Thursday 1.27.22 PM Update on Saturday 1.29.22 Storm

Good evening! Quick update on the storm. A bit has changed, so read on.

Hazards: Heavy snow causing travel disruptions. Gusty winds will cause a risk for isolated power outages, as well as likely some periods of blizzard conditions.

Timing: Snow begins in the early morning hours Saturday before sunrise. The heaviest snow will occur from late morning/midday into the evening hours, winding down by late evening and ending completely by midnight.

Amounts: Over the course of the day, one thing has become obvious: we are shifting to a major and potentially blockbuster snowstorm. In fact, this forecast – which I produced collaboratively with some UML classmates – may already be too conservative, as the late-evening model runs are going insane.

I would like to see the overnight guidance before committing to any further increase of totals, but here we go: I am forecasting a widespread 15-25″ of snow in eastern MA and southeast NH, with some towns potentially breaking 30″ in the heaviest snow bands. The snow will be generally very light and fluffy, though south of Boston it may get a bit heavier as temperatures will be a bit warmer. (The reduced fluff factor south of Boston is made up for by higher liquid-equivalent precipitation amounts.)

The next 24-36 hours will be critical for honing in on where the bands are likely to set up (more in the uncertainty section). Further to the west, expect a decrease in totals (though even now, it looks like I may need to shift some of the heavier totals to the west; I will wait until the morning to make any further drastic changes).

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Uncertainty: Well, well, well … the last 12 hours have been something. This evening, the remaining eastern-leaning guidance caved to further west solutions. It’s shaping up to be all-systems-go for a blockbuster storm, potentially of a historic nature. I’m not fully committing yet, but it won’t take much at this point. It seems likely that some towns will rocket past the 25″ ‘maximum’ on the map; the best chance is south of Boston but some guidance is hinting at a secondary maximum north and west of the city. This should hopefully become clearer over the next 24-36 hours. It’s not out of the realm of possibility that some places could see 30-45 inches of snow, as there is some possibility of extreme banding. I’m leaving it off the map for now, in part because the track could still wiggle a bit. Even then, barring a drastic change, I’m very confident we will see over a foot of snow in our area and likely quite a bit more than that. Right now, the bust scenario is just a regular large snowstorm.

Elsewhere on the map, the main question marks are western New England and Cape Cod/the Islands. Starting with western New England, the westward shift puts those areas in play for heavy snow; some guidance is still keeping totals limited out that way. The majority of models have caved toward a heavier solution even in that region, but just to be safe I will wait to make further changes. With regard to Cape Cod and the Islands, they are running the risk of the system coming so far west that it could make the snow very heavy and wet or potentially even mix with rain; this low ratio snow would cut back on totals a bit. The point here is that there’s still some work to be done on the edges, and the forecast will be refined more over the next 24-36 hours.

-Nathan

Thursday 1.27.22 AM Update on Saturday 1.29.22 Storm

Good morning!

Here’s a look at our incoming storm. Note that amounts may shift a bit – read on for more details.

Hazards: Heavy snow causing travel disruptions. Gusty winds will cause a risk for isolated power outages, as well as potentially some periods of blizzard conditions.

Timing: Snow begins in the early morning hours Saturday before sunrise. The heaviest snow will occur from late morning/midday into the evening hours, winding down by late evening and ending completely by midnight.

Amounts: This is where the forecast gets interesting. As of now, my forecast is for 10-18″ of snow for much of eastern Massachusetts, with less to the west. This will be a very fluffy snow, so the snow totals will likely be a bit higher than the normal 10:1 snow ratios you may see on some model projections. I will discuss the model uncertainty in the next section, since these amounts may shift a bit.

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Uncertainty: Where do I begin with this section?? The only truly certain thing is that we will (probably) see over 6 inches of snow as a coastal storm strengthens passing off the southeast coast of New England. One major model suite – the GFS and its ensembles – have a storm track further to the snow, which would give us less snow and a more run-of-the-mill snowstorm. (A run of the GFS last night had us getting almost nothing, with its ensembles having a similar idea).

However, every other model (and associated ensemble models) has us getting at least 9″ of snow. I don’t think the GFS is handling some of energy that will cause this storm very well, given the gulf between it and other models. It can’t be fully ruled out, of course, but I’m going with the model consensus of a more westerly track. However, some models are more to the west than others. Once you adjust for higher-ratio snowfall, some models project the potential for over 2 feet of snow, with others calling for a more modest but still sizable snow in the 10-15″ ballpark for the Lowell/Dracut area.

