Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
330 AM EDT Mon Mar 16 2026
Day 2
Valid 12Z Tue Mar 17 2026 - 12Z Wed Mar 18 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
WASHINGTON STATE...

Active pattern across the Gulf of Alaska will lead to another AR
contribution into portions of the Pacific Northwest as the main
IVT surge will adjust south into WA state after impacting
neighboring British Columbia the day prior. Looking at IVT values
between 500-700 kg/ms across northwest WA state with the surge
propagating far enough inland to impact the Northern Cascades.
Rainfall amounts between 2-3" will be common in the hardest hit
areas, mainly into the Olympic Peninsula, Chehalis River valley,
as well as the Cascades to the east of Seattle. Rates will lack
vigor to the point for a more substantial impact, so the threat is
mainly due to prolonged moderate to locally heavy rain prospects
falling over relatively moist soil layer present after being
impacted for weeks leading in. The previous MRGL risk was generally
unchanged with the threat leaning towards the lower-end of the risk
threshold. Areal hydrologic concerns are still viable with river
and small stream flooding the most notable potential impacts. 

Kleebauer


Day 2 threat area: www.wpc.ncep.noaa.gov/qpf/98epoints.txt