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| Clouds near and off the southeast U.S. coast, especially near Florida, are the beginning stages of a big nor'easter that will cause destructive coastal flooding and storm surges up and down the East Coast |
The storm is widely forecast to create coastal flooding and battering waves from Florida to New England.
Seasonal king tides that make those tides higher than most other times of the year are already causing some nuisance flooding along the coast.
That never used to happen during king tides, but the sea level is up now due to climate change, so now many coastal areas endure "sunny day" flooding.
Now, this big nor'easter is looming. It will add a ton of water to those king tides, ensuring that much of the shoreline in the East will not look the same next week as it does now.
The only bright side is the peak of the king tides will be beginning to pass by the time the storm gets its act together.
The storm has all the ingredients to cause havoc. It will be slow moving and strong. It will create intense east winds that will shove water into the bays and estuaries up and down the East Coast. That has the potential to cause major tidal flooding.
The powerful winds will stir up huge waves that will smack into shorelines. They'll make the swells generated by offshore hurricanes this summer and fall look like child's play.
In some places, the storm surges could almost rival the destruction from Superstorm Sandy in 2012.
The slow movement of the storm will ensure the battering waves will hit during multiple high tide cycles, causing serious beach erosion.
Forecasters expect coastal roads going under water, severe erosion of sand dunes, structural damage and evacuation.
Perhaps the most threatened spot is North Carolina, where offshore hurricanes last week caused a total of nine homes to topple into the water.
After those storms, the Outer Banks of North Carolina are especially vulnerable to new damage. Local residents expect more homes to fall into the water.
The storms last week have already pushed back the coastline in North Carolina a lot, considering it was just one event.
"Researchers with RCOAST, a coastal resilience startup based in North Carolina, mapped the area...using 3D scanners and drones. Preliminary analysis found the average shoreline retreat was 68 feet, with some stretches losing up to 141 feet of beach. 3D mapping shows over wash from the storms pushed sand as far as 298 feet inland"
That means homes that were once safe from storm tides no longer are.
The nine houses that have already falle into the water were built between 1973 and 1998 had a combined assessed value of more than $5 million. When they were built, they were behind the sand dunes and not prone to battering waves. But repeated storms shifted the barrier islands, aided by rising sea levels.
The nor'easter is forecast to bring several inches of rain to many areas near the East Coast, and that rain will be driven by wind gusts exceeding 60 mph and 50 mph just inland. But the main damage will be to the shorelines.
Though this will not be a tropical storm, it will have some characteristics of one. That fact could enhance rainfall and potentially cause even stronger winds.
The effects of this storm start today along the east coast of Florida and other parts of the Southeast. The storm should intensify as it slowly crawls north. The worst of the storm in the Mid-Atlantic and Northeast will likely hit on Sunday and Monday .
Storms such as this nor'easter have more destructive power than similar storms years ago because sea levels are higher due to climate change. Shorelines south of New England are quite flat, so a little big of sea level rise can have effects surprisingly far inland.
VERMONT EFFECTS
Unlike on the coastline, the storm will cause more good and harm in the Green Mountain State, but it's still unclear to what extent it will affect us.
The storm will want to head north toward us, at least for awhile. But yet another strong, dry, high pressure system over Quebec will block it. The storm will only get so far north, then get deflected back south and east.
That's why we're in this drought. The weather pattern since early August has featured these arid high pressure areas that block storms and moisture from reaching us.
The early consensus is the storm will have enough oomph to spread rain into at least southern Vermont. How much is the question, but early guesses are the rain could end up being beneficial. Not nearly enough to end the drought, but enough to take a tiny step toward easing it.
If we get lucky, far southern Vermont could see more than an inch of rain between Sunday afternoon and Tuesday morning.
The further north you get the less rain you'll see. The Quebec high pressure will be feeding dry air into northern Vermont as the nor'easter tried to send moisture north. The end result could be much of the rain evaporating before it hits the ground.
Still, for now, up to a quarter inch of rain could fall. That's not much, but we'll take anything we can get.
I'll emphasize these are all educated guesses for now. The computer models are all over the place with how much the nor'easter will affect northern New England.
The least likely scenario is that we get nailed with heavy rain. Don't get your hopes up for that one. It's possible the north will get no rain, too.
Note that there's will be a huge difference in air pressure between the strong high in Quebec and the nor'easter to our south.
That could set up the southern Green Mountains for some strong gusty winds toward Sunday and Monday. Nor'easters can cause strong downslope winds on the western slopes of the mountains. That could be the case with this storm Sunday night and Monday.
The strong winds are expected to avoid the northern Green Mountains.
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