Now that more disasters have been revealed, it’s time to look at them more closely in the upcoming dev diaries for Cities: Skylines - Natural Disasters. This time around we’ll introduce the Thunderstorm! It is about very bad weather that happens on an area approximately the size of one map tile. The main challenge with a Thunderstorm are the lightnings. They can start fires, both in the city and in forests.While the Thunderstorm is a disaster in itself, the effects it causes can also appear as separate disasters. Fires now spread in the city a lot easier than before, so having a lightning hit a building and set it on fire is a much bigger deal than previously. Fires spreading more easily will be part of the free update, so all users will experience some new challenges in their cities.As a wholly new thing, forest fires can also happen. They can start independently, but also be started by lightnings of a Thunderstorm. A forest fire may not pose a threat to the city, but the fire spreads in the woods also, and upon reaching the city, can also spread to buildings.The Fire Fighting Helicopters are important for both building fires and forest fires. Helicopters can reach buildings even when there’s no road connection, and can help the fire brigade get faster to distant locations or past traffic jams. There’s a new city policy that can be used to have areas where emergency road vehicles will not travel, so you can have helicopter only areas in the city. Smart use of helicopter only policies can help you to for example reserve the center of the city only for helicopter emergency vehicles, so citizens can get help fast and your roads will still be free of fire trucks and ambulances. Medical helicopters still need a Hospital to take the patients to, but because the Hospital is a separate building, you can have it in the middle of the city and place your Medical Helicopter Bases further out where they are out of way.Helicopters also handle forest fires. They can easily fly over a burning forest, empty their water buckets, and then return to a water source for more. The limiting thing is that forest fires need to be quite close to the city to be noticed by the Fire Brigade. To help with this, you can place rustic looking Firewatch Towers. These towers house tireless heroes who are always on the lookout for fires. Each tower has an operating range, affected a bit by the landscape (even heroes cannot see through mountains), and if within that range a forest fire starts, they immediately alert the Fire Brigade. Ideally, any forest areas next to the city should be covered by Firewatch Towers, so forest fires cannot reach to city unnoticed. Firewatch Towers are a small investment to keep the city safe, lest a roaring wall of fire suddenly appear from the forest and spreads to city buildings.The Thunderstorm itself can feel quite harmless, but the results of one striking when you are unprepared can be drastic. So Firewatch Towers help with forest fires, what about the buildings then? A policy comes to help! By setting a policy that it is mandatory for tall buildings to have Lightning Rods, you can significantly lessen the chance of buildings catching fire as a result of a lightning strike. There is an upkeep cost, but keeping citizens safe from fire is important.Disasters can spawn other disasters, but your city can be prepared to meet the challenge. Or you can just watch the world burn, that can be fun too!