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.

GEFS Ensembles North America 500 hPa Height 120
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.

JetBluePark
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.

gfs.prateptype_cat.us_ne.2018020500-loop
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

Weekly Outlook: January 29 – February 4, 2018

Who’s ready for some snow? Don’t worry, we’re not looking at a lot. In fact, parts of the region might not see any at all. We could see some more later in the week and possibly over the weekend too. Yes, we understand some of you have some plans next Sunday – something having to do with owls.

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The cold front that moved through on Sunday stalled out offshore, and low pressure will ride up along it later today into early Tuesday. This will result in some light snow across the region, mainly south and east of I-495. With the storm passing far enough to the south and east, most of the accumulating snow will be from Boston southward, and most snow across Cape Cod and nearby southeastern Massachusetts. Even in these locations, we’re talking about a few inches, possibly as much as 5 or 6 inches on the Cape.

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The GFS model is the closest to our thinking in terms of snowfall for late Monday into early Tuesday. Image provided by Pivotal Weather.

The snow ends Tuesday morning, but skies don’t start to clear out until Tuesday night when high pressure starts to build in. This results in a sunny but cold Wednesday. Clouds come right back in Wednesday night as a cold front starts to approach from the west. This will produce some showers on Thursday. The front will move through Thursday night, but the precipitation may linger into Friday morning. As the cold air moves in behind the front, the rain showers may change to snow showers before ending. Some models have tried to slow the front down and have a low pressure area ride along it. This would result in accumulating snow on Friday. While this is possible, most of the models have been trending away from this scenario, so it does not seem likely right now. Obviously, we’ll monitor this over the next few days.

High pressure returns later Friday into Saturday with dry and cold conditions once again. This brings us to Superb Owl Sunday. Another weak system will move across the region during the day. This will likely spread some light snow or rain into the area. Obviously it’s way too early to give amounts, but some accumulations are possible. If this becomes a threat, we’ll let you know later in the week.

GFS 50-STATES USA Mass & CT & RI Wind Chill Temperature 174
Heading outside after the Super Bowl Sunday night? The GFS is forecasting wind chills ranging from 0 to 20 below. Whether or not this verifies remains to be seen. Image provided by weathermodels.com

Monday: Cloudy and breezy, especially along the coast. Light snow developing late in the day, mainly south of Boston. High 33-40.

Monday night: Periods of light snow and snow showers, mainly south and east of Route 495. Accumulations range from a dusting outside of 128, to an inch or so from Boston to Providence, to 1-3 inches across southeastern Massachusetts and southern Rhode Island, and 3-5 inches across Cape Cod. Low 18-25.

Tuesday: Cloudy, snow showers ending by midday. High 27-34.

Tuesday night: Clearing and turning colder. Low 11-18.

Wednesday: Mostly sunny and chilly, clouds move back in late in the day and at night. High 25-32.

Thursday: Cloudy with some showers likely, changing to snow showers at night. High 38-45.

Friday: Snow showers ending early, some clearing late in the day. High 28-35 early, dropping in the afternoon.

Saturday: Partly to mostly sunny. High 20-27.

Sunday: Cloudy with a chance for some light snow or rain. High 33-40.

goats12
The G.O.A.T. has already tamed a Ram, Panther, Eagle, Seahawk, and Falcon to put them in his zoo. Expect a second Eagle to be there next week. Image provided by CBSBoston.

As for that game on Sunday, there’s an old saying – “Eagles may soar, but weasels don’t get sucked into jet engines.” Since most of the nation thinks that the Patriots are weasels, this quote actually applies to the game. The dynasty continues as Brady will hoist Lombardi Trophy #6 after a 27-23 victory over Philadelphia.

Weekly Outlook: January 22-28, 2018

Never in doubt, right? We all knew that the Patriots would come back to win that game, right? You know what is in doubt? What type of precipitation may fall across the interior during the day today.

