Weekly Outlook: March 12-18, 2018

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Another week, another nor’easter. Once again, the hype train has left the station and is heading down the track at top speed. Without further delay, let’s get right to it.

Low pressure moving across the Tennessee Valley Sunday night will redevelop off the South Carolina coastline early Monday, then head up the East Coast. The storm will pass south and east of Cape Cod while rapidly intensifying. As is usually the case, this will bring strong winds and snow to the region. Obviously, the strength of the winds and the amount of snow will be dependent on how close the storm passes to New England, among other things. As you probably heard on Sunday, the vast majority of media outlets, as well as all of the Facebook Forecasters, and even the National Weather Service, are calling for very heavy snowfall from this storm. The reason for this is that many of the models are forecasting these amounts. Well, as a noted colleague has said in the past – “If the models were as good as everyone thinks, there would be no need for meteorologists”. Oh, we still think there will be some heavy snow, and we’re expecting plowable amounts, but let’s pump the brakes on the talk of “1-2 feet” or “12-18 inches”, or our personal favorite cop-out “10-14 inches+” (adding the plus so that if anything higher than that falls you can claim that your forecast was accurate).

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GFS forecast for the progression of the storm on Tuesday. Loop provided by Tropical Tidbits.

Before the storm arrives, Monday will be a generally cloudy day, with temperatures right around where they should be in mid-March. Winds will start to pick up in the evening, and for most of the day on Tuesday, we’re looking at northeast winds of 20-30 mph, with gusts to 40-50 mph inland, and 60-70 mph at the coast. Yes, this may take down some additional trees, but coastal flooding will not be a problem this time, as tides are significantly lower than they were a week ago.

As for the snow, it should develop around midnight, give or take an hour or two, and quickly become steady and heavy. Heavy snow will continue into the morning, then lighten up a bit in the afternoon, winding down in the evening.  If you can work from home on Tuesday, we’d recommend it. Travel will be extremely difficult in the morning, as snow could be falling at the rate of an inch an hour or more, and it will be accompanied by strong winds, creating blizzard conditions at times.

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Official definition of a blizzard. Note, snowfall accumulations do not factor into this. Image provided by WCVB-Boston.

 

As for how much, well, as we mentioned above, we’re not going with the big amounts that many others are. Why? Well, for one, a portion of that snow is going to fall during the daytime. At this time of year, the sun angle is strong enough (equivalent to the end of September), then unless it’s falling heavily, it will have trouble accumulating. Now, it will be falling heavily in the morning, but probably not as heavily in the afternoon. So, you can slice a little off of those model snow maps right there. Another reason is that we expect the models to shift a little more with the track slightly farther offshore. That has been the trend during the day today, and if that continues, it will result in lighter amounts. Yes, unlike the Facebook Forecasters who just take the what the models say exactly and call it a forecast, we use experience and education to figure out where the models are likely in error, and adjust accordingly. As for amounts, that likely means a general 8-12 inches across most of the region, with isolated heavier totals, especially across southeastern Massachusetts and the Cape. Across the Outer Cape and Nantucket, there is the possibility of some rain mixing in, which would keep accumulations lower.

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The snowfall forecast from the Sunday late-afternoon run of the GFS is closest to our thinking for the next storm. Image provided by Pivotal Weather.

Once the system pulls away, an upper-level low will move into the region on Wednesday, keeping plenty of clouds in place, with some additional snow showers possible. The upper-level low may linger into Thursday, with only a little more sunshine, and a slightly lower chance for snow showers. High pressure finally starts to build in for Friday and Saturday. By Sunday, the next system approaches the region. Right now, this system looks warmer, with rain, but given the way this month has gone, does anyone wanna bet that it stays that way? Anyone? Anyone? Bueller? Bueller?

Monday: Any early sunshine disappears behind increasing clouds. High 37-44.

Monday night: Becoming windy with snow developing, becoming heavy at times. Low 26-33.

Tuesday: Windy with snow, heavy at times in the morning, tapering off late in the day. High 29-36.

Tuesday night: Snow ending in the evening, remaining mostly cloudy with winds gradually diminishing. Low 24-31.

Wednesday: Partly to mostly cloudy and breezy with more snow showers developing. High 32-39.

Thursday: More clouds than sunshine, breezy, chance for a few snow showers. High 34-41.

Friday: A mix of sun and clouds, still breezy, slight chance for another snow shower. High 33-40.

Saturday: Partly to mostly sunny. High 37-44.

Sunday: Becoming cloudy with a chance of rain or snow showers. High 41-48.

