Weather Wisdom

Friday's storm could bring 4-8 inches of heavy, wet snow

Latest update:
After two days of a rapidly changing forecast, it's time to wait for the precipitation to begin. Here are 10 things to be aware of this evening as we wait for a moderate snowstorm to reach the Boston region:

1. Although the precipitation begins as rain, it will change to snow in Boston by about 5 or 6 a.m., then progress to Cape Cod.

2. At times, the snow will come down at 1 to 2 inches per hour, an especially heavy rate for the morning commute.

3. The weight of the snow could create power issues.

4. It will be relatively mild during the storm, with temperatures around freezing.

5. Expect travel delays on the roads, rails, and tarmac.

6. The precipitation will end west to east in the afternoon.

7. North and west of Worcester, the snow will be lighter and not accumulate as much.

8. Winds will be gusty and contribute to possible tree damage from the already heavy weight of the snow.

9. There will not be a flash freeze Friday night, and weekend temperatures will remain above freezing.

10. It's too early to know how much more snow a storm on Tuesday may bring next week.


snowfall evening update.png


From this afternoon:
The computer guidance we all use to help make our forecasts continued its westward trend this afternoon and brings a plowable storm to the Boston area on Friday morning. I have updated my snowfall map below.

You'll notice a wide range of 4-8 inches. I put a pink circle in the area I think is most likely to be at the higher end of this scale. The snow will be heavy and wet, so there might be 6 or 7 inches on colder surfaces, but the roads won't have the full amount due to initial melting, thus my reasoning for a larger-than-typical range.

The snow will end in Boston in the early afternoon, but the damage to the commute in the morning will have been done. Some schools are likely to cancel if the snow is as heavy as it appears it will be tomorrow morning.

From this morning:

If you havenít looked at a weather forecast in over a day you might be surprised that some snow is coming. Indeed, some areas will be plowing snow Friday morning.

The warm air over us the past couple of days is being pushed out to sea by colder and drier air to our west, but the cold isnít moving very fast. It is going to become hung up or stuck just offshore.

A bit of a surprise

A couple of days ago, it appeared the front would be about 100 miles further east, and any renewed precipitation developing along it would stay out at sea. Now, with things slowing down, the front gets stuck closer to the coast, and the precipitation will be over eastern areas Friday morning. The map below shows the position of the front Friday.


fronts sf.png


Another tricky forecast
Like nearly all weather systems that creep up on us, a slight shift back out to sea or further west changes snow amounts. Also, there is still going to be enough warm air present with this system to see some rain at the beginning. Over the outer portion of Cape Cod, the rain will last longest, so snow amounts will be lower.

Messy Friday morning commute

The precipitation begins roughly between 1 a.m. and 4 a.m. Friday. It should be snowing in Boston for the entire morning commute Friday, which means a slow and messy drive to work. Fridays are typically lighter commutes, but with the snow, I expect a rough ride.

Most schools should stay open

Schools in some areas may have delayed openings, and over southeastern Massachusetts, there might be enough for a snow day. The snow will be over by mid to late morning in most areas, ending in Boston between about 9 a.m. and 11 a.m.

The snowfall map below will likely be modified later today. I expect the lines to shift east or west depending on computer guidance and trends.


snowfall evening update.png


Mild weekend with melting
The weekend is looking very nice with sunshine and mild air. The fresh snow cover will prevent temperatures from reaching the upper 40s, but lower 40s with sunshine and light winds will still be quite tolerable.

Primary Day storm
There is a possible additional storm for Tuesday, which is Primary Day in New Hampshire. It appears the southern half of New Hampshire as well as coastal/southern New England has the best chance of snow, but the storm is still five days away, and a lot can change.
One thing that is looking more likely is a period of very cold air at the end of next week. Some models have temperatures falling to near zero around Valentineís Day, and remaining cold for three to five days. This will likely be one of the colder periods we have seen in our relatively mild winter.

Please follow me on Twitter: @growingwisdom.

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