The Impacts Tab Is Here

The biggest addition in Beta 1.5.4 is the Impacts tab on every alert detail panel. Click any active alert and you'll now see two tabs at the top: Details (the existing view) and Impacts — a full breakdown of what's at stake in the affected area.

The Impacts tab pulls together data from five federal datasets to give you a real picture of who and what is in the path of a warning:

Population & Housing

Total population and household count for every county under the alert, pulled from the 2020 U.S. Census. You'll see the combined totals at a glance, with a per-county breakdown at the bottom.

Vulnerable Residents

Three numbers that matter most for life-safety:

• Elderly (65+) — from Census ACS 2022, with percentage of total population
• Children under 5 — same source, same format
• Mobile/manufactured homes — the housing type most vulnerable to wind and tornado damage, with percentage of total housing units

Infrastructure

A grid of critical facilities in the affected counties, sourced from the Census County Business Patterns (2021) and the USACE National Inventory of Dams (2024):

Hospitals · Nursing Homes · Urgent Care · Pharmacies · Schools · Colleges · Child Care · Power Plants · Water Treatment · Airports · Dams

Only facilities that actually exist in the affected counties are shown — no zero-count clutter.

Historical Flood Risk

A risk rating based on the number of federally declared flood disasters per county since 1953, sourced from FEMA OpenFEMA. Counties are rated from Minimal to Very High so you can immediately tell whether an area has a long history with flooding.

County Breakdown

Every county under the alert listed individually with population, so you know which jurisdictions are most exposed.

Bug Fixes

Storm Reports & Active Fires No Longer Block Alert Hover

When Storm Reports or Active Fires layers were enabled and then turned off, a transparent canvas element was left in the DOM — silently intercepting mouse events and breaking the alert polygon hover effect. The layers now correctly yield pointer control when disabled.

Sort Mode Now Applies Immediately

Switching sort order (Severity, Time, Event) in the sidebar now takes effect instantly without requiring a page refresh.

Alaska Filter & State Filter Apply Immediately

Toggling the Alaska exclusion, switching the state filter on/off, selecting individual states, or clicking state quick-pills in the sidebar now updates the alert list on the spot.

Expired Alerts Leave the Sidebar

The NWS API sometimes continues returning alerts for several minutes after their expiry time passes. The sidebar now filters them out client-side as soon as their timestamp is hit — and when a countdown timer reaches 00:00, the card is removed from the list immediately without waiting for the next server poll.

Data Sources Added

All of this data is pre-processed and bundled as static files — no real-time calls to external agencies when you open an alert.

NWSAlerts.net is an independent project and is not affiliated with NOAA, the NWS, or any U.S. government agency. Always follow guidance from your local NWS office during severe weather.