The Lion Roars Again

 

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You’re heard the phrase a million times: “March comes in like a lion and goes out like a lamb.” Well, the first half of that statement certainly was accurate this year, as much of the Northeast took a beating from last Friday’s storm. While many places are still trying to recover, we’ve got another one on our doorstep, and this one is promising to be more white than wet for much of the region.

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Forecast for the storm based on the High-Resolution NAM model. While not exactly what we’re thinking, this model is probably closest to our thoughts on how the system will play out. Loop provided by Tropical Tidbits.

The low pressure system that brought blizzard conditions to the Northern Plains and Upper Midwest over the past 36-48 hours will cross the Ohio Valley this afternoon and evening. By tonight, a secondary area of low pressure will develop off the North Carolina coast, and rapidly strengthen as it heads up the East Coast. It will likely pass very close to, possibly right over Cape Cod late Wednesday night, then move into the Gulf of Maine on Thursday. The exact track of the system will play a gigantic role in determining how far inland the rain/snow line penetrates. Some models keep the storm south and east of Nantucket, which could keep the rain/snow line confined to southeastern Massachusetts. Some models bring the storm across southeastern Massachusetts, with the rain/snow line getting as far inland as Springfield, MA and Manchester, NH. These are the two extremes, and much like Goldilocks and the Three Bears, we’re looking for something more in the middle.

There are a few different aspects of this storm that we need to worry about, depending on where you are located – strong winds, heavy rain, and heavy snow. We’ll start with the winds.

NAM-WRF 3-km Mass & CT & RI 10-m Wind Gust 37
Peak wind gusts as predicted by the High Resolution NAM model for 8pm Thursday evening. Wind gusts in excess of 40 mph are possible across most of the region, with gusts of 50-60 mph along the coast. Image provided by Weathermodels.com

Many parts of the region, especially along the coast and in southeastern Massachusetts and Rhode Island are already sensitive to hearing a forecast for strong winds, after last Friday’s system took down so many trees and knocked out power to hundreds of thousands of residents. Thankfully, winds won’t be as strong with this storm, but they’ll still be capable of causing damage, especially to trees already weakened by the last storm. Winds will pick up during the day on Wednesday, likely peaking Wednesday night into early Thursday. Sustained winds of 25-40 mph, with gusts to 60 mph are expected,especially along the coast. Luckily, tides are not as high as they were a few days ago, so coastal flooding isn’t as much of a concern, though some splashover is certainly possible around the time of high tide. As the storm passes by early Thursday, winds will shift into the northwest and start to ease. However, this storm will likely move into Atlantic Canada and not move much for a few days, so we may still be dealing with gusty winds (just not as strong), right through Friday.

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Rainfall forecast from the High Resolution NAM model through Thursday afternoon. Image provided by WeatherBell.

Next up is heavy rain. As we mentioned earlier, the rain/snow line is still a big question. However, in areas that stay all rain or mostly rain, such as Cape Cod, parts of southeastern Massachusetts and Rhode Island, rainfall will be heavy. Many places could see more than an inch of rain, possibly even 2 inches in spots. These are areas that saw 2 to as much as 5 inches of rain from the last storm. The ground is still saturated in parts of the region, and most of the rivers and streams remain fairly high. If you add another 1 to perhaps 2 inches of rain in a short period of time, you’re looking at more flooding in some areas.

Now, to the part that most of you want to know about – heavy snow. As the last paragraph and the map above show, this system will contain plenty of moisture. Away from the coast, temperatures will be near or just below freezing. That means that moisture will fall in the form of heavy, wet snow. The general rule of thumb is that 1 inch of rain equals about 10 inches of snow, but that is dependent on temperature. That’s why when temperatures are in the teens you get a fluffier snow where 1 inch of rain could mean 20 inches of snow. In cases like this, where temperatures will be close to freezing, that ratio could be closer to 8-to-1 (or even lower). Still, even at 8-to-1, you only need an inch and a half of rain to get a foot of snow. Complicating things is the rain/snow line. Places that see rain mix in will get significantly less snow than nearby areas that have no rain at all. Our best estimate right now is that the rain/snow line gets as far inland as Interstate 95, possibly a few miles farther. As the system passes by on its way into the Gulf of Maine on Thursday, that rain/snow line will crash southeastward towards the coast, changing everyone back over to snow before everything winds down Thursday afternoon. So, what does that mean for amounts?

Cape Cod/Southeastern Massachusetts: Less than 1″
I-95 corridor: 2-6″ (highly dependent on the rain/snow line)
MetroWest/NH Seacoast: 6-12″ (lightest amounts south & east where some rain could mix in)
Merrimack Valley/Southern NH: 8-14″, isolated heavier totals.

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The snowfall forecast from the NAM is probably closest to our thinking right now. Image provided by Pivotal Weather.

