Weekend Outlook: January 14-17, 2022

We’ve got a lot going on over the next few days across the region, and you probably won’t like most of it.

A storm system will develop off the Mid-Atlantic coast tonight, and rapidly strengthen as it heads northeastward, passing well south and east of the region on Friday. However, it will be close enough to spread some rain and strong winds into Cape Cod and possibly southeastern Massachusetts. At the same time, a cold front will drop down from the northwest, ushering arctic air back into the region. This may allow the rain to change to snow before it ends. Temperatures will quickly drop Friday afternoon and evening as gusty northwest to north winds continue to send the arctic air in. Any surfaces that are wet from the rain across southeastern Massachusetts will quickly freeze up Friday afternoon and evening, so keep this in mind if you’re heading out that evening.

Northerly winds may gusts to 35-45 mph on Friday, ushering arctic air into the region. Image provided by WeatherBell.

We’ll drop into the single numbers by Saturday morning, with some subzero lows north and west of Boston. With strong winds, wind chills will be well below zero Friday night and Saturday morning, so dress appropriately if you’ll be outside. Saturday looks to be a day similar to this past Tuesday with sunshine and some afternoon clouds, possibly a few snow showers across Cape Cod, and temperatures struggling to reach the lower to middle teens. Winds die down Saturday night, resulting in another chilly night, with subzero lows possible once again. Sunday starts off with some sunshine, but clouds start to move in during the afternoon as temperatures start to moderate. This brings us to the complicated part of the forecast.

With wind chills like this, Saturday morning will be a good time to stay inside. Image provided by WeatherBell.

Another strong low pressure system will develop across the Southeast and make its way up the East Coast on Sunday. There is still some uncertainty with the exact track that the storm will take, but for now it looks like it may stay near the coast or just inland, passing directly over, or just west, of our area on Monday, though this is subject to change. This track would result in snow changing to sleet and/or freezing rain and then plain rain across much of the area. However, this is far from a guarantee. There are still some models that bring the storm a little farther south and east, which would result in more snow and less rain, but as we’ve mentioned numerous times, the models have been less than trustworthy beyond 2 or 3 days recently. When (or if) a change to mix and/or rain occurs will also have a significant impact on how much snow accumulates. Given the amount of uncertainty, it’s still WAY too early to try and pin down any potential accumulations, but it’s safe to say that the farther north and west of Boston you are, the better the chance you’ll need to fire up the snowblower or find your shovels. We’ll try to post an update this weekend, once we have some better clarity on the storm.

There is plenty of uncertainty in regards to storm for Sunday/Monday. Images provided by Pivotal Weather.

Thursday night: Partly to mostly cloudy, rain may develop across Cape Cod towards daybreak. Low 26-33.

Friday: Mostly cloudy, rain likely across Cape Cod and southeastern Massachusetts, possibly changing to snow before ending, becoming windy. High 35-42, but temperatures will start to quickly drop in the afternoon.

Friday night: Clearing, windy, and much colder, except partly cloudy with a few snow showers across Cape Cod. Low -3 to +4, except milder across Cape Cod and the Islands.

Saturday: Partly to mostly sunny, breezy, and very cold, except partly sunny with a few snow showers across Cape Cod. High 10-17.

Saturday night: Clear skies with diminishing winds. Low -2 to +5, except milder across Cape Cod and the Islands.

Sunday: Sunshine to start the day, clouds move in during the afternoon. High 23-30.

Sunday night: Cloudy and becoming breezy with snow developing, possibly rain across Cape Cod. Low 14-21.

Monday: Snow, possibly changing to sleet/freezing rain/rain, especially the farther south and east you go. High 39-46.

Weekly Outlook: January 10-16, 2022

Dig out the thermals and heavy winter gear, some really cold air is on the way.

Temperatures will turn colder today despite some sunshine, but this is just the opening act for what is on the way. An arctic cold front will cross the region this evening. It may produce some snow showers or squalls, so if you’ll be out this evening, be prepared for a short burst of snow that could significantly reduce visibility and drop a quick coating on the roads. Once the front moves offshore, bitterly cold air will flood into the region for Tuesday and Tuesday night. Temperatures will drop below zero in parts of the region Tuesday morning. Despite plenty of sunshine Tuesday afternoon, highs may struggle to reach the lower teens across most of the area, with wind chills that are below zero. Across Cape Cod, there may not be as much sunshine, as northwest winds blowing over the relatively mild water of Cape Cod Bay could produce some ocean-effect snow showers, especially across the Outer Cape. We’ll have another bitterly cold night Tuesday night, with subzero lows possible once again, but as high pressure slides off to the east on Wednesday, temperatures should start to moderate. It’ll still be chilly, but highs should get into the 30s across the area.

