Transportation context
Official alerts may describe sharply reduced visibility affecting roads, bridges, airports or marine travel. This map preserves that wording but does not report measured visibility, crashes, closures, delays, pavement conditions or route safety.
How to read this
Fact: alert categories, times, descriptions and shapes come from NWS. Limit: visibility can change quickly and vary inside every alert area. Read the full official alert and follow transportation and local-authority guidance.
Source & runtime status
NOAA National Weather Service Alerts API and official affected-zone endpoints, requested directly in your browser. Anonymous and keyless; no alert snapshot is bundled. Geometry loading uses four-request concurrency, caching and an 80-zone ceiling. Source/license notes · NWS API documentation
