Natural Hazards Weekly — 2026-05-25

TITLE: Natural Hazards Weekly — Quiet seismic week, flash floods in WV, four new fire declarations

---

Seismic

The week's earthquake feed was notably quiet: the largest event captured was an M3.1 roughly 74 km east of King Salmon, Alaska — well below damage thresholds and unfelt at populated locations. No M4+ events appeared in the digest window despite the source title, suggesting a lull in significant U.S. seismicity.

• Background microseismicity dominated, with clusters of M0.3–M1.8 events along the San Jacinto fault zone near Anza and Julian, CA, plus induced-seismicity signatures near Toyah, TX (M1.6) in the Delaware Basin oilfield corridor.
• Alaska contributed three small events (M1.2–M3.1) across the Interior and Alaska Peninsula, and a single M1.8 struck 29 km SE of Mina, Nevada, within the Walker Lane belt.
• Bottom line for emergency managers: no shaking-driven response posture required this week, but the Anza swarm and West Texas activity remain worth routine monitoring.

Severe Weather

The dominant signal was an overnight flash flood event across central West Virginia, with NWS Charleston issuing back-to-back Flood Warnings shortly after 1 AM EDT on May 25 covering Barbour, Braxton, Doddridge, Gilmer, Harrison, Lewis, and Upshur counties through 6:30 AM EDT — a broad multi-county footprint indicating training convection over saturated terrain.

• A Severe Thunderstorm Warning and companion Flood Advisory hit San Saba County, TX just after midnight CDT (NWS San Angelo), with damage observed; a Special Marine Warning off the Florida Panhandle (Okaloosa–Pensacola, out to 60 NM) flagged immediate hazards to mariners around the same window.
• Widespread dense fog advisories through morning rush covered Michigan's Upper Peninsula (Luce, Schoolcraft) and a large swath of southern Ohio and northern Kentucky from NWS Wilmington — visibility-driven travel impacts rather than life-safety threats.
• A daytime Wind Advisory across Puerto Rico and the USVI (NWS San Juan, valid through 8 PM AST) covers essentially the entire commonwealth plus St. Thomas and St. John, consistent with a tightened trade-wind gradient.
• One "Test Message" for Montgomery and a Special Weather Statement for Atkinson/Clinch counties, GA round out the alert set; no tornado, hurricane, or winter products were active.

Federal Declarations

FEMA issued four new Fire Management Assistance Grants (FMAGs) in the past two weeks, signaling an early and geographically broad start to the 2026 wildfire season across the Southwest and California.

• DR-5636 (Bain Fire) in Riverside County, CA and DR-5635 (Sandy Fire) in Ventura County, CA were declared May 18–20, putting Southern California's fire footing back in the federal-assistance posture barely a month into meteorological summer.
• DR-5634 (Stinky Fire, Potter County) and DR-5633 (Hunggate Fire, Randall County) authorize FMAG support for the Texas Panhandle around Amarillo, where dry, wind-driven grass fires have been the recurring pattern.
• DR-5632 (Cow Creek Fire) in Levy County, FL (declared April 23) remains the only Southeast fire declaration in the window.
• The major declaration of note is DR-4910 for Super Typhoon Sinlaku, covering the entire Commonwealth of the Northern Mariana Islands — Saipan, Tinian, Rota, and the Northern Islands — for the April 11–18 incident period; recovery operations are now roughly five weeks in and will likely dominate Pacific-area FEMA logistics through summer.