Wind chills could be well below zero Tuesday morning. Image provided by WeatherBell.

Temperatures will turn colder again for the end of the week, but there are bigger concerns. We’ve cautioned you recently that the models have performed rather poorly beyond 2 or 3 days, and that is still the case, so this part of the forecast is highly uncertain. However, many models are showing the potential for a powerful ocean storm to develop late Thursday into Friday, and a second storm to do the same over the weekend. The fact that they all show this gives us a little more confidence that they both may actually develop. The problem is, that’s about all they agree on. They don’t agree on the timing of the storms, the track they might take, how strong they’ll get, and what, if any, impacts they may have up here. These are things that we’ll be keeping a close eye on as the week goes by, but for now, what you read below is our “best guess” (for lack of a better term), but it is very low confidence.

The models all have different ideas about a potential coastal storm on Sunday. Images provided by Pivotal Weather.

Monday: Partly sunny. High 23-30.

Monday night: Partly cloudy and breezy, some snow showers or squalls are possible during the evening. Low -2 to 5 north and west of Boston, 6-13 south of Boston, wind chills could drop to -10 to -20 by daybreak.

Tuesday: Mostly sunny and very cold, except partly to mostly cloudy with some snow showers across parts of Cape Cod. High 8-15, with wind chills below zero.

Tuesday night: Partly cloudy. Low -2 to +5.

Wednesday: A mix of sun and clouds, breezy, and milder. High 31-38.

Thursday: Partly to mostly cloudy. High 35-42.

Friday: Mostly cloudy and breezy, chance for some light snow or snow showers, mainly across southeastern Massachusetts and Cape Cod. High 28-35.

Saturday: Partly to mostly sunny and cold. High 21-28.

Sunday: Plenty of clouds with a chance of snow, especially in eastern Massachusetts. High 28-35.

Weekend Outlook: January 7-10, 2022

Our first snowstorm of the season is on the way for Friday, but it’s just part of a colder pattern we’re heading into for the weekend and beyond.

A variety of advisories, watches, and warnings are in effect across the region. Image provided by the National Weather Service office in Norton, MA.

Low pressure is moving across the Tennessee Valley this afternoon, and it will head east-northeastward, moving off the Mid-Atlantic coast tonight, passing south and east of New England on Friday as it intensifies. We’ll see snow developing before daybreak, and it may fall heavy at times during the morning, which will result in significant problems for the morning commute. The snow should come to an end by mid-afternoon across the region. Based on the trends in the models since last night, we are adjusting our snowfall forecast upwards a bit, but not that much. Here’s our latest projections:

Southern NH: 3-5″
NH Seacoast/Merrimack Valley: 3-6″
MetroWest/I-495 Belt: 4-7″
I/95 corridor/SE Mass/RI: 5-8″
Upper Cape Cod: 3-6″
Outer Cape/Islands: 1-3″

The National Blend of Models is closest to our thinking right now, but it may be a bit on the high side. Image provided by WeatherBell.

The storm pulls away Friday evening, and skies clear out as high pressure builds in, setting up a sunny but rather chilly Saturday, with many places likely staying in the 20s all day. With clear skies and fresh snowcover, temperatures will quickly plunge Saturday evening into the teens and possibly single numbers in some spots. Clouds stream back in late Saturday night as another system moves toward the region. While this system looks a bit milder, with southerly winds warming things up a bit on Sunday, the models have been trending less mild with every run. With that in mind, we’ll probably see some snow showers or a little freezing rain develop north and west of Boston Sunday afternoon, changing to rain by evening. Keep this in mind if you are going to be out and about Sunday afternoon. Elsewhere, just plain rain is expected. The rain may mix with some wet snow before winding down around daybreak Monday. After that, some of the coldest air thus far this winter will pour into the region. Temperatures may not rise much, if at all, Monday afternoon. The coldest weather looks to arrive on Tuesday, when highs may stay in the teens, with subzero lows possible Tuesday night. We’ll have more info on that in our Weekly Outlook early Monday morning.

