We had a blizzard on Thursday and some light snow this morning. So, you’re all set with snow for a while, right? Good, you get a 24-hour break. We’ve got another storm coming for Sunday and Monday, and this one is looking like it will be another significant one.

Low pressure currently moving across the Plains states will move into the Ohio Valley tonight, then off the Mid-Atlantic coastline later on Sunday, passing just south of New England. It is then expected to slow down in the Gulf of Maine Sunday night and Monday while rapidly intensifying. Cold air is already in place today, and some spotty freezing drizzle or flurries are possible this evening into Sunday morning. The steadier precipitation from the storm should arrive around midday Sunday, in the form of snow, and may quickly become moderate during the afternoon hours. A coastal front will likely set up once again, with temperatures in the lower to middle 30s to the east of it, and upper teens to lower 20s west of it. As this front pushes inland, snow will change to rain during the late afternoon  or evening from Boston southward. Inland, we may see a little freezing rain or sleet mix in, but it should be mainly snow. As the storm begins to intensify in the Gulf of Maine Sunday night and Monday, this coastal front will collapse back towards the coast, changing everything back to snow, as gusty northerly winds send cold air back across the region. Snow continues into Monday morning, before tapering off around midday, though some snow showers may continue into the afternoon.

Having said all that, there are still a few details to be worked out:

1. How close does the storm come to the South Coast/Cape Cod.
2. How rapidly does the storm intensify in the Gulf of Maine.
3. How close to the coast does the storm slow down in the Gulf of Maine.

We need to resolve the factors to get a truly accurate forecast, but unfortunately, most of that won’t be known until the storm is ongoing. We are fairly sure that the strong winds will be confined to coastal areas, and mainly on Monday as the storm really intensifies to the east. Sustained winds of 25-35 mph with gusts to 50 mph or more are possible, especially from Cape Ann to the South Shore and Cape Cod.

So, by now, you’re wondering, how much snow this time? Here’s what we’re thinking:

Cape Cod: 1-3″, mainly Monday from the backlash behind the storm.
South Shore/Boston/Providence: 4-8″, possibly a little more, especially the further inland you get
MetroWest: 5-10″
Merrimack Valley: 8-12″
Southern NH/MA North Shore: 10-14″
NH Seacoast/Southern Maine: 12-16″

We may revise this forecast late tonight or Sunday morning, if time allows. Also, just to give you fair warning, we may be dealing with yet another snowstorm in the Wednesday/Thursday time frame.

Have you finished cleaning up your driveway from the blizzard yet? Good, because we’ve got a 1-2 punch coming this weekend with more snow, though the 2nd storm, while stronger, may end up as rain for a portion of the area.

Don’t let today’s sunshine fool you, it’s going to snow again tonight. A Saskatchewan Screamer (also known as an Alberta Clipper) will race this way, spreading clouds back in late today. There will be little wind associated with this storm, so we’ve got that going for us. Light snow will develop around midnight and continue through the morning, tapering off an ending around midday. Most of us will see between 1 and 3 inches from this storm, with a few 4 inch totals possible. That’s not a big deal, right? Especially after what we got yesterday.

After that, we turn our attention to Sunday, because that might be a bigger deal. That storm, like so many of the other ones we’ve had this winter, will likely not be all snow for everyone. However, where it does stay all snow, we could be looking at several inches of heavy, wet snow – the kind that nobody likes to shovel.

Low pressure will head into the Ohio Valley then towards the eastern Great Lakes this weekend. It will then redevelop off the Mid-Atlantic coastline and head east-northeastward, passing near or over Cape Cod, because really starting to intensify in the Gulf of Maine. How close it comes to the Cape and how quickly it starts to intensify are the biggest things that will impact our forecast. We’ll try to iron out those details in the next 24 hours, and have another post tomorrow, after the first system winds down.

“Luck. Runs. Out.” – Metallica

If you’ve been enjoying the relatively snowless and mild winter, then the opening line to the Metallica song “All Nightmare Long” is an appropriate line today, because your luck has run out. We’ve got a snowstorm coming tomorrow, and it’s going to impact both the morning and evening commutes, so plan ahead.

