Heavy Rain/Snow, Winter Weather

Snow Makes a Return

We’ve got a significant snowstorm on the way to the region for Saturday night. Hang on, we’re being told that even though the last week or so has felt like January in North Carolina, we’re still in Massachusetts, not North Carolina. So, let’s start over. We’ve got some snow on the way for Saturday night, but it shouldn’t be a big deal by New England standards.

Winter Storm Warnings and Winter Weather Advisoies are in effect for much of the Northeast. Image provided by Pivotal Weather.

A cold and very dry airmass is in place across New England to start Saturday, thanks to a high pressure area moving across Northern New England. Temperatures are starting the day in the single numbers and teens, with dewpoints near or below zero. Meanwhile, a storm system will be moving out of the Great Lakes and heading for Northern New England later today. That will be out weather-maker for tonight and early Sunday.

Saturday is starting on a very chilly note across the region. Image provided by Weathermodels.com

We’ll see high clouds start streaming in by midday, and they’ll thcken up during the afternoon. It’ll take some time for the air to moisten up, but it will eventually, and snow will start falling right around dinnertime for most of us, a little earlier to the west. This will be a fast-moving storm, with the snow actually tapering off and ending around midnight. It looks like any rain/snow line will be confined to southeastern Massachusetts and Rhode Island. After midnight, a little freezing drizzle or some flurries are possible as the system starts to pull away, but the accumulating snow should be all done.

Our storm quickly moves across the region this evening and tonight. Loop provided by Tropical Tidbits.

The snow could fall at a decent clip during the evening hours, with some places possibly seeing an inch per hour. So, if you’tre going to be out and about, take it slow and drive carefully. How much snow are we expecting?

Cape Cod/South Coast: 1-3″
Southeastern Mass/I-95 corridor (Boston/Providence): 2-4″
MetroWest/Merrimack Valley/NH Seacoast: 3-5″
Southern NH/Southern Maine: 3-6″
Central NH: 4-8″

The High-Resolution NAM model is probably closest to our thinking on snowfall with this system. Image provided by WeatherBell.

Behind the storm, Sunday will be a nice day, with developing sunshine and temperatures in the 30s to near 40, which will help melt some of the new snow. You’d better get out and clean up the driveway though, because everything is going to freeze solid Sunday night as another arctic airmass settles into the region. Temperatures may not get back above freezing until Wednesday afternoon, possibly not until Thursday, but a warmup is expected for the end of the week.

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Heavy Rain/Snow, Winter Weather

Another Messy Monday

As we head into the home stretch of 2019, it looks like the year is going to end with a wintry mess.

Winter Storm Watches are in effect across interior portions of New England and eastern New York. Image provided by Pivotal Weather.

The storm system that produced heavy snow in the Plains and strong to severe thunderstorms in the Mississippi Valley on Saturday will head into the Great Lakes on Sunday, then just mill around in the Midwest for Monday and early Tuesday. Clouds will stream into our area later Sunday ahead of the system, but as is usually the case with a storm that far west, the warmer air that we usually find on the east side of a storm system won’t make it in here, at least at the surface (that becomes important later on).

Sunday will be a mild day (by late December standards) as high pressure moves out, but temperatures should drop below freezing during the evening. We’ll see precipitation start to break out before midnight across much of the area. While there will still be cold air in place at the surface, warmer air will be starting to move in aloft. So, we should see sleet and some freezing rain developing, with some snowflakes, mainly from central and southern New Hampshire northward. Some accumulations are possible, especially from the Seacoast up into the Lakes Region, but only a few inches at most before a change to sleet occurs. Along the South Coast, this will be mainly rain with temperatures above freezing.

The NAM model shows the progression of the storm system and how the precipitation changes from sleet to freezing rain, to rain across the region. Loop provided by Tropical Tidbits,

With a frontal system stalled out south of New England, we’ll have generally east to northeast winds on Monday. This will allow parts of southeastern Massachusetts and Rhode Island (mainly south and east of Interstate 95), to warm above freezing as somewhat milder air moves in off the ocean. Across inland areas, it’ll be a much different story.

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

Cold air will remain in place for most of the day on Monday and into Monday night. Meanwhile, a few thousand feet above the ground, warmer air will be moving in. This will mean sleet at first, but as that warmer air layer grows thicker, the sleet should transition over to freezing rain. When that transition occurs is still a bit of a question mark.

NAM model forecast for temperatures at 700mb (about 10000 feet) for midday Monday. Temperatures will be above freezing across most of our region that high up, melting any high-level snowflakes falling into that part of the atmosphere. Image provided by the College of DuPage.