Still another point of uncertainty that follows this line of thinking is the western edge of the snowfall, and how sharp it will be. This likely won’t matter in eastern MA and southeast NH, but it may be an issue for the forecast in central/western MA and southwest NH. It’s possible that the western snowfall gradient could be a lot tighter than my forecast shows; this is a point of contention where there isn’t a consensus among models.

The long in the short here is that a massive snowstorm isn’t off the table and neither is a run-of-the-mill snowstorm, but right now I think a middle-of-the-road solution is more likely.

I’ll update this tonight as necessary.

-Nathan

Friday 12.17.21

Good evening everyone! We are within 24 hours of the onset of our first notable snow of the season. Below is what you need to know!

Precipitation Type
This will be a very tough storm to predict the exact precipitation type. At this point, it looks like snow will change to a mix with sleet/rain or potentially pure rain, but the exact changeover time, the amount of mixing, and other variables are up in the air. As of now, though, it looks like the Lowell area will see at least some accumulating snow of note. This uncertainty is because a warm layer aloft will cross above southern New England, but only reach as far north as somewhere near the MA/NH border. Unfortunately for the Lowell area, this means a tougher forecast, as we will be right near the edge of significant mixing. Recent trends favor the mixing reaching into southern New Hampshire. There is at least an outside chance of some freezing rain, but the highest risk for freezing rain will be in central and western MA. 

Timing and Impact
Flurries are possible Saturday morning, but any snow of note will begin by midday Saturday. Precipitation will have the most impact on travel Saturday afternoon and evening, but won’t end completely until around sunrise Sunday. The good news is that given the long duration of the system, the precipitation won’t be overly heavy, though it will be enough to cause travel impacts (especially Saturday afternoon and evening when precipitation is likely to peak). Barring any impacts from freezing rain, the travel impact won’t be major, but it will make things quite slow nonetheless. Mixing with sleet may make roads especially slick. If you have to be out on the roads, make sure to take it slow and leave plenty of distance.

Amounts
There is some uncertainty here given the extent of mixing is still up in the air. That said, a general 2-5″ looks likely in the vicinity of the MA/NH border, including Dracut. Given recent trends that favor more mixing, I currently expect the lower half of the range to verify, but amounts will rapidly increase just to the north

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a widespread 5-8″ snow is likely for much of New Hampshire, Vermont, and western Maine. Further to our south, meanwhile, amounts will drop off quickly as mixing and rain become more dominant. Any snow in most locations will be heavy and wet (with the possible exception of far Northern New England).

I’ll likely have one final call tomorrow morning on this system. Changes are still possible, so stay tuned.

-Nathan

Thursday 12.16.21

Good evening everyone! It looks like we have our first notable snow event of the season on the horizon. Below is what you need to know!

Precipitation Type
This will be a very tough storm to predict the exact precipitation type. At this point, it looks like snow will most likely eventually change to a mix with sleet/rain or potentially pure rain, but the exact changeover time, the amount of mixing, and other variables are up in the air — and a mostly-snow solution is also possible, as is a solution with very little snow. As of now, though, it looks like the Lowell area will see at least some accumulating snow of note. This uncertainty is because a warm layer aloft will cross above southern New England, but only reach as far north as somewhere near the MA/NH border. Unfortunately for the Lowell area, this means a tougher forecast, as we will be right near the edge of significant mixing. There is at least an outside chance of some freezing rain, but the highest risk for freezing rain will be in central and western MA. 

Timing and Impact
Snow will begin by mid- to late-morning Saturday. Precipitation will have the most impact on travel Saturday afternoon and evening, but won’t end completely until around sunrise Sunday. The good news is that given the long duration of the system, the precipitation won’t be overly heavy, though it will be enough to cause travel impacts (especially Saturday afternoon and evening when precipitation is likely to peak).

Barring any impacts from freezing rain, the travel impact won’t be major, but it will make things quite slow nonetheless. If you have to be out on the roads, make sure to take it slow and leave plenty of distance.

Amounts
There is some uncertainty here given the extent of mixing is still up in the air. That said, a general 2-5″ looks likely in the vicinity of the MA/NH border, including Dracut. It’s a fair question as to whether we will be on the lower or higher end of the range; it’s too early to sort that out. To the south, expect a quick drop-off to little/no snow as mostly rain is likely south of the Mass Pike as well as along much of the coastal plain. Especially locally, amounts could decrease dramatically with only a slight change in the track of the system.

To our north, a widespread 5-8″ snow is likely for much of New Hampshire, Vermont, and western Maine. The snow in most locations will be heavy and wet; however, if you are headed up to far northern New England (north of Concord, NH), the snow will be a bit fluffier up that way. (The amounts will be similar though, because the fluff factor to the north compensates for lower liquid equivalents).

