Henri Heads for the Hamptons, Grace Grows Greatly

Tropical Storm Henri has made the long-awaited northerly turn and now is heading towards New England or Long Island while Hurricane Grace has rapidly strengthened as it nears the coast of Mexico.

Satellite loop of Tropical Storm Henri. Loop provided by NOAA.

As of 11pm Friday, Tropical Storm Henri was centered about 615 miles south of Montauk, New York, moving toward the north at 9 mph. Maximum sustained winds were near 70 mph. Henri is expected to strengthen for the next 24 hours or so as wind shear begins to lessen and the storm remains over the warm waters of the Gulf Stream. Henri will likely become a hurricane on Saturday.

Watches and Warnings are in effect for a large portion of the Northeast coast. Image provided by the National Hurricane Center.

With a ridge of high pressure building in to the east of Henri, and an upper-level low pressure area developing over the Great Lakes, Henri will be steered northward for the next 24 hours, Beyond that, the upper-level low will start pull Henri northwestward and slow it down as it begins to approach Long Island or Southern New England. Since it will be over cooler water at that time, it will begin to weaken. Current forecasts show that Henri may still be a minimal hurricane at landfall, but there is also a good chance that it may weaken to a tropical storm by the time it reaches land.

The various members of the GFS and ECMWF Ensembles show landfall anywhere from New York City to Cape Cod. Image provided by Tomer Burg.

Although the exact track and intensity are still in question, the general impacts should be similar to most tropical systems that impact the Northeast. These systems tend to become lopsided, with the strongest winds mainly to the right of the center, and most of the rain shifting to the left of the track. The current forecast of a track towards eastern Long Island would mean that gusty winds and the highest storm surge would impact parts of Rhode Island and southeastern Massachusetts, including Cape Cod. The storm surge will be compounded by the fact that with a full moon on Sunday, tides will be astronomically high, exacerbating any storm surge flooding. The western track would also mean that the heaviest rain and greatest threat of freshwater flooding, would shift to Long Island, western portions of Connecticut and Massachusetts, and eastern New York.

Expected peak storm surge associated with Henri. Image provided by the National Hurricane Center.

While the winds won’t be particularly strong across much of Southern New England, tree damage could be more extensive that you’d normally expect. It has been a very wet summer across the region, with many places receiving 10-20 inches since the beginning of July. As a result, the ground is saturated across much of the area, so it won’t take strong winds to knock trees over. It also will result in more extensive flooding in areas that receive heavy rain.

Rainfall totals of 4-8 inches are possible where the heaviest rain falls. Image provided by Weathermodels.com

As the steering currents weaken late Sunday and Sunday night, Henri or what’s left of it, may stall out across western New England or eastern New York, then eventually start moving eastward, bringing more rain to parts of central and northern New England. Conditions will improve from west to east on Monday as the storm departs and high pressure starts to build into the region.

Satellite loop of Hurricane Grace. Loop provided by NOAA.

Meanwhile, in the Bay of Campeche, Hurricane Grace rapidly intensified into the Category 3 Hurricane this evening, with maximum sustained winds near 105 mph. As of 11pm, Grace was centered approximately 75 miles east-southeast of Tuxpan, Mexico, moving toward the west at 10 mph. A Hurricane Warning is in effect for the Mexican coastline from Puerto Veracruz to Cabo Rojo. Grace may strengthen a little more before it makes landfall in Mexico overnight, with storm surge and strong winds likely near the coastline. Rainfall totals of 6-12 inches and heavier will result in flooding and mudslides across the region.

Weekend Outlook: July 9-12, 2021

We’re not sure if you’ve heard, but Tropical Storm Elsa is heading this way. It have have some impacts around here tonight and Friday.

Flash Flood Watches are in effect for much of the Northeast, with Tropical Storm Warnings along the coast. Image provided by Pivotal Weather.

As of 2pm EDT, Elsa was centered about 25 miles southwest of Raleigh, NC and moving toward the northeast at 20 mph. Maximum sustained winds are down to 45 mph. A Tropical Storm Warning is in effect for the coast of Connecticut from New Haven eastward, coastal Rhode Island, and nearly all of the coast of Massachusetts from the Mouth of the Merrimack River southward (sorry Salisbury, you don’t get to play), including Cape Cod and the Islands. Elsa will continue northeastward tonight, turning more toward the east-northeast on Friday, likely passing right across southeastern Massachusetts.