Tuesday looks like a very cold day across the region. Image provided by Weathermodels.com

Thursday night: Becoming cloudy, snow developing 2-5am. Low 23-30.

Friday: Breezy with snow, possibly heavy at times in the morning, ending 12-3pm. High 28-35.

Friday night: Clearing, colder. Low 11-18.

Saturday: Plenty of sunshine, chilly. High 24-31.

Saturday night: Clear through the evening, clouds start to move back in late at night. Low 10-17, but temperatures may rise a bit after midnight.

Sunday: Cloudy and breezy with showers likely in the afternoon, possibly starting as snow or freezing rain north and west of Boston. High 37-44.

Sunday night: Showers changing to snow showers before ending by daybreak. Low 22-29.

Monday: Becoming partly to mostly sunny and colder. Temperatures hold steady or drop a bit during the day.

Weekend Outlook: June 4-7, 2021

The first weekend of meteorological summer is upon us, and it’ll certainly feel like summer around here.

A warm front will move across the region this afternoon, and as an upper-level disturbance swings through tonight, those two will combine to bring in some showers and thunderstorms. While a few of them may produce some heavy rain near the South Coast, most of us shouldn’t see that much rain tonight. Another upper-level disturbance crosses the region on Friday accompanying a dying cold front. This will produce another round of showers and thunderstorms, mainly during the afternoon and evening. A few of these storms could produce downpours and gusty winds.

Last weekend’s rain erased the developing drought for much of southern New England. Image provided by the National Drought Mitigation Center.

Once everything moves offshore Friday night, high pressure builds back in for the weekend and Monday. We’ll dry out on Saturday and with developing sunshine, temperatures should get well into the 80s away from the South Coast. For Sunday and Monday (and into the middle of next week), we’ll have a Bermuda High in place, which means southwest winds pumping very warm to hot and humid air into the region. Temperatures will be near or just above 90 for most of us on Sunday, and on Monday, highs will reach the lower to middle 90s, perhaps even some upper 90s, which will be close to the record highs for much of the region. While it won’t be as humid as it normally is deeper into the summer, it’ll be fairly humid by early-June standards, with dewpoints in the 60s, meaning that it will feel like mid to upper 90s during the afternoon.

Monday is looking rather toasty. Image provided by Weathermodels.com

Thursday night: Cloudy with a few showers or a rumble of thunder, mainly along the South Coast. Low 59-66.

Friday: Plenty of clouds with some showers and thunderstorms possible, mainly during the afternoon. High 74-81, a little cooler along the South Coast. Offshore: Southwest winds 15-20 knots, gusts to 30 knots, seas 3-6 feet, visibility 1-3 miles in showers and fog UV Index: Moderate. Water temperatures are in the upper 50s to near 60.

Friday night: Showers and storms taper off during the evening, some clearing possible late at night. Low 56-63.

Saturday: Becoming partly to mostly sunny. High 83-90, cooler along the South Coast. Offshore: Southwest winds 15-25 knots, gusts to 30 knots, seas 3-5 feet, visibility 1-3 miles in morning fog. UV Index: High.

Saturday night: Partly cloudy. Low 64-71.

Sunday: Sunshine and a few clouds, becoming humid. High 88-95, cooler along the South Coast. Offshore: Southwest winds 10-15 knots, gusts to 25 knots, seas 2-4 feet, visibility 10 miles or better. UV Index: Very High.

Sunday night: Clear skies. Low 64-71.

Monday: Partly to mostly sunny. High 90-97, cooler along the South Coast. Offshore: West to southwest winds 10-15 knots, gusts to 25 knots, seas 2-4 feet, visibility 10 miles or better. UV Index: Very High.

Weekend Outlook: January 29-February 1, 2021

Bond villian Elliot Carver said it in “Tomorrow Never Dies”, but it’s appropriate for the forecast for the next several days – “Let the mayhem begin”

We start off with a developing low pressure system well offshore tonight. The system will continue to strengthen, but also continue to pull away, so it won’t directly impact us. However, it will produce northerly winds around here that will serve two purposes. First, they’ll continue to produce some ocean-effect snow across parts of eastern Massachusetts and the New Hampshire Seacoast, and second, they’ll usher in some of the coldest air thus far this winter.

Low pressure well south of New England shows up nicely on satellite imagery this afternoon. Loop provided by NOAA.

