What Every Boston Visitor (& Resident) Should Know
Extreme Boston weather . . . not what you want to experience when visiting Boston!
But depending on the season when you visit, you might.
The good news is that we seldom get hit by extreme storms.
But when we do get extreme conditions, there are 3 especially dangerous types you should be aware of:
Hurricanes followed by torrential downpours
Usually these storms are forecast well in advance - but our coastal location makes weather patterns unpredictable. Rapid changes in temperature and other conditions means extreme condition can develop with little to no warning.
If you're traveling to Boston, check the weather forecast before you come to see if extreme weather is predicted. And if it is, be sure you know what to do ... just in case.
Top photo credit: Make Way for Ducklings statues in Boston's Public Garden during a January snowstorm
What's a Nor'easter?
A nor'easter (sometimes also called a "northeaster," although you won't really hear it said this way around Boston) is a storm that occurs when an area of low pressure forms over the Atlantic Ocean and moves up the North American coast toward Boston as strong northeast winds blow in from the ocean ahead of it.
When the low pressure area and the strong northeast winds collide, a storm - usually quite a ferocious storm - results. In fact, wind gusts can and do exceed hurricane strength.
If the low pressure area stays over land to the left of the coastline, usually Boston will get just heavy rain.
Well, not just "heavy" - more like torrential downpours.
Flooding usually occurs as well, especially along the coast. If you have a smartphone, you will probably get automated weather alerts about flooding.
However, if the low pressure goes to the right and moves off the coast and over the ocean, that's when you need to really watch out!
If the temperature is cold enough, this low pressure movement can rapidly turn into a blizzard, bringing heavy snow, very strong wind, and destructive ocean waves.
Here's the worst part: if a circular pattern develops off the coast that continues to bring moisture over land, the storm can last for days!
While the frequency of nor'easters can be hard to predict, we typically experience one or more each year - sometimes merely rain, but during a typical year, you can count on snow as well. Occasionally a single storm will produce both - sometimes accompanied by thunder and lightening.
Not all nor'easters are blizzards, even when they produce snow - but when we do get a nor'easter producing blizzard conditions, look out!
Blizzards in Boston
Are all blizzards nor'easters?
No, blizzards - technically, a storm with winds greater than 35 miles per hour (mph), very low temperatures, and visibility of less than 1/4 mile for 3 or more hours - can form in various ways.
And, of course, not all nor'easters are blizzards because they may produce rain or sleet instead of snow, or even snow but without enough prolonged wind and lack of visibility to qualify as a blizzard.
Blizzards may actually produce very little overall snow - what makes them dangerous are the sustained high winds and your inability to see as the snow falls. But some do produce huge quantities of the white stuff.
The most infamous nor'easter-turned-blizzard in recent memory, the Blizzard of 1978 , dumped huge amounts of snow across the Northeast for 2 days in early February and shut down Boston for a week.
Boston recorded an all-time record (for that time) for the quantity of snow falling within a 24-hour period. Plows could not keep up.
Many people were trapped on highways for up to 6 days until they could be rescued, although not everyone survived. Carbon monoxide poisoning killed a number of people who left their cars idling in an attempt to keep warm, not realizing that snow had blocked their tailpipes. Fallen electrical wires killed others.
Over 100 people died.
From your perspective as a Boston visitor, whether a huge storm is a blizzard or a nor'easter doesn't matter because your response needs to be the same: stay inside until it's over!
Sure, going outside to experience the storm sounds exciting, but it can be dangerous. Why risk an emergency room visit for frostbite - or worse?
Hurricanes impact Boston much less frequently than nor'easters and blizzards - but the rare direct hits can be destructive and very dangerous.
On average, the Boston area gets hit or brushed by a hurricane approximately once in every 6 years. A direct hit typically occurs only twice in every century.
To be considered a hurricane, a storm must sustain winds of at least 74 miles per hour, and form over the ocean. Category 5 storms are the worst, with winds exceeding 155 mph.
Fortunately, most Boston hits and brushes involve Category 1 hurricanes. However, they can still produce extensive damage, power outages, and flooding.
In 1954, Hurricane Carol struck with such force that high wind gusts toppled the steeple of Old North Church in the North End. In 1960, Hurricane Donna hit from the south with 80 mph wind. In 1991, Hurricane Bob passed over - quickly, thankfully - with 75 mph wind.
Right before Halloween in October, 2012, Hurricane Sandy hit Boston with Category 1 force as just fall tides reached their highest levels.
Fortunately, the city escaped relatively unscathed, although major flooding along with extensive damage from fallen trees and branches occurred in surrounding areas.
As with nor'easters and blizzards, if a hurricane strikes while you're here, stay inside!
Although Boston Harbor often protects the city from the brunt of the storm surges and flooding, air-borne tree branches and other articles zooming by due to high winds can be quite dangerous.
Fortunately, a local saying sums up it up accurately: "if you don't like the weather in Boston, just wait one moment. "
Summer thunderstorms end quickly. Bitter January blizzards abruptly give way to a few sunny days in the 50s or higher. Brilliant sunshine follows on the heel of a storm.
Stay inside on the relatively rare occasions when Boston weather conditions are quite bad. Otherwise, dress sensibly and know that if you don't like the weather at the moment, it's sure to change soon.