Finally, there’s the timing of this system. Snow will develop across the region around midday Wednesday, give or take an hour or two. Due to the higher sun angle at this time of year, it will have trouble accumulating on pavement at first, though grassy areas could see some accumulation. The snow will quickly change to rain across southeastern Mass, southern Rhode Island, and Cape Cod. The rain/snow line will continue moving northwestward, likely reaching the I-95 corridor near the evening rush hour. At the same time, the steadier and heavier precipitation will arrive. During Wednesday evening and night, snowfall may accumulate at the rate of an inch or more per hour. If you don’t have to be out Wednesday night north and west of Boston, then don’t. Driving conditions will likely be rather poor. The rain/snow line will crash to the coast early Thursday morning, with the steadiest precipitation winding down towards daybreak. Occasional snow showers may continue off and on through the afternoon, but most of the accumulating snow should be done in the morning. Expect a lot of school cancellations on Thursday, especially north and west of Boston.

If you’re wondering if this is winter’s last gasp – don’t count on it. Some of the models show the potential for another system early next week, but it’s still several days away, and there’s plenty of disagreement among the models as to the evolution of that system. We’ll worry about that, if we need to, this weekend.

Weekly Outlook: March 5-11, 2018

The cleanup continues after Friday’s powerful storm, but guess what? There’s another one coming! We do have good news and bad news though. The good news is that this one won’t be a strong, will contain less precipitation, the winds won’t be a strong, and the tides won’t be as high. The bad news? It’ll be colder, so many of you could be seeing some snow from this storm, potential a lot of it.

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Friday’s storm is still producing gusty winds across the area today, but they are nothing compared to what the system produced on Friday. Image provided by the National Weather Service office in Taunton, MA.

Friday’s storm is still impacting the region today, but it will finally move away late in the day. A disturbance rotating around the system produced some light snow and snow showers overnight into this morning, and winds remain gusty at times, though not nearly to the magnitude of Friday. As the storm pulls away, high pressure builds in later today and tomorrow with drier and seasonably cool conditions.

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The calendar year is off to a very wet start across most of Central and Southern New England and into the Mid-Atlantic states, and Wednesday’s storm will only add to that. Image provided by the Northeast Regional Climate Center.

As we head into Wednesday, things go downhill again. Low pressure moving across the Ohio Valley will start to weaken while a secondary area of low pressure develops off the North Carolina or Delmarva shoreline. This system will strengthen as it heads northeastward. Another period of gusty winds is likely Wednesday into early Thursday, but this time we’re talking about wind gusts of 40-50 mph along the coast, not 70-90 mph. The system will also spread precipitation into the region. Temperatures will be a little colder, so parts of the region will see snow, possibly significant snowfall. The big question is, how far inland does the rain/snow line penetrate? Some models bring it into the 128 or 495 belts. At least one model brings it all the way into southern New Hampshire. We should have some clarity on this over the next 24-36 hours, and we’ll have a special blog post Tuesday afternoon with our updated outlook on the storm. For now, the current thinking is that from Boston southward, this is mainly rain with some snow possible, north and west of Boston, some accumulation is likely, with significant accumulations possible, especially the farther north and west you go.

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Forecast for the midweek storm from the NAM model. Loop provided by TropicalTidbits.

Everything winds down early Thursday, but with an upper-level low pressure system moving through, some additional rain or snow showers are possible later Thursday and Friday. High pressure then builds in for the weekend, but by late Sunday, we’ll need to keep our eyes on a system moving into the Mid-Atlantic states that could impact us on Monday. We’ll worry about that system later in the week.

Monday: Mostly cloudy and breezy with some lingering snow or rain showers, mainly early. High 36-43.

Monday night: Becoming partly cloudy. Low 25-32.

Tuesday: A mix of sun and clouds. High 35-42.

Tuesday night: Becoming mostly cloudy, chance for snow showers towards daybreak. Low 25-32.

Wednesday: Windy with snow likely, changing to rain from Boston southward, possibly north and west of Boston as well. High 33-40.

Thursday: Snow or rain tapers off early, otherwise mostly cloudy and breezy. High 36-43.

Friday: More clouds than sunshine, breezy, chance for some snow or rain showers. High 36-43.

Saturday: Partly to mostly sunny and breezy again. High 37-44.

Sunday: A sunny start, then clouds start to stream in during the afternoon. High 41-48.

Stormy Friday On Tap

You’ve heard the news talking about it all week, and we mentioned it in our Weekly Outlook. A storm is coming on Friday, and it’s going to be a big one.

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Forecast for the storm based on the NAM model. Loop provided by Tropical Tidbits.

