Why does Bos/MA Get N'Easters? (Boston, Nantucket: college, suburbs, humidity)

[tberg224]

I spent a lot of time in Trumbull, Fairfield County, CT before I went to college in Boston.

I knew Boston would have more snow, but what I didn't expect and was surprised was at how late spring/summer arrived compared to Fairfield, CT, and how there really could be a lot more cool, damper days.

I was told by somebody that Bos and East MA gets N'easters due to the lack of gulf stream, or moreso, that NY has the gulf stream which typically brings warmer air, but that Boston is one of the few US cities north of it and as result, once that line is crossed, it gets a lot cooler and the pressure from it which is just off the LI sound leads to storms getting 'trapped' at sea near Bos and thus N'easter rain.

I'm not an MA native so could somebody explain to me why, since Boston and east MA is not THAT far north of Fairfield CT why it seems whenever you go from NY to BOS on I-84, once you get out of the Hartford metro area that

1) Fall comes a lot earlier
2) Spring, the leaves, and warm days, come a lot later
3) Why it's damp and N'easter's happen. I would think with cooler waters this would limit the amount of coastal storms, since they like warm temps.

Thanks.

[ChunkyMonkey]

Noreasters is not just a Boston phenomenon, it affects the entire Northeast including NYC and Connecticut.

It is all very temperature dependent. There are times where Spring seems to come early. This year it was very late. Generally, Massachusetts seem to have a lot of microclimates.

1) Fall comes earlier when you're outside Rte 128, but later when you are inside Rte 128. The reason is the urban heat island effect. This is the same reason why Boston does not get as much snow as its suburbs on average. There are many storms where you'll have snow outside 128, but rain within. Boston averages about 42 inches of snow per year only slightly more than coastal CT, which averages 30-40" per year.

2) Spring seems to come a later in Boston because of the sea breeze keeping temps down along the coast during April and May a good 10 degrees cooler than places that are 5 miles from the coast.

3) Cooler waters/temps do not limit storms, but they do limit the amount the water content. Noreasters dump lots of snow in the winter, 2 feet+ but if the formula is 1" for every 10" of snow. That's only less than 3" of rain comparatively, no where near the tropical downpours.

The problem with Noreasters is that they often are at their peak strength near Boston, which juts out into the ocean compared to NYC. So, we often get more precipitation. However, that said, it is very path dependent. A few years ago, NYC got over 2 feet of snow while Boston got 8".

Hope that helps.

[tberg224]

Fall comes earlier when you're outside Rte 128, but later when you are inside Rte 128. The reason is the urban heat island effect. This is the same reason why Boston does not get as much snow as its suburbs on average. There are many storms where you'll have snow outside 128, but rain within. Boston averages about 42 inches of snow per year only slightly more than coastal CT, which averages 30-40" per year.

I notice that when driving from CT to BOS, on I-84, once you leave Vernon, CT which is the last major area in metro Hartford, until Rt 128, spring comes MUCH later, MUCH, than in Hartford/CT and Boston.

To me, I find it amazing that simply crossing one highway or one town line does this, is the urban heat affect really THAT drastic that it causes sudden sharp changes like this?

Also, why is it metro BOS isn't as dense outside 128?
I mean 128 wasn't built until the 1900s, Boston is an old city, it's not like 128 is a river or anything, why is it this new manmade barrier has become a divide between dense and lighter developed metro Boston?

[tberg224]

Also as for N'Easters, I notice Boston in May and other times during the year gets socked with rain as a coastal low just sits in the Mass Bay.

Why does this happen, CT doesn't really get this, they can have long dry periods but in East MA they seem to have these systems of long dampness, is it a coastal low stuck in the Mass Bay from Maine/CA air or outside Cape Cod by Nantucket?

[tberg224]

Any responses?

[DaveV]

Maritime climate

Boston, Logan International Airport
Lat: 42.38 Lon: -71.03 Elev: 20.013
Last Update on May 31, 1:54 pm EDT
Overcast 60°F
(16°C)
Humidity: 75 %
Wind Speed: E 12 MPH
Barometer: 30.16" (1021.3 mb)
Dewpoint: 52°F (11°C)

New York City, Central Park
Lat: 40.783 Lon: -73.967 Elev: 144.029
Last Update on May 31, 1:51 pm EDT
Fair 91°F
(33°C)
Humidity: 31 %
Wind Speed: Calm
Barometer: 30.09" (1018.0 mb)
Dewpoint: 56°F (13°C)
Heat Index: 89°F (32°C)
Visibility: 10.00 mi.

[surfingatwork]

the gulf stream does come up to massachusetts but not until august. at that point it's around 60-100 miles offshore (from New bedford). my dh's hobby is offshore fishing. august/september are the biggest months for tuna (when the gulf stream is the closest to us - sometimes just 50 miles offshore).

[ChunkyMonkey]

Originally Posted by tberg224

Also as for N'Easters, I notice Boston in May and other times during the year gets socked with rain as a coastal low just sits in the Mass Bay.

Why does this happen, CT doesn't really get this, they can have long dry periods but in East MA they seem to have these systems of long dampness, is it a coastal low stuck in the Mass Bay from Maine/CA air or outside Cape Cod by Nantucket?

Since Mass juts out over the ocean, it is more susceptible to coastal storms that strengthen or stall over the gulf of maine. This is more prevalent during spring as the jet stream is beginning is retreat up north and is often in the area near easter mass.

[DreamworksSKG]

Cuz the wind comes off the ocean water---which is typically warmer than the air that time of year...and causes increased precip and the wind blows from the Northeast due to position of the low center

[findingmesomeday]

Those coastal lows form off the coast of North Carolina and the wind and ocean currents just suck them right up the eastern seaboard. As previous posters have said, they usually make landfall around MA since the state juts out into the ocean further east than NY, etc. But what also creates that fun N'oreaster effect is the way the wind swirls around the low, pulling the moisture in from the ocean and mixing it with cold air from Canada. The result? SNOW, and lots of it! Also heavy wind and high tides. Some N'oreasters can actually reach hurricane force winds.

After blasting MA, the storm continues on it's path up the coast until it hits Nova Scotia--another place famous for N'oreasters.