Out Like A Lamb? Not This Time

March is supposed to come in like a lion and go out like a lamb, or so the old saying goes. Well, it certainly came in like a lion, but now it’s also going to go out like a lion too. Don’t worry, a repeat of the April Fool’s Blizzard in 1997 is not coming, but we do have some snow to worry about across parts of the region.

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Looks like an active day for severe weather from the Ohio Valley to the Gulf Coast today. Image provided by the Storm Prediction Center.

The storm that we’ll have to contend with Friday into Saturday is moving into the Midwest today, with plenty of severe weather expected ahead of it. This system has already produced a lot of severe weather from the Southern Plains and Texas into the Mississippi Valley over the past couple of days. Don’t worry, we won’t have to contend with severe weather up here. As the storm heads into the Midwest, it will eventually redevelop off the Mid-Atlantic coastline and pass south of New England late Friday into Saturday. Meanwhile, high pressure will move into eastern Canada, keeping some marginally cold air in place, setting the stage for a return of wintry weather to New England.

We’ll have some snow or rain showers developing Friday morning, but with temperatures in the 30s to lower 40s, we won’t see much, if any, accumulation during the daytime. The sun angle is getting relatively high, so even with the cloud cover, it still is strong enough to prevent much accumulation, at least on paved surfaces.

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Forecast for the high-resolution NAM model for the Friday/Saturday storm system. Loop provided by Pivotal Weather.

After the sun sets, things get a lot more complicated. Without the sun, and with temperatures dropping into the lower to middle 30s, along with the heaviest precipitation moving in, we’re looking at a changeover to snow for most places, especially away from the coastline. The problem is, some warmer air looks like it will move in aloft for a while. With a warm layer aloft, the snow that’s falling melts, then starts to refreeze as it moves back into the colder air below that layer. The result is sleet, and possibly a lot of it well inland. This will significantly cut back on snowfall accumulations.

Once we get into Saturday morning, a change to rain is likely for much of the region, but even where it stays mostly snow, we won’t have much additional accumulation, at least on paved surfaces.  A few showers may linger into Sunday as an upper-level storm system moves across the region, then high pressure brings sunshine and seasonably cool temperatures in for Opening Day at Fenway on Monday.

So, how much snow are we looking at? We’ve bumped up amounts a little since yesterday, but nothing significant:

South of the Mass Pike: A coating at most.
Metro Boston: 1-2″
128 Belt: 2-4″
Merrimack Valley: 3-5″
NH Seacoast/North Shore: 3-6″
Southern NH: 4-7″
Worcester Hills/Monadnocks: 5-10″

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The high-resolution NAM model is probably closest to our thinking for snowfall amounts. Image provided by WeatherBell.

Before you ask, no, this is probably not the last time we’ll see snowflakes this season. It may be the last “snowstorm”, but even that’s not a definite. Remember, we’ve had snowstorms around here into late April and early May before.

March Madness Has Arrived

It’s time for March Madness once again, and we’re not talking about the NCAA Basketball Tournament. No, this time we’re talking about the relentless hype ahead of a March snowstorm. You’d think that we’ve never had a big storm around here in March before with the way the media is reacting. It’s almost as if everyone has forgotten about the storms in 199319972007, and 2013, never mind the ones we’ve had in April (or May).

Well, enough about that, let’s get right to the details of the storm. Low pressure is moving across the Ohio Valley today while a second area of low pressure is starting to develop off the Southeast coast. As the Ohio Valley system weakens tonight, it will transfer its energy to the coastal storm, and then the fun really begins.

The low will move up the coastline tonight into Tuesday and rapidly strengthen. Snow will break out across the region around daybreak Tuesday, and will fall heavy at times from mid-morning into the evening. Snowfall rates of 1-3 inches per hour seem likely. The snow will be accompanied by winds gusting to 40-50 mph at times, even higher near the coast, and especially across Cape Cod. This may create blizzard conditions at times, with significant blowing and drifting snow expected. We’d recommend that you stay off the roads, as travel will be dangerous at best during the daytime hours. The good news is that the storm will be moving relatively quickly, so the snow will taper off in the evening, and end at night.

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Strong winds will accompany the storm on Tuesday across much of the region. Image provided by WeatherBell.

