New Year Brings Storm with Predicted Heavier Rain, Strong Winds, and Flood Risk

NWS Rainfall Forecast Timeline

Rain that began spreading into Northwest California on Wednesday is expected to intensify later Friday and continue into the weekend, bringing increasing risks of flooding, strong winds, and coastal impacts, according to the National Weather Service Eureka.

Light to moderate rain moved from south to north Wednesday night into Thursday as a weak low-pressure system developed offshore and tracked toward the region. Forecasters said this first system was not expected to bring especially heavy rainfall, with totals generally ranging from about half an inch to an inch and a half, and locally up to two inches in favored locations. After several dry days, rivers and streams had largely receded, making flooding unlikely during this initial period. Winds associated with the early system were also expected to remain relatively light.

Predicted Rainfall for Friday

Conditions are forecast to deteriorate later Friday as a stronger and wetter storm system approaches. Meteorologists say this system is expected to deliver a brief but intense period of heavy rain along with strong southerly winds Friday into Friday night. Rainfall totals of one to two and a half inches are possible during this window, with the strongest wind gusts expected along coastal headlands and nearby mountain ranges, particularly from southern Humboldt County northward. Some guidance suggests gusty winds could also extend into Mendocino and Lake counties.

Another disturbance is forecast to follow closely on Saturday, potentially bringing even stronger winds and renewed heavy rainfall. Additional rain totals of one to four inches are possible from Saturday through Sunday as moisture becomes focused over Northern California. Forecasters caution that if this pattern stalls, flooding concerns will continue to increase through the weekend and possibly into early next week.

Due to the cumulative rainfall expected from multiple systems, a Flood Watch is in effect from Friday afternoon through Sunday evening for Southern Humboldt and Trinity counties, as well as Mendocino and Lake counties. Small streams and urban areas are expected to see the earliest impacts, while mainstem rivers are forecast to rise sharply and will need close monitoring for potential flood stage exceedances.

Coastal Flood Watch

Coastal flooding is also a concern as very high tides continue through January 4. Storm surge combined with strong southerly winds could push saltwater onto normally dry ground around Humboldt Bay, particularly during morning high tides Thursday through Saturday. A Coastal Flood Warning is in effect for Humboldt Bay Thursday morning, with a Coastal Flood Watch remaining in place for the entire Northwest California coastline through Saturday. Low-lying coastal roads, beach access points, and exposed stretches of Highway 101 and Highway 1 could see wave run-up or saltwater flooding near peak tides.

Marine conditions are expected to worsen late Thursday night into Friday, with gale-force winds and steep, wind-driven seas developing. Hazardous conditions may persist into Saturday and possibly again early next week.

Forecasters advise residents to stay alert for updated watches and warnings and to plan around periods of heavier rainfall. High-intensity rain, particularly Friday night and again Saturday night, could lead to rapid rises in small streams and localized urban flooding.