The 20-minute countdown, live
Drop strikes on the map. A strike inside 10 miles starts a 20:00 lightning delay. Every new strike inside the ring resets it to 20:00. Strikes outside the ring don't count. When the clock hits zero, everyone gets the all clear.
No strikes within 10 mi.
Push alerts appear here…
Simulation for illustration only. Click or tap anywhere on the map to place a strike yourself.
Powered by the National Lightning Detection Network
The National Lightning Detection Network (NLDN) is a ground-based network of lightning sensors spread across the United States, owned and operated by Vaisala Xweather and running continuously since 1983. When lightning hits, multiple sensors pick up its electromagnetic signal; by comparing when and from which direction each sensor heard it, the network pinpoints where and when the strike happened — within seconds.
It's the same kind of data that professional lightning-warning systems used by golf courses, schools and stadiums rely on. StrikeClear receives this strike data through Vaisala Xweather and checks every strike against your pool's 10-mile ring.
StrikeClear is an independent product of Landfall Lightning and is not affiliated with or endorsed by Vaisala. Figures at right are as published by Vaisala.
Source: vaisala.com — National Lightning Detection Network, accessed Nov 2026.
What that means for you: for strikes more than about 3 miles away, Vaisala says the alert arrives before you'd hear the thunder. No more guessing from the guard chair.
How it works
We pin your pool
We set your pool's exact location and a 10-mile alert radius (configurable).
Strikes detected in seconds
Cloud-to-ground strikes are detected nationally and checked against your ring as they happen.
Pushes only when it matters
Lifeguards, managers, residents or your family get a push when a delay starts, when it resets, and when it's all clear.
Who it's for
HOAs & pool associations
Board members and residents see why the community pool closed and exactly when it reopens. Fewer calls, fewer arguments, one consistent policy.
Pool owners
Backyard pools, swim clubs, hotels and apartment communities. Know when to get everyone out of the water and when it's OK to go back in, without watching the radar.
Pool service & management companies
One documented lightning policy across every pool you clean, manage or staff, with alerts going straight to your techs, guards and clients.
Swim clubs & lifeguard teams
Keep practices, meets and guard rotations on schedule with an objective, shared restart time.
About the 20 minutes
The National Weather Service's message is simple: "When thunder roars, go indoors." NWS guidance is to wait 30 minutes after the last thunder before going back outside. Many professional lightning policies instead use a 10-mile radius and a 20-minute reset based on detected strikes — that's what our pilot uses by default, and both the radius and the timer are configurable to match your own policy.
StrikeClear is a decision aid, not a guarantee of safety. Lightning can strike without warning and not every strike is detected. Always follow your organization's safety policy and lifeguard judgment.
Bring StrikeClear to your pool
HOA boards, community pools, swim clubs and pool companies: we're onboarding a small group of pilot pools around Wilmington, NC and beyond. Homeowners: get on the list and we'll let you know when the app launches.
Book a pilot Get notified at launchor email kwj627@gmail.com