The big wildcard at this point is the exact track of the storm. Some of the models are trying to indicate that the storm will move across southeastern Massachusetts late in the day, while others keep the storm near or just east of Cape Cod. The farther the storm tracks to the west, the more likely a change to sleet and/or rain becomes across southeastern Mass, possibly as far inland as the I-95 corridor. Obviously, that will have a big impact on snowfall totals.

So, how much snow are we looking at? Well, many in the media have been throwing out amounts like 1-2 feet or some other ridiculous numbers. The fact is, with a storm moving as quickly as this one is (it’s only going to snow for about 12-15 hours), it’s tough to get amounts that high. Our forecast is as follows:

Cape Cod: 3-6″ on the Outer Cape and Islands, 5-10″ closer to the Canal

SE Mass/RI: 6-10″ from I-95 south and eastward, 10-16″ north and west of there.

The remainder of Central & Eastern Mass/N RI/Southern NH/southern ME: 12-18″, with isolated heavier amounts.

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GFS model forecast for snowfall through Wednesday evening. This model most closely matches our thinking for snowfall right now. Image provided by Pivotal Weather.

 

Even though the snow will be winding down Tuesday night, Wednesday won’t be a great day for cleanup. With an upper-level low moving across the region, and the storm itself getting cranked up in Atlantic Canada, it’ll be cloudy, windy, and cold, with scattered snow showers. While there shouldn’t be much additional accumulation. Another inch or two is possible in a few spots.

 

Weekly Outlook: March 13-19, 2017

Spring is almost here. Just keep reminding yourself of that. Red Sox Opening Day is 3 weeks from today. Marathon Monday is 5 weeks from today. Before you know it, we’ll be walking around in shorts and enjoying warm weather. Got those thoughts in your head now? Good, because this week will feel like the middle of winter. In case you haven’t heard and thanks to the relentless TV and internet hype, everyone has heard, the “Storm of the Century of the Week” is going to paralyze the region for the next 6 weeks. OK, we got caught up in the hype for a second. Seriously though, we’ve got ourselves a significant snowstorm heading our way for Tuesday.

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GFS model forecast for the progression of the storm from Monday evening through Wednesday evening. Loop provided by Pivotal Weather.

 

The week starts off with the proverbial “calm before the storm” on Monday, as high pressure keeps us dry and chilly. Low pressure will be moving across the Ohio Valley while a second area of low pressure starts to take shape off the Southeast coast. As the Ohio Valley system weakens, it will transfer its energy to the coastal storm, and then things really start to happen.

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It’s gonna blow on Tuesday. The wind that is. NAM model forecast for wind gusts Tuesday afternoon. Image provided by WeatherBell.

The low will move up the coastline Monday night into Tuesday and rapidly strengthen. Snow will break out across the region towards daybreak Tuesday, and will fall heavy at times from Tuesday morning into Tuesday evening. When we say heavy, we mean HEAVY, as in 2-3 inches per hour at times. The snow will be accompanied by winds gusting to 40-50 mph at times, even higher near the coast, and especially across Cape Cod. This may create blizzard conditions at times. If you’ve got plans for Tuesday, either get there by daybreak, or wait until evening to get there, because driving won’t be fun during the daytime hours, and could be quite hazardous. The good news is that the storm will be moving relatively quickly, so the snow will taper off in the evening, and end at night. The other potential good news is that the snow will likely change to rain for a time across Cape Cod. That changeover could make it into southeastern Massachusetts as well, but how far inland is still a big question. Obviously, that will have a big impact on snowfall totals.

So, how much snow are we looking at? You’ve probably heard the apocalyptic forecasts out there of 1-2 feet, or 15-30 inches, or some other crazy ranges. The fact is, with a storm moving as quickly as this one is (it’s only going to snow for about 12-15 hours), it’s tough to get amounts that high. Our preliminary numbers are:

Cape Cod: 3-6″ on the Outer Cape and Islands, 5-10″ closer to the Canal
SE Mass: 6-12″ where it mixes with rain, 10-16″ where it doesn’t.
Southern NH/ME: 10-16″
Eastern/Central Mass: 12-18″, with some isolated heavier amounts.

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GFS model forecast for snowfall through Wednesday evening, This model most closely matches our thinking for snowfall right now. Image provided by Pivotal Weather.