A cold front is moving across the region this afternoon, replacing last night’s unexpected cold air with milder air. Yes, that doesn’t sound right, but it’s what’s actually happening. As it moves offshore, it will stall out south of New England and high pressure will build in to our north, replacing the relatively mild air of this afternoon with more seasonably cold conditions tonight. At the same time, a wave of low pressure will ride along our stalled out cold front across the Tennessee Valley and into the Mid-Atlantic states. Once it moves off the coast early Thursday, it will intensify as it passes south and east of New England. With cold air settling in, and low pressure passing just south of New England, you get a snowstorm. It won’t be a blockbuster storm, since it’ll be moving too quickly, but we’re still looking at moderate to heavy snow.

OK, time for some specifics. First the timing. This will be a 10-12 hour storm for most of us. The snow should develop right around the morning commute, roughly the 6-8am time frame. It should end right around the evening commute, roughly the 6-8pm time frame. The worst of the storm will be between about 10am and 4pm, when snow could fall at the rates of 1-2 inches (or more) per hour.

Next up – temperatures, since they have an impact as well. We’re going to have a boundary set up across eastern Massachusetts that is called a coastal front. We had the same thing happen last night. East of the front (right along the coast), temperatures will be in the upper 20s to lower 30s, resulting in a wet, heavy snow. West of the front, temperatures will be in the upper teens to lower 20s, resulting in a much drier, fluffier snow. Right along this boundary is usually where the heaviest snow falls. So, where does that front set up? Right now, it looks like somewhere right along I-95 across eastern Mass.

Next up, the winds. Strong winds will likely be confined to eastern Massachusetts, especially along the coast, as always. Sustained winds of 20-30 mph are possible near the coast, with some gusts to 50 mph. Away from the coast, we’re looking at gusts of 20-30 mph. Nothing like some of the worst storms we’ve seen, but it’ll creating blowing and drifting, reducing visibility at times.

So, that leads us to the part you’re all most interested in – how much snow are we going to get? For most of us, this will be a moderate snowfall event. Here’s the breakdown for what we’re thinking:

Central NH (Concord): 3-6″
Southern NH (Manchester/Nashua/Portsmouth): 4-8″
Merrimack Valley/Central MA (Lawrence/Lowell/Fitchburg/Worcester): 5-10″
Cape Cod: 5-10″ (maybe a little less on the Outer Cape/Nantucket)
North Shore/SE Mass (Beverly/Plymouth/Fall River): 6-12″
Rest of Eastern MA/RI (Boston/Providence/Brockton/Framingham): 7-14″ with isolated heavier totals possible.

Once the storm goes by, we’re looking at a breezy and cold day on Friday, with temperatures likely staying in the teens or lower 20s across the entire area. Then, Friday night and Saturday brings another Saskatchewan Screamer (Manitoba Mover? Albert Clipper?) which could drop a quick 2-4 ” of snow. There’s another storm right behind that for Sunday night into Monday, but the models are indicating that storm could feature more rain than snow. We’ll keep an eye on it anyways. The active pattern likely continues into next week as well.

A developing storm system will bring heavy snow to parts of the Southeast and New England this weekend, while the West Coast braces for a lot of much-needed rainfall.

We’ll start on the West Coast, where a series of storm systems will bring plenty of rain to drought-stricken California. While this will not alleviate the drought that has been ongoing for years, it will help to put a big dent into it. The first of the storm systems will move in tonight, and by the time the last one moves through next Friday, rainfall totals of 5-10 inches will be widespread across much of central and Northern California, with many locations, especially along the coast and western slopes of mountains receiving 10-20 inches or more.

At the higher elevations, especially in the Sierra Nevada, incredible amounts of snow are expected. The snowpack, which much of the region depends on for water in the summer as it melts, is already above normal, and over the next week, some locations might see 6-12 FEET of new snow from these storm systems.

Back in the East, a storm system is riding along a stalled out front across the Southeast, producing some snow across parts of the Tennessee Valley and the Southeast. As this system draws in moisture from the Gulf of Mexico and the Atlantic, and runs into an arctic airmass already settling into the region, it will produce heavy snow in places that normally don’t see a lot of snow, such as Georgia, the Carolinas, and the Virginia Tidewater area. In these places, even a dusting of snow can cause traffic nightmares, so heavy snow can bring these areas to a standstill, which is why one friend of the blog in the Raleigh area refers to it as “The Great White Plague”.

The heaviest snow from this system is expected across the Appalachians, as you’d expect, and into the Virginia Tidewater area, as the storm gathers strength while moving into the Atlantic. Of course, the 6-12 inches expected across much of North Carolina will cause its own problems, but luckily, the bulk of the snow will fall tonight and Saturday, minimizing the travel problems.

