Weather - wassup?

[Merrymeeting]

I know we're entering a period of unsettled, cold weather. But the current readings around the lake are interesting.

I'm watching a few hardy boaters paddle by the webcam in Wolfeboro, with others comfortably watching onshore. Doesn't look cold.

Weirscam is reporting 54 degrees. Weather Underground says 54. But Black Cat Weather Cam says 44, with lows in the last few hours close to 40. Is the front moving in that fast or is the Weather Cam reading low today?

[upthesaukee]

Some of the temperature difference can be as a result of the air moving over dramatically colder surface, such as Black Cat Island having ice all around it.

In my own yard, yesterday standing in front of the snow piles at the edge of my driveway, it was noticably colder than on the back side of them where it is grass and pine trees.

The air moves across the cold ice and water and is chilled. The air around the airport in Laconia may have a small effect from Lily Pond, but the relative warmth of the earth will have the temps higher. Just Mother Nature doing her best to keep us on our toes.

[White Rook]

Saw a few small boats on the Proctor's Cottages webcam Saturday.

[CanisLupusArctos]

Originally Posted by Merrymeeting

Weirscam is reporting 54 degrees. Weather Underground says 54. But Black Cat Weather Cam says 44, with lows in the last few hours close to 40. Is the front moving in that fast or is the Weather Cam reading low today?

To see if a front is passing, check the graphs on the Black Cat WeatherCenter page (www.blackcatnh.com/weather). Usually when a front has passed you'll see all the graphs showing some kind of change at about the same time, with the telltale sign being a wind shift.

But the island does have its own microclimate. Over the years, the biggest difference I found was that the air temperature doesn't stray too far from the water temperature unless the lake is frozen (and with an insulating layer of snow on top.) Last summer, our highest temperature was 87 F -- recorded on the same day the rest of New England was around 100.

Some other notes on Black Cat Island's microclimate:

- First frost of autumn is usually several weeks after the mainland's first frost, sometimes not until after ice-in. When the rest of the area drops into the 20s for the first time of the season, the water temperature is usually around 50. We'll get down to the upper 30s with pea-soup fog (a result of the air-water temp difference), while everyone else is scraping frost off their windshields under clear skies.

- When the winds on the mainland are light & variable (or calm,) the lake produces its own breeze from the SE at 5-10 mph.

- On summer days there is often a "sundown wind" that arises from the SE about an hour before sunset, picks up to around 25 mph (great time to sail), and drops off to calm about an hour after sunset (don't forget the aux. motor).

- Sometimes there is wind on the lake when there is very little (or much less) wind anywhere else.

- The mountains to the north and south of the lake act as the sides of a bobsled track for storms and wind, even while winds elsewhere take different directions.

- The mountains also act as a funnel, amplifying winds the way alleys in a city do. This was most noticeable in 1999 when Tropical Storm Floyd came up the east coast. The seacoast of NH had relatively little damage while the NW corner of Winnipesaukee had hundreds of trees down.

- This winter, the island experienced the major snowstorms similar to the way the Rochester area did. Even while towns around the lake were getting snow, the island was changing over to sleet and freezing rain. My guess is that when the storms got close enough to kick up the winds from the SE, the "bobsled track" mentioned above started channeling the warmer ocean air farther inland than it was otherwise reaching. The warmer air only had to reach Alton and then it got a free ride up the lake.

A note on WeatherUnderground: It's the same as the WeirsCam, because WeirsCam uses one of WeatherUnderground's self-updating stickers. I think it's from the Weirs Beach weather station and if you want a similar sticker for your site, just look up your favorite weather station on WeatherUnderground (even Antarctica if you want...) and follow the directions for putting its sticker on your site. Black Cat Island is among them.

[Island Life]

Originally Posted by CanisLupusArctos

The mountains to the north and south of the lake act as the sides of a bobsled track for storms and wind, even while winds elsewhere take different directions (the two most popular wind directions here are NW and SE - look at a map of the lake and you'll see why.).

Very interesting post, Canis. I noticed we had a lot wind from the SW last summer (more than the previous summer) - or was this just my imagination?

[CanisLupusArctos]

Originally Posted by Island Life

I noticed we had a lot wind from the SW last summer (more than the previous summer) - or was this just my imagination?

I think you're right. Checking the hand-written records from last summer (they're computerized now), July had 14 days with winds from the W, SW, or S... August had 13 days of the same. June had none.

There were 29 days with missing wind direction data, most in June, but I don't think that matters because the entire month was chilly (which wouldn't have happened if we'd had SW winds.) The only exceptions were on the 1st, 18th, and 19th with temps around 80, but winds were calm on those days.

In late July and early August we saw the most SW winds and a noticeable Gulf Of Mexico influence. There were several days with dewpoints in the lower 70s (about as humid as it usually gets in New England) and on August 1 and 2 we had dewpoints of 79 and 78. Those readings usually don't travel too far beyond alligator alley... and they arrived here via a SW wind.