First, we’ll look at the ocean-effect snow. It’s been ongoing since early this morning, and will continue off and on into this evening. While it won’t amount to much for a good chunk of the region, right along the coast, especially Cape Ann, coastal Plymouth County, and Cape Cod, could see an inch or two in spots. On Friday, a disturbance rotating around the ocean storm will bring some more ocean-effect snowfall back into Cape Cod. This could result in additional accumulations, especially across the Outer Cape, where a few inches is possible.

A few inches of snow may accumulate across the Outer Cape over the next day or two. Image provided by Weathermodels.com

Back to the cold air. This past week has been rather chilly compared to the rest of January, but temperatures have only been near to a little below normal. That’s going to change tonight and this weekend. Skies will start to clear out tonight (except for Cape Cod), and it’s going to get cold. Temperatures will likely drop into the single numbers for much of the region tonight, but it will remain quite breezy, so we’re looking at wind chills of 10 to 20 below zero Friday morning. Wind Chill Advisories have been posted from Worcester County westward, but even without the advisory, you should know enough to dress warmly if you have to go outside.

Bundle up before you head outside Friday morning because it’s going to be chilly. Image provided by WeatherBell.

Friday looks rather chilly as well. Some clouds may move in from the ocean, but even in places where the sun is out, it’ll still be breezy and cold, with daytime highs only in the teens to lower 20s. Skies clear out again Friday night and winds will start to diminish, so we’re looking at another cold night, with some places possibly dropping below zero. Saturday should feature a lot of sunshine, but it will still be cold, with highs only in the upper teens to lower 20s. After another bitterly cold night Saturday night, temperatures should start to moderate a bit on Sunday, but we’ll also see clouds starting to move back in ahead of another storm system heading this way. This brings us to Monday.

For several days now, most of the forecast models have been showing the potential for a storm system to impact the Northeast early next week. They’ve bounced around with the details on strength, timing, and track, but in general, there’s been a fairly strong signal that something is going to happen around here after we flip the calendar to February. Well, that signal hasn’t gone away, and the Universal Hub website has upgraded to a Level 2 on the French Toast Alert System. In other words, don’t worry just yet. However, knowing how the media can be around here, and knowing what the models are showing, we’re issuing our own Extreme Hype Watch. An Extreme Hype Watch is issued when conditions are favorable for media hype of an event to reach extreme levels within the next 48-72 hours. If conditions warrant, a Hype Advisory or Extreme Hype Warning will be issued as the event draws nearer.

As for the system itself, there are still plenty of questions that need to be answered. We’ll have a large high pressure area in eastern Canada keeping some cold air in place. It’s not quite in the ideal position for a big storm here, but it is there. We’ll have a low pressure system moving through the Midwest that will redevelop over the Mid-Atlantic states, then head northeastward, likely passing south and east of New England, close to the “benchmark”. The benchmark is at 40 degrees North latitude and 70 degrees West longitude, about 90 miles south of Nantucket. Storms that pass over that spot are usually (but not always) in a prime position to deliver heavy snow to much of the region. Storms that pass north and west of there usually end up with a rain/snow line farther inland, and storms that pass south and east of there don’t always deliver snow far inland. This is more of a general rule than an absolute, but it’s something we look for. The other issue we have is that an upper-level low pressure area will be moving in, and the storm may get stuck underneath it, which could stall it out or have it meander around south of us for a day or so, which would result in an extended period of precipitation.

In addition to the models, another tool we use is analogs. You will most often hear about these in relation to a seasonal pattern or a hurricane season, but we can also use them for individual storms. Basically, we compare the pattern to previous setups, and see how it compares, and see what those previous setups produced to give us an idea of what is possible. Now, these analogs are run compared to the forecast of one model, so if that model isn’t the one your using, then the analogs might not be of much help. Based on the midday run of that model, the best analog for the pattern early next week is the storm of January 26-28, 2015. You may recall that storm received an extreme amount of media hype, and did produce very heavy snow around here, but was considered a “bust” in New York City, where the actual amounts fell well short of the forecast. It also was the storm that essentially kick-started our 6-week snow blitz (and also was responsible for the formation of the original StormHQ Facebook page). Using the Top 15 analogs for the forecast pattern, here’s the average of snowfall from those 15 systems:

Analog snowfall forecast for Monday-Tuesday. Image provided by the Cooperative Institute for Precipitation Systems (CIPS).