Once this storm moves off the Mid-Atlantic coast it will head northeastward, passing a couple of hundred miles south and east of Cape Cod. Normally, this would mean just a little bit of light snow for parts of Southern New England, and for the most part, that’s what we’re expecting. However, for southeastern New England, mainly south and east of I-95, it’ll be a different story from Saturday afternoon into Sunday morning.

There are a couple of factors that will enhance snowfall totals across this region. First, with northeasterly winds blowing off the Atlantic, we’ll get some ocean-effect snowfall. This is similar to the lake-effect snow that you often see near the Great Lakes. While we’re not going to get buried like Buffalo does, it will add a bit more snow than we’d normally see with a storm like this. Second, it’s going to be cold out. Now, this might seem like an obvious statement because it’s winter and it’s always cold. What we mean is that temperatures will only be in the upper teens to middle 20s. This means that it will be more of a fluffy snow, which will pile up quicker than a much wetter snow. We already saw this with the light snow that fell earlier this morning.

The snow should start to develop across Cape Cod and southeastern Massachusetts Saturday morning, and will quickly spread inland. The snow should spread as far inland as Worcester and southern New Hampshire, but it will quickly retreat eastward again, ending in most places during the evening. The exception is Cape Cod and parts of Plymouth County, where northerly winds behind the storm may keep the ocean-effect snow going into the early hours of Sunday morning.

The NAM model is probably the closest to what we are thinking for snowfall. As you can see from the map above, we’re not expecting more than an inch or two from southern New Hampshire into Central Massachusetts. Points north and west of Boston and Providence, including the Merrimack Valley, will likely see 2-5 inches. Along and south of Interstate 95, including the southern and eastern suburbs of Providence and Boston, we’re thinking 6-10 inches, with the best chance for more than 10 inches of snow across parts of Plymouth County and Cape Cod, where the ocean enhancement will play a big role.

Behind the system, with fresh snow cover, temperatures will get even colder. Monday morning, temperatures will be in the single numbers across much of the region, with some sub-zero readings likely. The next storm moves in later on Tuesday, and although it will start as some snow or a wintry mix, milder air will move in, with the bulk of the precipitation falling in the form of rain Tuesday night into Wednesday.

By now, you’ve probably heard from your favorite TV meteorologist that there’s snow in the forecast for Thursday. While parts of the region will likely see some snow on Thursday, the vast majority of us will not.

High pressure will provide us with some chilly weather for the next few days. Temperatures will likely dip near or below freezing across much of the area tonight and again Wednesday night. So, we’ve got cold air in place, and a storm system heading our way on Thursday. That means it’s going to snow, right? As famed college football analyst Lee Corso would say “Not so fast my friend”. Allow us to explain.

As that high pressure area moves off to the east, winds will shift into the east and southeast across the region. Water temperatures off the coast are still in the 50s to lower 60s, so a wind off the water will allow temperatures to moderate. Thursday will still be a chilly day, with temperatures mainly in the 40s, but the air will remain dry, thanks to the high pressure area. As the precipitation arrives from the west during the afternoon, it will fall into that dry air, evaporating before it hits the ground. This will also allow temperatures to drop through a process called evaporational cooling. Temperatures may drop into the upper 30s to lower 40s before the air moistens up enough for the precipitation to hit the ground.

With temperatures likely near or just above 40, we’re looking at mainly rain across most of our region. Oh sure, there could be a renegade snowflake or ice pellet mixed in at the start across parts of southern NH or central MA, but for the most part, we’re looking at rain, and possibly a decent amount of it. Much of the region could receive between 0.75″ and 1.50″ of rain from this system, which will help put a dent into the ongoing drought.

Farther to the north and west, especially across the higher elevations of the Berkshires, Monadnocks, and the mountains of Northern New England, temperatures will be cooler, and the precipitation will arrive faster, thus increasing the chances that it starts as snow. Even in these locations, warmer air will move in Thursday night, allowing the snow to change over to rain. Before that happens, we could see a little accumulation, especially at the higher elevations, where a few inches may accumulate. The best chance for accumulating snow actually looks to be across the Adirondacks of northeastern New York, where the warm air will have a tough time getting in.

Once we get past this system, we could be looking at a wet weekend and start of next week. A couple more storms may move across the region, bringing us several bouts of much-needed rainfall. It does not look like there will be more snow with these systems, except possibly across the mountains of northern New England.