Nor’easter Impacts, Large Battering Waves and Coastal Erosion
John Cannon, NOAA/National Weather Service Maine Beaches Conference July 12th, 2013
Partnerships:
NERACOOS NOS Wells National Reserve Maine Geological Survey City of Hampton and Saco NOAA in New England Group ME/NH Emergency Mgrs. & City Officials Coastal Services Center Maine Sea Grant Mass CMZ NART, NHDES …And many others… Coastal Hazards
L Severe thunderstorms – Damaging winds, hail and Lightning
L Marine Hazards – Hurricanes, Tsunamis, Rip Currents, Cold Water Drowning, Freezing Spray Oil Spills, Artic Sea Smoke
L Winter Storms – Ice Storms – Blizzards – Nor’easters… L Large Ocean Waves: Coastal Erosion and Coastal Flooding
L Fresh Water Flooding
Marine Buoy Networks Monitoring Ocean Waves in the Gulf of Maine www.NERACOOS.org
The Wave vs. Coastal Inundation Paradox Which is the greater threat for your location ???
The Patriot’s Day Storm, 2007 Saco, Maine A Dangerous Combination: As Wave Heights & Storm Tides Increase…the Threat of Coastal Damage Increases
Coastal Flooding and The Relationship between High Storm Tides and Large Ocean Waves
25 Major Flooding 20 15 Moderate Flooding 10 Minor Flooding 5 Splash-over 0 Fresh Water Flooding Wave Height (ft) Height Wave 10 11 12 13 14
Storm Tide (ft)
Figure 8: The empirical relationship between storm tide, waves and coastal flooding (1980-2007).
Wave Climatology Portland, Maine (2007) So Large Waves (combined with high storm tides) Lead to coastal erosion and damage
Wave Growth Factor of… 1. Wind speed 2. Fetch 3. Duration
1. Increased Wind Speeds: Allow for Wave Growth L East Coast Cyclogenesis can trigger… – Intense Nor’easters and “Hybrid” storms
Gulf Stream Serves Important Role in Winter Storms
Info on Hybrid Storms See… http://moe.met.fsu.edu/cyclonephase/ The Relationship Between Wind Speed and Wave Energy
As winds increase…wave energy increases dramatically
2. Fetch: The longer distance winds travel over water, the greater the wave growth (NE, E or SE Flow)
Storm Force Winds
Patriots Day Storm: April 16, 2007
What about a “Moving Fetch”? Strong Wind Field Moves with the Large, Building Waves Local Example: Feb. 26, 2010 Waves During February, 2010 Nor’easter
Rapid increase in wave height February, 2010… Storm Impact Saco, Wells, Popham
Courtesy P. Slovinsky 3. Duration: Slow moving, long duration storms tend to produce larger waves (by creating a full sea state)
“The Perfect Storm”: Time Scale Often Days and Not Hours Fast Moving Systems: Do not have time to produce large waves in Northern New England
Hurricane Bob no issues A Conceptual Model of a Storm that Produces Large, Battering Waves in ME/NH
Strong and Persistent winds with a “Moving Fetch”
Feb 26th, 2010 Intense Nor’easter Produced Significant Erosion/Damage A few final thoughts about Large waves
“Wave Setup”
Water rise due to breaking waves - - potential energy of large ocean waves is converted into the kinetic energy required to maintain an anomalous surge of water near the shoreline. “Wave Run-up”
Leads to Splash-over
[The highest 2 % breaker run-up can be mathematically computed (Water rise ~ ½ York Beach Maine the predicted breaking wave height plus 50 cm)] “Waves: Bathymetry & Beach Orientation”
Storm surge (sloshing effect) versus erosion
http://www.nhc.noaa.gov/HAW2/english/storm_surge.shtml
Long Period Waves
L Tropical Systems: Hurricane Bill, Acadia (2009) – Dangerous surf and rip currents – 13 Injuries with fatalities, Erosion
“Very” Long Period Waves
“Meteo-Tsunami” Boothbay Harbor, Oct. 2008 RADAR ANIMATION Base Reflectivity Loop
Cell movement 82 kts Coastal Flood & Erosion Forecast Tools (Partnerships Underway to predict erosion/damage due to wave action) Stockdon (USGS) Empirical Collision Model Mignone 2013 Elements of Storm Impact Scaling Model
Swash Regime: Minimal erosion/effect on the dunes 7 Least potential Hazard
Elements of Storm Impact Scaling Model
