4:30 p.m. update
A blizzard warning has now been posted for much of southern and eastern Maine. This means visibility is going to be under a quarter mile for at least three hours because of the snow and wind. The worst time for the storm will be Saturday after midnight through the first half of Sunday.

Earlier Post
A blizzard watch remains posted for much of southern and eastern Maine. A winter storm watch is still in effect for the rest of the area later Saturday and Sunday. The storm is still on track to hit the area this weekend, potentially bringing blizzard conditions to the most populated areas of the state.

In my blogs, I try to address people’s expectations. If I am stuck in traffic on the highway or on a plane that’s delayed, I can usually handle the inconvenience if I know what’s going on. I believe if we have a good idea what a storm will bring, it makes it easier to deal with. It’s the surprises no one likes.

It’s frustrating to hear that the snow will end at 8 p.m. only to have it still snowing at 11 p.m. By the way, it’s equally frustrating for the forecaster. I sometimes scream at the radar when I’ve forecasted the snow to stop at a certain time and it still hasn’t stopped. The radar never listens.

The upcoming storm’s biggest surprise could come from its intensity and its movement offshore. The accumulation maps you are seeing Friday are all based on the intensity of the storm occurring at a certain position off the coast and on the expectation that the storm keeps  moving once it does intensify.

The setup for the storm is this: We have a strong piece of energy with limited amounts of snow moving through the area Saturday afternoon and evening. As this area reaches the warm waters of the Atlantic it will spawn a much larger storm. This larger storm will then contain a lot of moisture, some of which is going to spin down the coastline and bring our area a period of heavy snow and potentially blizzard conditions.

The storm will end when its center moves far enough east to taking its precipitation shield out to sea. The difficult part of the forecast is that as the storm is moving away, it will be getting stronger and the its coverage increasing. So, even as the low pressure area departs, it can still spin snow along the coast.

The radar images below show how the snow will move in and out during the storm. The darker greens and yellows over New England are very heavy snow. The reds and yellows off the coast are actually thunderstorms over the warmer waters.

Timing
Snow will start across the area Saturday afternoon and evening. If you have errands and other normal Saturday activities, the roads won’t become snow-covered until between after 3 p.m. The snow will quickly accumulate, but the wind won’t be an issue and travel will just be slowed, not even close to impossible.

I’ll be updating here and on Twitter @growingwisdom throughout the storm.
Follow @growingwisdom

Saturday evening
It’s Valentine’s Day on Saturday and I am sure lots of folks want to go out to dinner. I would still go, but understand there will be some areas of snow, and roads won’t be bare. The height of the storm won’t arrive until Sunday morning and the winds won’t have increased. There actually might be a break in the snow between what falls Saturday evening, and the intensification of the storm that causes the snow to resume early Sunday morning. If blizzard conditions are going to occur, this is when it will happen.

Sunday
The storm will be going at peak intensity during the morning and winding down during the afternoon.

Snow bands should be rotating southwest around the back of the storm, which will be intensifying in the Gulf of Maine. As the storm grows stronger, winds will continue to increase and peak late in the morning or early afternoon.

The wind will whip the snow into drifts and blow it off the ground. A blizzard means visibility is a quarter mile or less because of falling or blowing snow. The snow may lighten up in the early afternoon, but the winds will still be creating blizzard conditions, especially along the immediate coastline. The snow should be ending between 4 and 9 p.m., lastly farthest Down East.

Snow totals
This storm shouldn’t develop into something that brings over 2 feet of snow to the area. That said, we do have the potential for a foot or more along the coast. I put the low end of the snow at 8 inches as of Friday morning, but as the newer models arrive Friday I’ll shrink the projected range. It could be that we see the lower ends of the ranges, so please don’t focus on just the higher numbers.

Snow weight
The cold air will keep the snow light and fluffy. The snow will blow off many higher rooftops, but create drifts on the roofs that are lower. You’ll need to assess for yourself if snow removal makes sense after the storm. If you don’t have issues with ice dams and it’s not too deep, you can leave the snow up there. It does act as a good insulator.

Coastal issues
The storm will cause some beach erosion and perhaps a bit of splashover during high tide Sunday morning. The position of the storm is such that winds won’t be directly coming at the coastline from the east or northeast. It’s not an astronomically high tide. Since the storm is moving quickly, the Sunday evening high tide should be less problematic.

Power line problems
Winds will be strong enough to blow down some tree limbs, etc., along the coast and this can always causes a loss of power. The snow will be light so the weight of it won’t be an issue on power lines. During the blizzard in January many of us kept power; I think it will be a similar situation with this storm.

Portland International Jetport
The strong winds will create big issues on the runways Sunday. If winds reach 50 mph, flights are halted regardless of the snow. I think Sunday is a non-starter for most planes. Monday will be a day when the airlines are trying to get all the equipment back in place.

Next storm
There is the chance for more snow during the middle of next week. I have no confidence in whether it will be a significant storm or miss us completely. We’ll have to wait a few more days to see how the trends develop.