Things will slowly improve on Wednesday, but with an upper-level low moving across the region, we can expect some occasional snow showers, and winds will remain quite gusty as the storm gets cranked up over Atlantic Canada. High pressure starts to build in on Thursday, but it will likely be another blustery and cold day. For the holiday on Friday (it is Evacuation Day after all), it’ll be another sunny and chilly day, but winds will start to diminish as high pressure continues to build into the region. Clouds return on Saturday, then a weak cold front moves through Saturday night, bringing some snow showers in. An upper-level low may hang around into Sunday, possibly producing more snow showers.

Monday: Plenty of sunshine to start, clouds increase during the afternoon. High 26-33.

Monday night: Becoming cloudy, snow developing towards daybreak. Low 16-23.

Tuesday: Hazy, hot and humid. Windy with snow, heavy at times. High 26-33, except 33-40 across Cape Cod.

Tuesday night: Snow tapers off and ends, winds gradually diminish. Low 15-22.

Wednesday: Partly to mostly cloudy and breezy with a few snow showers possible. High 24-31.

Thursday: A mix of sun and clouds, still breezy. High 23-30.

Friday: Partly to mostly sunny. High 28-35.

Saturday: Sunshine fades behind increasing afternoon clouds. Chance for light snow or snow showers at night. High 30-37.

Sunday: Mostly cloudy with a few snow showers possible. High 31-38.

We will have an update on the storm Monday afternoon. Hopefully, things will be a little clearer by then. Remember, spring is just around the corner. If you keep telling yourself that, you might even start to believe it.

 

Welcome Back Winter

It seems as though we went through this last week, but once again, after a taste of early Spring, Mother Nature is about to remind us that March can still bring plenty of wintry weather to the area.

Today is the transition day, as strong winds usher much colder air into the region behind a cold front that crossed the region late Wednesday night. While temperatures are still in the 40s, things are about to change, and most of you probably won’t like it. That cold front will stall out south of New England today, and low pressure will ride along it across the Mid-Atlantic states, passing south of us on Friday. Meanwhile, high pressure will build in north of New England, bringing plenty of cold air with it. Let’s see now, cold air moving in from the north and moisture moving in from the south. What happens when you combine those? That’s right, you get SNOW! Luckily, we’re not looking at a lot of snow this time. Let’s get to the details:

Snow should start to develop early in the morning, possibly even starting as a little rain across Cape Cod and southeastern Massachusetts. The snow may fall at a pretty good clip during the morning hours, tapering off and ending during the afternoon.Since we’re into mid-March, the sun angle is roughly the same as the end of September. In other words, fairly strong. So, once we get past sunrise, even though it’ll be cloudy, the snow will have a tougher time sticking to paved surfaces. That’s the good news. The bad news is that a lot of the snow will fall before then, so the roads may not be that pretty for the morning commute.

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Forecast from the NAM model for the progression of Friday’s storm. Loop provided by Pivotal Weather.

OK, so the snow ends in the afternoon and we’re done right? As noted college football analyst Lee Corso used to say “Not so fast my friend”. As the storm moves into the Gulf of Maine, a piece of energy, called a Norlun trough (Explained here by Matt Noyes), may produce some additional light snow from the North Shore up into southern New Hampshire and south coastal Maine through the evening hours. It won’t amount to much, but could be just enough to screw up the evening commute well north of Boston.

So, how much snow are we looking at? North of the Mass Pike, probably less than an inch, if any snow falls at all. From the North Shore into Boston and it’s immediate southern and western suburbs, probably 1-2 inches. For the South Coast, roughly south of Route 44, 2-4 inches should do it, with a little more possible across parts of the Cape and Islands.

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The High Resolution NAM model most closely matches our thinking with regards to snowfall on Friday. Image provided by WeatherBell.

All in all, not a big deal, especially by New England standards. What will be a big deal is the cold air behind the storm. Similar to last Saturday, this Saturday will be quite chilly, especially with fresh snowcover. High temperatures may struggle to get into the lower 20s, but wind chills will be in the single numbers and below zero. So, if you’re heading outside, make sure you bundle up. It’ll feel more like January than March.

