All amenities open

How often we look: every 4 minutes right now

When lightning is anywhere in the area we check every 60 seconds. When the sky is clear we check every 4 minutes, and the moment a single strike appears we speed back up. Outside the hours an amenity is watched we stop checking altogether, unless something is still closed. Detection to alert runs about a minute behind real time — the weather service publishes a strike 15 to 20 seconds after it lands, and we look at most 60 seconds later.