A backdoor cold front will drop down across the region today, bringing much cooler conditions in. at the same time, moisture and warmer air will stream in aloft. This means we’ll be looking at some occasional showers and drizzle across the region today and tonight. Across interior portions of eastern Massachusetts into southern New Hampshire, temperatures will be near or a little below freezing through the morning, so anything that falls will be freezing drizzle or possibly some sleet. So, if you’ve got to go anywhere in the morning, like work or school, use some caution, as things could be a little slippery. Temperatures will rise into the middle to upper 30s this afternoon, changing everything to plain rain. However, by this evening, temperatures may drop back close to freezing from the Merrimack Valley northward, meaning we could be looking at some more freezing drizzle in spots.

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Some locally heavy rainfall amounts are possible on Tuesday. This combined with melting snow could result in some flooding in some areas, especially ice jam flooding along some rivers. Image provided by WeatherModels.com

That backdoor cold front heads back northward as a warm front late tonight into Tuesday morning, but it will take its time. Temperatures will rise overnight fairly quickly from Boston southward, but points north and west will see temperatures slowly creep up until the front moves through later Tuesday morning. Once it moves through, temperatures will rise into the 40s north and west of Boston, lower to perhaps middle 50s from Boston southward. However, the warmer air will be accompanied by a batch of rain, some which could be locally heavy. Low pressure moving into southeastern Canada will drag a cold front across the region late in the day. This front produced severe weather across parts of the Southern Plains on Sunday. While we’re not expecting severe weather around here, it’s not out of the question that you may see a flash of lightning or hear a rumble of thunder Tuesday afternoon, mainly south of Boston.

That front moves through Tuesday evening, then high pressure builds in for Wednesday, Thursday, and Friday with sunshine along with windy and colder conditions. We’ll start to warm up again on Saturday, but clouds will also stream in ahead of the next storm system. That system will bring us some more rain and mild temperatures Saturday night into Sunday.

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Wind chills will be back into the single numbers Friday morning when you head out the door, so dress appropriately. Image provided by WeatherBell.

Monday: Some freezing rain/drizzle north and west of Boston in the morning, otherwise cloudy with periodic showers and drizzle. High 34-41.

Monday night: Freezing drizzle may return north and west of Boston in the evening, otherwise, occasional showers and drizzle continue. Low 30-37 in the evening, then temperatures slowly rise overnight.

Tuesday: Showers becoming steady rain, possibly heavy at times from late morning into late afternoon. A rumble of thunder can’t be ruled out, mainly south of Boston. Becoming windy, especially in eastern Massachusetts. High 48-55.

Tuesday night: Showers end in the evening, followed by clearing skies. Low 28-35.

Wednesday: Partly to mostly sunny, breezy, and colder. High 34-41.

Thursday: Sunshine and a few clouds, still breezy. High 23-30.

Friday: Mostly sunny, breezy, and chilly. High 27-34.

Saturday: Increasing clouds, breezy, and milder, with showers likely at night. High 41-48.

Sunday:  Showers ending early, followed by clearing. High 46-53.

Finally, just for entertainment purposes, you may recall that right after the Patriots won the Super Bowl in 2015, we had a fairly sizable snowstorm around here the next day. In 2017, right after the Patriots won the Super Bowl, we had another, smaller in scale, snowstorm 2 days later. Well, someone must have let the GFS know that the Patriots won today, because it suddenly has a snowstorm around here the day after the Super Bowl. Given that it’s 2 weeks away, we put absolutely zero stock in this forecast, but we thought you’d find it humorous.

 

Weekly Outlook: January 8-14, 2017

So, has the past week been cold enough for ya? Don’t worry, the cold air is finally departing, and we’ve even got some actual mild air in the forecast. We’ve also got the potential for a wintry mess too, so let’s get to the details.

MonthTDeptNRCC
The first week of January has seen temperatures average 15-25 degrees below normal across most of the Northeast. Image provided by the Northeast Regional Climate Center.

The week starts off with clouds and some snow showers (rain showers across Cape Cod) ahead of a cold front. Don’t worry, we’re not expecting much (if any) accumulation, but the bigger story will be temperatures actually getting into the 30s across the area. It’s going to feel downright balmy compared to the past week. The front moves through tonight, and the snow or rain showers end. High pressure builds in for Tuesday and Wednesday with drier conditions, but temperatures will remain close to where they should be in early January. After that, we jump on a bit of a rollercoaster.