Some models are showing the potential for significant amounts of sleet from interior eastern Massachusetts into southern New Hampshire, with significant ice accretion from freezing rain across the Worcester Hills, Monadnocks, and the Berkshires. No matter what happens, travel will be very slippery across the interior on Monday,

The High-Resolution NAM model is forecasting a LOT of skeet across the interior. Image provided by WeatherBell.

By Monday night, a secondary area of low pressure should develop south of Long Island, and it will head northeast, moving across Cape Cod early Tuesday, then into the Gulf of Maine. As it moves close to the area, it should help force the warm air farther inland, allowing temperatures to rise above freezing across most of the area. However, once it moves into the Gulf of Maine, colder air will settle in behind it, both at the surface and aloft, changing everything back to snow showers before the precipitation winds down Tuesday morning.

Significant ice accretion could result in major issues including tree and power line damage across the interior. Image provided by WeatherBell.

We’ll update this forecast as well as a look at New Year’s Eve and New Year’s Day in our Weekly Outlook early Monday morning.

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Extreme Temperatures, Heavy Rain/Snow, Winter Weather

Messy Tuesday, Frigid Thursday

The Winter Solstice is Saturday, but winter will certainly make it’s presence felt over the next few days.

The low pressure system that produced severe weather across the South on Monday will head northeastward, impacting our area on Tuesday. The storm will be moving fairly quickly, and it doesn’t have a lot of cold air to work with, so we’re not expecting a big snowstorm. That doesn’t mean it won’t cause any problems.

Winter Weather Advisories are in effect for most of the region. Image provided by Pivotal Weather.

Snow will develop around midnight across parts of Connecticut and Southern Rhode Island, gradually spreading northward across the rest of the region before daybreak. The snow should quickly change to rain after daybreak across the South Coast and Cape Cod. As warmer air moves in aloft, a change to sleet and freezing rain will start to take place across the interior, with plain rain along the coast as milder air moves in off the still relatively mild ocean. Right now, it looks like the mixing may get as far north as the Merrimack Valley during the afternoon. North of there, precipitation should stay all snow. The precipitation will lighten up during the afternoon, but won’t completely end until the evening or first part of the overnight.

The morning and evening commute will both be impacted by this storm, but the greater impacts will certainly be during the morning commute. Not only could icing be a problem, especially in parts of Connecticut and Rhode Island, we could be looking at a band of moderate to heavy snow along and south of the Mass Pike. With temperatures expected to drop below freezing at night, many roads could ice back up, so untreated surfaces could become slick, especially in areas that changed over to rain during the afternoon.

Icing could become a significant problem across parts of Connecticut and Rhode Island on Tuesday. Image provided by Pivotal Weather.

As for how much snow to expect, we haven’t changed our thinking much from our earlier forecast.

South Coast/Cape Cod: Less than 1″
Southeastern Massachusetts (including the I-95 corridor): 1-2″
MetroWest/North Shore: 1-3″
Merrimack Valley: 2-4″
Central + Southern New Hampshire/NH Seacoast: 3-6″

The High Resolution NAM model is probably closest to our expectations for snowfall. Image provided by WeatherBell.

Behind this system, we’ve got to pay attention to an arctic cold front that will move across the region late Wednesday. It could produce some snow showers or squalls as it moves through. These won’t impact everyone, but in places they do, visibility could rapidly drop, and a quick half an inch to an inch of snow could fall.

Wind chills will likely drop below zero across most of the area Wednesday night into Thursday morning. Image provided by Weathermodels,com

Behind that front, some of the coldest air so far this season will settle in for Thursday. Wind chills will be below zero during the morning hours, and actual temperatures may not make it out of the teens during the afternoon. Friday will see temperatures start to moderate a bit, but it will still remain quite chilly, even by December standards.

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Heavy Rain/Snow, Weekly Outlook

Weekly Outlook: December 16-22, 2019

We’ve got another week coming up with just about everything Mother Nature has to offer. Well, not quite everything, since we won’t have a warm day this week. To make up for it, we’ll have at least one day that is extremely cold. How’s that for a trade off?

The week starts off with high pressure in control. That means we’ll have some sunshine, less wind, and chilly temperatures today. The sunshine will not last long though, as clouds quickly move in ahead of our next system. That storm will move from the Tennessee Valley into the Mid-Atlantic states, passing south of New England on Tuesday. That’s about the only part of the storm that isn’t complicated.

