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AGUS74 KWCO 081953
HMDNWC

National Hydrologic Discussion - EXPERIMENTAL
NWS National Water Center - Tuscaloosa AL
200 PM CST MON DEC 8 2025

Considerable flooding expected, with landslides possible across portions of
the Pacific Northwest beginning late Monday and will continue through the
week...Rain and snowmelt may generate urban and small stream flooding
across portions of the Northern Rockies this week...

.Pacific Northwest...
A series of frontal systems will bring periods of heavy rainfall through at
least mid-week across western WA and OR with considerable river flooding
and widespread urban and small stream flooding expected. The flooding
impacts will be greatest tonight through Wednesday when the
heaviest rainfall (daily totals of 2 - 5", locally up to 10") is expected.
Soils are saturated and daily rainfall through the week will sufficiently
prime the hydrologic environment. Due to the saturated soils, landslides in
the steep or mountainous terrain are possible mid-week as heavy rainfall
lingers across the region. Widespread minor to scattered major river
flooding is forecast with rapid rises beginning to occur late this
evening, particularly in the foothills of the Cascades and will continue
through the end of the week. Many of the rivers and streams are forecast to
experience multiple peaks throughout the week as multiple rounds of
rainfall move across the basins. While the magnitude and extent of
responses continues to fluctuate somewhat due to the timing of the event,
confidence in Considerable flooding impacts remains high.

.Northern Rockies...
Multiple rounds of rainfall and snowmelt may generate urban and small
stream flooding across portions of northern ID and southwestern MT Monday
night through Thursday. A Limited impacts area persists across this region
given the forecast rainfall and potentially significant amounts of SWE loss
(up to 2") over the next several days.

//KD

Additional National Water Center products are available at
www.weather.gov/owp/operations

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