Storm · 8 min read
Atmospheric River Prep Checklist for Vancouver, WA Homeowners
We see the same three losses every January and February: roof intrusion at the same valleys, basement seepage in the same neighborhoods, and downspout failures at the same five-foot setback. The forecast gives you 48-72 hours of warning. Here's what to actually do with it.
May 16, 2026 · By Dmitry Zinovyev
Atmospheric rivers are now the dominant winter weather event in the Pacific Northwest. We get four to seven per season, and the worst of them deliver three to six inches of rain in 24 hours on saturated ground. The damage profile we see after each event is almost identical: same valleys leaking, same basements seeping, same downspouts overwhelmed. Most of it is preventable in the day before the event with two hours of work. This is the checklist we send our own clients when the forecast lights up.
What to do in the 48 hours before
1. Clear every gutter and downspout
The number-one cause of roof intrusion we see is a clogged downspout. Water backs up in the gutter, overflows behind the fascia, runs down the wall cavity, and shows up in the ceiling below two days later — long after the homeowner blames the storm. A two-hour gutter clean before a forecast event prevents this entirely. Pay particular attention to gutters under deciduous trees (fir-needle pileup at the elbow is the most common failure point in this region) and to valley downspouts on multi-pitch roofs.
2. Check every downspout discharge point
Downspouts that discharge within five feet of the foundation are the number-one cause of basement and crawlspace water intrusion in the Portland metro. A six-foot flexible extension at each downspout, aimed away from the foundation and pitched downhill, costs $30 and prevents the most common basement-water call we run.
3. Walk the perimeter and identify the low spots
Look at the ground next to your foundation. If it slopes toward the house anywhere, water will pool there and find a path inside. You don't need to regrade in 24 hours — but you do need to know where the puddles will form so you can place sandbags or temporary diversion before they get critical. Pay attention to window wells, basement entries, and any cellar door.
4. Inspect roof penetrations and valleys
Vent boots, skylights, chimney flashing, and the valleys between roof pitches are where roof intrusion starts. From the ground with binoculars (don't climb a wet roof) check for visible flashing damage, lifted shingles, or dark patches that suggest existing moisture. If you can see daylight where you shouldn't, call a roofer that day — emergency tarping is much cheaper than the rebuild after three inches of water gets inside.
5. Test the sump pump and battery backup
Pour a five-gallon bucket of water into the sump pit and verify the pump cycles on and discharges. If you have a battery backup (you should, in this region), confirm it activates when you disconnect mains power. Forty percent of the basement-flood calls we run during major events trace back to a sump pump that wasn't tested before the season started.
6. Pull anything valuable off basement floors
Books, electronics, family photos, art, anything porous and irreplaceable — get it onto shelves, off the floor, or out of the basement entirely. Even a half-inch of intrusion is enough to total a stack of stored boxes that sat in standing water for six hours.
7. Document everything before the storm
Walk through your property with your phone camera and shoot the interior of every room, the exterior of every wall, the basement, the garage, and the yard. If a claim comes out of the event, this is your before-state evidence. It takes ten minutes and it has saved insurance claims for several of our clients when the adjuster questioned the pre-existing condition of a damaged item.
What not to bother with
Some prep advice gets repeated every winter that doesn't actually change outcomes much in this region. Skip these unless you have unusual exposure:
- Boarding up windows. Pacific Northwest atmospheric rivers don't produce the wind-driven debris that justifies window protection. Skip unless you're in a wildland edge where falling-branch risk is real.
- Stocking sandbags for whole-house perimeters. Sandbags are point solutions for known leak paths (basement entries, low garages, identified low-grade sections). A perimeter of sandbags around a slab-on-grade house does nothing.
- Filling the bathtub for drinking water. We do not lose municipal water to atmospheric river events in this region. Save the prep time for actual loss-reduction work.
- Generators for a 24-hour outage. Most atmospheric river outages in the metro are under 24 hours; refrigerator and freezer contents survive that without intervention. Reserve generator prep for genuinely long-duration outages like the 2024 ice storm.
What to do during the event
Once the rain is falling hard, your work has shifted from prevention to monitoring. Walk the basement and crawlspace every two hours. Watch the lowest spots in the yard. If you see standing water near the foundation, an active leak inside the envelope, or your sump pump running continuously without keeping up, that's the threshold for emergency response.
Document any intrusion immediately with photos and video. The faster you document, the cleaner the insurance claim. Don't disturb materials yet — wet drywall, soaked carpet, and saturated framing all need to be assessed before anyone starts cutting and bagging.
When to call us
Standing water of any depth in a finished space, active intrusion through ceiling, wall, or foundation, or a sump pump that has been running continuously for more than four hours — all of those are restoration calls, not later-this-week calls. We dispatch 24/7 across Vancouver, WA and the Portland metro with a 60-minute on-site target. We tarp, extract, dry, and document — and we coordinate with your insurance carrier from the first hour.