Following a chilly morning, placid and seasonal conditions on Saturday will give way to southerly air flow and much warmer temperatures early next week. Highs look to be in the 60s on Monday in many locations, and particularly in the west, with 70-plus degrees possible in spots.
But starting around Tuesday, a ponderous low-pressure area off the West Coast should slowly begin to impact the region with increasingly unsettled and eventually cooler weather. More clouds, breezes, and augmented rain chances are likely to spread eastward around mid-week.
Cooler temperatures are expected on Tuesday for highs in the west, and that cooling is forecast to eventually affect lows in eastern areas by the end of the week. Although it is always difficult to know several days in advance how these slow moving lows will progress, the general trend could be as follows: Given the upper level southerly air flow, and low level easterly flow around Tuesday/Wednesday, rain chances may be elevated even in normally dry central Washington.
Regardless of how late next week unfolds, the weather on Monday and perhaps Tuesday is generally anticipated to be the warmest of the year so far. This first true interval of spring-like conditions should be accompanied by quicker plant and crop development, and potentially also a characteristic March resurgence of bugs and pollen.
• Frosty on Saturday morning
• Very mild days spreading from west to east from Sunday to Tuesday
• Increased mountain snowmelt and rising streamflow
• Very mild nights for early-to-mmid next week
• Unsettled with increasing rain chances, breezes, and cooler afternoons on Tuesday and Wednesday
• Cooler mornings and possibly drier later next week
• March 17 to March 23 outlook: Overall, near to below average temperatures and near average precipitation are expected during the 8-to-14 day time frame.
• Mostly dry.
• Highs in the mid to upper 50s on Saturday, and upper 50s to mid 60s on Sunday.
• Lows in the 30s on Saturday morning, and mid 30s to low 40s on Sunday morning.
• Rain likely on Tuesday and Wednesday, and a chance of rain or showers thereafter.
• Highs in the 60s on Monday, and then cooler.
• Lows in the mid 30s to 40s on Monday morning, and then warmer, and cooler later in the week.