Bellingham's proximity to the Fraser River valley occasionally subjects it to a harsh winter weather pattern (termed a 'north-Easter') wherein an upper-level trough drives cold Arctic air from the Canadian interior southwesterly through the Fraser River Canyon. Such an event was recorded on November 28, 2006, when air temperatures of were accompanied by winds. Wind chill equivalents reached according to NOAA. Several days into this pattern, local ponds and smaller lakes freeze solidly enough to allow skating. Outflow winds can collide with a Gulf of Alaska moisture and create ice, snow, or heavy rains. This transition can also lead to freezing rain, referred to as a "silver thaw" that produces hazardous roads among other inconveniences.