The Weather Pattern is Stuck: Temperate, Mild Weather Ahead

Sometimes the weather gets stuck in a totally benign pattern, with little threat of heatwaves, wildfire explosions, heavy rain, or anything else of note.

During the next week or so, we will be stuck in such a boring pattern, with great benefits for our region.

To demonstrate this benign situation, consider the forecast upper-level (500 hPa pressure, about 18,000 t) for Sunday morning.   A ridge of high pressure is inland, and a trough of low pressure is off the northwest coast.

Fast forward to next Friday evening (below).  Very similar!

This pattern produces moderate, unremarkable weather over our region, with no heat waves.  

To illustrate this, below are the temperature forecasts for Seattle and the Tri-Cities for the next ten days.

BORING.   Seattle rises into the mid to upper 70s.   The Tri-Cities into the 90s.  Very typical.

The forecast upper-level pattern is associated with modest atmospheric rivers, moving moisture from the southwest to the northeast.  

To prove this to you, below are the forecast water vapor transport from Sunday and next Friday.   The moisture plumes are evident. When the moisture reaches our shores, expect rain.

There will be regional precipitation, particularly over southwestern British Columbia.  The total precipitation through Sunday evening is shown below.   The Olympics and North Cascades will get a piece of it. 

Total through next Saturday morning is impressive.   Will damp down any wildfires across southwest British Columbia.

Getting moisture this time of the year....typically the warmest and driest period for our region.. is very good news and will help this summer end with normal or below normal wildfire acreage numbers.   Also favorable for Northwest agriculture.

Thunderstorms Possible This Evening in Western Washington

 9:30  Update

The showers and thunderstorms are here (see radar image).  And cooler air is moving in from off the ocean.

Lightning at 8:10 PM:

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A line of thunderstorms is now moving up western Oregon at this time and is heading into western Washington.

A little after 2 PM, the thunderstorms were evident in the infrared satellite image, with the lightning indicated by red crosses.

A visible satellite image around 3 PM  showed the area of boomers clearly

The weather radar at 3:45 PM clearly indicates some impressive thunderstorm cells:

For short-term forecasts, the chosen tool is the NOAA HRRR model.  Here is the predicted radar image for 8 PM today.   Storms into southwest Washington and around Portland.

At 11 PM, they had moved northward towards Puget Sound.

Thanks to Dr. Peter Bender for suggesting a look at this.