Surviva-List
Wednesday, September 9, 2026
The Signal
Storm waves cross southern Santa Catarina's barrier spit and lay sediment fans across its back like spilled sugar, and researchers now know exactly what conditions trigger it. The same physics guards the Outer Banks, Galveston's west end, and Fire Island. Millions of people sleep behind one strip of sand tonight, and most of them have never measured its height.
The Brief
Six years of vanishing sand on a Brazilian barrier spit just produced the clearest overwash trigger map we have, and it applies to every US barrier island. Two M5.0 quakes overnight: Cafayate, Argentina and 154 km south of Sarangani, Philippines. Great Sitkin and Kilauea both sit at aviation ORANGE. The Raccoon River at Des Moines is under a flood warning through Saturday. And the DRC's Bundibugyo Ebola outbreak remains the most severe event on the board.
By The Numbers
6
Years of overwash mapped in Santa Catarina
Monthly, annual, and decadal timescales stacked together, which is why the study caught the two-storm sequence single-event surveys always miss.
2
Volcanoes at aviation color code ORANGE
Great Sitkin in the Aleutians and Kilauea on Hawaii Island are both at WATCH, putting the Anchorage ash corridor and Hawaii air quality on the same alert tier.
K5
Geomagnetic index reached September 8
Plus a continuing 2MeV electron flux alert Wednesday morning, the combination that degrades satellite health and HF radio right when coastal responders lean on both.
12
FEMA housing registrations, Disaster 4936, Hawaii County
Zero inspected, zero approved so far. Small numbers, but the inspection clock is the metric that decides whether families get help in weeks or months.
“Barrier islands do not fail in the storm that breaks them. They fail in the storm before, the one that quietly took a meter off the dune and nobody measured.”
Lead Story
Vanishing sand has a schedule now. A team tracking the barrier spit of southern Santa Catarina, Brazil from 2017 to 2023 published what actually triggers overwash, the moment storm waves stop hitting a beach and start crossing it entirely, and the answer is not the wave height everybody stares at on the app.Overwash is not erosion. Erosion pulls sand sideways and offshore. Overwash lifts it up and throws it inland, laying down fan-shaped tongues of sediment called washover fans across the back of the spit, burying roads, marsh, and septic fields in a single night. The Santa Catarina team logged those fans monthly, annually, and across the full six-year arc. The pattern that emerged is ruthlessly simple. It takes a surge riding on an already elevated water level, meeting a dune crest that a previous storm already shaved down. Two storms, not one. The first one sets the trap.That is the finding that travels. The same barrier-spit physics governs North Carolina's Highway 12 corridor, Bolivar Peninsula, Fire Island, and Louisiana's Chenier plain, where the road, the water main, and the power feeder all run down the same ribbon of sand. IPCC AR6 Chapter 9 is blunt about the trend line: every centimeter of sea level rise raises the platform the surge starts from. No rapid attribution study exists for Brazilian overwash specifically, and I will not pretend otherwise. But the mechanism does not need attribution to be actionable.Below: two orange volcano alerts, a river cresting in Des Moines, an Ebola outbreak WHO has not downgraded, and a geomagnetic hit that touched K5 yesterday.
World Coverage
Sarangani, Philippines · earthquake
A magnitude 5.0 breaks offshore in the Celebes Sea south of Sarangani, no tsunami threat issued. Mindanao's southern coast has absorbed this rhythm for decades, and the exposure is not the shaking, it is the unreinforced masonry in Glan and Maasim that a 5.0 barely tests and a 6.5 flattens. The circum-Pacific belt logged its second M5.0 of the day within hours.
Des Moines, Iowa, United States · flood
NWS Des Moines issued a flood warning at 4:59 AM Tuesday for the Raccoon River at the Fleur Drive gauge, running through 7 AM Saturday. Polk County holds roughly half a million residents, and Fleur Drive is the artery to Des Moines International. Inland river flooding kills more Americans annually than any single hurricane category, mostly in vehicles.
Aleutian Islands, Alaska and Hawaii Island · volcanic
Alaska Volcano Observatory and Hawaiian Volcano Observatory both posted WATCH status with ORANGE aviation codes Tuesday evening. Great Sitkin sits under the North Pacific great-circle flight corridor, where ash is an engine-out problem for hundreds of daily crossings. Kilauea's issue is vog: sulfur dioxide drifting downwind into Ka'u and Kona, where residents with asthma feel it before any instrument reports it.
