Glenn's Blog: Coastal Flooding: Think it Was Bad This Time? - NBC 10 Philadelphia




    James McGee

    Record Coastal Flooding
    The water reached record levels with the Blizzard of 2016 in several places along the coast. Lewes, Delaware, Cape May, NJ and Stone Harbor, NJ, among others broke records set in Sandy in 2012 or the 1962 Nor’easter. It was a combination of winds gusting to hurricane force for a few hours plus a natural high tide enhanced by a full moon. Serious flooding occurred along the Jersey Shore in many places. Why the Shore FloodedWhy the Shore Flooded

    NBC10 First Alert Weather cheif meteorologist Glenn "Hurricane" Schwartz gives us a break down of the shore flooding being seen since the snow fall and how each high tide is going to impact the area more and more.
    (Published Thursday, Jan. 28, 2016)

    What Makes it Extra Troubling
    Record coastal flooding almost always occurs because of onshore winds over a long period of time. High tides occur about every 12 hours, and when a Northeast or East wind persists, each succeeding high tide gets higher than the last. That is what happened with the Nor’easter of 1962. It lasted for days, and FIVE high tides. The Jersey Shore wasn’t very populated back then, which was a good thing. The floods cut Long Beach Island into pieces, as the ocean met the bay. Waves more than 40 feet were reported at Rehoboth Beach, Delaware, which destroyed the boardwalk. Beachfront homes were destroyed over multiple states. And 40 people died in the storm. Glenn Explains Why Margate Floodings is so BadGlenn Explains Why Margate Floodings is so Bad

    Flooding along Ventnor Avenue in Margate, New Jersey. NBC10 First Alert Chief Meteorologist Glenn "Hurricane" Schwartz explains why flooding is worse here than some other shore communities.
    (Published Thursday, Jan. 28, 2016)

    So, wait a minute….we just broke a record that took FIVE successive high tides and THREE DAYS to build with a storm that only took ONE high tide to do it (we were lucky-the winds changed, and the next 2 high tides were not as high as the first). Think about how high the water would have been if the storm had stalled like the ’62 storm, allowing the water to start at record levels, and build, and build, and……

    Here are some incredible home videos shown by reporter Amy Rosenberg in an article from 2013.

    Do a simple web search for “1962 Nor’easter” and take a look at the pictures-up and down the coast, from LBI to Delaware. It’s chilling. And yet the Blizzard of 2016 had higher tides in some places. Historic Flooding at the ShoreHistoric Flooding at the Shore

    Not many people were at the shore in those days, especially in March, when the storm hit. That damage was from the ocean, even in Margate (where many people apparently think this can’t happen-see below). I’m not talking about Bayside flooding, where the water rises and moves gently down the street. On the ocean side, there is enough force and power to knock down houses and push them blocks inland. That power is potentially deadly, unlike the floods from the Bay.

    And Then Came Sandy
    And then there’s Sandy. Sandy had weakened from a Category 3 hurricane after it hit Cuba, and wasn’t even classified as a hurricane by the time it made landfall near Brigantine, NJ. You know the rest: the 2nd costliest storm in U.S. history. In New Jersey, the worst damage was clearly at the northern beaches, which were on the right, or stronger side of the storm.

    Here is what the ocean did at Mantoloking:

    Oct. 31, 2012: Mantoloking, N.J.- A closer look.
    Photo credit: Getty Images

    That’s the ocean meeting the bay, just as it did in Long Beach Island in 1962. Record coastal flooding occurred at some beaches in South Jersey and Delaware, but it wasn’t as bad as in North Jersey.

    And imagine how bad it would have been if it was still a Category 3 hurricane? It could have been that strong in July or August, when the ocean temperatures were highest, rather than the end of October, when it did hit.

    And the Extra Scary Part
    Why did the Blizzard of 2016 have a higher coastal flood level than the ’62 Nor’easter anywhere in New Jersey or Delaware? That’s because sea levels have risen considerably in recent decades. Look at how much it’s risen-and also the trend.

    Photo credit: NOAA

    Sea level has risen worldwide in the past 50+ years, but more along the U.S. East Coast than in most other areas. Do you think this trend is simply going to stop, or reverse itself? Of course, it won’t. Twenty years from now, the average tide level will be significantly higher than today. So, a storm like the one last weekend will lead to a significantly higher flood stage than today. And that means significantly more damage. It also means a much greater threat of severe ocean flooding. And a much greater chance of the ocean meeting the bay-especially in places like Margate, that don’t have dunes to protect their beaches.

    This is for You, Margate, and Other Coastal Areas:
    The flooding that we showed in Margate during the storm was from the Bay, and not the ocean. This seems to have given many people there the idea that it did NOT flood on the ocean side. But it did. Here are a couple of pictures from Amy Rosenberg at Exeter Street and Iroquis Avenue:

    Photo credit: Amy Rosenberg
    Photo credit: Amy Rosenberg

    Yep, that’s flooding from the ocean-from a storm with just ONE high tide! Imagine a Nor’easter with FIVE high tides-each higher than the last. Oh, and it’s 10 or 20 years from now when sea level is even higher than it is now. That water from the ocean is coming in, and only well-designed and managed dunes could stop it. Otherwise, the ocean will meet the bay in Margate, water will rampage through the streets, knocking $10 million homes around like they were toys, threatening the lives of anyone who dared stayed on the island.

    (I have a special affection for Margate and its people, as illustrated in a past blog)

    Hey, Margate, is that worth continuing to reject a FREE dune project?

    Glenn “Hurricane” Schwartz
    Chief Meteorologist, NBC10 Philadelphia