A guide to the types of advisories issued during hurricane season

Hurricane Fiona has passed through Puerto Rico, leaving much of the country without power, and is now expected to make landfall in the Dominican Republic Monday.

The storm will then make its way toward Turks and Caicos on Tuesday, and in advance, the National Hurricane Center has issued several advisories for countries in the region.

But what do they all mean?

Hurricane vs. tropical storm

The NHC has issued warnings across the Caribbean for two types of storms – hurricanes and tropical storms.

Hurricanes are the last stop in the hierarchy of tropical cyclones. They have wind speeds of 74 miles per hour and greater. Before that, they are tropical storms, which have wind speeds ranging from 39 to 73 mph. And before the cyclones become storms, they are classified as tropical depressions, which have maximum wind speeds of 38 miles per hour.

A watch vs. a warning

Both hurricane and tropical storm watches are issued when one is possible somewhere in the area, but not guaranteed. They are typically issued within 48 hours of the cyclone's anticipated arrival. When these are issued, you should review your evacuation plan and listen to the latest guidance from local officials.

A hurricane watch for Fiona is currently in place on the north coast of the Dominican Republic, while a tropical storm watch is in effect for the southern coast.

Hurricane and tropical storm warnings are more serious and are announced when one or the other is expected in that area. These are typically issued within 36 hours of their anticipated arrival. During these, all storm preparations should be completed, or evacuations should be made if directed.

Both types of advisories can be accompanied by storm surges and river and coastal flooding.

Hurricane warnings for Fiona have been issued in Puerto Rico, Turks and Caicos and the north-south corridor of the Dominican Republic.

Tropical storm warnings have been issued for the north coast of the Dominican Republic and southeastern Bahamas.