Winds may gust to 40 mph or more across parts of RI and southeastern MA on Friday. Image provided by WeatherBell.

Tropical systems have different characteristics when they get up this way, compared to how they look in the Caribbean or Gulf of Mexico. They take on a “rain to the left, wind to the right” appearance. This means that the heavy rain shifts to the left side of the storms track, while most of the strong winds are to the right of the track. In this case, that means most of the wind will be confined to parts of southern RI, southeastern MA, and the offshore waters, but much of the rest of the region can expect heavy rain. How much rain? Rainfall totals of 2-4 inches and possibly heavier, most of it falling between about 8am and 2pm on Friday. Oh, an just to add to the fun for the folks in southern RI and southeastern MA, these systems can and usually do produce some short-lived weak tornadoes, mainly in the right-front quadrant of the storm.

Elsa will produce heavy rain, especially north and west of I-95. Image provided by Weathermodels.com

Before Elsa gets here, we’ll have some showers and thunderstorms to deal with this evening and tonight, thanks to a stalled out frontal system draped across the South Coast. Once Elsa’s rain moves out late Friday, high pressure will try to build back in on Saturday, but we’ll still have plenty of moisture around, which means we could pop a few showers and thunderstorms Saturday afternoon. Warm and humid air moves back in for Sunday and Monday (and into the middle of next week), with some showers and thunderstorms possible each afternoon, especially Monday.

Thursday night: Cloudy with showers and thunderstorms during the evening. Rain and showers redevelop late at night. Low 60-67, a little warmer along the South Coast.

Friday: Windy with rain, heavy at times, tapering off in the afternoon. High 72-79. Offshore: East Coast Southeast 15-25 knots, gusts to 40 knots, becoming northwest late in the day, seas 3-6 feet. South Coast: Southeast to south winds 20-40 knots, gusts to 50 knots, seas 6-10 feet.

Friday night: Showers end in the evening, then becoming partly cloudy. Low 62-69.

Saturday: Partly sunny, chance for an afternoon shower or thunderstorm. High 73-80. Offshore: West to northwest 5-10 knots, seas 3-6 feet.

Saturday night: Clear to partly cloudy. Low 59-66.

Sunday: Intervals of clouds and sunshine, a shower or thunderstorm is possible during the afternoon. High 75-82. Offshore: East to southeast winds 5-10 knots, seas 2-4 feet.

Sunday night: Partly to mostly cloudy. Low 61-68.

Monday: Partly sunny, chance for a few afternoon showers or thunderstorms. High 77-84. Offshore: South winds 5-10 knots, seas 2-4 feet.

Elsa Makes Landfall, What’s Next?

After bringing heavy rain and gusty winds to portions of the Caribbean and Florida over the past several days, Tropical Storm Elsa made landfall in northwestern Florida this morning. It’s not done yet though, not by a longshot.

Radar loop of Elsa making landfall Wednesday morning. Loop provided by Weathermodels.com

As of 2pm EDT, Tropical Storm Elsa was centered about 105 miles west of Jacksonville, Florida, moving toward the north at 14 mph. Maximum sustained winds have decreased to near 50 mph. Tropical Storm Warnings remain in effect for part of northwestern Florida, and for the Atlantic coast of Georgia and South Carolina. A Tropical Storm Watch is in effect north of there all the way up to northeastern New Jersey.

Model forecasts for the track of Elsa. Image provided by Tropical Tidbits.

The forecast for the next 36 hours is fairly straightforward. Elsa will turn northeastward, moving across parts of Georgia, the Carolinas, and into Virginia while gradually weakening. Gusty winds, and heavy rain are likely, with rainfall totals of 3-5 inches and locally heavier likely producing flooding in many areas. In addition, to the east of the storm’s center, some tornadoes are also possible.

Once it gets into the Mid-Atlantic states later Thursday, we have a bit of uncertainty in the forecast. Elsa will continue northeastward, and may start to become extratropical. When this happens, the stronger winds cover a larger area, compared to tropical systems, where the strongest winds are found very close to the center. Many models show Elsa starting to strengthen a bit again. This is likely when it is starting to become extratropical. Elsa may move back over water south of Long Island, but that will depend on when it begins to turn more toward the east-northeast. This has implications for Southern New England.

Elsa will produce heavy rain up and down the East Coast over the next few days. Image provided by WeatherBell.

