WeatherWatcher: Big change to rain and wind on the way

Heavy Rains in Lake Forest Park
October 10, 2015
Photo by Carl Dinse

A major weather pattern change is occurring Wednesday night and Thursday morning. An atmospheric river, better known as a Pineapple Express, is heading our way. This is looking like the most significant surge of rainfall we've had in a couple of years.

Light rain is falling in the area Wednesday night and Thursday morning. We may see a short break before the main events start moving in Thursday afternoon through Saturday evening.

Winds are expected to pick up as well, with gusts as high as 40 mph possible Thursday night into Friday.

Rains continue Friday, Friday night, Saturday, Saturday night, with the rain breaking up into showers late Saturday night or Sunday morning.

Total precipitation values by Sunday could be between 1.75 inches and 4 inches of rain, possibly more. Our average total monthly rainfall for December is 5.15 inches of rain so this is a pretty big event.

This is not exactly unusual, as these were common events in the late 90s and early 2000s. We've typically seen at least 1-2 of these events in any given winter season. Some years they produce several inches of rainfall, other years only about 1-2 inches of rainfall.

We start drying out Sunday through Christmas day, with just a chance of showers here and there. A white Christmas is not likely this year. Temperatures will be near 50°F for a high until Saturday, where we cool down to the mid-upper 40s for a high temperature. Lows will start creeping from the low 40s into the mid 30s again once we get through Saturday as well and into next week.

Today in historic weather: 29 years ago, on December 18, 1990, we had a strong arctic front with a convergence zone move through the area at about lunch time. This event was never forecasted, and was a complete surprise for the region. It brought over 8 inches of snow in about 30 minutes. Later in the evening thunder snow moved through Shoreline and power was out in many neighborhoods with strong north winds gusting over 40 mph.

When all was said and done around 12 inches of snow had fallen in the area and temperatures plummeted to the low 20's and upper teens. The snow and cold lasted well past Christmas Day that year, with another arctic blast hitting the region before New Year's.

For current weather conditions visit www.shorelineweather.com