When is a hurricane/tropical storm warning put into effect for a specific region?

A hurricane/tropical storm watch is put into place when it is possible for tropical storm conditions to hit the region within 24 hours.

Hurricanes, Tropical Cyclones and Typhoons

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Based upon 2013 numbers, US electricity generated by coal was 39%. What was the percentage generated by renewables?
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MegaCities: Top 10 Most At-Risk Cities
1.Tokyo68
2.Los Angeles25
3.Manila18
4.Bandung17
5.Santiago16
6.Nagoya9.4
7.Osaka9.4
8.Jakarta9
9.Lima8
10.Chengdu7.5
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