Elsa will continue to produce heavy rain and gusty winds across the Mid-Atlantic states and into Southern New England later Thursday into Friday. However, the strongest winds are found to the right of the center. If the storm passes near or just south of New England, that means that the strongest winds will stay offshore, possibly impacting Cape Cod and the Islands. However, if the storm stays inland, and moves across Southern New England, then a period of strong to damaging winds could impact parts of Connecticut, Rhode Island, and Southeastern Massachusetts on Friday. Sustained winds of 20-30 mph, with gusts of 50-60 mph would be possible. A track even farther to the west (which is possible), could result in those strong winds impacting the New York City, Providence, and Boston metropolitan areas on Friday.

Where will Elsa track in relation to southern New England? Images provided by Pivotal Weather.

Conditions will improve across New England on Saturday as Elsa (or what’s left of it) moves into Atlantic Canada, and beyond that, the Atlantic looks quiet for a while, which is fairly typical for early July. Plumes of Saharan Dust are making their way across the Atlantic and into the Caribbean, which suppresses tropical activity.

Weekend Outlook: April 16-19, 2021

It’s not April 1, and this isn’t a joke – there’s snow in forecast for parts of our area.

Low pressure is moving off the Mid-Atlantic coast this afternoon while an upper-level low pressure area moves in from the west. The upper-level low will draw the surface low northward towards southeastern New England while it intensifies. Rain is spreading across the region this afternoon, and it will become steadier and heavier tonight as the low moves up the coast. With the upper-level low moving in, we’ll have some very cold air aloft. As the rain becomes heavier, it will pull the cold air down from above, a process called “dynamic cooling”. As this occurs Friday morning, we’ll see the rain change over to snow across the hills from northwestern Rhode Island and central Massachusetts into southwestern New Hampshire. Some wet snow may mix in across the lower elevations of southern New Hampshire and northern Massachusetts as well but we’re not expecting much, if any, accumulation, and what does accumulate will be mainly on grassy surfaces because the pavement is too warm, and air temperatures won’t drop below freezing. It’ll be a different story across the hills from Worcester County into the Monadnocks of southwestern New Hampshire, where several inches may accumulate. Even heavier snow is possible for the Berkshires and the Green Mountains of Vermont. We should note that there are some models that are forecasting accumulating snow, and in some cases quite a bit of it, across most of eastern Massachusetts and Rhode Island. While we can’t completely rule out this scenario, we’re not expecting it to occur.

Most of us won’t see much, if any, snow from this system. Image provided by WeatherBell.

The surface low will pass near or over Cape Cod or southeastern Massachusetts Friday afternoon, allowing any mixed precipitation to change back to all rain and milder air moves in. The rain will taper off to showers in the afternoon, but the showers may not completely end until early Saturday as the system slowly starts to move away. Given the recent lack of rainfall, we’re starting to see drought conditions develop. With 1-2 inches of rain expected from this storm, we’ll help put a nice dent in that developing drought.

Much-needed rain is expected over the next 48 hours. Image provided by Weathermodels.com

Saturday won’t be quite as chilly as Friday, but we probably won’t see much sunshine either as the system only slowly moves away. High pressure starts to build in on Sunday with more clearing and milder temperatures. However, an upper-level disturbance will be moving through, so a couple of pop-up showers can’t be ruled out. Patriots Day on Monday is shaping up to be a nice Spring day with partly sunny skies and mild temperatures, but again, a pop-up shower can’t be ruled out as another weak upper-level disturbance crosses the region.

Monday looks to be a mild day. Image provided by WeatherBell.

Thursday night: Periods of rain, possibly heavy at times, changing to snow across the hills from northwestern Rhode Island and central Massachusetts into southwestern New Hampshire, breezy. Low 33-40.

Friday: Windy with rain mixed with snow at times in the morning, tapering off to showers during the afternoon. High 37-44, possibly a little warmer south of Boston.

Friday night: Cloudy and breezy with showers ending. Low 33-40.

Saturday: Plenty of clouds, possibly a few showers near the coast, some sunny breaks may develop in the afternoon. High 44-51.

Saturday night: Partly to mostly cloudy. Low 32-39.

Sunday: Intervals of clouds and sunshine, slight chance for a shower. High 49-56.

Sunday night: Clear to partly cloudy. Low 33-40.

Monday: Partly sunny, slight chance for a shower. High 56-63.

