The passage of a warm front which consists of bubbles or
pockets of warmer air in various sizes emanating from a
low pressure system can bring a sudden rise in temperature
at the surface over which it is passing. With the advent of
computerized weather stations these bubbles of warm air
passing over such a station can be caught by the weather
instruments and stored for later viewing. Such an event
accured at my station suddenly on December 13, 2001 at
around 10 PM. I was getting ready to quit for the night and
was resetting my temperature gauges for the day when I
notice that the temperature had risen substantially in the
passed hour. Upon checking the temperature plot from the
computerized weather station I discovered that I had
recorded a beautiful bubble of warm air passing over head
in the past hour.
From the previous days downloads of
weather images off the Internet I knew that there was a low
pressure system passing to our northwest into Canada, and
that there had been warm fronts developing around it. The
surface analysis and jet stream charts show this beautifully.
And as the graphs from my station shows, one of the pockets
of warm air had passed directly over Chelsea, Vt and my
instruments had recorded it’s passing.
The second graph
also shows that there was a shift in the wind that directly
coincided with the bubble of warmer air. The blue lines
indicate average wind speed and the purple ones give the
direction of the wind. At the same time the instruments
showed that there was also a small bubble of high pressure
which passed by during the next twenty four hours and
brought a small amount of precipitation just before the
entrance of a much colder air mass coming down from Canada
the following day.
Without the capability of these new computerized
weather stations to process and store the conditions taking
place from minute to minute, many of these bubbles of warm air
passing overhead would probably never be noticed, except
that the high temperature for the day had taken place in the wee
hours of the previous night.
