El Niño roof prep for Sonoma County: a checklist for winter 2026–27

El Niño 2026–27 · Updated October 18, 2026

Companion guides: flood prevention · roof prep · drying and mold timeline · North Bay Pros storm prep

What the forecast says

NOAA's Climate Prediction Center has an El Niño Advisory in effect. Its October 8, 2026 discussion calls a strong-to-very strong El Niño likely through January–March 2027 (better than an 83% chance) and notes that impacts with an event this size are "larger, though not guaranteed." For a Sonoma County roof, that means a better-than-usual chance of long, wind-driven storms, not a promise of them. CPC's next update is November 12, 2026.

The City of Sonoma put it plainly in its October 16, 2026 winter notice: El Niño "does not guarantee" flooding or severe storms, but the City is preparing for heavy rain, flooding, strong winds and power outages (City of Sonoma). That's the right mindset for your roof too.

Now (October and November)

1. Look at your roof from the ground. Use binoculars. Look for missing, curled or slipped shingles, cracked tiles, lifted metal trim, and debris piled in valleys. Don't climb up yourself.
2. Check the attic with a flashlight on a dry day: stains, daylight through the deck, damp insulation or rusty nails.
3. Clean gutters and downspouts. The City of Sonoma notes that leaves and yard debris in gutters and storm drains restrict drainage when heavy rain arrives, and asks residents to keep gutters and drainage areas clear (City of Sonoma). Make sure downspouts discharge away from the foundation.
4. Trim back branches that overhang or touch the roof. Hire a tree professional for anything near power lines.
5. Book an inspection or repair early. Roofers get booked fast once storms start. A pre-season roof inspection is the cheapest insurance you can buy.
6. Sign up for SoCoAlert to get County emergency notices.
7. Plan for power outages. Ready.gov advises flashlights for every household member, a power bank, and carbon monoxide detectors with battery backup on every level.
8. Tune in: Sonoma County Emergency Management's "Sonoma Winter Ready 2026" virtual town hall is October 21, 6:00–7:30 p.m. PT (City of Sonoma).

Before each big storm

• Clear any new leaf buildup from gutters and the downspout tops, if you can do it safely from the ground or a stable ladder.
• Secure patio umbrellas, furniture and anything that could blow into the roof or windows.
• Put buckets, towels and a tarp somewhere easy to reach indoors.
• Know where your main electrical panel and water shutoff are.
• On the lower Russian River, watch the Guerneville river forecast. Highway 116 at Drake Road closes at 33 feet, so call a roofer before roads close if your roof is already compromised.

During the storm

• Stay off the roof. Wind and wet surfaces make it dangerous.
• If a leak starts, contain the water, move belongings and photograph damage.
• If a ceiling bulges with water, a small hole at the lowest point lets it drain into a bucket. Keep clear of light fixtures and shut off power to the area if water is near wiring.
• If a tree hits the house, leave the affected rooms and stay away from downed lines.
• Running a generator? Only outdoors, at least 20 feet from windows, doors and attached garages (Ready.gov).

After the storm

1. Document all damage, inside and out, before cleanup when it's safe to wait.
2. Get the roof covered. A professional emergency tarp fastened to framing beats a loose tarp with bricks.
3. Dry the inside fast. The EPA says drying wet materials within 24 to 48 hours usually prevents mold (EPA). Our sister sites cover water damage drying and the drying and mold timeline after a storm.
4. Hire carefully. After big storms, CSLB warns about unlicensed contractors. Verify the license on CSLB, pay no more than 10% or $1,000 down (whichever is less), and remember that unlicensed contracting in a declared disaster area is a felony (CSLB).
5. Schedule the permanent repair promptly. Tarps wear out.

If you're also at flood risk

Roof prep is only half of it if you live near a creek, the Laguna, the Petaluma River or the Russian River. Read our companion guide on El Niño flood prevention for Sonoma County homes.

Sources

• NOAA CPC: ENSO Diagnostic Discussion, Oct 8, 2026
• City of Sonoma: Planning ahead for winter weather (Oct 16, 2026)
• SoCoAlert sign-up
• Ready.gov: Power outages
• CNRFC: Russian River at Guerneville
• EPA: A Brief Guide to Mold, Moisture and Your Home
• CSLB: license check
• CSLB: disaster information

Sources checked October 18, 2026.

Frequently asked questions

This page is general information, not legal, insurance or medical advice. Sources are linked in the text. Sonoma Roof Repair is a referral service and doesn't perform the work.