More Snow on the Way

This shouldn’t be a surprise, since it’s February, but there’s snow in the forecast.

Today’s sunshine and cool temperatures are a product of high pressure building in across the eastern Great Lakes. However, as that high slides off to the east, low pressure, currently in the western Gulf of Mexico, will slowly make its way toward the region. However, it’s not as simple as a storm system passing off to the south and bringing in some snow. This will actually be a three-part system that lasts quite a while.

Aside from a few high clouds, most of the Northeast is enjoying sunshine this afternoon. Loop provided by NOAA.

The initial low pressure system will move off the Southeast coast and head northeastward, passing south of the area late Thursday and Thursday night. This will spread some light snow in Thursday afternoon and evening, mainly south of the Mass Pike. As that system pulls away, another weak system will emerge from the Carolina coast, spreading more snow in. This will overspread most of the area. Along the South Coast, we’ll see some milder air move in, especially aloft, which will likely result in some sleet or rain mixing in. That system pulls away early Friday, but yet another weak system follows in its wake, passing south of the area during the day on Friday, with even more snow expected, even down to the South Coast, as some cooler air filters in behind the previous system. That system finally pulls away Friday night, but with an upper-level low pressure system moving across the Northeast, some more snow showers are possible on Saturday.

It’s important to note that this isn’t your classic Nor’easter with a powerful system off the coast, strong winds, and bursts of heavy snow. Instead, we’re just left with a series of weak systems that will produce off-and-on light snow for a period of 24-to-36 hours across the region. Of course, even light snow will add up if it persists for that long, but this isn’t the “blockbuster” 1-to-2 feet that we sometimes receive at this time of year.

So, how much are we expecting?

Central NH (Concord): 2-4″
Southern NH (Manchester/Nashua): 2-5″
NH Seacoast/Merrimack Valley: 3-6″
MetroWest/MetroBoston: 4-7″
Southeastern Massachusetts/RI: 5-9″
South Coast: 4-7″
Cape Cod: 3-6″ (heaviest near the Canal)

The NWS Blend of Models is probably closest to our thinking right now. Image provided by Weathermodels.com

Another system may bring in some light snow or rain on Monday. We’ll have a little more detail on that in our Weekend Outlook tomorrow.

Weekly Outlook: February 15-21, 2021

This week is going to be messy with not one but two different storms that will produce a variety of precipitation across the region.

We start off the week with plenty of clouds and some light snow and/or freezing drizzle this afternoon as a weak system passes well south of the region. However, another storm system will be moving out of the Tennessee Valley and heading our way. This is the same storm that wreaked havoc on Texas and the Southern Plains over the weekend. At one point over the weekend, all 254 counties in Texas were under a Winter Storm Warning. We’re not sure if that has ever happened before, but it’s certainly a rare event. That storm will head northeastward today, moving up the Appalachians. It will then redevelop south of Long Island tonight, and pass near or across southeastern Massachusetts Tuesday morning.

A variety of watches, warnings, and advisories are in effect across the Northeast ahead of the next storm system. Image provided by Pivotal Weather.

With the low passing to our south, cold air will remain in place for much of the region, mainly north and west of Boston. As milder air moves in aloft, we’ll see snow change over to sleet and then freezing rain this evening and tonight. Before it changes over, we’re looking at an inch or less of snow for much of Massachusetts and Rhode Island, with an inch, possibly 2 inches across southern New Hampshire. Once you get north of Concord, NH, several inches are possible before the flip to sleet/freezing rain. An extended period of freezing rain is possible in parts of the area, especially from the Merrimack Valley into Southern New Hampshire. This will obviously result in hazardous driving conditions, but also will increase the threat of power outages due to downed trees and wires from the weight of the ice. From Boston southward, we’re looking at mostly rain, with temperatures above freezing. How far inland that above-freezing air gets is still a question mark, but right now, we’re thinking that areas north and west of Interstate-95 will likely stay below freezing the entire time. Most of the models try to bring the warmer air all the way into the Merrimack Valley or even Southern New Hampshire. However, the models also tend to overestimate how quickly the cold air will erode, especially when there is snow on the ground. Plus, they have significantly underestimated the magnitude of the cold air that moved in across Texas and the Southern Plains over the last few days. For these reasons, we’re going to stay a little colder than the models. Across Cape Cod and parts of southeastern Massachusetts, cold air won’t be an issue, and in fact, temperatures could get to 50 or even warmer for a while Tuesday morning if the storm passes across southeastern Massachusetts instead of just to the south.

