12/5/19 – Today’s Forecast and Storm Recap

Good morning! This is a two part post: the forecast for today and tomorrow, and a summary of the winter storm from earlier this week.

Today will be mostly sunny and 40, with a west wind of 5-10 mph. Tonight will be mostly clear and 19, with a northwest wind of 5-10 mph.

Tomorrow will be mostly cloudy and 32, with a chance of snow showers, and a light west wind. A coating to an inch of snow is possible if we get any snowfall out of this.

Speaking of snow, we are coming off the heels of what would be a major storm for any time of the year, but especially early December. This unusual two-part system recorded a total of 20.2″ snowfall in Dracut, with 12.3″ falling in the first part of the system (before midday Monday, but primarily Sunday evening) and 7.9″ in the second part of the system (after midday Monday, primarily Tuesday morning). Amounts ranged from 20-30″ in most of northern Massachusetts and southern New Hampshire, as well as much of southern Vermont; total snow was 12-20″ in southeast, central, and far southwest New Hampshire, parts of interior northeast Massachusetts (east of Methuen, as well as south of I-495), and south-central and southwest Massachusetts. The Greenfield, Mass. area saw a local minimum snowfall, with an area of amounts below 20″ surrounded largely by higher amounts. Most of the immediate Massachusetts coastline saw 6-12″, with 3-6″ and lower for coastal southeast Massachusetts.

Post Event Snow Analysis - 12-01 to 12-03-19.png

All this snow fell despite sleet cutting in at points during the storm. Sleet (and rain) resulted in a significant drop in snow amounts south of the Mass Pike and at the coastline. Further inland, brief sleet mixing in interior locales resulted in a minor decrease in amounts compared to the potential, but still well above my forecast from Saturday morning:
Slide6.jpg

The overall forecast from midday Monday (below), which was adjusted to include what had already fallen and what was forecast to occur, was closer, but still fell short in many spots because many locations – especially in western and central spots – vastly over-performed on the back-end of the system. 7-14″ was a hair too high in a handful of coastal locations, but woefully low almost everywhere else – particularly locations that did not see as much snow during the first part of the system. Of course, southwestern Massachusetts isn’t my main area of focus, but Springfield ended up with 18″ of snow, including 11″ in the second half of the system. The second half forecast is what killed the whole forecast; the forecast for the whole system from Saturday (above) is not an unreasonable representation of what actually fell during the first half in most locations.

Screen Shot 2019-12-02 at 12.24.48 PM (2).png

Screen Shot 2019-12-02 at 12.24.52 PM (2).png

This system was fairly unusual in its two-part nature; given precipitation stopped in most locations for a while, it could have been treated as two separate systems for forecasting purposes. I attempted to partially fulfill that by creating two maps, but as you can tell by the remaining snow map (which is for anything after noontime Monday), things went sideways. The eastern 4-10″ zone did reasonably, but the interior forecast was way too low in general.

With that in mind, these two-part systems don’t occur quite like this one too often; on to the next one!

Have a great day!
-Nathan

12/2/19 – Afternoon Update

Good afternoon! Quick forecast update.

After getting 12″ of snow last night and early this morning, we are in a bit of a lull at this time. Snow will be ramping up this evening and overnight before ending late in the morning tomorrow.

Screen Shot 2019-12-02 at 12.24.52 PM (2).png

I am expecting 4-10″ of further snowfall before the end of the storm; the reason for the wide range is because we will be near some extremely heavy snow bands. If we can get into the very heavy snow, there is even a chance we could exceed 10″ overnight; if not, we still end up with somewhere in the vicinity of 6″ more. When the system is all done, we will have somewhere in the 14-22″ range for total snowfall between the two parts of the system (although I’d scale it to at least 16″ in tandem with the first part of the forecast).

Screen Shot 2019-12-02 at 12.24.48 PM (2).png

Additional school delays and cancellations are possible tomorrow. I might update this later depending on how the mesoscale patterns play out as the second phase of the storm plays out.

-Nathan

11/30/19 AM Update on 12/1 to 12/3 Storm

Good morning!

While I’m writing this up, may as well offer up a forecast for today: sunny, high 33, northwest wind 5-10 mph, with gusts of 20-30 mph at times. Now onto the storm.