As you can see, there is a signal for a significant snowstorm, which is why we’re going to be monitoring this closely for the next several days. We’re not going to post any model snow forecasts yet because there’s still too much uncertainty. We’ll let the media and Facebook Forecasters take care of that. If conditions warrant, we’ll issue another blog post either Saturday or Sunday as the details become more clear.

Thursday night: Mostly cloudy along the coast with a few snow showers across the Cape, clearing inland, breezy. Low 1-8.

Friday: Intervals of clouds and sun, more snow showers across Cape Cod, windy. High 13-20.

Friday night: Lingering clouds across Cape Cod, clear elsewhere, still breezy during the evening. Low 2-9.

Saturday: Plenty of sunshine, except for some clouds across the Outer Cape. High 16-23.

Saturday night: Clear skies. Low 0-7.

Sunday: High clouds stream in. High 22-29.

Sunday night: Thickening clouds. Low 12-19.

Monday: Cloudy and breezy with a chance of snow (or possibly rain south of Boston) High 30-37.

Record Heat and Cold, Snowstorms, Droughts, and Tropical Storms – What’s Next?

September is when we start to transition from Summer to Winter, but this September is starting off with a bang.

Intense heat has been common across much of the West for the past few days. Temperatures well over 100 degrees were widespread during Labor Day Weekend, especially across California, with numerous records set. One location, Richmond, on the eastern side of San Francisco Bay, reached 107 degrees Monday afternoon, tying their all-time record, originally set on September 15, 1971. Several other locations set monthly records for September as well. The worst of the heat has passed, but it will remain hot on Tuesday, with highs likely topping 100 across much of interior California and the Desert Southwest, possibly setting a few more records. Temperatures should gradually cool down a little more as we get toward the middle and latter portion of the week.

Another hot day is likely across interior California on Tuesday. Image provided by WeatherBell.

Heat was also common across the Plains and Rocky Mountains over the weekend, but big changes are developing thanks to a strong cold front. Denver set a record high of 97 on Sunday, then reached 93 on Monday. On Tuesday, that 93 will get reversed, with a daytime high closer to 39 (The high for the calendar day will be the 46-degree reading at midnight). On top of that, accumulating snow is likely. Even by Denver standards, this is quite early in the year for snow. Their all-time record for earliest snow is September 3, 1961, but on average Denver doesn’t see its first flakes until October 18. This won’t be the 1st time that Denver hit 90 one day and then had measurable snow the next. On September 12, 1993, Denver recorded a high of 92 degrees, and on September 13, they had 5.4″ of snow.

While a few inches of snow are likely in Denver and onto the adjacent High Plains of eastern Colorado and western Nebraska, heavier snow is likely across the mountains on Colorado and Wyoming. Across the higher elevations, snowfall totals in excess of a foot are likely. While the snow will likely last a while in the mountains, at the “lower” elevations on the Plains, it will disappear quickly. High temperatures in Denver will be back into the 60s by Friday, and near 80 by the end of the weekend.

Heavy snow is likely in the higher elevations of the Rockies. Image provided by the College of DuPage.

While the snow will get a lot of the headlines, the cold air behind the front will be making headlines of its own. The first frost and freeze of the season is likely across parts of the Dakotas, Montana, and northern Minnesota Tuesday and/or Wednesday morning, with lows in the upper 20s and 30s. The cold air will continue to push southward across the Great Plains during the day on Tuesday, with numerous record lows expected Wednesday morning as far south as the Texas Panhandle. The cold air will eventually spread eastward, but will be modified significantly before it reaches the Eastern United States.

Record lows are likely across the Plains and the Rockies Wednesday morning. Image provided by Weathermodels.com

While plenty of (frozen) precipitation is expected across the Rockies, the lack of precipitation is causing problems across the Northeast, specifically New England. Aside from a few showers with a cold front on Thursday, generally dry weather is expected across much of New England this week, and things don’t look that promising for much of next week either. This shouldn’t be a surprise, as precipitation has been generally below to well below normal across the region since the Spring. In some areas, the amount of rain has only been around 50-60% of normal since April 1. Drought conditions have developed across nearly all of New England, and for a good portion of the region, it is now considered a severe drought. What the region needs is a series of systems that can produce moderate rainfall to help alleviate the drought (too much at once won’t help that much), but prospects for that aren’t promising at this time. In fact, rainfall looks to remain below normal for much of the remainder of September.

Drought conditions are worsening across New England. Image provided by the National Drought Mitigation Center.