Everything winds down by early afternoon, then skies clear out, with colder air returning for Tuesday night and Wednesday as high pressure builds in. From Boston southward, this means that everything will quickly ice back over Tuesday evening as temperatures drop below freezing. Keep this in mind if you’ll be out an about, as many untreated surfaces will become slick. Although Wednesday will feature sunshine, it will be quite chilly, with temperatures likely staying in the 20s to lower 30s, which is as much as 10 degrees below normal.

Temperatures will be 5-10 degrees below normal on Wednesday. Image provided by Weathermodels.com

By Thursday, another system will approach the region, and this one also looks messy, but a little colder. This system will likely stay south of the region, but some milder air will move in aloft. So, once again, we’re looking at snow, changing to sleet and freezing rain, and possibly plain rain in some areas. The airmass ahead of this system will be a little colder than the one we have in place today, so we could be looking at more snow before the changeover, especially from the Merrimack Valley northward. However, this one could also feature a period of freezing rain across the interior. Details like this are nearly impossible to pin down 4-5 days in advance, so we’ll get into more detail towards midweek as things become clearer.

Thursday night and Friday are looking messy once again. Images provided by Pivotal Weather.

High pressure returns next weekend with drier and colder conditions once again. There are some signs that the colder weather we’ve been dealing with for much of the month could start to retreat in Canada next week, but that’s a long ways away, and things can still change.

Above normal temperatures next week? It’s possible, at least according to one model. Image provided by WeatherBell.

Monday: Cloudy with some light snow or snow showers, possibly mixed with a little sleet or drizzle, especially along the coast. High 27-34.

Monday night: Light snow during the evening, mainly from the Merrimack Valley into Southern New Hampshire, eventually changing to sleet and freezing rain, except precipitation falls mainly as rain south and east of Interstate 95. Low 25-32 during the evening, then temperatures may rise a few degrees overnight.

Tuesday: Freezing rain across the interior and rain in the coastal plain ending by early afternoon. High 30-37 north and west of Interstate 95, 38-45 south and east of I-95, potentially as warm as 45-55 across parts of southern Rhode Island, southeastern Massachusetts, and Cape Cod during the morning.

Tuesday night: Clearing, breezy. Low 14-21.

Wednesday: Sunshine and some late-day clouds. High 25-32.

Thursday: Cloudy, light snow is possible late in the day, possibly changing to sleet and freezing rain at night. High 26-33.

Friday: Snow, sleet, freezing rain, and rain ending in the morning, breezy. High 33-40.

Saturday: Intervals of clouds and sun, breezy, a few flurries are possible. High 25-32.

Sunday: Partly to mostly sunny. High 27-34.

Super Snow Sunday?

It seems as though we are getting a snowstorm after all tomorrow. It won’t be a big one, or a long-duration one, but it will impact your Sunday.

At the end of our Weekend Outlook, we mentioned the chance for snow on Sunday, but closed with this:

“Overall, not a big deal for most of us. Parts of the South Coast could see a few inches of snow depending on how far north the ocean storm actually gets, but otherwise, we’re not anticipating much accumulation across the region, unless things change in the next day or two.”

Well, things have changed. Low pressure will move off the Mid-Atlantic coastline tonight, and pass south and east of Nantucket on Sunday, farther north than we were thinking on Thursday. This will result in accumulating snow for most of the region, with this ending up as a moderate snowstorm far parts of southeastern Massachusetts.

Low pressure will pass south and east of the region on Sunday. Loop provided by WeatherBell.

Snow will develop from southwest to northeast during the morning, and from late morning into mid-afternoon, snow may be moderate to heavy at times, with snowfall rates of 1 inch per hour or more. The snow will start to wind down by late afternoon or early evening, just in time for the Super Bowl to begin. For most of us, this will be just a snow storm. However, for parts of Cape Cod and the Islands, there is a chance that some sleet or rain could mix in, which would keep accumulations down slightly.

So, how much are we expecting?

Central NH (Manchester/Concord): 2-4″
Southern NH/North-Central MA: 3-5″
NH Seacoast/Merrimack Valley: 4-7″
The Rest of Eastern MA/RI: 5-9″, except 3-6″ across the Outer Cape and Islands and the immediate east coast of MA

The NWS Blend of models is probably closest to our thinking right now. Image provided by Weathermodels.com

As was pointed out to us by a colleague for parts of Southeastern Massachusetts, this will be one of the biggest storms this area has seen in a few years. Using Middleboro as an example. they have only received 6 or more inches from a single storm twice in the last 3 years – 6.5″ December 2-3, 2019, and 8.5″ on March 4, 2019.