Democratic Republic of the Congo · health
The August 28 Disease Outbreak News confirms additional cases and deaths since the August 14 report, all inside the DRC. Bundibugyo virus is the rarer Ebola species, and it has been off most newsrooms' radar for weeks. This remains the single most severe event across all 83 monitored today, and containment there is what keeps it from becoming an aviation-corridor story.
Global · space
SWPC logged a K-index of 5 at 17:51 UTC Monday with an extended K4 warning behind it, and the 2MeV integral electron flux alert renewed at 05:38 UTC this morning. Elevated electron flux is the quiet satellite killer, charging spacecraft interiors over days. GPS precision degrades at exactly the moment coastal survey drones need centimeter accuracy.
Surviva Spotlight
Powered by Real-Time Intelligence
Take today's board and run it through the app. Great Sitkin and Kilauea both moved to ORANGE at 19:02 and 18:38 UTC yesterday; if you keep volcano alerts on and you live in Ka'u or Ocean View, that hit your phone last night with the downwind vog geometry, not just the word WATCH. The Charleston coastal flood advisory drops as a block-level alert for Coastal Colleton, not a three-county blob. If the Raccoon River gauge at Fleur Drive crosses its next stage threshold, the family SOS network fires automatic check-ins to everyone you have listed in Polk County within 30 seconds, and you see who has not answered. And the dune-height habit from today's lead story is exactly the kind of thing a saved location reminder is for, once a month, after every surge. This is what it means to be prepared before the headline breaks.
The One Thing
Today's Essential Takeaway
If you take nothing else from today's briefing: overwash risk runs on a countdown you can actually read. T-minus 30 days is where southern Santa Catarina sat before its worst washover events, a dune already lowered by an earlier storm and nobody measuring. T-minus 72 hours is when the surge forecast appears and the crest height becomes unchangeable. T-minus 24 is when the evacuation route across the sand is still passable. T-minus 6 is when it is not, and the decision has already been made for you by whoever did or did not carry a tape measure in August.Right now, for most US barrier coasts, we are between T-minus 30 days and T-minus 72 hours, in the only window where you can still change the outcome. Go stand at your beach access. Look at the dune. If the wrack line, the debris the last high water left, sits at or above the crest, your island has already been told what happens next. Believe it.
— Ato Phoenix
Mission Briefing
Walk to your nearest beach access and photograph the dune next to a person for scale, then compare after the next surge event. That single habit is the whole finding from today's Santa Catarina study, applied to your block. (usgs.gov/coastal-change)
If you live in Coastal Colleton or Charleston County, stay out of the surf through 10 PM tonight. NWS Charleston has HIGH rip current risk plus a half foot of inundation forecast in the advisory. (weather.gov/chs)
Polk County, Iowa readers: identify a second route to work that does not cross the Raccoon River at Fleur Drive before Saturday's 7 AM warning expiration. (water.noaa.gov)
Ka'u and Ocean View residents, check vog forecasts before outdoor work today. Kilauea sits at ORANGE and SO2 exposure hits asthmatics before instruments flag it. (vog.ivhhn.org)
Trans-Pacific travelers this week, expect possible reroutes if Great Sitkin escalates. Build two hours of buffer into connections through Anchorage. (avo.alaska.edu)
Patch anything running Adobe Commerce or Magento today. CISA added an actively exploited template-engine flaw on September 8, and small business storefronts are the soft target. (cisa.gov/kev)
Apply the September 8 Microsoft Windows Update Stack privilege-escalation patch on any machine holding your family's emergency documents. Local escalation to SYSTEM means everything on that box.
Hawaii County residents with Disaster 4936 registrations: confirm your FEMA inspection is scheduled. Twelve valid registrations show zero inspected so far. (disasterassistance.gov)
Print one paper map of your evacuation route this week. K5 geomagnetic activity plus a continuing electron flux alert means GPS degradation is a live scenario, not a theoretical one.
Boaters near South Padre Island, check the new Coast Guard temporary safety zone on the Laguna Madre published in the Federal Register September 8 before you launch. (federalregister.gov)
Preparedness Guidance
Start with the coast, because that is where today's science lands. If you live on or behind a barrier island, your job this week is to establish a baseline, not to buy anything. Photograph your dune crest with a person or a fence post for scale. Find the wrack line and note whether it sits above or below the crest. Do it again after every surge event, including the ones that make no news. The Santa Catarina work says the storm that breaches you is usually the second one, which means the measurement you take in September is the one that matters in October.
