This coast gets two storm seasons: nor'easters from September into April and tropical systems from June through November. East winds along the axis of Long Island Sound drive surge into the western end, which is why Stamford, Greenwich and Norwalk take storms differently from inland towns.
Key takeaways
- The National Weather Service says nor'easters are most frequent and most violent from September to April.
- East winds along the axis of Long Island Sound caused high surge in the western Sound during Hurricane Sandy.
- The National Weather Service assessment of Sandy estimated inundation possibly as high as 6 feet above ground in parts of Fairfield and New Haven counties.
- Unofficial reports put Sandy gusts at 76 mph at Bridgeport Airport and 70 mph at Greenwich.
- Irene's surge ran 2 to 4.8 feet along the Connecticut and Rhode Island coasts, and rainfall locally exceeded 10 inches.
- A hurricane barrier protects against surge and does nothing for a roof.
What is a nor'easter?
A nor'easter is a strong low-pressure system that brings heavy rain or snow, gale-force winds and sometimes coastal flooding. It needs no name to do damage, and it does most of its work between September and April.
The National Weather Service describes a nor'easter as a strong low-pressure system affecting the Mid-Atlantic and New England. Such storms nearly always bring heavy rain or snow, gale-force winds, rough seas and sometimes coastal flooding. They are most frequent and most violent between September and April, which makes them the main winter load case on this coast. A nor'easter does not arrive with a name or an eye, and so it is easy to underestimate. It can run for a day or more, and the wind can stay in one direction for long enough to build water against the shore.
What reaches a roof in a nor'easter is usually a combination of loads at once: wet snow or rain, plus a steady easterly wind blowing off the water. The wind pushes against the windward slopes and gets under any edge that is already lifted. Rain driven sideways finds the gaps that a calm rain would never reach, such as the laps at a step flashing or the joint at a chimney. A roof that came through one wet storm can still show the damage only after the next one, once the underlayment has taken on water and the ceiling below has begun to stain.
Why does the western Sound take more surge?
Water piles up at the western end of the Sound when east winds blow along its axis. The surge reaches the shore towns there, including Stamford, Greenwich and Norwalk, and it can flood low ground before the wind drops.
The National Weather Service explains that east winds along the axis of Long Island Sound drive surge into the western end of the Sound. The wind pushes water up the length of the basin, and the water has nowhere to go but up the shore. That is the mechanism that makes this stretch of coast different from inland New England, where the same storm reaches the land mainly as rain and wind. Here the storm's water arrives on the same wind that brings the rain, so the two loads reinforce each other.
The effect is strongest when the surge arrives at high tide and the wind stays on the water for hours. Low streets and waterfront properties take the water first, at the foundation and the lower walls. The roof then faces the wind that drove the surge, and it is the wind that tests the edges, ridges and flashings. A house that stayed dry at the foundation can still carry storm damage high up, which is why a roof check belongs in any post-storm review of a shorefront property, even when the flooding seemed to stop short of the house.
What did Sandy do to the western Sound?
The National Weather Service assessment of Hurricane Sandy estimated inundation possibly as high as 6 feet above ground in parts of Fairfield and New Haven counties. Peak gusts reported at Bridgeport Airport and Greenwich were unofficial, and the Service labels them that way.
Sandy in October 2012 showed what the western Sound can take. The National Weather Service's assessment of the storm says the surge came from east winds along the axis of the Sound, and it estimated inundation possibly as high as six feet above ground in parts of Fairfield and New Haven counties. A figure like that is a regional estimate, not a survey of any one street, and it describes water that reached the ground floors of many houses. For a homeowner the useful lesson is that the surge line and the roof line are not the same, and both need checking after a storm of that kind.
The wind side was as serious. The National Weather Service's New York office recorded unofficially reported gusts of 76 miles per hour at Bridgeport Airport, 70 at Greenwich, 69 at Norwalk and 68 at Trumbull. The Service calls these unofficial spotter and station reports, and the label matters. The numbers are useful for seeing the pattern across the shore, where the wind was strongest and how it moved. They are not a measurement for any single roof, and they should not be quoted as one when a claim or a repair is being discussed.
What did Irene do in western Connecticut?
Irene crossed western Long Island and then southeastern New York and western Connecticut. Surge ran 2 to 4.8 feet along the Connecticut and Rhode Island coasts, and as many as 3 million people lost power for up to a week.
The National Weather Service's assessment of Hurricane Irene in August 2011 describes a center that crossed western Long Island and then southeastern New York and western Connecticut. Along the Connecticut and Rhode Island coasts the surge ran 2 to 4.8 feet. Those are the sourced figures for the surge, and they describe the coastline as a whole rather than any one harbor or waterfront lot, so they should be read as the pattern of the storm and not as a forecast for a particular house.