Beyond this, our next chance for some snow will be with another weak system on Tuesday. That storm will produce a little light snow, possibly rain south of Boston. However, given the performance of the models more than a day or two out, would you really be surprised if it becomes something bigger? We’ll have more on that in our Weekly Outlook Monday morning.

Weekly Outlook: February 1-7, 2021

March is supposed to come in like a lion, and it still may, but for now, February is going to as well.

As you may have heard, it’s going to snow today. We’re not going to rehash that too much, since we just wrote a very detailed post about the storm Sunday evening, and our thinking really hasn’t changed much. Suffice to say, snow will become heavy at times this afternoon and tonight, changing to rain for the immediate coast and Cape Cod. It’ll start to wind down early Tuesday, but occasional snow showers and periods of light snow continue on Tuesday with rain eventually going back to snow near the coast. Strong winds this afternoon and tonight slowly diminish on Tuesday as well.

The NWS Blend of Models is still closest to our thinking with snowfall for the current storm. Image provided by Weathermodels.com

So, let’s get to what comes next. On Wednesday, the storm pulls away, heading towards Nova Scotia, but we may still have a few snow showers around, especially during the morning. Skies may start to clear out late in the day. The airmass behind the storm isn’t that cold, so unlike past storms, we don’t have to worry about another arctic blast freezing everything up. High pressure then builds in for Thursday and the sun should return, with temperatures right around where they should be in early February.

Average high temperatures in early February are in the middle to upper 30s across the region. Image provided by Weathermodels.com

Friday and the weekend are when things get interesting again. You may recall a few days ago when some of the tv meteorologists were talking about a big warmup and rainstorm around here for this coming Friday, which would help get rid of a lot of the snow we’re getting today. Well, that’s not quite what’s going to happen now. Yes, low pressure will still travel into the Great Lakes and then Ontario, passing well north and west of us, and temperatures will moderate a bit on Friday. However, temperatures will likely only get into the upper 30s to lower 40s, which is still a little above normal, but not the 50s some of the models were showing a few days ago. We’re also not looking at a lot of rain either. There will likely be some precipitation ahead of a strong cold front, and much of it will be rain, but it might not start as rain across the interior.

The cold front moves through Friday night and high pressure starts to build in with colder air once again. It won’t be as cold as what we had this past weekend, but temperatures will be near to perhaps a little below normal. That’s not the end of the story though. That cold front likely stalls out across the Southeast and then a wave of low pressure will move out of the Gulf of Mexico and start to ride up along the front. Some of the models are showing the potential for that system to bring in some more snow next weekend. It’s still 6-7 days away, and most of the models have not performed that well beyond 2-3 days for quite some time, so we’re not completely convinced of this yet, but it’s something we’ll start to focus on once we get our current storm out of the way. If it starts looking more likely, we’ll have more details in our Weekend Outlook Thursday afternoon.

The models have lots of differences in timing and track of a potential system next weekend. Images provided by Pivotal Weather.

Monday: Becoming windy with snow, heavy at times by late afternoon, changing to rain along the coast. High 28-35.

Monday night: Windy with snow, heavy at times inland, and rain from Cape Cod and parts of southeastern and coastal Massachusetts. Precipitation tapers off toward daybreak. Temperatures hold steady or rise a few degrees overnight.

Tuesday: Cloudy and breezy with periods of light snow and snow showers, except rain showers for southeastern Massachusetts. High 30-37, a little warmer across Cape Cod and possibly southeastern Massachusetts.

Tuesday night: Cloudy and breezy with additional snow showers possible. Low 21-28.

Wednesday: Cloudy with a few more snow showers possible early, some glimpses of sunshine are possible in the afternoon. High 29-36.

Thursday: Partly to mostly sunny. High 32-39.

Friday: Cloudy and breezy with showers developing, possibly starting as snow or a wintry mix north and west of Boston. High 38-45.

Saturday: Some early sun is possible otherwise mostly cloudy with a chance of snow or rain. High 33-40.

Sunday: Mostly cloudy with snow or rain possible. High 32-39.