Second threat, entirely different category: space weather. A K5 hit Monday and the electron flux alert renewed at 05:38 UTC this morning. Practically, that means GPS precision degrades and HF radio gets unreliable at high latitudes. Your countermeasure costs nothing. Print a paper map of your evacuation route and a second one of your family rally points, and put them in the glovebox today. Add a battery or hand-crank NOAA weather radio, the piece of gear that works when the constellation does not. And patch your machines: CISA flagged actively exploited Adobe Commerce and Windows Update Stack vulnerabilities on September 8, and losing your document folder to a ransomware crew mid-evacuation is a compound failure nobody plans for.
The meta-lesson from today is measurement asymmetry. We have exquisite instrumentation pointed at incoming threats and almost none pointed at our own defenses. Nobody publishes your dune height. Nobody grades your evacuation route. Nobody tests your family's rally plan. Every one of those is measurable this week, by you, for free. That is not a burden. That is the leverage.
The Phoenix Signal
Pattern recognition from the editorial desk
Sand has been treated as scenery for a hundred years. It is not scenery. It is the last three meters of load-bearing structure between a storm surge and a bedroom, and we inspect bridges, elevators, and boilers while leaving that structure entirely unmeasured. What the Santa Catarina team really did over six years was hold up a mirror: the ocean side of the equation is instrumented to the centimeter, and the land side is a shrug. I keep coming back to how cheap the fix is. A drone. A phone. A neighbor with a tape measure and a calendar reminder. We have been waiting for an agency to hand us a number that we could have measured ourselves all along.
— Ato Phoenix
Coming Next
Aleutian Islands, Alaska · next 24h
Watch for:AVO holds Great Sitkin at ORANGE / WATCH as of 19:02 UTC Tuesday. Watch for increased seismicity or an ash emission report that would move it to RED.
Escalation signal:Any confirmed ash cloud above 20,000 feet in the North Pacific flight corridor.
Polk County, Iowa · 24-48h
Watch for:The NWS Des Moines flood warning runs through Saturday 7 AM CDT. Watch the Fleur Drive gauge for a second rise driven by upstream rainfall on already saturated ground.
Escalation signal:A second crest higher than the first, which is the signature that precedes levee stress.
Democratic Republic of the Congo · 3-7 days
Watch for:WHO published Disease Outbreak News on August 14 and August 28. The next update is the one that tells us whether transmission chains are shrinking or branching.
Escalation signal:A confirmed case outside the current affected health zones, or any case in a border province.
Global · next 24h
Watch for:K5 was reached Monday with an extended K4 warning; the 2MeV electron flux alert renewed Wednesday morning. Watch for a return to storm-level Kp with flux still elevated.
Escalation signal:Kp 6 or higher with sustained electron flux, which pushes satellite operators into safe-mode decisions.
Mindanao, Philippines · 24-48h
Watch for:The M5.0 south of Sarangani produced no tsunami threat. Watch whether the sequence stays isolated or begins clustering offshore in the Celebes Sea.
Escalation signal:A follow-on event above M6.0 in the same offshore zone.
Three things over the next 48 to 72 hours. First, Great Sitkin: any move from ORANGE to RED reroutes North Pacific aviation within hours, and that corridor carries the logistics tail for Hawaii and Alaska response. Second, the Raccoon River at Des Moines, where the warning runs to Saturday 7 AM and saturated ground turns any new rainfall band into a levee-loading problem. Third, SWPC. If Kp returns to 5 or higher with the electron flux alert still running, satellite operators start making real decisions.
What I will be watching overnight is quieter: whether any US coastal management agency picks up the Santa Catarina methodology during peak week. The tools are free, the physics is published, and hurricane season has three weeks of peak left. Somebody is going to be first. I want to know who. Stay satisfyingly prepared. — The Surviva-List Editorial Team
Editor's Note
From the Editorial Desk
Overnight the feeds handed me twin M5.0 quakes in Argentina and the Philippines, two volcanoes sitting at orange, and a K5 geomagnetic punch. I led with sand instead, because a six-year record out of southern Santa Catarina just answered a question every coastal community keeps asking after the fact: which stretch breaks first.Watch dune crest elevation, not wave height, over the next 48 hours. NWS Charleston already has Coastal Colleton and Charleston under a coastal flood advisory with a half foot of inundation and dangerous rip currents through 10 PM tonight.Sand is infrastructure. Six years of Brazilian data just told us how to inspect it.
— Ato Phoenix, Editor-in-Chief
