Friday Evening Update: It's Getting Real: Flood and Winter Storm Watches Now Up In Vermont For Possibly Serious Storm

The National Weather Service in South Burlington has 
greatly increased expected snow totals from the 
Sunday/Monday storm. Click on the map to make it
bigger and easier to see. Take the map with a grain of
salt. Big changes in the forecast either way are still likely,

 Like the headline says, this is getting real. 

It's beginning to look like this will be one serious storm hitting Vermont. Heavy rain, heavy, wet snow, wind, power outages, travel disruptions and more are all in the cards. If the forecast holds, this will really be a nasty one.  

A flood watch is now in effect for all of Vermont, covering the period from about noon Sunday to noon Monday. Flood watches are also up in most of the Northeast from Delaware to Maine. 

A winter storm watch is in effect for northern and central Vermont outside the Champlain Valley and in the Adirondacks for late Sunday evening to Monday evening. 

 It's beginning to look like the snow threat is more dire than the flood threat. But you still have to pay attention to the flood issue. 

With that list of problems, let's take 'em one at a time. 

FLOODING

While other parts of the forecast keep shifting, the rainy part of all the predictions remain consistent. Rain will move into Vermont during the morning or early afternoon in Vermont and pick up in intensity toward evening. 

It'll be warm, with highs in the 45 to 52 degree range, and humidity will be high for this time of year. That'll get the high elevation snow melting pretty fast. 

As we head into Sunday evening and night, it'll stay warm. The rain will come down pretty hard, with maybe a few periods of bonafide downpours as a cold front nears and crosses Vermont.

Rivers statewide will rise sharply overnight Sunday into Monday. The larger rivers will keep rising even after Monday's changeover to snow, which I'll get into shortly. 

Most rivers in the Green Mountain State will at least get to bank full.  Rivers most likely to go into minor flood are the Winooski and Mad rivers and the Otter Creek. 

The National Weather Service and the USGS has the 
Winooski River at Essex Junction going solidly into at 
least minor flood stage by Monday morning. 

At this point, the Winooski looks like it might not reach flood stage at Montpelier. Even if it does, it won't attack downtown Montpelier like it did in July, so we're good there. Toward Chittenden County, the Winooski River is expected to solidly go into flood stage.

For Monday commuters, forget North Williston Road. It will likely be under water and closed. It's possible water could cover Route 2 in Jonesville and possibly Bridge Street in Richmond. Again, this won't be nearly as bad as July, but it's worth noting. 

Low lying roads in Warren, Waitsfield and Moretown could go under water due to Mad River flooding late Sunday and Monday. Same is true for roads right along Otter Creek in Rutland and Addison counties. 

Since it's always dark this time of year, flooding is especially dangerous, as you often can't see flooding ahead of you as you're driving until it's too late. So be careful

SNOWSTORM

The forecast continues to look nasty for a changeover from rain to heavy snow.

This could be a real, big mess. I'll repeat myself, the snow end of this storm might well be worse than the flood portion.  

At this point, anyway, heavy wet snow could amount to five to 10 inches in the winter storm watch zone, with 12 to 18 inches possible in the mountains. Winds will be increasing during the snow, which would really make the power outages worse. 

As for the Champlain Valley, I still have no idea if we will have a lot of snow on Monday or just a little.

The heavy snow will come courtesy of a likely "bomb" storm that will form near the Middle Atlantic States and move northward into eastern New England. Storms are centers of low atmospheric pressure and generally speaking, if the central pressure of a storm is falling, that storm is strengthening.

If the central pressure falls at least 24 millibars within 24 hours, it's a bomb cyclone. When a storm is "bombing," it more often than not causes severe rain, snow and/or wind. 

The National Weather Service office in South Burlington explains this afternoon that computer models indicate the cold front will come through a little sooner than originally forecast Sunday night, and our storm will move northward a little further east than first planned.

That sets Vermont up for particularly heavy snow.  

That said, there's a chance I'm hyperventilating for no reason. I guarantee changes to the snow forecast, and meteorologists really have no idea how much snow will actually fall. The current forecasts are just early guesses.

You can tell how uncertain forecasts are by looking at the National Weather Service probabilities for snow accumulation. For instance, the forecast for Burlington is for 2.9 inches of snow, but there's a chance it could be as much as 10 inches and there's a chance it could be just a dusting.   

There will be short distances as well between areas that get a lot of snow and those that escape. St. Albans, in contrast to Burlington, is set up for 8.3 inches of heavy, wet snow, but it could be as much as 15 inches there or as little as three. 

At this point, anyway, the Monday morning commute looks like it might be a disaster, at least if current forecasts hold. Rain will switch to snow west to east during the predawn hours west, and toward dawn east in Vermont. 

One glimmer of hope: For what it's worth, the Friday late afternoon run of the American computer model makes the storm much weaker and further east than previous forecasts. If that were to happen, this storm wouldn't really be that big a deal. But definitely DON'T count on that. At least until we see more consistent forecasts 

Snow in many areas will coming down at a rate of an inch per hours, which is pretty extreme if you're talking about heavy, wet snow. Drier snow tends to accumulate faster.

Heavy, wet snow is harder to drive through since it compacts under tires into a watery ice, which is as slippery as you can get. Visibility would be terrible too, especially since winds are forecast to get pretty gusty. 

Again, if the forecast turns out as they're thinking now, I would expect a lot of power outages. On Sunday evening, charge your devices and drag out the LED candles. You might need them. Don't use regular candles with real flames. They're a fire hazard. This being the Christmas season, I'm sure you can find some inexpensive and very nice LED candles during any shopping trips Saturday or Sunday. 

Finally, winds look really gusty on Monday, which would make any power outages worse.  Again, we still don't know the strength or position of the storm. This all could be a false alarm, or it could be real trouble. As always, stay tuned.