Here Comes the Snow

We really haven’t had a decent-sized snowstorm around here since mid-December. That will change in a hurry on Monday. As a result, the Extreme Hype Watch we issued on Thursday has been upgraded to an Extreme Hype Warning.

Low pressure moving across the Ohio Valley this afternoon is just one ingredient in the mix for the upcoming storm. Image provided by the Weather Prediction Center.

High pressure remains in place across Quebec, keeping plenty of cold air in place across the Northeast this afternoon. Meanwhile, low pressure is moving across the Ohio Valley, producing a swath of snow from the Great Lakes into the Mid-Atlantic states. As that low moves eastward, it will weaken tonight, but a new area of low pressure will develop off the Mid-Atlantic coastline. At the same time, and upper-level low pressure area will also move toward the East Coast. As the new surface low gets caught underneath the upper-air low pressure area later Monday and Monday night, it will stall out or meander around south of Long Island. Eventually, it will resume an east to northeast motion on Tuesday, passing south and east of Nantucket before moving into the Gulf of Maine.

Snow is falling from Chicago to New York City late this afternoon. Loop provided by Weathertap.

As we mentioned, an Extreme Hype Warning has been issued, which means you’ll see blanket coverage from the network stations around here, hourly updates even when they go to regular programming, and of course, obligatory live shots from (take your pick):

  • The side of an Interstate
  • Logan Airport
  • A local DPW salt pile
  • A beach showing the rough surf and coastal flooding
  • A Dunkin Donuts where they are talking to a plow operator
  • All of the above

You’ll also get network reports about how the snow is creating chaos in New York City, how it put Washington at a standstill, and possibly how it dumped heavy snow on the Midwest. The latter is debatable, because anything west of the Appalachians is considered “flyover country” to the media around here.

OK, we’ve explained what’s going on in the big picture, now let’s focus on some of the details for our area (Southern New Hampshire, Eastern Massachusetts, Rhode Island):

Winter Storm Warnings are in effect from Maine to Virginia.

As you can see on the radar above, snow is already moving into the Tri-State area, and will continue to make slow progress northward tonight. By morning, east to northeast winds will start to increase around here, and we’ll see some ocean-effect snow showers develop in parts of southern New Hampshire and eastern Massachusetts. These aren’t directly related to the storm, but may drop 1/4-1/2″ of snow. This is also a common occurrence before some storms around here. The snowfall from the storm will move in during the late-morning and early afternoon hours and should become moderate to heavy by late afternoon or early evening. Snow may fall at the rate of an inch or two per hour at times. This will continue overnight with precipitation starting to taper off before daybreak. For much of the region, that precipitation will fall as all snow, but a change to rain is likely along the coast and across parts of southeastern Massachusetts and southern Rhode Island. How far inland that rain-snow line penetrates will obviously have a large impact on accumulations. Right now, we don’t expect it to get past Interstate-95, and it might not even get that far.

By Tuesday morning, the steady precipitation will taper off, but the storm will still be south of Long Island. So, what we’re looking at is occasional snow showers and periods of light snow throughout the day, with rain or mixed precipitation in southeastern Massachusetts and southern Rhode Island, This likely won’t add too much accumulation, but in some places, we could see another inch or two. As the low finally gets moving, colder air will work its way back in, changing everywhere back to all snow before it ends late Tuesday night or Wednesday morning.

There are several factors that could cause problems around here. First and foremost is the wind. Northeast winds will increase to 15-25 mph inland, and 20-30 mph along the coast, with gusts of 30-50 mph. This will create near-blizzard conditions at times Monday night, with reduced visibility and blowing and drifting snow. If you don’t have to go out Monday night, stay home. Driving will be extremely hazardous. Across Cape Cod and the Islands, a High Wind Warning is in effect. Sustained winds of 25-35 mph with gusts to 60 mph are possible here. Winds will only slowly diminish across the region on Tuesday.

Peak wind gusts of 40-50 mph are expected across the region. Image provided by WeatherBell.

Along with the wind, we have coastal flooding to worry about. A Coastal Flood Watch is in effect for eastern Massachusetts, mainly for the high tide cycles Monday night and Tuesday morning. Those strong northeast winds, combined with tides that are still astronomically high, will likely produce some coastal flooding, especially in some of the normally prone areas (like Morrissey Boulevard in Boston). By Tuesday afternoon, winds will become more northerly, reducing the coastal flood threat.