Meanwhile, as we approach the climatological peak of hurricane season, the Atlantic is once again getting more active. Tropical Storms Paulette and Rene both developed on Monday in the central and eastern Atlantic respectively. Paulette is expected to remain a tropical storm for the next several days while remaining over open water. It is not expected to be a threat to land. Meanwhile, Tropical Storm Rene moved into the Cabo Verde Islands Monday night and early Tuesday, producing heavy rain and gusty winds. It will likely strengthen over the next couple of days, possibly becoming a hurricane later this week. Once it pulls away from the Cabo Verde Islands, it is also expected to remain over open water for much of this week, presenting no additional threat to land.

Satellite loop showing Tropical Storms Paulette and Rene in the central and eastern Atlantic. Loop provided by Tropical Tidbits.

Those systems aren’t the only ones in the Atlantic that are being watched. An area of low pressure a couple of hundred miles west-southwest of Bermuda is expected to drift westward or northwestward over the next day or two. Some development of the system is possible. It may bring some rainfall into parts of the Carolinas and Southeast later this week. The other area that is being watched isn’t immediately apparent right now, as it is still over western Africa. A tropical wave is expected to emerge from the west coast of Africa later this week. Forecast models show the potential for this wave to develop rather quickly once it moves into the Atlantic. It could threaten the Cabo Verde Islands over the weekend.

The peak of hurricane season is during the middle to latter half of September. Given how active this season has been so far, there will likely be more systems developing. There are only 4 names left on this list for this season – Sally, Teddy, Vicky, and Wilfred. Once the list is exhausted, the Greek alphabet is used. This has only happened once before – in 2005. During that season, there were 28 named storms of which 15 became hurricanes.

Weekly Outlook: July 27-August 2, 2020

Heat and humidity continue across the region for a couple more days before relief arrives on Wednesday.

Heat Advisories are in effect for much of the region for today and Tuesday. Image provided by Pivotal Weather.

A ridge of high pressure remains in control, so stifling heat and humidity will remain in place until Tuesday. Today looks to be the hottest day, with temperatures well into the 90s. A few places could reach 100, but triple-digit heat shouldn’t be widespread. It will be very humid as well, sending the heat index well above 100 across the region, but dewpoints may actually drop a bit during the afternoon. Tonight will be downright uncomfortable without air conditioning, as low temperatures will only drop into the middle to upper 70s in many areas, and some urban areas, especially Boston, may not drop below 80.

Temperatures may struggle to drop below 80 in some spots Monday night. Image provided by WeatherBell.

Tuesday will start off very warm and humid, so it won’t take much to send temperatures above 90 once again, but clouds will also start to increase in the afternoon as a cold front approaches the region. This front may produce a few showers and thunderstorms late in the day and at night. Some of these storms may produce some heavy downpours and gusty winds, but we’re not expecting widespread severe weather.

There is a marginal risk for severe weather on Tuesday across the region. Image provided by the Storm Prediction Center.

The front slides offshore early Wednesday, then high pressure builds in for the rest of the week and into the weekend. It be a bit cooler, but still near to a little above normal for the end of July, but the more noticeable effect will be that it is drier, with dewpoints only in the 50s to lower 60s.

Monday: Sunshine and some high clouds around, hot and humid. High 92-99.

Monday night: Clear to partly cloudy. Low 72-79.

Tuesday: Sunny early, then clouds move in with some showers and thunderstorms possible late in the day. High 90-97.

Tuesday night: Showers ending during the evening, though possibly lingering for much of the night near the South Coast. Low 67-74.

Wednesday: Lingering clouds along the South Coast early, otherwise becoming partly to mostly sunny and not as humid. High 85-92.

Thursday: Sunshine and some afternoon clouds. High 83-90.

Friday: A mix of sun and clouds. High 81-88.

Saturday: Partly to mostly sunny. High 81-88.

Sunday: Partly sunny. High 82-89.

Model forecasts for the track of a tropical disturbance in the Central Atlantic. Image provided by WeatherBell,

Finally, we’ll mention the tropical disturbance in the Central Atlantic, since the hype train is already getting set to leave the station. Yes, there are a few models that show a potential threat to the East Coast in about 7-10 days. These should be treated the same as model forecasts in January that show a raging blizzard 7-10 days out. The probability of it happening is still fairly low. The system itself hasn’t even become a tropical depression yet. That may occur later Monday or Tuesday. If (when?) it does, we’ll write a blog post about the storm and it’s future. For now, it has our attention, but that’s it.