Snow will develop across much of the region before daybreak on Tuesday. Yes, that means your morning commute on Tuesday will be even worse than normal. The snow should quickly change to rain along the South Coast. Away from the coast is where the problems start. Warmer air will move in aloft, with a change to sleet, freezing rain, and eventually plain rain expected to work its way northward on Tuesday. How quickly it moves northward, and how far north that changeover gets are still up in the air. Obviously, this has a major impact on how much snow accumulation we can expect. The other problem is, how long do some areas stay sleet or freezing rain, as this will have a significant impact on road conditions.

The High-Resolution NAM model shows the progression of the the precipitation and changeover line with the next storm system. Loop provided by WeatherBell.

So, how much snow can we expect before the changeover? Obviously, this is still a low-confidence forecast, despite the fact that it’s only a little more than a day away. Here’s what we’re thinking for now:

South Coast/Cape Cod: Little to no accumulation
Southeastern Massachusetts/Rhode Island (South and East of I-95): A coating to 2 inches.
Northern Rhode Island/MetroWest/North Shore/Merrimack Valley/NH Seacoast: 1-3″
Southern NH (Nashua-Manchester): 2-4″
Central NH (Concord-Lebanon): 4-7″

We’ll try to do an updated blog post late Monday, once we get a little more clarity on some of the details.

The GFS model is probably the closest to our thinking for snowfall amounts right now. Image provided by Weathermodels.com

So, everything winds down Tuesday evening, and then things improve on Wednesday, right? Not so much. A strong cold front will move across the region during the afternoon. This front may produce some snow showers or possibly snow squalls as it moves through during the afternoon and evening. Behind the front, some much colder air settles in for Wednesday night and Thursday. Now, it won’t be as cold as it was in the Dakotas and Minnesota, where it stayed below zero all day Saturday and Sunday (Can someone please explain why people choose to live in North Dakota?), but many parts of our area could stay below 20 all day on Thursday. When you fact in the wind, it will feel like it’s below zero, especially during the morning.

Heading out before daybreak Thursday? Bundle up, because wind chills will likely be below zero across the region, Image provided by WeatherBell.

High pressure builds in for Friday with dry weather, but it shouldn’t be as cold as Thursday. This brings us to the weekend. This is where things get questionable again. You may have heard some chatter online about a big snowstorm this weekend. Well, it’s a possibility, but then again, it’s also possible that the Patriots defense won’t give up a single point for the rest of the season. Most of the models have been signalling that there will be a potent storm system developing off the East Coast this weekend. Every now and then, one of the runs puts that storm right off of Cape Cod and shows the potential for a blizzard, sending all of the Facebook Forecasters into a frenzy. Of course, these same models have also shown the same storm moving off of Florida and then eastward across the Bahamas instead. Will there be a strong storm? Probably. Will it impact us? Probably not. However, one thing that may happen, is a weak system moving eastward bringing in a period of light snow sometime either late Saturday or Sunday. Given where the storm forms, it’s not really an Alberta Clipper, calling it a Dakota Dasher would probably be more accurate.

Nearly every run of the GFS over the past 5 days has had a strong storm near the East Coast this weekend. However, the placement and strength of the storm has varied on every run. Loop provided by Pivotal Weather.

If you’re really looking ahead, right now Christmas Eve and Christmas Day look dry and seasonably chilly.

Monday: Some sunshine early, then clouds thicken up. High 30-37.

Monday night: Cloudy with snow developing after midnight. Low 23-30.

Tuesday: Snow, changing to sleet, freezing rain, and plain rain from south to north. Areas north of the Mass Pike may never go to plain rain. High 27-34 north and west of Interstate 95, 34-41 south and east of Interstate 95.

Tuesday night: Precipitation ends in the evening, then skies clear out late at night. Low 21-28.

Wednesday: Morning sunshine, clouds return in the afternoon with some snow showers or squalls possible late in the day, becoming windy at night. High 30-37.

Thursday: Sunshine and a few clouds, breezy, and cold. High 17-24.

Friday: Partly to mostly sunny. High 22-29.

Saturday: Mostly cloudy, chance for some light snow or snow showers late in the day and at night. High 29-36.

Sunday: Partly to mostly cloudy with a chance of snow showers, especially in the morning. High 34-41.

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Extreme Temperatures, Heavy Rain/Snow, Weekly Outlook, Winter Weather

Weekly Outlook: December 9-15, 2019

Given a choice, would you prefer cold weather or warm weather? What about a choice between rain, snow, or dry weather? Well, you’re going to get ALL of these this week!

Temperatures could reach 60 across parts of the area on Tuesday. Image provided by WeatherBell.

