WeatherWatcher: Moderate Atmospheric River is over

File photo by DKH

Our atmospheric river event has ended, bringing us a 3-day storm total of 3.86 inches of rain. Areas south of downtown Seattle received over 5 inches of rain. We were somewhat protected from the brunt of this system by the Olympic mountain rain shadow. With this weather system December has now made it to about average for total rainfall in the month.

Rainfall compared to average at the North Ridge / Echo Lake weather station.

This kind of rain is actually typical in the area every couple of years. We had a lot of these systems during the winters of the 1990s. They are so numerous that I am not able to easily go back and pick out the last time it rained more than this in the past five years. The last wet weather system or series of events we had that stands out to me is October 27 - November 1, 2012. During that five day stretch we had 7.19 inches of rain collected in the North Ridge / Echo Lake weather station.

Sea-Tac airport, which is the official record keeping station for the Seattle area, had their wettest three day stretch since April 5, 1991. December 20, 2019 was Sea-Tac's wettest day since November 6, 2006, and beat out February 8, 1996 as the next wettest day.

The Forecast is somewhat uncertain for the next week. Colder air is moving in but there still is uncertainty as to how cold it might get, and what moisture might be around. Right now it appears we will be warm enough for any moisture to fall as rain. We are expecting temperatures to range between a high in the low 40's and lows in the mid to upper 30's.

Sunday through Monday we are looking at cloudy skies, with a chance of rain. Monday night the clouds move out to a mostly clear night, with sunny skies on Tuesday. Tuesday night clouds move back in with a chance of rain into Christmas morning.

There's a very slight chance that rain on Christmas morning could have some snow flakes mixed in early in the morning. The rest of the holiday is expected to be mostly cloudy with a slight chance of rain into the evening.

Thursday through next weekend there is a slight chance or chance of rain on and off, with mostly cloudy skies. We might have a break in the clouds during the day on Thursday.

For current weather conditions visit www.shorelineweather.com