Weather

Staying Mild Before The Weekend, But Much Colder After Halloween

In order to receive accumulating snow in late October or the first week in November, a lot of things have to happen atmospherically. In the middle of winter it’s still necessary the key ingredients of a snowstorm are there, but by then the ground is cold, the air is colder and the ocean has also cooled. These variables make it easier for the atmosphere to produce snow as opposed to rain.

Of course, we also need a storm to take just the right track and become sizable enough to bring a large amount of precipitation.

wind speed.png

Halloween Storm
This weekend all the models agree a big ocean storm will form. The image above is from the GFS model. It shows a large storm east of Maine Sunday. All the black lines around the low (L) are isobars and indicate a lot of wind.

There is, as is usually the case, disagreement among the individual models on the exact position of the low.

For southern New England and even southern Maine it’s unlikely there will be much accumulating snow. This isn’t to say if everything comes together just right some snow couldn’t stick on the grass, the car tops or the walkway for a short time early Sunday morning. This would be the exception at least the way things look today.

sfc11114.png

While, it appears the storm will peak in intensity far enough away so the majority of the area escapes a big snowstorm. Both the European and American models do put out some big snowfall totals for extreme eastern Maine and parts of Nova Scotia. The models are showing over a foot of snow in parts of Maine and close to 2 feet in Canada. While this isn’t impossible, the numbers do seem exaggerated. I think it’s also possible the ski areas of Maine see a plowable snowstorm depending on the track.

GFS Model.png

This storm’s intensity is out of the ordinary for this time of the year. When storms are unusual we call them anomalous. The greater the anomaly of the storm the more difficult the models have in forecasting the solution. For the upcoming storm, according to this morning’s discussion from the National Weather Service, the core of the low at around 10,000 feet is forecast to be as much as 5 standard deviations below normal. You might not remember your statistics class, but that is a highly anomalous number.

gfs_t500_sig_east_11115.png

Today, after the fog burns off, it will be mostly cloudy and mild. Highs reach the 60s to near 70F with a few spots hitting the lower 70s. A line of showers pushes through in the early afternoon over western areas and exists the coast before sunset. Not everyone will see rain.

Advertisement:

Two nice days follow with sunshine and seasonable temperatures. Highs will be in the upper 50s Thursday and mid-50s Friday. Saturday brings clouds and a period of rain. It’s going to be very chilly over the weekend with highs in the 40s. Places in the hills Sunday stay in the 30s!

Halloween
For those going out Friday evening for Halloween it looks dry and partly to mostly cloudy. The sunset is Temperatures will be about 50F-45F from 5PM until 10PM Sunset is at 5:39PM.

Weekend Recap

Saturday will be cool and blustery with showers possible. Highs in the 40s. Sunday morning we could see a leftover shower or rain or snow and then partial sunshine returns, but it’s cold. Highs in the upper 30 in the Worcester hills and lower 40s along the coast.

I’ll be updating the forecast on Twitter, please feel free to ask me questions there.


Remember to set your clocks back one hour before you go to bed Saturday night. The sun will go down before 5 PM on Sunday evening and it’s going to feel like winter.

Jump To Comments

Conversation

This discussion has ended. Please join elsewhere on Boston.com