Finally, we get to the part you’re all interested in – how much snow? The good news is that they heaviest snow from this storm will likely be south and west of us, from southeastern New York and northern New Jersey into parts of Pennsylvania. Many locations in this area could see 20 or more inches of snow before everything winds down. Even New York City could see a foot to perhaps a foot and a half of snow. Around here, there will likely be many reports in excess of a foot, especially north and west of Boston. As for specifics, here’s what we’re thinking:

Cape Cod: 1-3″, heaviest near the Canal
South Coast/Immediate East Coast: 3-6″
Interior Southeastern Massachusetts/I95 Corridor from RI into Eastern MA: 6-10″
Areas North and West of Interstate-95 (including southern/Central NH): 10-15″ with some heavier amounts possible.

Our thinking is closest to what the NWS Blend of Models is showing. Image provided by Weathermodels.com

Obviously, some of these amounts are dependent on when/if rain starts to mix on or a complete change to rain occurs. Most of the accumulating snow will occur between late Monday afternoon and daybreak Tuesday, but there will still be some snow falling during the day on Tuesday.

Another storm will move in late this week, but this one looks to be milder, with rain for a bigger chunk of the region, though snow is a possibility across the interior. We’ll have more on that in our Weekly Outlook tomorrow morning.

Christmas Weekend Outlook: December 24-28, 2020

We’ve got a couple of busy days coming up, and not just because it’s Christmas.

Low pressure is moving across Iowa this afternoon, producing blizzard conditions across parts of the Upper Midwest and Northern Plains. That system will impact us over the next few days, but in a different way. As it moves toward the Great Lakes, it will start to send milder air into the region tonight, but more noticeably tomorrow. Southerly winds will gradually increase tomorrow, becoming quite strong tomorrow night and into Christmas morning. Sustained winds of 15-30 mph are likely, with wind gusts to 50-60 mph or more possible. This could result in power outages, so don’t be surprised if you wake up Christmas morning and can’t charge up those new electronics you found under the tree.

Damaging wind gusts are possible across much of the region Thursday night and Christmas morning. Image provided by WeatherBell.

Wind isn’t the only issue we’ll have. Rain will move in Thursday night, and continue into Christmas Day. While it may not be raining the entire time, there will be some bands of heavy rain, with rainfall totals in excess of an inch possible in many areas. The rain, combined with temperatures climbing above 50, will help to melt a lot of the snow that is on the ground. This could result in some flooding issues in some spots, but widespread flooding doesn’t look likely.

The ECMWF shows how our snow cover could quickly disappear over the next few days. Loop provided by Weathermodels.com

As this storm system moves into southeastern Canada, it will drag a strong cold front across the region on Christmas Day. Although the day will start mild, likely in the 50s for most of us, temperatures will drop during the afternoon. If the cold air moves in fast enough and the precipitation is slower to move out, we could even see some wet snowflakes before everything winds down late in the day. At night, temperatures will continue to drop, meaning that the wet roads will likely start to ice over if they are not treated, as they won’t have had much time to dry before the cold air moves in.

The GFS model shows the warmer air move in on Christmas Eve, then quickly get replaced on Christmas Day. Loop provided by WeatherBell.

High pressure builds in for the weekend with dry and seasonably cold conditions. It may still be a bit breezy on Saturday, adding to the chill, but Sunday may also be a few degrees milder. By Monday, we’ll be watching another storm system passing to our west, with some showers possible.

Wednesday night: Becoming partly to mostly cloudy. Low 23-30 this evening, but temperatures may start to rise a bit after midnight.

Christmas Eve: Mostly cloudy, becoming breezy in the afternoon. High 48-55.

Thursday night: Cloudy and windy with showers developing, becoming steady rain late at night. Temperatures gradually rise overnight.

Christmas Day: Cloudy with rain likely, possibly heavy at times, windy in the morning. High 53-60 in the morning, temperatures drop during the afternoon.

Friday night: Mostly cloudy and breezy with any lingering showers ending in the evening, possibly mixed with a few wet snowflakes, some clearing is possible late at night. Low 22-29.

Saturday: Becoming partly to mostly sunny. High 28-35 (welcome back to December).

Saturday night: Clear skies. Low 19-26.

Sunday: Partly to mostly sunny. High 32-39.

Sunday night: Increasing clouds. Low 22-29.

Monday: Mostly cloudy and breezy with a few showers possible. High 42-49.