Friday, December 7, 2007

Weekend forecast update

For Seattle.
Synopsis...A high pressure is currently settling in over the region providing cold and dry conditions. Temperatures will drop below freezing tonight and Saturday night. This pattern will persist through much of the weekend, however a weak upper level disturbance may bring a chance of precipitation on Sunday. With cold air in place, the precipitation could be in the form of snow. There is very little confidence in the forecast for Sunday as the forecast models are in great disagreement at this time.

Forecast confidence/certainty explanation:
Forecast certainty (FC) levels: very low, low, moderate, high, very high.
FC = very high means there is a lot of certainty in the forecast.
FC = very low means there is little certainty in the forecast.

The forecast:
Friday night...decreasing clouds and cold with lows in the mid 20's to around 30 in urban areas near water. FC = high.

Saturday....Partly cloudy with highs around 40. FC = high.

Saturday night...Partly cloudy with lows in the mid 20's to around 30 in urban areas near water. FC = low.

Sunday...Increasing clouds with a 30% chance of precipitation. Highs around 40. There is a 20% chance the precipitation will be in the form of snow. FC = very low. Monitor the forecasts throughout the weekend for updates.

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