Wednesday, December 28, 2011

Much colder today

There is no better example of a dramatic forecast miss than predicting heavy snow and ending up with rain. That was always a possibility with this storm as so much warm air at all levels was moving north with it. The dynamics were just not there for a snowstorm and the storm itself moved across New York state instead of Vermont bringing with it rain. We were counting on colder air arriving at the same time as the precipitation, it just did not happen. As a result it was mostly a rain event across Ontario and Quebec. I measured too much rain, close to 50mm but I believe this was melting snow as well at the onset tipping the scale.  The airport measured only 14.4mm which is more in line with what this system had to offer.

We are waiting for the arrival of a potent arctic front this morning that will have temperatures plummeting all day on strong northwest winds (30-60km/h). This has already happened in Ottawa where it was -5C at 6am while we are sitting at 1C. Winds have started to increase here on Ile Perrot out of the west (20-30km/h) so expect the cold air shortly. Temperatures are currently as good as they will be today and will steadily drop to overnight lows of -17C with cold wind chills in the minus 20's. Needless to say all this water will freeze so watch out for icy roads and sidewalks. Some light snow will accompany the front, perhaps as much as 5cm locally. This will be enough with the winds and falling temperatures to make roads dangerous again today.

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