Low pressure will head into the Great Lakes on Thursday while high pressure moves offshore. This means southwest winds will bring unseasonably mild air into the region. Temperatures will get well into the 40s in many locations. We’ll have plenty of clouds, but will anyone care with those temperatures? We didn’t think so. Friday looks to be even warmer, with upper 40s and 50s for much of the region, possibly even close to 60 if you believe one model (see below). It’ll be accompanied by rain and gusty winds, but again, is anyone going to care? It’s going to be mild!

GFS Fri Max
Yes, this is really the GFS forecast for Friday’s high temperatures. Image provided by Weathermodels.com

Saturday is where we get to the real problems. As that initial system moves by, a cold front trailing it will move towards the region while another system moves towards the Northeast from the Tennessee Valley. The question is, and it’s a fairly important one, when does that cold front move through the area?  One model says that it waits until Sunday morning, so Saturday would be another warm, but wet day. Another model brings the front through on Saturday, with cold air rapidly moving in, which means that we could have some freezing rain or a cold rain to deal with across much of the area.  So we could be in the 50s and raining, in the 20s with freezing rain, or somewhere in between. That’s a wide variety of options, and at this point, we’re not sure which way to go. Complicating matters is the fact that the Patriots play the Titans in a playoff game in Foxboro that evening, so the weather could impact the game. Things should start to get a little more clear as the week goes on. Conditions should improve on Sunday, behind the system.

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The various members of the GFS Ensemble show a wide range of possibilities around here Saturday night. Everything is on the table – snow, sleet, freezing rain, rain, or nothing at all. Image provided by WeatherBell.

Monday: Cloudy and breezy at times with a few snow or rain showers possible. High 30-37.

Monday night: Mostly cloudy, some clearing takes place late at night. Low 22-29.

Tuesday: Becoming partly to mostly sunny and breezy. High 33-40.

Tuesday night: Clear skies. Low 10-17.

Wednesday: A sunny start, then skies cloud up in the afternoon. High 31-38.

Thursday: Mostly cloudy and milder with a chance for a few showers. High 44-51.

Friday: Breezy and mild with periods of rain likely. High 50-57.

Saturday: Mostly cloudy with a chance of……something. Quite frankly, that’s about the only thing we’re certain of at this point.

Sunday: Clearing, breezy, and colder. High 29-36.

Thursday Will Not Be a Fun Day

So, as you may have heard from the relentless media hype over the past few days, we’ve got a storm headed our way on Thursday. While this will be an extraordinary storm for places like Florida, Georgia, and the Carolinas, up here, we’ve seen a lot worse.

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Snowfall accumulations of 2-5 inches from northern Florida into eastern North Carolina? That doesn’t happen too often. Image provided by Weathermodels.com

Snow and sleet have been falling today across portions of northern Florida, Georgia, and South Carolina. Several inches are expected to fall today, especially along the coastline. Given how rarely this happens in some of these locations, it will probably bring the region to a halt, while those of us in the North point and laugh. Don’t worry, our time is coming tomorrow.

The storm that is producing the snow down South will move up the East Coast later today and Thursday, rapidly intensifying as it does so. You may have heard the terms “bombogenesis” or “weather bomb” used as part of the media hype in the last few days to describe this storm. These are terms that have been around for quite some time. Bombogenesis happens when the lowest pressure of a storm drops more than 24 millibar in a 24 hour period. This happens several times a year with storms off the East Coast. It is nothing out of the ordinary. The reason this storm is getting the attention, aside from the Southern snow, is that the pressures are much lower than a typical winter storm. This will be a strong storm system, but again, we’ve had powerful storms off the East Coast plenty of times before.

