Hydrologic Outlook issued December 27 at 1:59PM PST by NWS Portland OR

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Dec 27, 2024

ESFPQR

A series of storm systems will continue to bring a wet weather
pattern across northwest Oregon through the weekend. This will lead
to rises on rivers and creeks through at least December 30th. The
Luckiamute River has the highest chance of hitting minor flood stage
at 95%. There is a 40-45% chance that the Pudding River will reach
minor flood stage, and a 20-25% chance that the Wilson River,
Siuslaw River, and Marys Riverwill reach minor flood stage.

Heavy rainfall may also lead to ponding of water, general lowland
flooding and localized urban flooding, especially in low lying areas
or other areas with poor drainage. Heavy rainfall will also increase
the potential for landslides in areas of steep terrain and debris
flows over areas that have been burned by wildfires over the past
few years.

There is still some uncertainty regarding the exact track of the
Sunday system. There is currently a 10% chance the southern
Willamette Valley will receive 2-3" of rain and the adjacent higher
terrain of the Coast Range and Cascades will receive 3-5" of rain
Saturday evening through Sunday morning. This represents the worst
case scenario, which would result in more widespread flooding
issues. That said, the most likely scenario is 1-2" of rain in the
southern Willamette Valley and 2-3" in the adjacent higher terrain
of the Coast Range and Cascades. This would result in minor and less
widespread flooding. Shifts in the forecast storm track can change
the current outlook, so be sure to monitor weather.gov/portland for
the latest weather updates, as well as any watches, warnings, or
advisories that may be issued. To view the latest river forecasts,
visit water.noaa.gov/wfo/pqr.

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