Quote:
Originally Posted by webmaster
If you check the WeatherCAM Facebook feed on our home page CLA said:
Maybe CLA can comment on how unusual this is.
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It's unusual for the reason that it doesn't happen every day, but is not unusual given the weather situation at the time. Warmer air was moving into the region. Being heavier, cold air hugs the ground. When it's retreating (thus allowing the warm air to move in) it leaves the ground last. That's how we get ice storms in the winter -- rain falls from above into cold air hugging the surface. Warm air often arrives at altitude first, when the cold air is retreating and warm air moving in. In winter sometimes, Mount Washington will be above freezing while here at the lake we're many degrees below freezing. If my memory is correct, that happened during the ice storm of 1998. They were above freezing with rain while the cold air filled the valleys below, and the rain froze on contact with surfaces in those valleys.
This time, Mount Washington had temps typical of *their* summertime, while we weren't exactly hot. The truly summer air (at the surface) was still a bit to our south. A basic cross section of a warm front (imagine...) shows the warm air slanted forward in the direction of travel. It arrives first aloft, and gradually builds its way down to the surface.