We start the week with low pressure moving into the Great Lakes and then eventually up the St. Lawrence Valley. With low pressure passing to our north and west, we’ll be on the warm side, with rain expected, mainly in two waves. The first one will come in today, with rain developing this morning, and continuing into tonight, when it cold be locally heavy. The warm air should move in south of Boston fairly quickly, but it may take until tonight to get into the Merrimack Valley and southern New Hampshire.

Warm air comes in today, and is quickly pushed out by cold air late Tuesday into Wednesday. Loop provided by Weathermodels.com

We’ll have a bit of a lull tomorrow morning, but a cold front will approach later in the day, with rain coming back ahead of that front. We’ll still be on the mild side, that is until the front comes through. Temperatures will quickly drop behind the front late Tuesday and Tuesday night but the precipitation may linger, so we will likely see rain changing to snow Tuesday night.

The NAM model shows the progression of the storm with 2 waves of rain followed by some snow. Loop provided by Tropical Tidbits.

On Wednesday, a little disturbance will move across the region, bringing us some additional light snow, mainly in the morning. There’s still a bit of uncertainty with this, but plan on the morning commute being impacted. We’re probably only looking at a few inches, but all it really takes to screw up the morning commute is a few flakes at all. High pressure builds in late in the day and into Thursday with drier and much colder weather.

A few inches of snow could really mess up the Wednesday morning rush hour. Image provided by Pivotal Weather.

By Friday, temperatures start to moderate again as the high slides offshore. It’ll still be chilly (it is December after all), but not quite as cold as Thursday. The weekend looks even milder once again, but that’s because we’ll have another storm system passing to our north and west, so we’re looking at another round of rain, possibly heavy once again.

Saturday could end up quite mild once again, but wet as well. Image provided by WeatherBell.

Monday: Cloudy and becoming breezy with periods of rain and showers. High 49-56.

Monday night: Cloudy and breezy with rain likely, possibly heavy at times, tapering off late at night. Temperatures hold steady or possibly rise a few degrees.

Tuesday: Cloudy and breezy with showers redeveloping late in the day. High 53-60, but temperatures start to quickly drop from northwest to southeast during the afternoon.

Tuesday night: Cloudy with rain changing to snow during the evening. Low 26-33.

Wednesday: Cloudy with light snow ending around midday. Skies clear out at night. Temperatures hold steady or drop a few degrees during the day.

Thursday: Plenty of sunshine, but cold. High 24-31.

Friday: Becoming mostly cloudy. High 32-39.

Saturday: Cloudy, breezy, and milder with rain likely. High 46-53.

Sunday: Partly to mostly cloudy and breezy, chance for a few showers. High 42-49.

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Heavy Rain/Snow, Weekly Outlook

Weekly Outlook: December 2-8, 2019

Winter’s back, and it’s not going anywhere for a while. We’ve got more snow on the way in the next 24 hours, so we’ll get right to it.

Some moderate to heavy snowfall totals were observed on Sunday, especially north and west of Boston. More will be coming today into Tuesday. Image provided by the National Weather Service in Norton, MA.

We went into great detail yesterday, so we won’t spend too much time on today. Basically, the daylight will be fairly quiet as the low move towards the Gulf of Maine. We’ll have some occasional showers and/or drizzle across eastern Massachusetts, with freezing drizzle or a few flurries farther inland and up into southern New Hampshire. Late in the day, temperatures will start to drop, so things could get icy across eastern Massachusetts as well.

The High-Resolution NAM model depicts the progress of our storm system today into Tuesday. Loop provided by Tropical Tidbits.

Tonight is when things get interesting again. As the low pressure area moves into the Gulf of Maine it will intensify and become a pretty potent system. With gusty north to northwest winds keeping most of the area quite chilly, we’ll snow moving in from the ocean, on the backside of the storm. It is still uncertain how far inland that snow will get and how much will fall. We’re fairly confident that there’s going to be a band of heavy snow that sets up, but we’re still thinking that the heaviest stays just offshore. Still, with light to occasionally moderate snow going through Tuesday afternoon, we’ll still see some decent amounts, especially close to the coast. How much more? We think that much of the region could see 3-6″ between Monday night and Tuesday afternoon, with lesser amounts into southern New Hampshire. From the North Shore up into the New Hampshire Seacoast , another 4-7″ may fall.

The High Resolution NAM model is closest to our thinking for snowfall tonight into Tuesday. Image provided by WeatherBell.

Everything winds down Tuesday night, then high pressure builds in for Wednesday and Thursday with dry and chilly conditions. An Arctic front will move across the region late Friday, with a few snow showers or squalls ahead of it. After that, high pressure returns next weekend with even colder weather on Saturday. By Sunday, the high will slide offshore and temperatures will start to moderate, but will likely still be below normal for early December.