 

The biggest impacts from this storm will be felt along the coastline. We’ve already got astronomical high tides due to the full moon we had this week. As in the storm churning up the Atlantic and strong winds (more on that in a moment), and you’ve got a recipe for major coastal flooding. Parts of the coastline, especially east-facing shorelines, could see flooding worse than they saw with the storm in early January. Coastal flooding was already observed during the Thursday afternoon high tide without any impacts from the storm. What do you think is going to happen when you have onshore winds of 30-50 mph and 20-40 foot seas? Yeah, nothing good.

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The Wave Watch Model shows a long eastern fetch and 20-30 foot seas slamming into New England Friday evening. Things won’t improve much over the weekend. Image provided by WeatherBell.

As we mentioned above, strong winds will impact most of the region starting late Thursday night and especially on Friday as the storm begins to intensify in the waters south of New England. High Wind Warnings are already in effect for much of the region. Sustained winds of 25-45 mph with gusts of 60-70 mph are likely, especially near the coastline. Some gusts in excess of hurricane force are possible, especially across Cape Cod. With winds this strong, power outages are likely, so make sure you are prepared for that possibility. Winds may start to diminish a little on Saturday, but as the storm heads southward and grows even larger, it will continue to produce gusty winds across the region right through the weekend.

GFS 50-STATES USA Mass & CT & RI 10-m Wind Gust 36
GFS forecast for wind gusts across the region Friday evening. The red color is 50 knots (58 mph). The brown is hurricane force 64 knots/74 mph). Image provided by Weathermodels.com

 

In addition to the damaging winds and coastal flooding, heavy rain is also expected across the region. Rain will move in after midnight tonight, and continue for much of the day on Friday, heavy at times. The storm is drawing moisture northward from the Gulf of Mexico and the tropics, and as it moves into the relatively cooler air in place here, it will wring it out across the region. We’re looking at rainfall totals of 1 to 3 inches across the region, with some heavier amounts possible, especially across southeastern Massachusetts and Rhode Island. We’ve already had a wet start to the year, and the ground is close to saturated, so this will likely result in flooding in many areas. Rivers are also running fairly high, especially for this time of year, so river flooding will also become a concern.

GFS 50-STATES USA Mass & CT & RI Total Precipitation 72
GFS forecast for rainfall through Sunday morning. Image provided by Weathermodels.com

Now we get to the tricky part of the forecast, where the greatest uncertainty lies – snowfall. There’s not a lot of cold air in place when the storm moves in, and we don’t have a big high pressure area to the north to help keep any cold air around. However, there is some cold air aloft, and as the system gets cranked up, it may try to tap into that cold air. As we get into some of the heavier bands of precipitation, it may drag some of that cold air down, changing the rain to snow in some areas. This isn’t the type of thing we can predict well in advance, so trying to pinpoint now is futile. However, don’t be surprised if some places change over to snow for a while during the day on Friday. Of course, some of the higher elevations, especially in the Worcester Hills, Monadnocks, and Berkshire, should have enough elevation to have quite a bit of snowfall from this system. It will be the heavy, wet snow that nobody likes either. You know, the type that weights down tries and power lines, making it even easier for them to snap when you get wind gusts of 50 mph or more. The other thing we’re concerned about with snowfall is what happens on the backside of the system. As the storm starts to pull away late Friday, colder air will settle in behind the system. The questions are: 1. How quickly does that cold air move in? and 2. How much precipitation is still around? Right now, we wouldn’t be surprised to see some locations pick up a quick 1-3 inches, possibly even more. There’s also a chance that the colder air moves in too late, and many places see little to no snow at all. The worst-case scenario, and we’re not completely ruling it out yet, is that places change over to snow in a burst of heavy precipitation during the afternoon (like we mentioned above), and never change back. If that were to happen (and the place where that would be possible would be mainly north and west of Boston), then very heavy snowfall amounts would become more likely. For the record, we’re not expecting this, but we are a little wary that it’s at least possible.

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Snowfall forecast through Sunday evening from the NAM model. Image provided by Pivotal Weather.

 

By Monday, high pressure builds in, and everything calms down. We may have another storm to deal with towards the middle of next week, but we’ll worry about that one after we get through this one.

Weekly Outlook: February 26-March 4, 2018

Yup, the hype train has left the station again and is rolling down the track. You may have heard that there’s a storm coming later this week. We’ll set the record straight between hype and reality, fact and fiction, in this outlook.

The first half of the week, also known as the last 3 days of February (and the last 3 days of meteorological winter) will actually be quite pleasant. High pressure will be in control with sunshine and mild temperatures. It’s not the early taste of spring that we had a week ago, but we doubt there will be many complaints. After that, things start to get complicated.

