Mesoscale Precipitation Discussion 0071
NWS Weather Prediction Center College Park MD
450 AM EDT Sun Mar 16 2025

Areas affected...portions of western and southwestern Oregon

Concerning...Heavy rainfall

Valid 160849Z - 162049Z

Summary...Persistent rainfall is expected to continue to pose a
risk for flooding and localized flash flooding.  Another 2-5
inches of rainfall are possible through at least 21Z today.

Discussion...The ongoing regime supporting heavy rainfall
continues, and very little has changed over the past 12 hours. 
60-70 knot low to mid-level flow remains oriented perpendicular to
the Oregon Coast and Cascades, promoting orographic lift and
continued rainfall amid 500-750 kg/m/s integrated water vapor
transport values.  0.1-0.3 inch hourly rain rates have persisted,
resulting in 1-3.5 inch rainfall totals over the past 24 hours -
highest across southwestern Oregon coastal ranges.  This regime
will continue to persist most of the day, with only a slow
southward shift in the low/mid-level jet axes and attendant
precipitation maxima.  Another 2-5 inches of rainfall are expected
areawide - with highest rainfall totals expected across
southwestern Oregon (coastal ranges in particular).  This
long-duration rainfall event will result in a gradual increase in
flood potential.  Streamflows across the region are already above
average, further supporting the idea of enhanced/efficient runoff
with additional rainfall as the day progresses.

Cook

ATTN...WFO...EKA...MFR...PDT...PQR...

ATTN...RFC...CNRFC...NWRFC...NWC...

LAT...LON   44892238 44782181 44212150 43242174 42422193
            41972324 42032432 42822462 43952437 44222390
            44522317