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Definition of “bombogenesis”. It’s a fairly common occurrence. Image provided by Weather.com

As the storm gets cranked up off the East Coast, it will generate strong winds,, especially along the coast. While we’re looking at wind gusts to 40-50 mph, possibly even higher, things could be a lot worse. We don’t have a large high pressure system to our north (more on that in a minute). If we had a high to our north, increasing the pressure gradient between the storm and the high, winds would be even stronger. The tighter the gradient, the stronger the winds. This is why we can have strong winds with weaker systems, if there is a large high in place to the north.

Along with the winds, coastal residents also have to worry about coastal flooding. Since we’re just past the full moon, tides remain astronomically high. Add in strong onshore winds, and residents along north to northeast facing beaches could experience some coastal flooding around the midday/early afternoon high tide on Thursday. By the time we get to the high tide Thursday night, winds will have shifted into the west or northwest, thus limiting the flooding potential.

Back to the high pressure, or lack thereof, to our north. High pressure has been sitting to our north or northwest all week, which is why we’ve been frigid since before New Year’s. That high has shifted offshore now, allowing somewhat milder air to settle in today. Normally, to get heavy snow, we need that high pressure area to stay to our north or northwest, to lock the cold air into place. With that not the case this time, we’re going to have to deal with a rain/snow line. That seems hard to believe given how cold the past week has been, but it is the case. Water temperatures are still in the lower 40s off our coast, so a strong onshore wind will warm up the lowest layers of the atmosphere enough for a change to rain. This seems like across Cape Cod, but the question becomes, how far inland does that rain/snow line penetrate? The models have varying ideas on this, but a portion of southeastern Massachusetts may see a changeover.

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Winter Storm Warning are in effect for virtually the entire East Coast, with Blizzard Warnings (in red) for parts of coastal New England. Image provided by NOAA.

So, we’ve talked about strong winds, coastal flooding, and a rain/snow line. Now, for the only part that most of you are interested in – snow. First, we’ll talk about the timing. Snow should develop from south to north across the region between about 3 and 6am. So, by the time most of you wake up, it will likely be snowing. The snow will end between 7 and 10pm for most of us. The worst of the storm will be between about 9am and 4pm. Snow will be moderate to heavy at times, which combined with strong winds, will create whiteout or blizzard conditions, especially along the coast. If you don’t have to be out tomorrow morning/afternoon, we’d recommend staying where you area. Blizzard warnings have been posted for parts of eastern and southeastern Massachusetts, the NH Seacoast, as well as coastal and Downeast Maine. Remember, the amount of snowfall has absolutely nothing to do with blizzard conditions. You can have a blizzard with no snow falling at all. By definition, you have a blizzard when visibility is 1/4 mile or less due to falling or blowing snow and you have sustained winds or gusts to 35 mph or more for 3 consecutive hours or more.

So, how much snow are we looking at? There isn’t really one model that we completely agree with, so we’re going with a blend of the ideas. Because the storm will be moving along fairly quickly, we’re not looking at any blockbuster amounts. The trickiest part is where the rain/snow line sets up.  Right now, we’re thinking somewhere close to the Cape Cod Canal. As for amounts, here’s the breakdown:

Outer Cape Cod/Islands: 3-5″
Upper Cape Cod: 4-8″
Southeastern Massachusetts (south and east of I95): 8-14″
Northern RI/Interior Eastern Massachusetts/North Shore: 6-12″
Central Massachusetts/Merrimack Valley/Southern NH/Seacoast: 5-9″

The biggest wild card is Southeastern Massachusetts, especially the closer to Cape Cod you get. The farther the rain/snow line moves inland, the less accumulations will be. This is the area of biggest “bust potential”.

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The Canadian HRDPS model is probably closest to our thinking, but not exactly the same. Image provided by WeatherBell.

Once the storm moves by, we’ll slowly clear out on Friday, but gusty northwest to west winds will usher another arctic blast into the region. Saturday may be even colder than any of the days we’ve had over the past week. Especially with fresh snowcover, temperatures will plunge again, with the worst of it on Saturday, when high temperatures likely stay in the single digits. Sub-zero lows are likely across much of the region Saturday morning and especially Sunday morning.