What's sitting under America's active National Weather Service alerts right now: the people, their homes, and what those homes are worth. Storm-based warnings (tornado, severe thunderstorm, flash flood) are matched to the 85,000 census tracts inside their actual polygons, not whole counties. Updated every five minutes.
| ALERT | AREA | HOME VALUE | PEOPLE | MOBILE HOMES | 65+ | ENDS |
|---|
The people and homes come from the Census Bureau's American Community Survey (2020–2024, five-year estimates) for every census tract, about 4,000 people each. "Home value" is the Census's aggregate value of owner-occupied homes: what owners say their homes would sell for. Rentals and businesses aren't included, so this is a floor on what's exposed, not the full replacement cost.
Which tracts are "in" an alert: a tract counts when its center (the Census internal point) falls inside the warning polygon. Alerts with no polygon (watches, heat and winter products, most advisories) use their NWS forecast zones or fire-weather zones. A home under two overlapping warnings is counted once in the totals.
The year so far uses Iowa Environmental Mesonet's archive of every storm-based warning polygon, counting each warning's first polygon once. "Home value warned" adds up every warning, so a house warned three times counts three times. "Warned at least once" counts each house once. Past years are measured against today's homes and values.
This shows what was under the warning, not what was damaged. Most warned homes come through fine.