Finally, we’re aware of the uncontrolled hype on the Internet (and TV) about a potentially major snowstorm on Tuesday. Right now, it’s a potential storm and nothing else. We’ll certainly keep our eyes on it, and if a threat does materialize, we’ll let you know well in advance. For now though, it’s nothing more than a figment of the computer models’ imaginations. We don’t participate in hype or speculation here at StormHQ, so we’re going to leave it at that.

Record Highs, Blizzard Conditions, and Severe Weather – February in the Nation’s Midsection

“In the Spring, I have counted 136 different kinds of weather inside of 24 hours.” – Mark Twain

It’s not quite spring yet, but this quote is still appropriate. Much of the nation’s midsection has been enjoying temperatures more typical of April than February for the past week, with a few hundred record high temperatures broken. That is about to change, as Mother Nature will remind the region that is still February.

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Numerous record highs are expected across the Plains and Midwest again today. Image provided by WeatherBell.

Of course, they will still have one more warm day today, with highs well into the 60s and 70s likely setting more records. However, a cold front will sweep across the region, bringing an end to the record heat, and setting the stage for a snowstorm.

The low pressure system that brought more rain to California over the past couple of days will head eastward, bringing some snow into the Rockies today. As that system moves into the Plains on Thursday it will start to strengthen, drawing moisture northward from the Gulf of Mexico while cold air flows southward on the backside of the storm into the Northern Plains. Where these airmasses meet, snow will develop across the Central Plains states. The snow will be accompanied by winds of 20-30 mph, gusting to 40 mph or more at times, resulting in near-blizzard conditions across portions of South Dakota, Nebraska, southeastern Wyoming, and eastern Colorado on Thursday.

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More than a foot of snow may fall in a swath from the Plains into the Upper Midwest. A lot of these same places are going to be in the 60s and 70s today. Image provided by Pivotal Weather.

As the system heads eastward, snow will move into portions of the Mississippi Valley and the Upper Midwest on Friday. The heaviest snow looks to stay just south of the Twin Cities, but even there, moderate to heavy snow is likely. By the time the storm moves out on Saturday, a foot or more of snow is possible in a swath from the Central Plains into the Great Lakes.

Snow isn’t the only threat from this system. As the storm moves eastward, record warmth will remain in place across the Midwest. With warm, moist air in place and a strong cold front approaching from the West, strong to severe thunderstorms are possible across portions of the Lower Great Lakes and Ohio Valley on Friday. Some of the stronger storms that form may contain damaging winds, hail, and possibly tornadoes.

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The Storm Prediction Center has already highlighted the Midwest as an area to watch for severe weather on Friday. Image provided by NOAA.

The system will continue to move eastward, bringing some rain to the East Coast on Saturday, which may cause problems for hockey fans in the Steel City. The next NHL Stadium Series game (Ed – Enough with the outdoor games already. It jumped the shark a long time ago), is scheduled for Saturday at 8pm between the Pittsburgh Penguins and Philadelphia Flyers. The daytime hours will likely be mild with rain, but the rain may change to snow late in the day as temperatures tumble. Either way, it won’t be a pleasant night for fans to be sitting in the stands at Heinz Field. Here at Storm HQ, we despise the Flyers, so we hope their fans not only have to sit through the weather, but watch their team get thumped too.

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That’s former UMass-Lowell RiverHawk (and StormHQ favorite) Scott Wilson hoisting the Stanley Cup last June. Image provided by Toronto Star.

Once it gets past Pittsburgh, that front will head eastward, bringing some rain to us here in New England. It probably won’t be a lot of rain, but temperatures will be in the 50s and possibly 60s ahead of the front on Saturday. Once the front comes through, Sunday will be windy and colder.

Here We Snow Again

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.

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Forecast from the NAM model for the upcoming storm. Loop provided by Pivotal Weather.

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″

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The High Resolution NAM model most closely resembles our forecast for the upcoming storm. Image provided by WeatherBell.

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.

 

More Snow This Weekend?

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.

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How much snow actually fell during yesterday’s blizzard. Our forecast worked out almost perfectly. Image provided by National Weather Service – Taunton.

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.

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Just some light snow is expected late tonight and Saturday morning. Image provided by WeatherBell.

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.

Snowy Thursday Expected

“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.

