In a late-season weather event, an atmospheric river has made its way into western Washington, bringing with it heavy rainfall and the potential for flooding. Sunday and Monday have been designated as Pinpoint Alert Days, with the heaviest rain expected to fall during this period.

According to estimates, the region is set to experience a significant amount of rainfall from Sunday to Tuesday. A Flood Watch has been issued for Snohomish, King, Pierce, Mason, and Lewis counties, with the possibility of river flooding and urban flooding.

The latest river forecast indicates that the Snoqualmie River at Carnation is nearing "minor flood stage" by Monday afternoon. While this may have some impact on agricultural interests, particularly in floodplain areas like the Snoqualmie Valley, the overall effect of this atmospheric river event in early June is expected to be positive.

Typically, the Pacific Northwest experiences such soaking rainfall in the lowlands and mountains during the fall and winter months. However, this late-season event will help delay the start of serious wildfire concerns by several weeks, providing much-needed moisture to the region.

As for wind conditions, breezy conditions are expected to increase ahead of the front, with south/southwesterly winds having minimal impacts. The forecast also indicates a weaker system that will keep rain in the forecast until Tuesday, with lingering showers possible until early Wednesday.

Looking ahead, a ridge of high pressure is expected to amplify, setting the stage for a significant warm-up heading into next weekend. High temperatures are anticipated to reach the upper 70s, with possible peaks of 80 degrees on Friday and Saturday.

Overall, while the late-season atmospheric river brings some challenges in the form of heavy rain and potential flooding, it also holds the promise of mitigating wildfire risks and ushering in a bout of warmer weather. Residents are advised to stay informed, remain cautious in flood-prone areas, and enjoy the brief reprieve from the start of summer heat.