An Atmospheric River rated AR Level 1 is forecast to make landfall along the U.S. West Coast within the next seven days, according to the Center for Western Weather and Water Extremes (CW3E).
GovOneStop® forecasts the AR Level 1 to possibly strike the West Coast on Tuesday, April 14, 2026.
Although, an AR 1 is technically classified as “Weak” — it can have strong characteristics capable of producing beneficial water supply contributions but also posing a meaningful hazard including heavy rainfall, river flooding, debris flows, and high winds in certain areas.
Residents of Washington, Oregon, California, and Idaho should begin preparing now.
What to Expect
- Heavy, prolonged rainfall — particularly along coastal ranges, the Cascades, and the Sierra Nevada
- Elevated river levels and potential flooding — especially in flood-prone watersheds and low-lying areas
- Debris flow and landslide risk — heightened in post-wildfire burn scar zones
- Strong to damaging winds — possible along the coast and through mountain passes
- Sierra and Cascade snow — heavy snowfall possible at higher elevations with rain-snow level fluctuations
Instructions / How to Prepare
- Monitor official forecasts frequently. Check the CW3E AR Landfall Tool, the National Weather Service (NWS), and NOAA’s Physical Sciences Laboratory AR Portal for updated timing, location, and intensity guidance.
- Monitor for alerts. Check GovOneStop.com/alerts for how to monitor public safety alerts, weather warnings in your area.
- Prepare your home and property.
- Clear storm drains, gutters, and downspouts.
- Secure or move loose outdoor items that could become projectiles in high wind.
- If you live in a flood-prone or burn scar area, consider sandbags and have an evacuation plan ready.
- Assemble an emergency kit. Include water, non-perishable food, medications, flashlights, batteries, a portable phone charger, and important documents in waterproof bags.
- Plan for travel disruptions. Heavy rain, snow, flooding, and downed trees may close roads and highways. Check Caltrans, ODOT TripCheck, and WSDOT before traveling.
- Know your risk. Visit FEMA’s Flood Map Service Center to determine if you are in a flood zone. If you are in or near a recent burn scar, be especially vigilant for debris flow warnings.
- Follow local emergency management directives. If evacuation orders are issued, leave immediately. Do not attempt to drive through flooded roadways — Turn Around, Don’t Drown.
About CW3E AR Scale Forecasts
The Center for Western Weather and Water Extremes (CW3E) at UC San Diego Scripps Institution of Oceanography uses the NCEP Global Ensemble Forecast System (GEFS) to generate AR Scale forecasts for western U.S. landfall locations over 7- and 16-day windows.
The AR Scale, developed by researchers categorizes atmospheric rivers on a 1-to-5 scale based on integrated water vapor transport (IVT) intensity and duration.