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GFS model forecast for the progression of our Thursday storm. The darker blues are moderate to heavy snow. Loop provided by Pivotal Weather.

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.

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Temperature forecast for Noon Thursday based on the WRF model. Note the sharp temperature gradient across eastern and southeastern Massachusetts. Image provided by WeatherBell.

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.

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This model (the GFS) most closely resembles our thinking for snowfall across the region. Image provided by Pivotal Weather.

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.

Wintry Mess Tonight and Wednesday?

Another storm system is set to move into the region later today and into Wednesday. While this one will produce a wintry mess across parts of the area, for the majority of us, it won’t be a big deal.

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Current surface map as of 10am EST Tuesday. Image provided by NOAA.

 

A low pressure system is currently moving into Michigan. This is the same system that brought heavy snow to the central and southern Rockies and a significant ice storm to the central and southern Plains and parts of the Mississippi valley over the past few days. This storm will head towards the eastern Great Lakes this evening and start to weaken, while at the same time, a secondary area of low pressure will develop south of New England.

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NAM Model forecast for the next 48 hours across the Northeast. This model is closest to our thinking for this storm. Loop provided by Pivotal Weather.

 

Along and south of the Mass Pike, this is mainly a rain storm. Rain will develop around dinner time this evening, might be heavy overnight, and will taper off to showers or drizzle Wednesday morning, but likely doesn’t end until Wednesday evening. For Western and Central New England, we have bigger issues.

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Freezing rain forecast through Thursday morning across the Northeast, Image provided by Pivotal Weather.

Across the Berkshires, Catskills, and Adirondacks (and possibly the higher elevations of the Monadnocks and Worcester Hills), we’re looking at freezing rain, possibly a lot of it. Temperatures aloft will warm above freezing, but a thin layer of colder air will remain just above the surface. Since that layer is the ground layer in the hills, it will fall as freezing rain. Driving along I-90 through the Berkshires and also west of Albany out to about Utica could be very slick later today into early Wednesday. As the secondary storm takes over early Wednesday, colder air will move back in, changing the freezing rain over to snow, with a little accumulation possible.

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This graphic shows the difference in how you get snow vs sleet vs freezing rain. Image provided by NOAA.

 

Meanwhile, we’re looking at some snow across portions of central and southern Vermont and New Hampshire and into southwestern Maine. In areas that stay all snow, mainly across central New Hampshire and Vermont, we could see as much as 4-8 inches fall by the time the storm winds down late Saturday. The tricky forecast is from coastal Maine and New Hampshire into southern New Hampshire and northern Massachusetts. In these areas, precipitation likely starts as snow this evening, but a change to sleet and eventually rain should take place overnight tonight or Wednesday morning, with a change back to snow possible late Wednesday as the system starts to wind down. How long that change takes will have a big effect on how much snow accumulates. Right now, it looks like we could see as much as 3-5″ near Manchester, NH, dropping down to 2-4″ around Nashua, and maybe an inch or less across the Merrimack Valley and the Seacoast, including Lowell, Lawrence, and Portsmouth. As you can see, with such a sharp gradient between several inches and virtually nothing, only a slight shift in the forecast can have a big difference in what actually falls across these areas.

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Snowfall forecast through Thursday morning. Image provided by Pivotal Weather.

 

The good news is that there isn’t much colder air following this storm. Temperatures will remain near to a little above normal for much of the remainder of the week, with highs mainly in the 30s and 40s. Contrast that with Alaska, where low temperatures for the next several mornings will range from 25 to 55 below zero across much of the state.

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Brutally cold air has settled into Alaska and will remain in place for much of the week. Image provided by WeatherBell.

 

“Great White Plague” Takes Aim on Southeast and New England

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.

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A parade of storms will assault the West Coast this week. Loop provided by Tropical Tidbits.

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.

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Snowfall totals of 6-12 feet are possible across the Sierra Nevada over the next week. Yes, we said feet, not inches. Image provided by WeatherBell.

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.

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GFS model forecast for snow across parts of the Southeast and Mid-Atlantic states through Sunday morning. Image provided by Pivotal Weather.

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.

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NAM Model forecast for snowfall through Sunday evening. Image provided by Earl Barker’s Weather Models.

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.