A Chilly Weekend is Coming, a Little Snow too?

By now, you’ve heard the TV meteorologists talking about how it’s going to snow, or you’ve read the headlines about an “historic May snowstorm” that’s coming. As usual, we at Storm HQ will avoid the hype and just give you the facts. Yes, there will be some snowflakes around here and no, it won’t be a big deal at all.

A cold front is moving across the Great Lakes this afternoon, and it move across our area tonight, with plenty of clouds and possibly a few showers. Behind that front, much colder air will start to move into the region. This is an anomalously cold airmass for early May, and in fact, is more representative of early March. That front is expected to stall out near the South Coast, and then a wave of low pressure will develop along the front and ride along it, crossing southern New England Friday night and early Saturday.

The ECMWF model shows the progression of the system for Friday into Saturday. Loop provided by Pivotal Weather.

We’ll have some rain moving in Friday afternoon and evening, but as the sun sets and temperatures drop, some wet snow will start to mix in. The most likely spots for snow are in the hilly terrain from northern Rhode Island across Worcester County and into the Monadnocks of southwestern New Hampshire, as well as out in the Berkshires. However, we wouldn’t be surprised if there was some wet snow mixed in with the rain even into the suburbs of Boston.

As we mentioned with the last few storms, it’s awfully tough to get accumulating snow into early May for a variety of reasons. For one, the ground is fairly mild. Any accumulations will be mainly on grassy surfaces, as pavement temperatures are much too warm now. Secondly, temperatures may not even drop to freezing, but could stay in the middle to upper 30s. Third, the intensity of the precipitation will be key. Heavier precipitation will bring down colder air from aloft, resulting in the change to snow, whereas light precipitation will tend towards more rain.

As far as accumulations, as we said, we’re not expecting this to be a big deal for most of us. You may wake up Saturday morning, if you’re up early enough, to see a little bit of a coating on grassy surfaces, decks, and car roofs/windshields. As we mentioned, most of the accumulations will be confined to the hilly terrain, where a few inches could fall.

Snow is fairly rare once you get into May. Using data for Lowell, snow has been recorded 5 times during the month of May over the past 92 years, and measurable snow only twice.

5/11/1945 – Trace
5/1/1953 – Trace
5/10/1977 – 2.6″
5/6/1996 – Trace
5/18/2002 – 1.0″

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

The snow is only part of the story though, and in fact, a minor part. As the storm intensifies while pulling away on Saturday, gusty winds are expected across the area. West winds of 15-25 mph with gusts of 40-50 mph are expected, especially along the coast. At the same time, an upper-level low pressure area will be moving into the region, bringing in very cold weather. That upper low may trigger a few rain or snow showers in the afternoon, but the cold temperatures will be the story. High temperatures likely will stay in the 40s, which may set records for the lowest high temperatures for the date in many locations.

Record low high temperatures are possible across parts of the region on Saturday. Image provided by Weathermodels.com

The really cold weather will be short-lived, as we will start to moderate on Mother’s Day as high pressure builds in. However, if you’re hoping for some sustained warmth, it’s not coming anytime soon. There are some hints that we may get out of the pattern that’s kept us quite chilly for most of April and early May in another 10 days or so, but a “warm” pattern is still a ways off.

Temperature forecast for the next 45 days for Bedford, Massachusetts based on the 51 members of the ECMWF Ensemble forecast. Image provided by Weathermodels.com

The image above is the high and low temperature forecast for Bedford for the next 45 days, based on the ECMWF Ensemble, which has 51 separate members. The solid red and blue lines in the middle of each graph are the “normal” highs/lows for each day. The green dot is the average of the 51 members for each day (which is also represented numerically in the middle of the 2 charts), and the shaded gray area is the area that between 1/4 and 3/4 of the members fall. The horizontal blue lines above and below that are the extreme on each day. As you can see, this model is forecasting temperatures to remain well below normal through May 14-15. After that, temperatures generally average near or a little below normal until June 9. Granted, “normal” for those dates is upper 60s to near 70 for high temperatures, so it’ll be milder, but still a little cooler than we should be. Finally, we get to near or a little above normal for a sustained period around June 10. Now this is just one model, so take it with a grain of salt, but it’s done fairly well diagnosing the general details of our weather pattern for several weeks now. There is hope that you can finally take your summer clothes out of storage, perhaps as early as next weekend.

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.

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.