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By the end of the week, a “blocking” pattern will set up. The large upper-level high pressure area over Greenland will slow down the progression of storms eastward across the Eastern U.S. Image provided by Weathermodels.com

A “blocking” pattern will set up across the Eastern US. Normally, the jet stream flows west to east, steering storms across the country. When there’s a dip in the jet stream (a trough), we tend to have colder than normal temperatures, along with stormier conditions. We’ll have one of those troughs move into the East later this week, and it will eventually break off from the jet stream (called a “cut-off low”). At the same time, a large upper-level high pressure area will set up shop over Greenland. This will block the eastward progression of storms, meaning that the storm we’re expecting later this week won’t be in a hurry to leave. However, it could also be a good thing. How? If the ridge of high pressure continues to build in, it could deflect that storm farther to the south. Good for us, but bad for places like New York City, Philadelphia, or even Washington.

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The GFS Ensemble forecast for Friday evening shows the wide range in possible solutions. The mean solution is for a 987mb low centered east of Virginia Beach and south of Nantucket. The red numbers are the locations of the various ensemble members and their strength in millibars (add a 9, so 74 is really 974mb). Image provided by Tropical Tidbits.

The models still haven’t come to a consensus on what will happen for the end of the week. There are several things that we need to figure out before we can come up with a forecast that we’ll have any confidence in. What are those factors? Where will the low pressure area track? How strong will it be? How much cold air will be in place before the storm arrives and when it’s impacting the region? How strong will that high pressure area to the north be?  These details will likely take a few more days to be resolved. So, if you hear others, especially in the media, talking about the “3-day storm” or the “snowstorm” that will impact us later this week, take it with a giant grain of salt. Nobody, including us, can say with any degree of confidence, what will happen. We could have heavy rain, heavy snow, strong winds, or all of the above. The only thing we can be reasonably confident about is the fact that some coastal flooding seems likely. The highest tides of the month are expected at the end of the week, and with a storm of some sort off the East Coast, that will likely lead to some coastal flooding across parts of the area. Things should start to improve over the weekend, but even that will depend on the progression of the storm.

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The potential exists for wind gusts of 30-60 mph across the region from the storm, especially along the coast, with even stronger winds across Cape Cod and the Islands. Image provided by WeatherBell.

Monday: Early clouds, then becoming mostly sunny and mild. High 47-54.

Monday night: Clear skies. Low 26-33.

Tuesday: Plenty of sunshine. High 46-53.

Tuesday night: Clear to partly cloudy. Low 31-38.

Wednesday: Some early sun, then clouds filter in as the day goes on. High 52-59.

Thursday: Mostly cloudy and becoming breezy with some rain or snow possible late in the day and at night. High 46-53.

Friday: Windy with rain or snow possible. High 35-42.

Saturday: Windy with a chance for more rain or snow, especially early. High 36-43.

Sunday: More clouds than sun, breezy, chance for a few snow or rain showers. High 35-42.

Weekly Outlook: February 19-25, 2018

70 degrees. In July, that’s a chilly high temperature. In February, it’s a record breaker. We’re going to be challenging and possibly breaking some records this week. Don’t get too used to it though, as our early taste of Spring will be short-lived.

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With a ridge of high pressure aloft along the East Coast and a Bermuda High at the surface, we’re looking at a couple of mild days Tuesday and Wednesday. Image provided by Tropical Tidbits.

The week starts out with a warm front moving towards the region, spreading in some clouds, and eventually showers on Monday. The front moves through Monday night, then a Bermuda High sets up shop for a couple of days, with unseasonably mild conditions expected for Tuesday and especially Wednesday. How mild? Most locations should reach the upper 50s to middle 60s on Tuesday. On Wednesday, most places should get into the 60s, with some lower 70s possible, especially north and west of Boston. Of course, there is an exception. Along the South Coast, the southwest winds that will bring warmer air in for the rest of us will be blowing in off of water that is still in the 30s. So, these locations will likely stay in the upper 40s and 50s both days. Still nice, but it’s not 60s and 70s.

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Record High Temperatures across the region for Wednesday February 21. It’s a safe bet that many of these records will fall. Data provided by the Northeast Regional Climate Center. For a complete list of the cities on this map with the record high data, open this PDF file.

A cold front moves through Wednesday night, bringing a few showers with it, but also bringing an end to the mild weather. Showers may linger along the south coast into early Thursday before the front pushes offshore, then high pressure builds in from the north with much cooler conditions for Thursday and Friday. Of course, “much cooler” is relative, as these temperatures will still be near to a little above normal for late February. Another storm system then moves in from the west, with some precipitation likely late Friday into Saturday. It should fall mostly as rain, but a period of snow or freezing rain is possible, especially across the Merrimack Valley and southern New Hampshire Friday night into Saturday. We’ll keep an eye on this situation as the week goes on. Another system quickly follows with more rain or snow on Sunday.

