Forecast Worsens In NW Vermont; Lots Of Damage In South, Midwest

Click on the map to make it bigger and easier to see. The Saturday
morning update to expected ice accumulations.Expect some
ice damage in areas shaded in red. Purple areas can expect
a lot of damage and power outages. 

Northern New York and northwestern Vermont are screwed.

These areas now appear all set to receive a damaging ice storm.   By Sunday morning, a lot of homes and businesses will be without power, and a lot of trees and branches will be on the ground in what will likely be the worst ice storm since 1998.  

As of this morning, the National Weather Service in South Burlington had extended the ice storm warnings that were already in effect for northern New York eastward to encompass Grand Isle county and the western half of Franklin County in Vermont.

In northern New York, ice accumulations are expected to be over an inch in spots. That's more than enough to cause severe damage to trees and power lines. In the ice storm warning zone in Vermont, ice is forecast to be a half to three quarters of an inch thick by Sunday morning.  That's also more than enough to cause a lot of damage.

(As noted yesterday, the criteria for an ice storm warning is if a half inch or more of ice from freezing rain is likely to accumulate. If less than a half inch of freezing rain ice will accumulate, the National Weather Service will go with a winter weather advisory.)

The only real reason this won't be as bad as 1998 is because the freezing rain won't last as long. Instead of a three day affair, the freezing rain will all come within a 12 hour period, give or take, tonight and tomorrow morning.

VERY WET AIR

What this storm has in common with 1998 is the extreme availability of moisture for this time of year.

One common way meteorologist use to determine how much moisture is available for a storm is something called Precipitable Water, or PW.  The measurement doesn't necessarily tell you how much precipitation is going to fall, but it goes like this: If there is one inch of PW, then if all the moisture above that location condenses out, they'd get one inch of rain. You never get all of the moisture condensing out of the atmosphere, but PW is still a good guide for expected rainfall.

Precipitable Water in the atmosphere over northern New York and much of northern Vermont will be at or near record highs for January tonight.  That means rain or freezing rain will come down hard, extremely hard for January.

Total rain or melted ice in northern New York with this storm is expected to be around two to three inches. In northern Vermont, slightly less will fall, with totals expected by NWS South Burlington to be in the one to two inch range.

For comparison, total precipitation for the entire month of January is usually between two and 2.5 inches of rain.

FORECAST STILL TRICKY

As we've been describing, this storm is bringing wet and record warm air up the East Coast.  Places from central New England on down through the Middle Atlantic States and maybe points south will have a lot of record highs today and Sunday.  It could get as high as 80 degrees in West Virginia and the upper 60s in southeastern New England.

Meanwhile, just as the heaviest rain is expected to move into northern New York and Vermont that shallow cold front will come down from Quebec.  Warm air will still roar northward above this cold front, so the precipitation will come down as rain and freeze on contact down on the North Country.

Cold air is more dense than warm air and tends to sink toward valley floors, so this cold air will creep southward more easily where it isn't blocked by mountains. That means it will get cold tonight in the Champlain and St. Lawrence Valleys pretty easily

In Vermont, the cold air has got an open shot to get down as far as Rutland, but it remains to be seen how far the chilly air does get.  There will be a sharp temperature contrast in Vermont, with 20 degree temperature differences late tonight and early Sunday with miles of each other.

Sunday morning, it will probably be in the 20s in far northwestern Vermont and near 60 in the southeast corner.

The varying temperatures so close to each other means its hard to determine who will get ice and how much when you get south and east of Franklin County, Vermont.

Burlington is a wild card. It's the most populated area of the state. It's hard to say if there will be enough ice there to cause a fair amount of damage or will the ice be not that bad? It's almost imposssible to tell.

A weather front will sweep west to east across the region Sunday morning and afternoon, mercifully ending the freezing rain as a brief period of snow, with little accumulation.  Gusty winds with and behind the front will probably cause more damage and power outages and ice-laden trees in the north sway and possibly collapse in the breeze

FLOODING WORRIES

Expected precipitation (rain and melted ice) for the upcoming storm
Areas in yellow and orange can expect to at least 1.5 inches of
precipitation, which is an awfully lot for January. 