Collision Regime: Erosion of dunes/ Some splash-over 7 aves impact dune 7 Leads to erosion Elements of Storm Impact Scaling Model
Overwash Regime: Splash-over & Backwater flooding 7 Dune overwash 7 Destruction of Dune 7 Road closures
Elements of Storm Impact Scaling Model
Inundation Regime: Coastal Flooding 7 Dunes are effectively underwater Test site
Stockdon Equations: December 27th, 2012 Storm
L Seas 21-25 feet at high tide (nearshore buoys)
L Astronomical tide only 9.5’ in PWM Harbor + Storm surge 2.5’ = Yields Storm tide 12.0 feet (FS=12.0 ‘)
L On a sunny day, 12.0 feet = minimal issues – But not this day
Coastal Impact Tools Coastal Flood Nomogram based on Storm Tides/Waves
Available at www.NERACOOS.org Expand Nomograms to other “Hot Spots” Rockland: FS ~ 12.5+ ft/ waves not a big issue
Bath/Woolwich: FS ~ 12.5+ ft + heavy rains
Portland: FS = 12 ft/commercial street floods at 13.5 ft
Saco: FS ~ 12.75’ (Splash-over begins with 10+ ft waves + mdt-high storm tides causes flooding & closings of roadways)
Wells/York/KBunk: FS ~ 12.75’ (Splash-over begins with 15-20 ft waves + moderate/high storm tides) Hampton: FS ~ 10.75 feet (Fort Point Gage)] (Splash-over mainly with ~ 15 - 20 ft waves + moderate/high storm tides)
Available on our “Marine Wiki Page”
Scituate Hampton Coastal Flooding and Splash-over Forecast Matrix
Forecast Wave Height (Ft) (Buoy “B”)
0 2.5 5.0 7.5 10.0 12.5 15.0 17.5 20.0 22.5 25.0 27.5 30.0 32.5 14.00 Mj Mj Mj Mj Mj Mj Mj Mj Mj Mj Mj Mj Mj Mj 13.75 Mj Mj Mj Mj Mj Mj Mj Mj Mj Mj Mj Mj Mj Mj 13.50 Mj Mj Mj Mj Mj Mj Mj Mj Mj Mj Mj Mj Mj Mj 13.25 Mj Mj Mj Mj Mj Mj Mj Mj Mj Mj Mj Mj Mj Mj 13.00 Md Md Md Md Md Md Md Md Mj Mj Mj Mj Mj Mj 12.75 Md Md Md Md Md Md Md Md Md Mj Mj Mj Mj Mj NECOFS Forecast Storm Tide (Ft) 12.50 Md Md Md Md Md Md Md Md Md Md Mj Mj Mj Mj (MLLW, Fort Point, NH) 12.25 Md Md Md Md Md Md Md Md Md Md Md Mj Mj Mj 12.00 MI Mi Mi Mi Mi Mi Md Md Md Md Md Md Mj Mj 11.75 Mi Mi Mi Mi Mi Mi Mi Md Md Md Md Md Md Mj FS ~ 10.75 ft 11.50 Mi Mi Mi Mi Mi Mi Mi Mi Md Md Md Md Md Mj 11.25 Mi Mi Mi Mi Mi Mi Mi Mi Mi Md Md Md Md Md 11.00 Mi Mi Mi Mi Mi Mi Mi Mi Mi Md Md Md Md Md 10.75 Mi Mi Mi Mi Mi Mi Mi Mi Mi Mi Md Md Md Md 10.50 Mi Mi Mi Mi Mi Mi Mi Mi Mi Mi Mi Md Md Md Statement Optional 10.25 Ac Ac Ac Ac Ac Ac Ac Mi Mi Mi Mi Mi Md Md 10.00 Ac Ac Ac Ac Ac Ac Ac Ac Mi Mi Mi Mi Mi Md Issue Coastal Flood Advisory 9.75 ------Ac Ac Mi Mi Mi Mi Mi Issue Coastal Flood 9.50 ------Ac Ac Mi Mi Mi Mi Warning 9.25 ------Ac Ac Mi Mi Mi 9.00 ------Ac Ac Mi Mi 8.75 ------Ac Ac Mi 8.50 ------Ac Ac 8.25 ------Ac
Ac = Action stage. High water levels or wave action with limited or unknown impact. Mi = Minor coastal flooding or splash-over along several roads and basements Md = Moderate coastal flooding or significant splash-over along numerous roadways. Isolated structural damage. Mj = Major coastal flooding with widespread flooding of vulnerable roadways. A few homes severely damaged
Hampton NECOFS Model
L This is “Part II” of NECOFS high res model following Scituate – Model development focusing on Hampton, NH due to high frequency of coastal inundation – Splash-over occurs along the Hampton Seawall as well
Hampton/ Seabrook Watershed boundary
Bridge
Hampton/Seabrook Beach Hampton Goal: To provide high resolution inundation forecasts for Hampton Tide Gage Installation 12/11/2012
FS ~ 10.75’ December 27, 2012
February 8, 2013 Visualization Experts: UNH Partnership
Courtesy CSC New ESTOFS Storm Surge Model
“Sandy’s” Verification Portland: Actual Storm Surge = 2.5’ Storm tide = 11.50’ Waves = 22’ Winds 1026g37kt at high tide
Fort Point: Actual Storm Surge = 1.7’ …Climatology Aids… Top Ten Tides Portland, Maine
1. 14.70’ - Feb 7, 1978 (Blizzard Of ’78) 2. 13.98’ - Jan 9, 1978 3. 13.40’ - Dec 4, 1990 4. 13.31’ – Mar 16, 1976 5. 13.29’ – Nov 20, 1944 6. 13.29’ – Nov 30, 1945 7. 13.28’ – April 16, 2007 8. 13.18’ – Jan 2, 1987 9. 13.18’ – Oct 30, 1991 10. 13.09’ – Apr 7, 1978
Splash-over along a seawall
- courtesy Bruce Budd Tide Return Periods: We are Overdue!
