We are at the beginning of a historic rainfall event, with one- or two-day rainfall in the top five of historical records on Puget Sound. Some other locations we do even better.
Impressively, the Snoqualmie River is predicted to be flooded with record flows any day in late May or the first half of June.
Rain will begin mid-day Sunday and will last for several days.
Let’s start with the forecast rain totals through Tuesday morning (below). Wow…the majority of our mountainous areas will receive over 3 inches, with some limited areas seeing over 5 inches.
An extremely violent atmospheric river, quite rare in early June, will flood the area. The Sunday afternoon steam transport map illustrates this (see below). This will be impressive in November. June, amazing.
What’s amazing is that this plume of moisture may have originated from Southeast Asia!! (see map below at the same time). Another Chinese import (😃).
Prolonged heavy rain is forecast to bring the Snoqualmie River into flood stage–and the highest level ever observed for this time of year (see chart below from the NOAA/NWS Portland River Forecast Center) . The orange line represents the flood level and the red upward arrow represents the highest historical flood level each day.
How unusual is this event?
Below are SeaTac’s top ten precipitation values for the first half of June. The currently predicted two-day rainfall total at that location is about 1.5 inches, so it could be the third or fourth wettest total since 1945,
Keep dry!
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Notification
I will be doing a podcast about this event later today.
I will be teaching ATMS 101 this fall – an introductory atmospheric science class.
The class will be held in person at UW and available on Zoom. So people can take it remotely.
If you are over 60 years old, you can take the class through access Program for a very small fee (about $20). Over the past few years, hundreds of people have done so.
So, if you are a UW student interested in learning about weather or a non-student interested in the subject, I welcome you to join me this fall.