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At least one model (in this case the GFS) is showing the potential for a wintry mix Friday night as a storm system moves through. Image provided by WeatherBell.

Monday: Becoming mostly cloudy and breezy with showers possible late in the day. High 42-49.

Monday night: Showers likely in the evening, otherwise mostly cloudy and breezy. Low 39-46 in the evening, then temperatures rise overnight.

Tuesday: Becoming partly sunny, breezy, and milder. High 57-64, except 49-56 along the South Coast and across Cape Cod.

Tuesday night: Partly to mostly cloudy. Low 46-53.

Wednesday: Partly sunny, breezy, and warm. Showers possible at night. High 65-72, except 49-64 along the South Coast and across Cape Cod.

Thursday: Clouds gradually giving way to some sunshine late in the day, turning much cooler. High 41-48.

Friday: A sunny start, then clouds return. Showers likely at night, possibly starting as some snow or freezing rain in the Merrimack Valley and Southern New Hampshire. High 37-44.

Saturday: Mostly cloudy and turning milder with a chance of showers, possibly some wintry mix early in the day across southern New Hampshire. High 47-54.

Sunday: Cloudy and breezy with a chance of rain or snow. High 36-43.

 

A Saturday Night Special

The last few days have been fairly mild around here, and even milder air is coming in for the first half of the upcoming week. So naturally, we’re talking about a snowstorm for tonight.

Low pressure is over the Tennessee Valley at midday, and will quickly move towards the Mid-Atlantic coastline this evening, passing south of New England as it intensifies tonight. Even though the sun is shining now, clouds will quickly move in this afternoon, with snow developing late this evening, around 9pm or so, give or take an hour. Snow will continue overnight, with the possibility for some briefly moderate to heavy snow. Since most of you will be sleeping, this shouldn’t cause too many problems. A change to rain seems likely across parts of Cape Cod and the Islands, possibly even into extreme southeastern Massachusetts.

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Forecast for the progression of the storm based on the NAM model. Loops provided by Tropical Tidbits.

Everything winds down near or a little after daybreak. For most of us, a general 3 to 5 inches of snow is expected, with a few spots possibly seeing 6 or 7 inches. Across Cape Cod, where a change to rain is likely, amounts of 1 to 3 inches seem more plausible at this time.

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The NAM model is probably closest to our thinking for snowfall totals with this storm. Image provided by WeatherBell.

The snow won’t last too long though. The sun will return Sunday afternoon, with temperatures getting up into the 40s. That will help to quickly melt a lot of what fell overnight. Temperatures will drop back below freezing Sunday night, so things may ice up once again. Use caution if you’re heading out for anything. Even warmer weather is heading in for the start of the week. A warm front will move through on Monday, with some showers preceding the front late in the day. Once the front moves through, unseasonably warm conditions are expected for Tuesday and especially Wednesday. On Tuesday, high temperatures should get into the upper 50s and 60s away from the South Coast. On Wednesday, we could challenge some record highs, with some places possibly making a run at 70 degrees. A cold front will move through late in the day on Wednesday, bringing an end to the warm weather, so enjoy the early taste of Spring while it’s here.

GFS 50-STATES USA Mass & CT & RI 2-m Maximum Temperature 105
Yes, temperatures could reach or exceed 70 in parts of the region on Wednesday. Image provided by Weathermodels.com

Weekly Outlook: February 12-18, 2018

Arctic Outbreaks. Blizzards. Sub-zero wind chills. These things are common around here in the month of February. None of them will be in the forecast this week. In fact, this week will be rather quiet and, believe it or not, mild (for the most part).

The week starts off with a cold front pushing offshore and high pressure building into the Northeast. Any lingering showers will end in the morning, but skies will only gradually clear out. Monday night and Tuesday will be clear and chilly as the high settles in. As the high moves offshore, milder conditions are expected on Wednesday, but clouds will also start to move in as a cold front starts to slowly approach from the west. Thursday will be a cloudy and mild day, with a few showers possible. The front finally pushes through on Friday with some rain and cooler conditions expected. High pressure returns for the weekend with dry and cooler conditions once again.

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Snowfall forecast from the GFS model between late Sunday night and next Sunday night. Notice that except for the Berkshires, no snow is forecast across Southern New England. Image provided by Pivotal Weather.