Notice I mentioned the precipitable water, above. Areas in northern and central New York and northern and central Vermont that don't get a lot of ice will get a lot of rain.

 Flood watches are still up for all of Vermont except near the Canadian border, and the far southern two counties, where it won't rain nearly as hard as further north.

Very mild air today across all of Vermont and tonight in all but northern Vermont will quickly melt what snow we have out there. All this rain will add the runoff with the melting snow will set probably set up some floooding.  

The first problem will be small streams and creeks tonight, which could wash out parts of roads, driveways and culverts.

The water will then flow in to more major rivers. As it stands now,  forecasts call for moderate flooding on parts of the Winooski and Mad Rivers and Otter Creek, with minor flooding elsewhere.

You've heard the terms minor and moderate flooding bandied about, and here's what they mean:

Minor flooding means few, if any buildings will get flooded, and just some roads, fields, parklands and flood plains will go under water.

Moderate flooding means some buildings might start to flood, roads will be closed by flooding and a few spots might have to be evacuated.

SAFETY:

I'll re-up some tips I put out yesterday here in this space:

1. Today is the day to buy batteries, bottled water and other supplies you'll need to get through power outages that could easily last hours, and perhaps a few days in some spots, especially in northern New York. Remember, especially if you have well water, the pump for the water won't work without electricity.

2. Charge your devices today and this evening, too, so they'll have a full charge in case you need them tomorrow. Remember, Vermont's spotty cell service might be even spottier in areas that get freezing rain, as power outages can affect things, too.

3.  Grab some cash from your bank or ATM, and fill up the car's gas tank. If there's power failures, gas pumps won't work, and stores won't be able to process debit or credit card purchases.

4. If you have a generator, please, please make sure the exhaust is at least 15 feet from the house if posssible and pointed away from the house. You don't want to die of carbon monoxide poisoning.

5.  This should go without saying, but stay away from fallen wires, even if they don't seem like they have electricity flowing through them. Stay out from under ice-laden trees, too. You never know if or when they'll collapse.

6. Check on the elderly and ill, and make sure they're warm enough. If not, and if possible, bring them to someplace that IS warm.

7.  This should be another "Duh!" tip, but don't drive through flooded roads.  It doesn't take much water to sweep a car away.  An additional hazard is the water this time of year is cold, making your chances of dying of drowning and/or hyperthermia greater and quicker.

8.  When this is over and you need to drive somewhere get all the ice off all of your car or truck. Ice flying off your vehicle on the highway can hit the car behind you, breaking their windshield or causing them to lose control and create a crash.  Store your vehicle in a garage if you can. If not, and to make things easier, cover as much of your vehicle with a tarp as you can and secure the tarp down so it doesn't blow away.

After the freezing rain ends, carefully remove the tarp and your vehicle should largely be ice-free.

DANGEROUS NATIONAL WEATHER

As expected, there's widespread damage from severe thunderstorms and some tornadoes in the South, a lot of flooding in other spots, and a bunch of freezing rain and ice damage in the Midwest.

So far, there have been reports of three deaths in Lousiana due to either tornadoes or severe storms.

In Logan, Arkansas, a tornado destroyed a house but the family who lived there was not hurt because they were in a storm shelter, the National Weather Service reported. Damage from the severe thunderstorms was reported from Texas to Tennessee.

Severe thunderstorms and possible tornadoes were ongoing early this morning from Kentucky to the Gulf Coast.

Alabama and parts of Mississippi and Georgia are under the gun today for severe storms and possible tornadoes.

A huge area encompassing much of Missouri and Illinois and substantial chunks of adjacent Arkansas and Oklahoma were under flood warnings this morning.

The ice storm that will affect northern Vermont tonight and tomorrow has already brought widespread  icing from Oklahoma to the Great Lakes.