Another update will be posted by tomorrow evening. The situation will continue to evolve, so stay tuned!

-Nathan

Monday 10/25/21

Good morning! We’ve got a garbage weather week ahead by most standards, with lots of rain and periods of gusty winds.

Expect rain throughout this morning, giving way to cloudy skies; the high will be around 50, with a northeast wind at 5-10 mph. Tonight will be cloudy and 46, with rain after midnight, and a northeast wind of 5-10 mph, as an early-season Nor’Easter begins to affect the area.

Tuesday will be cloudy and 54, and Tuesday night will be cloudy and 47. Expect largely continuous rain throughout the timespan, and a northeast wind of 10-20 mph, with gusts up to 35 mph possible. Expect somewhere between 2″ and 4″ of rain by Wednesday morning (with a slight chance we could exceed 4″); as a result, flooding issues are a strong possibility Tuesday into Wednesday. Remember to avoid flooded roadways – turn around, don’t drown! Additionally, given the strong wind gusts, some minor wind damage and scattered power outages are possible. The risk is a little higher than normal for a wind event like this, given most trees are still fully leaved; however, the highest chance for power outages and wind damage will be to our south and east, where gusts over 50 mph are likely.

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The steady rain wraps up Wednesday morning, with cloudy skies in its wake. A few showers are possible Wednesday afternoon and evening as well, with a high around 53. Clouds will decrease Wednesday night, with a low around 41. Thursday is hands-down the pick of the week, with a high around 55 and mostly sunny skies. Thursday night will have increasing clouds, with a low around 39. Friday will be mostly cloudy and 53, with a chance of rain in the evening with a system that doesn’t look too intense, but will be enough to likely make the whole weekend crappy.

Hey, it could be worse. October 29th (Friday) and October 30th (Saturday) have been littered with numerous high-end New England weather events in recent history. The 1991 Perfect Storm, the 2011 Snowtober storm, Hurricane Sandy in 2012, and a wind and rain event in 2017 (that knocked power out for 80% of Dracut electric customers) all impacted our area on October 29 and/or October 30. We also saw an early-season snow event on October 30 last year that wasn’t particularly impactful, but impressive by October standards with a widespread 4″+ of snow. It appears this weekend will not be like any of those systems.

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Have a great day!
-Nathan

Wednesday 9.29.21

Good morning!

With mostly sunny skies, expect a high around 64 today, with a north-northwest wind at 5-10 mph; gusts up to 20 mph are possible. Tonight will have increasing clouds, with a low around 45, and a northwest wind around 5 mph.

Thursday will be partly cloudy and 61, with a slight chance of showers around midday, and a northwest wind of 5-10 mph. Thursday night will be mostly clear, with a low around 41, and a light northwest wind.

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Friday will be mostly sunny and 64; Friday night will be mostly clear and 42. Saturday will be mostly sunny and 65; Saturday night will have increasing clouds, with a low around 49. Sunday will feature mostly cloudy skies, with a high around 65 and a chance of showers.

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Have a great day!
-Nathan

Monday 9.13.21

Good morning!

With mostly sunny skies, expect a high around 78 today, with a west-northwest wind of 5-10 mph. Tonight will be mostly clear and 52, with a light north wind. Tuesday will be mostly sunny and 74, with a light wind – initially coming from the north, but shifting to the south throughout the day. Tuesday night will feature increasing clouds, with a low around 62, a chance of a scattered shower late, and a south wind around 5 mph.

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Wednesday will be partly sunny and 83, with a chance of afternoon thunderstorms. Showers are possible Wednesday night, with a low around 64. Thursday will be mostly cloudy and 71, with a chance of showers. The shower threat continues into Thursday night, with a low around 60. Showers are likely Friday, with a high around 72.

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Have a great day!
-Nathan

Tuesday 9.7.21

Good morning!

With sunny skies, expect a high around 79 today, with a west wind of 5-10 mph. Tonight will be clear and 57, with a light southwest wind.

Wednesday will be mostly sunny and 83, with a south wind of 5-15 mph. Wednesday night will have skies turning cloudy, with rain likely late, a low around 66, and a southwest wind of 5-15 mph.

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Going into Thursday, rain is likely for much of the day, with a high around 74; embedded thunder is also possible. Showers are possible early Thursday night, giving way to clearing skies with a low around 56. Friday will be sunny and 73, Friday night will be clear and 53, and Saturday will be sunny and 75.

