forkyfork

forkyfork

Posted
Posted
3 hours ago, uncle W said:

next week Florence will be effecting us...How much rain will we get?...will it make this list?...

rainfall in NYC from a tropical storm/hurricane...

date.................amount........

Sept 1882.......10.63"

Sept 1944.........7.76" great Atlantic hurricane

Aug 2011..........6.87" Irene

Aug 1955..........6.32" Connie

Aug 1971..........5.96" Doria

Sept 1938.........5.74"

Sept 1934.........5.48"

Sept 1999.........5.44" Floyd

June 2013.........4.77" Andrea

Aug 1879..........4.59"

Aug 1976..........4.28" Belle

Oct 1877...........4.07"

Aug 1893..........3.94"

Sept 1904.........3.85"

Aug 1991..........3.72" Bob

Sept 1985.........3.58" Gloria

July 1960...........3.56"

Sept 1954.........3.30" Carol

Sept 1960.........2.42" Donna

missing 3.54" from hanna in 2008

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Hitman

Hitman

Posted
Posted
7 hours ago, gravitylover said:

^^ It's amazing how much more rain I got here from Floyd than the city got, nearly 10" more! I don't remember the total from Irene but I think it was also considerably more than the 7" on that list.

Ha, I was just thinking the same thing.  I had just moved into my house a few months before.  Massive flooding here. There is a brook that runs through the property.  The runoff from Floyd completly rearranged it, ripping rocks and earth from an old dam and one bank and depositing it downstream.  It was crazy town.  Have t seen it like that since.

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gravitylover

gravitylover

Posted
Posted
6 hours ago, Hitman said:

Ha, I was just thinking the same thing.  I had just moved into my house a few months before.  Massive flooding here. There is a brook that runs through the property.  The runoff from Floyd completly rearranged it, ripping rocks and earth from an old dam and one bank and depositing it downstream.  It was crazy town.  Have t seen it like that since.

Chances are you won't see anything like that again for a long, long time. That was something truly amazing. The rain gauge in Fahnestock St Park recorded over 15" of rain that afternoon and most of the area along the Taconics got 14 or more. I don't remember the numbers down in Poughkeepsie but I want to say it was over 12" especially in the hills just east of town. The only other time I've seen rain anywhere near that heavy was in Cordova AK in July of 1989 when we got 11" in just a few hours in town and near 14" at the top of the mountains right above town. If I never see rainfall rates like these two again it will be ok, the devastation that much water in hilly terrain creates is overwhelming and you're absolutely powerless to do anything other than watch. Seeing 60 foot tall trees getting tossed and splintered like matchsticks and watching cars get picked up and washed into ravines is scary stuff :yikes:

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Hitman

Hitman

Posted
Posted
5 hours ago, gravitylover said:

Chances are you won't see anything like that again for a long, long time. That was something truly amazing. The rain gauge in Fahnestock St Park recorded over 15" of rain that afternoon and most of the area along the Taconics got 14 or more. I don't remember the numbers down in Poughkeepsie but I want to say it was over 12" especially in the hills just east of town. The only other time I've seen rain anywhere near that heavy was in Cordova AK in July of 1989 when we got 11" in just a few hours in town and near 14" at the top of the mountains right above town. If I never see rainfall rates like these two again it will be ok, the devastation that much water in hilly terrain creates is overwhelming and you're absolutely powerless to do anything other than watch. Seeing 60 foot tall trees getting tossed and splintered like matchsticks and watching cars get picked up and washed into ravines is scary stuff :yikes:

Actually, I was up in vt for Irene.  That was biblical.  We were trapped in the mrv for 3 days before there was any road access into or out of the valley.  The destruction along the mad river was incredible.  We were staying at about 2000’ and so had no clue of the devastation until we ventured out the following morning.  

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