Monday: Some lingering showers near the South Coast early in the day, otherwise cloudy in the morning, with clearing in the afternoon. High 40-47, except for southeastern Massachusetts and Cape Cod where temperatures will start the day 48-55 then drop.

Monday night: Becoming mostly clear. Low 16-23.

Tuesday: Plenty of sunshine, clouds start to move back in late in the day. High 29-36.

Tuesday night: Partly to mostly cloudy. Low 21-28.

Wednesday: Early clouds, then becoming partly to mostly sunny and milder. High 41-48.

Thursday: Chance for some showers early, otherwise partly to mostly cloudy and mild. High 52-59.

Friday: Some morning showers, then gradual clearing, breezy, and turning cooler. High 46-53 early, then temperatures drop in the afternoon.

Saturday: Sunshine and some afternoon clouds. High 29-36.

Sunday: Mostly sunny. High 40-47.

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It’s a little less than 1500 miles to Fort Myers, but it’ll feel like Spring around here this week as pitchers and catchers report to Spring Training. Image provided by Redsox.com

While it won’t be in the 80s around here this week like it will in Fort Myers, pitchers and catchers report tomorrow. Spring training has arrived, which means we’re that much closer to the end of winter. That doesn’t mean we’re done with snow, but we’re getting there. Don’t forget about the Bruins and Celtics too, and, we’re also less than 3 weeks away from the start of the season for the Revolution.

If you are looking for other signs of Spring, take the following with a grain of salt, but both the GFS and ECMWF models are showing next Tuesday to be a mild day ahead of a cold front. We’re not ready to jump on board with that forecast yet, since it’s still 8 days, but it certainly looks nice. How nice? We’ll let the GFS map do the talking:

GFS 50-STATES USA Mass & CT & RI 2-m Maximum Temperature 216
GFS model forecast for high temperatures across the region on Tuesday February 20. Don’t get your hopes up just yet, it’s still 8 days away and a lot can change between now and then. Image provided by Weathermodels.com

 

A Messy Wednesday On The Way

While some of you saw a few snowflakes this morning, there’s a lot more on the way tomorrow, and it’s going to make a mess of your afternoon commute.

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GFS forecast for the progression of Wednesday’s storm system. Loop provided by Pivotal Weather.

 

Low pressure will move out of the Tennessee Valley tonight, and head towards Southern New England. With high pressure over Atlantic Canada, we’ll have some cold air in place to start the day before the clouds quickly fill in by daybreak. When the precipitation moves in around midday, it should start as snow for most of us. However, it’s not going to stay that way.

Warmer air will move in off the Atlantic, quickly changing the snow over to rain across Cape Cod, with little to no accumulation. The changeover will also take place by early to mid-afternoon across southeastern Massachusetts. In these locations, mainly south and east of Interstate 95, accumulations of 1-3 inches are expected before it goes to rain. Farther to the north and west, things get a little more complicated.

NWS NDFD 2.5-km Mass & CT & RI 2-m Daily High T 2
Temperatures may not get above freezing north and west of Boston on Wednesday, meaning freezing rain could be a threat for some areas. Image provided by Weathermodels.com

That warmer air may not penetrate much farther inland than I-95 at the surface, but aloft, it probably will. When you’ve got below-freezing air at the surface and above-freezing air aloft, you get freezing rain (or sleet) – something we’ve already dealt with several times this winter. While many of the models are trying to send temperatures into the middle to upper 30s, we’re not buying it. The models almost always try to move warm air in too quickly, so we’re ignoring them. We do expect a change to freezing rain from the I-95 corridor up into the Merrimack Valley during the afternoon and evening, which will limit snowfall accumulations a bit, but also drop a layer of ice on top of everything, potentially making even more of a mess of the afternoon rush hour. For these areas, we’re expecting snowfall totals of 2-4 inches closer to I-95, and 3-6 inches up into the Merrimack Valley, as well as over towards the Seacoast of New Hampshire.

Farther inland, across interior southern New Hampshire, there are fewer questions, but everything isn’t set in stone just yet. Some freezing rain is possible, especially along the MA/NH border (including places like Salem, Nashua, and Manchester), but we’re not completely convinced that it will happen. This is something that really can’t be determined until the storm is ongoing and we see how far northward that warm air penetrates. For now, we’re allowing for this possibility, and conservatively forecasting 4-8 inches of snow. If there is no changeover, and the precipitation stays all snow, then amounts could be a bit higher, with totals of 6-10 inches becoming more common. Once you get north of Manchester, from Concord up into the Lakes Region, snowfall totals of 8-12 inches should be the norm.

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While we don’t agree with how it arrives at these numbers, the snowfall totals from the NAM are closest to what we are thinking. Image provided by WeatherBell.