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Have a nice day!
-Nathan

 

Wednesday 9/1/21 – Significant Flooding Possible Tonight

Good morning! For those of you visiting my site from the UML Weather Center social media pages (due to the continued outage of the Weather Center site), welcome back to campus, Riverhawks!!! I’m Nathan Coram, co-President of the AMS student chapter and a senior in the meteorology program. This is my local forecasting site I’ve been using for 6 years now (to the day, actually!), and I’ve used this a few times as a stand-in for the Weather Center blog and forecast site this summer. That site was knocked down by the IT outage in June, and is just passing its final security checks in the coming days. The site will then be brought back online for the public to use.

With mainly cloudy skies, expect a high around 72 for today, with a mainly calm wind. The remnants of Hurricane Ida will deliver a significant impact to our area this evening into tomorrow morning. Far and away, the main impact will be heavy rain. Rain begins this evening, which could cause some issues for the evening commute. The heaviest rain will be overnight tonight into the morning commute tomorrow, before winding down.

Expect 2 to 5 inches of rain, with a newly increased likelihood of reaching the higher end of that range as forecast trends bring heavier rain further north. Some locations in Southern New England will likely see 5-8″ of rain, but the best chance of that is south of the Mass Pike. Flooding impacts are likely tonight and tomorrow morning; there is a possibility of a major impact for the morning commute tomorrow. Given the high amount of rain in a relatively short amount of time (combined with the overall rainy stretch we have been in), expect smaller bodies of water to rise fast. Urban area, poor-drainage area, and small stream flooding could be very serious. The possibility exists for flooding in some smaller rivers as well. Some basements may even flood, so have a plan to handle water in the basement. The highest risk of serious impacts remains south of the Mass Pike; however, the risk of a serious impact covers all of Southern New England and potentially the southern tier of Northern New England. Overall, this could be a very serious flooding event, so be prepared NOW for possible disruptions!

Gusty winds are also a possibility tonight and tomorrow, with gusts up to 35 mph possible. While this won’t be the main issue, some pockets of wind damage are possible. Expect a low around 58 tonight, and a high around 68 tomorrow. Sustained winds will be out of the northeast at 5-15 mph, shifting to the north and eventually northwest at 10-20 mph. Skies clear out in the afternoon Thursday as Ida’s remnants move away. Expect mostly clear skies Thursday night, with a low around 54, and a northwest wind of 5-10 mph.

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Going forward, expect a nearly perfect start to Labor Day weekend. Expect a high around 69 with mostly sunny skies Friday. Friday night will be mostly clear and 53; Saturday will be mostly sunny and 76; and Saturday night will be partly cloudy. Sunday will also be a very good day, but there is a slight chance of an afternoon shower; expect a high around 75 with partly sunny skies. Showers are possible Monday as an upper-level low may cross the area, though it’s early and still outside the scope of the 5-day forecast, so Monday may still be salvageable – stay tuned.

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Have a good day!
-Nathan

Tropical Storm Henri – 8 AM Saturday 8.21.21 Update

Good morning! Tropical Storm Henri is headed right for the south coast of New England, although it will weaken very rapidly as it makes landfall, which will lead to limited impacts outside of far southern New England and southeast New York. Trends yesterday brought the landfall area all the way to western Long Island with a second landfall in southwest Connecticut. The NHC forecast as of 8 am (below) reflects an idea similar to this, although overnight guidance actually brought the track to the east, with a landfall over southeast Connecticut or Rhode Island now being more likely.

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In any event, barring a dramatic shift in the landfall toward Cape Cod, we should remain east of the track, which leaves the Lowell/Dracut area (and surrounding areas of northeast MA and southern NH) out of the heaviest rainfall. Right now, it looks like a half-inch to 1.5 inches of rain is likely here, mostly Sunday afternoon into early Monday morning. Well to the west, over 4″ of rain is possible in portions of western CT, western MA, and southeast NY. However, given the amount of rain we have had recently, minor flooding issues are still possible. Always remember to avoid flooded roads. In the event there is a bigger track shift to the east, that could put us in play for 2″ or more of rain and I’ll have an update if that becomes more likely.

As for wind, the strongest winds will also stay away from our area. Tropical storm force sustained winds are likely for a portion of the CT/RI coasts, Long Island, and potentially southeast MA for a period of time Sunday evening. The system will dramatically weaken as soon as it makes landfall, so in our region, expect winds of 10-20 mph, with a period of gusts of 30-40 mph, Sunday afternoon and evening. While it won’t be a major issue locally, minor damage is possible. This shouldn’t be affected too much by any track shifts, as the storm would have to retain some strength as it approaches the Mass Pike and beyond for us to truly get into some stronger winds. It looks like that is not going to happen, as the storm looks to weaken dramatically upon landfall.

I will have an update this afternoon if changes to the forecast warrant. Have a good day!

-Nathan