How Cold Was It?

[Bill O]

Temperatures fell like a rock last night once the winds died down, but there was some huge variations depending on your location.

Our place in the Champlain Valley of Vermont fell to -16F. But Burlington and Saranac Lake were much warmer.

Meanwhile, down in CT, our hill top location by the Sound only got to 13F, but places 10 miles inland fell to 0F. The coldest night of the season so far.

[mtruman]

Pretty cold on Mt Washington too. 24 hour conditions show a peak wind gust of 118mph early yesterday afternoon with a temp of about -10 at the time. The current summit temperature is climbing really rapidly over the last few hours and the forecast shows summit highs in the upper 20s by tomorrow. Quite the change!

[krummholz]

I'd be interested to hear Bill's theory about why his location in the Champlain Valley of Vermont was so much colder than Burlington. Topography, with sinking cold air? Or you're actually at a higher elevation? Wouldn't think latitude (whatever it might be) would make much of a difference. I'm sure you have an idea.

[Bill O]

Not latitude. Topography is more important than absolute elevation. We're a few hundred feet higher than BTV, but instead of being on a flat airfield we are in a very small sink at the edge of a swamp.

The major factor was wind. BTV never really went calm where as my location did. BTV hit -7, Saranac Lake -13 and our farm at -16. With calm winds cold air can settle to the lowest points. Looking closely at my data I can see that the temperature fluctuated by as much as 5 degrees with even a 1mph puff of wind.

Proximity to Lake Champlain has something to do with it as well. Not in driving the actually temperature up, but keeping a steady breeze going as air rose above the relatively warm lake.

[krummholz]

Interesting. I live on the west side of Cape Ann, and windspeed and wind direction make a huge difference in temperature for us. I remember last summer during a heat wave the Weather Channel was reporting a temp in the low 70s because their data came from a place on Gloucester Harbor where the southerly wind came over the water and cooled everything down. On our side of Cape Ann, we would have needed a northwest wind to cool us down. We were at around 90 degrees at that same time, just a few miles away. By now the ocean has cooled down to the point that a northwest wind only makes us colder. (And that's pretty much what we get through the winter--like the past few days! Brrrr!.)

[Bill O]

On the Sound in CT we'll get that 70 or 80 degree day in April and right by the water it is in the 40s.

This is quite a bit different than the weather over New England this morning though. In your case the wind is advecting a different air mass over your location. This morning the wind was mixing up the cold air that had settled at the surface.