The snow will come down heavy at times during the afternoon across the region, tapering off during the evening. It looks like places that change to freezing rain or rain should go back over to snow at night before everything finally winds down and ends around midnight, give or take an hour. We’re not expecting much additional accumulation once it changes back to snow, but some places could pick up a half an inch to an inch.

NAM-WRF 3-km Mass & CT & RI 2-m Temperature 56
Temperatures will stay below freezing all day Thursday, so make sure you get the driveway cleared quickly, or you’ll need some skates to get to your car or mailbox. Image provided by Weathermodels.com

Colder air will settle in behind the storm for Thursday and Friday, so anything that you haven’t cleaned up will freeze solid Thursday morning. Another weak system may bring in some light snow Friday and Friday night, but as of right now, we’re not expecting much accumulation from that system.

Weekly Outlook: February 5-11, 2018

Sure, that wasn’t the outcome that most of us wanted, but cheer up – there’s snow on the way! Wait, that doesn’t make you feel better? Well, before you know it, Spring will be here. After all, today is Truck Day, and pitchers and catchers report to Fort Myers a week from tomorrow. Does that make you feel better?

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The first sign of spring is upon us – today is Red Sox Truck Day, when all of the equipment gets loaded up and shipped down to Fort Myers for spring training. Image provided by Boston.com

The week will actually start off with a couple of dry but chilly days. The system that brought us some rain Sunday night will pull away, and high pressure builds in for Monday with sunshine and cold temperatures. Tuesday will be another chilly day, but the sunshine will be replaced by clouds as low pressure approaches from the southwest. Since the pressure over us today and Tuesday will be moving into Atlantic Canada, it won’t be in an ideal spot to keep the cold air locked into place on Wednesday, meaning that we’ll be dealing with a rain/snow line. Snow will spread across the area during the day on Wednesday, but the question is – how far inland does the rain/snow line penetrate? There’s plenty of disagreement between the models, so we’ll likely have a special blog post about this later on Tuesday, as the details should be more clear by then (we hope). Right now, we’re thinking that the rain/snow line gets to at least I-95, possibly all the way to I-495. Where it stays all snow, we’re talking plowable snow, likely in excess of 6 inches. The best chance for that will be in southern New Hampshire. Elsewhere, some accumulation is expected, with the amounts dependent on how quickly a change to rain occurs, if it occurs at all.

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The GFS tries to bring the rain/snow line into the Merrimack Valley with the mid-week storm. Other models have different ideas as to how far inland the changeover happens. Loop provided by Pivotal Weather.

Everything changes back to snow before ending Thursday morning, then high pressure builds back in later on Thursday. However, a quick-moving system spreads clouds back in on Friday, with a little bit of light snow Friday night into Saturday morning. Another system quickly follows for Sunday. Right now, this one looks to be warmer, with mostly rain across the region, however, it’s a week away, and a lot can change between now and then. We wouldn’t be surprised at all if the models trend colder, and that system ends up as more of a snow threat than it currently looks like. We’ll worry about that one later in the week.

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Football season may be over, but Patrice Bergeron (pictures) and the Boston Bruins are serious contenders for the Stanley Cup. Remember how warm it was for their parade in 2011? Wouldn’t that be nice right about now? Image provided by NHL.com

Monday: A cloudy start, then becoming partly to mostly sunny and breezy. High 33-40 in the morning, then temperatures hold steady or drop a bit in the afternoon.

Monday night: Clear skies in the evening, then clouds start to roll back in after midnight. Low 15-22.

Tuesday: More clouds than sunshine. High 32-39.

Tuesday night: Partly to mostly cloudy. Low 18-25.

Wednesday: Cloudy with snow developing, changing to rain at least as far inland as I-95. Becoming windy across Cape Cod and southeastern Massachusetts. High 31-38, except for southeastern Massachusetts, Cape Cod, and southern Rhode Island, where temperatures could jump into the 40s towards evening.

Thursday: Any lingering snow or rain ending early, then gradual clearing is expected. High 28-35.

Friday: A sunny start, then clouds move back in. Some light snow is possible at night. High 25-32.

Saturday: Mostly cloudy, some snow showers possible in the morning. High 35-42.

Sunday: Cloudy with a chance of rain or snow, becoming windy across Cape Cod and southeastern Massachusetts. High 38-45, possibly warmer across southeastern Massachusetts, Cape Cod, and southern Rhode Island.

NBA: Boston Celtics at Philadelphia 76ers
The Bruins aren’t the only team in town primed for a deep post-season run well into the Spring and early Summer. Kyrie Irving and the Celtics are also having a great season. Image provided by NBA.com