While many of us dream about a Hawaiian vacation during our gray winter weather, sometimes the islands pay us a visit.  Before you have visions of luaus, sunny beaches, and hula dancers… this taste of the islands is a little different.  It’s coming in the form of rain, and a lot of it for some neighborhoods. 

Check out the enhanced satellite image above.  The colors of orange and red show the where the deepest moisture is located.  This moisture plume stretches over 2,500 miles to our southwest near Hawaii.  This warm moist subtropical air is an atmospheric river, but is often referred to as a "pineapple express" because of its origin near the Hawaiian Islands. 

The flow between high pressure off the California Coast and a large area of low pressure over the North Pacific, is aiming the upper level winds of the jet stream right at us.  This is driving in all of that moisture that will be over our area through Thursday.

During this event, the heaviest rain will be focused over the North Coast and toward the Canadian border around Whatcom and Skagit Counties.  Puget Sound will be seeing rain at times; it will not be a complete washout.  Here are the forecast rainfall totals through Thursday evening: 

Puget Sound: 0.25 to 1.5 inches of rain.  Areas in the Olympic Mountain rain shadow will be on the lower end.  This looks to be around the North Kitsap Peninsula and around downtown Seattle.  It will still be wet around Seattle, but some neighborhoods around the city will be on the drier end this week. The Cascade foothills will see some of the higher amounts.   

Whatcom and Skagit Counties: 1 to 3 inches of rain.

Washington Coast:  2 to 6 inches of rain.  The highest totals will be along the North Coast. 

With all of the colder air bottled up to our north, temperatures will be in the upper 50s… near 60 on Wednesday and Thursday.  

A Flood Watch is in effect from Tuesday afternoon through Thursday afternoon.  With high snow levels, around 6,000 feet, there will be a lot of runoff into our local rivers.  Any flooding is expected to be minor at this point.  The rivers most likely to reach flood stage are the Skokomish, Snohomish, Snoqualmie, Tolt, and Bogachiel.  

This pattern will be breaking as we head into Friday.  The atmospheric river weakens and shifts out of our area.  Fewer scattered showers are forecast for Friday.  A cold front will be moving in this weekend, but the computer models are all over the place in terms of timing.  Right now, scattered showers and lower temperatures are the trend for Saturday and Sunday.  Highs fall back down into the low 50s. 

Have a great day!