Temperatures may stay below freezing all day on Saturday. Image provided by WeatherBell.

Monday: Cloudy and breezy with showers and drizzle across eastern Massachusetts, flurries and freezing drizzle elsewhere. High 29-36 north and west of I-95, 37-44 south and east of I-95, though temperatures in this area will start to drop in the afternoon.

Monday night: Cloudy and breezy with precipitation becoming steady light to occasionally moderate snow. Low 24-31.

Tuesday: Cloudy and breezy at times with snow ending by early afternoon, some sunshine may develop in the afternoon the farther west you go. Additional accumulation 1-3″ in southern NH, 3-6″ most elsewhere, except 4-7″ from the North Shore to the NH Seacoast. High 30-37.

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

Wednesday: More clouds than sunshine. High 34-41.

Thursday: A mix of sun and clouds. High 32-39.

Friday: Partly to mostly cloudy with some late-day snow showers or squalls possible. High 34-41.

Saturday: Sunshine and a few clouds, breezy. High 26-33.

Sunday: A mix of sun and clouds. High 36-43.

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Heavy Rain/Snow

Better Find Those Shovels

We warned you yesterday, and now it’s just about here. The first winter storm of the season, coincidentally falling on the first day of meteorological winter.

Low pressure is moving into the Great Lakes this afternoon while a secondary area of low pressure is starting to develop across the Delmarva Peninsula This secondary low will move northeastward tonight, then meander around south of Long Island, before drifting eastward on Monday. This will spread snow into the region later this afternoon and evening. Snow may fall moderate to heavy at times during the evening and into the first part of the overnight. As warmer air moves in aloft and at the surface, a change to sleet and then rain is expected along the coast, pushing inland as the night moves on. There’s still a bit of a question as to how far inland that changeover occurs. Right now, our best estimate is somewhere around the Massachusetts/New Hampshire border, give or take 10 miles.

Winter Storm Warnings and Winter Weather Advisories are in effect for much of the Northeast. Image provided by Pivotal Weather.

Precipitation should lighten up considerably toward daybreak as the low moves southeast of New England. We’ll still have occasional snow showers with some drizzle or freezing drizzle as the intensity lightens up, with only light accumulations during the day , mainly north and west of I-95. If you’re south and east of I-95, these will be mostly rain showers, as temperatures will likely be in the upper 30s or 40s, thanks to a coastal front.

The ECMWF model is fairly similar to our thinking for how the storm progresses. Loop provided by Pivotal Weather.

As the low moves east of Cape Cod on Monday, an upper-level low pressure system will move overhead, pulling the system northward into the Gulf of Maine, where it will start to intensify and also slow down. This will result in another period of steady snow Monday night into midday Tuesday. There will likely be a band of heavier snow that sets up on the backside of this storm. Exactly where that band sets up is still a question. Several models want to keep moderate snow going to much of the day Tuesday across most of eastern Massachusetts and into the New Hampshire Seacoast and most of Maine. We’re still not convinced that will happen. Right now, we think it’s more likely that band stays just offshore, clipping the Seacoast and the Eastern Massachusetts coastline. If we need to make changes to this part of the forecast, we’ll do so in our Weekly Outlook early Monday morning.

Again, the big question – how much snow can we expect? Our thinking isn’t very different than yesterday:

Cape Cod: 1-2″ (mainly on Tuesday)
Southeastern MA: 2-5″ (1-2″ Sunday night, another 1-3″ Tuesday)
I-95 corridor (Boston/Providence): 3-6″ (1-2″ Sunday evening, 2-4″ Monday night/Tuesday) The farther away from the coast, the higher the amounts.
North Shore/MetroWest: 4-8″ (3-5″ Sunday night, 1-3″ Monday night/Tuesday) The farther away from the coast, the higher the amounts.
Merrimack Valley: 6-12″ (4-8″ Sunday night, 2-4″ Monday night/Tuesday)
Central and Southern NH: 8-12″ (6-10″ Sunday night, 1-2″ Monday night/Tuesday)
NH Seacoast: 10-15″ (6-9″ Sunday night, 3-6″ Monday night/Tuesday)

Once again, the GFS Ensemble Mean is closest to our thinking with respect to snowfall totals. Image provided by WeatherBell.

The good news is that the rest of the week looks storm-free. It’ll be chilly (it is December after all), but no more snowstorms for now. Don’t expect that to continue for the rest of the month.

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