Snow begins during the afternoon Sunday, in the 12 to 4 pm time frame, before ramping up after sunset. The heaviest snow will be overnight Sunday night into Monday morning; this will yield significant impacts to the Monday morning commute, likely leading to all area schools being closed for Monday. Snow continues throughout the day Monday, and doesn’t wrap up until around sunrise Tuesday morning, therefore creating an impact to the evening commute time Monday, and potentially even the Tuesday morning commute, although the Tuesday commute time will have minor impacts compared to the two Monday commute times.

There is a slight chance that snow could briefly mix with sleet Monday morning, but I think this system is going to remain mostly or all snow given the vertical temperature profiles with this system. Mixing will be a much more significant problem to the south, as well as at the immediate coastline. Even if we do see some sleet, I don’t think it will be enough to dramatically lower our snowfall total, barring a dramatic change in the forecast.

As for amounts, I think we will see around a foot of snow; I thus have Dracut and the area in the 10-15″ range, along with much of interior northern Massachusetts and southern New Hampshire. The bullseye of this storm is in east-central New York, southern Vermont, and northwest Massachusetts with 15-20″ of snow expected, and perhaps up to 2 feet in some spots.

Going back down the scale, expect 5-10″ near and south of the Mass Pike and inside of I-95/Rt. 128, as mixing with sleet will be a more significant issue in these areas. The 5-10″ zone includes Boston and its northern suburbs, the North Shore (except Cape Ann), the Newburyport area, easternmost areas of southern New Hampshire, the Springfield area, the southern suburbs of Worcester, most of northern Connecticut, and far northwest Rhode Island.

From there, amounts decrease sharply in Rhode Island, southeast Massachusetts, and southern Connecticut, where this system will be much more of a sloppy mix. Cape Ann in northeast Massachusetts is also in the 3-5″ zone.

Slide6.jpg

Slide7.jpg

I’ll have more on this later today!
-Nathan

11/22/19

Good morning!

With cloudy skies, and a chance of afternoon showers, expect a high around 53, with a southwest wind at 10-15 mph, with gusts of 20-30 mph at times.

Tonight will have clearing skies, a low around 26, and a west wind of 5-15 mph, and gusts of 20-30 mph at times.

Tomorrow will be mostly sunny and 45, with a west wind near 5 mph.

Have a great day!
-Nathan

11/15/19

Good morning!

With sunny skies, expect a high around 50 today, with a southwest wind of 5-10 mph, and peak gusts of 20-25 mph. Tonight will be clear and 18, with a northwest wind of 5-10 mph, and peak gusts of 20-25 mph.

Tomorrow will be sunny and 33, with a north wind of 5-10 mph; tomorrow night will be mostly clear and 14, with a light north wind.

weather 2019-11-15.001.jpeg

Going forward, Sunday will have increasing clouds and a high around 36. Sunday night features a low around 30, and a chance of freezing rain (perhaps starting as light snow or sleet). The freezing rain threat continues until just after sunrise Monday; this could pose a significant impact to the Monday morning commute depending on how the system evolves.

Rain is likely for the rest of Monday, with a high around 36. Monday nigh will be 30, with rain ending overnight (perhaps ending as some sort of wintry precipitation). Tuesday will have a high around 45, with decreasing clouds.

weather 2019-11-15.002.jpeg

Have a great day!
-Nathan

11-14-19

Good morning!

With increasing clouds, expect a high around 37, with a light south wind. There is a slight  chance of flurries this afternoon. Tonight will be mostly cloudy and 25, with a calm wind.

Have a great day!
-Nathan

11/12/19

Good morning!

With cloudy skies, and rain starting mid-morning, expect a high around 37 today, with a west wind around 5 mph. Rain will change to snow around midday, with perhaps brief period of freezing rain possible.

A light glaze of ice is a possibility; in terms of snow, a coating to an inch is possible (we’ll likely end up closer to a coating) before snow ends during the evening, probably after dark. I don’t have a snow map for this system because my template refuses to open, so I think I will have to rebuild my map template. The amount of coatings to 1″ is consistent throughout Southern New England.

Skies will clear after dark, with a low around 14 tonight, and a west wind of 10-15 mph; some gusts over 25 mph are possible.

Tomorrow will be sunny and 28, with a northwest wind of 10-15 mph.

Have a great day!
-Nathan