Sunday, October 29, 2017

Sunday Morning Update On Big Northeast Storm

Visible satellite photo at midmorning Sunday shows lots
 of clouds overe the eastern U.S. You can see sort of
a spin starting in the Carolinas. That is the start
of what will be a very strong storm roaring
through the Northeast tonight and Monday. 
Rain, locally heavy had already broken out by and before mid morning Sunday in parts of the eastern United States as the big promised storm gathers its energy.  

As we mentioned yesterday, much of the heavy rain would target much of New York State and that's already beginning.

New York's St. Lawrence Valley was already getting downpours at mid-morning Sunday, and the main storm that will come through tonight is only starting to get its act together much further south over the southeastern United States.

In fact, I'm beginning to think the heaviest rain with this storm will fall in the St. Lawrence Valley, with perhaps five inches of rain there. I also think parts of New Jersey might get slammed because there are signs some torrential thunderstorms will set up there.

The current rain band over the St. Lawrence Valley is just the first salvo. When the storm gets cranking, it's expected track, a little west of northbound from roughly the New Jersey coast into eastern New York, then a little west of Montreal, favors eastern and central New York for heavy rain.

While this storm, as expected, will cause big time flood problems in some parts of the Northeast, especially New York State and maybe parts of New Hampshire and Maine, it's looking like this will be an even more widespread wind event.

High wind warnings and watches cover most of the Northeast, with the most destructive winds expected along the coasts and in the higher elevations of New England and New York.

Gusts could reach 70 mph on the coasts from New Jersey northward through Maine. Similar gusts could hit higher elevations of the Northeast as well. Widespread gusts of 50 mph or more will probably cover the entire region. Expect lots of fallen trees and lots of power failures tonight and Monday morning especially.

Here in Vermont, the flood threat for this storm, while not gone, has eased. It looks like the heaviest rain will go by just to our west, as I described above. Another band of heavy rain and flooding could strike New Hampshire, especially near the White Mountains, and western Maine.

Flood watches are still up in southern Vermont, as the rain is expected to be pretty heavy there.

The National Weather Service in South Burlington, Vermont is going with roughly one to two inches of rain across Vermont, with maybe a little less in the Northeast Kingdom and maybe a little more in southwestern Vermont.

The slow moving cold front that this storm will be riding northward along has pressed a little further east than I imagined. It had moved into Vermont this morning and is pretty much stalling out. As the main storm develops and moves northward tonight, that front will jog westward.

When that happens, it'll open the door for strong southeasterly winds, especially in the mountains and along the western slopes of the Green Mountains. Those strong southeasterly winds are why some of the flood concerns have eased in parts of Vermont: When the wind blasts down the western slopes of the mountains, it tends to compress and dry the air somewhat, leading to less rain.

Once the storm gets to our north Monday, very strong winds will blast out from the west, most affecting northern New York, higher elevations in Vermont and possibly the Champlain Valley.

Things to think about during the storm:

1. Flooding: It'll rain hard tonight especially, and flooding is much harder to see when it's dark. Any flooding that does happen could come on very fast. Careful with the driving tonight, or better yet, don't bother. This is especially true in the Adirondacks, Catskills and St. Lawrence Valley of New York, and parts of northern New Hamphire and western Maine, which has the biggest flood threat.

Also note that a lot of leaves are coming down, so storm drains in urban areas will become clogged, causing street flooding. On top of that. bunches of leaves can form dams on small brooks and streams. Then these dams suddenly let go, potentially causing a brief but intense and dangerous local flash flood.

2. High Winds: Even though it's raining out, get your lawn furniture and Halloween decorations and such indoors now, before the wind gets really cranking. You don't want that stuff blowing around tonight and tomorrow. I'd also get flash lights and LED candles ready to use in case of power failures. I'd also keep the smart phone fully charged.

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