Rainfall in Connecticut and New York locally exceeded 10 inches, and tropical-storm-force winds and rain left as many as 3 million people without power for up to a week, mainly across Connecticut and Long Island. For a roof, the lesson is that the tropical track matters on this coast. A storm that passes to the west can still deliver surge, heavy rain and strong wind to the shore, and a roof that is not checked after that kind of storm may leak for weeks before anyone notices the stain. The timing of the leak is often the last clue a homeowner gets, so note the date of the storm when it arrives.
How does wind lift and tear a roof?
Wind does its damage at the edges, the ridges and the corners first, where it can get under the shingles and lift them. A shingle that has lost its seal or its nails tends to lift in the next gust, and the underlayment behind it is then exposed.
Wind pressure is highest at the windward eave, along the rakes and at the ridge, which is usually where the first shingles go. Once the edge of a shingle lifts, the wind can get underneath it and pull up the next course. Nails that were driven too high or were not fully seated let a shingle come free far more easily than one that is well fastened. A lifted row can then flap in the wind until the nails tear through the shingle, and a torn shingle leaves a clean gap that the next rain will find.
Torn shingles leave the underlayment and the decking open to rain, and the rain then runs down to the first ceiling it can reach. Missing shingles at the ridge, a bent or lifted drip edge and damaged flashing at a chimney are the usual places a technician looks first after a storm. The wind damage shingle repair visit usually starts at those points, because a single lifted course can hide water damage a few rows further down the slope.
Why do flashings and gutters matter after a wet storm?
Flashings and gutters take the wet weather at the joints, and a lifted or open flashing is a common path for water after a storm. On a shorefront house, the fixings, the gutters and the metal flashings are worth checking first.
Flashing is the metal that seals the joint between the roof and a wall, a chimney or a skylight. When wind bends it or the sealant opens, rain runs behind the flashing and the damage shows up well after the storm, as a stain on the ceiling near that wall. The same storm can leave one flashing bent and the one beside it intact, so the check has to be done joint by joint rather than by looking at the roof as a whole from the street.
Gutters full of debris can back water up over the eave and into the fascia, so clearing them before and after a storm is one of the simplest steps a homeowner can take. On a house close to the water, check the fixings and the metal flashings at the eave, the valleys and the wall junctions. Note what you find, photograph it with the date, and leave the repair to a technician who can match the metal and fix it properly. Most of the damage that a careful look finds is small, and most of it is cheaper to fix when it is found early.
What can you check from the ground after a storm?
From the ground, look for shingles or pieces of flashing in the yard, bent gutters, a gutter pulling off the fascia and any sign of ponding. Do not climb onto a wet roof to inspect it. If you see any of these, or water is reaching a ceiling, call the line.
Walk the perimeter once the wind has dropped and before you go near a ladder. Shingle debris in the yard or on the driveway, a gutter that sags or has pulled from the fascia, a vent cap knocked askew and a chimney cap with missing pieces are all visible without climbing. Photograph anything you find, with the date visible, before you clean it up or move it. The photographs are the first record of the storm's effect, and they are the easiest thing to lose once the cleanup starts.
The Stamford Hurricane Protection Barrier protects downtown from surge, and it does nothing for a roof. A house inside the protected area can still lose shingles to the wind, and a house outside it can take water at the foundation. Ask for a roof inspection after a storm, even when the damage looks small from the ground, because the places that matter most are the ones you cannot see from the sidewalk. A roof inspection gives you a written record of what was checked.
Frequently asked questions
Do nor'easters need a name to cause damage?
No. The National Weather Service describes nor'easters as nearly always bringing heavy rain or snow, gale-force winds and sometimes coastal flooding. They are most frequent and most violent from September to April. A storm that never gets a name can still lift shingles and push water past a flashing.
Does a hurricane barrier protect my roof?
The Stamford Hurricane Protection Barrier guards downtown from surge, and it does nothing for a roof. Surge and wind are different risks, and a roof needs its own check after any storm. Ask a technician to look at the roof whatever the barrier does for the street. The two protections answer different questions.
Why are Sandy's gust figures labeled unofficial?
The National Weather Service labels Sandy's peak gusts at Bridgeport Airport, Greenwich, Norwalk and Trumbull as unofficial spotter and station reports. Those numbers are useful for seeing the pattern across the shore. They are not a measurement for any single roof, and they should not be quoted as one.
Will a crew come out the same day after a storm?
A visit the same day happens only when a technician is free. The line is answered around the clock, so a call at night is taken and logged. No arrival time can be promised for a storm call. Tell the technician what you see and where it is, so the call can be sorted quickly.
Should I go on the roof to look for damage after a storm?
No, not while the roof is wet, icy or still in strong wind. A fall from a roof is a serious risk, and wet shingles are slippery. Check the ground, photograph what you can see from it, and let a technician do the roof work. A ladder set on firm ground is the most you should use.
Sources
This guide is general information for Fairfield County homeowners, not a substitute for an on-site inspection. Prices are estimates. See our disclaimer.