Frequency Portland, Maine (Return Period) 13.0’…once every 10 yrs (last time Apr 16, 2007) 13.5’…once every 50 yrs (last time Feb 7, 1978) 14.0’…once every 170 yrs (last time Feb 7, 1978)
Spring Tide Data: Normal: 10.4’ above MLLW Maximum: 11.7’ above MLLW Coastal Services Center Social Science of Storm Surge Team L Team – Working with social scientists, marketing and communications specialists, social media experts
L Goals – Develop and test effective storm messaging – Create new products and tools for different audience groups
Verification: Storm Reporter Website http://reporter.me.stormsmart.org/
New Account Start Here!!!
User: johncannon We need your help!
Become a Coastal Storm Reporter. “Storm Based” Beach Profiling 2012-2013 Beach Profiles Examples from four notable storms: “Cold Season”
7 Hurricane Sandy (October 28th, 2012) 7 Early Season Nor’easter (December 27th, 2012) 7 Blizzard of 2013 – “Nemo” (February 8th, 2013) 7 Slow Moving Nor’easter (March 8th, 2013)
March, 2013 Sandy…
7 Good lead time (“well behaved - slow moving storm”) allowed for early activation of beach monitoring IOSN3 East Winds: 0848G56 Peak wind 64 kts Seas: 25’ Every 11 sec Sandy’s Impact Significant Erosion Wells Beach (Casino Point, WE00)
Note Date Before
After Gooches Beach GO02 (Little Change after Sandy)
Little Change December 27th Nor’easter
Buoy “B” (High Tide) Seas=25’ every 11s
Winds NE = 0551g56kt
Beach Profile Changes (Following December 27th Storm) Erosion FE01 Erosion FE02
Displaced Eroding Edge of dune Before Before
After After Camp Ellis CE01 (Little Change)
December 27th Storm Measureable Gains (FE04) Sand accretion moved north up the beach?
Gains Blizzard of 2013
“NEMO”
Wells, Maine (February 8th) “Storm Based” Beach Profile
* All-time record snowstorm Portland, Maine February 8th “Blizzard” Gooches Beach
L Tree stumps 3000-4000 yrs old based on radiocarbon
“I'd estimate the waves were between 12-16 feet high and really rolling in. Our sea wall took a battering and various parts of it were floating around in the surf, including sections of our new ramp. The town BPW tried to protect it by piling sand on the seaward side of it, which took almost no time at all to wash away” – J. White Before After
CE01 Gain near dune structure NNW Flow: Gain in profile Loss below dune near landward structure side of the dunes GO02 (very little change) March 8th Storm
A large…slowing moving storm (984 mb). Full sea state 20’+ waves every 14 seconds. Gale force N winds. PWM=11.8’ . Storm surge 1.77’. “Splash-over”: March, 2013 Gooches Beach: GO01
Gains
Losses
Gains near the dune structure, loss further down the beach Gooches Beach: GO02 (little change) Wells Beach: WE00 (gain near the dune structure)
After
Before FE03 (loss throughout the profile) CE02 Surf St. Saco
Gain along the profile adjacent to the geotubes Gains near dune structure (Monthly)
Concrete Seawall Losses below
Rocky Area Less Volume Loss (slight Volume increase) during Dec- Jan Period Dana Willard, Long Sands Beach Results…
. 4 Significant coastal storms this year…
. Easterly winds: considerable erosion throughout the profile
. Northerly winds: mixed results
Results…
. North…Northwest winds: mixed results but mainly gains noted near the dune structure
. First successful “storm based” surveys were completed! Thanks!!!
. Most dune surveys (6 out of 9) have shown accretion of sand in the profiles since this winter
Challenges of “Storm Based” Monitoring
7 Lack of daylight
7 Short “heads up” on approaching storms
7 Tides sometimes high during the middle of the daylight hours
7 Storm surge and Wave action often an issue when completing the beach monitoring Challenges of “Storm Based” Monitoring
7 False alarms: Network Activation
7 Camp Ellis and other locations a challenge to monitor due to geotubes/mitigation efforts etc.
7 Work (Meteorology) “gets in the way”
7 Poor visibility Thank You for your time!!! Questions/Comments???