Here’s what to expect as the Keys get hit by Hurricane Irma

Tropical storm force winds were expected to arrive in the Florida Keys by Saturday morning from Hurricane Irma.

Tropical storm force winds are sustained winds of 39 miles per hour. Typically, public transportation, first responders, and drawbridges close hours before those wind speeds are forecast.

Rains associated with Irma were moving across the Keys Saturday morning, with hurricane force gusts possible, according to the National Weather Service.

The weather service predicts surface wind speeds of 126 miles per hour before 6 a.m. Sunday at American Shoal Lighthouse and Looe Key Lighthouse in the lower Keys on the Atlantic Ocean side. Higher wind speed gusts are expected.

The weather service also forecasts 107 mph winds with gusts of 125 mph by 9 a.m. Sunday at Key West Mooring Field, on the Gulf of Mexico side of Key West. Forecasts of 113 mph winds are expected by Sunday morning at Sand Key Light—off the coast of Key West on the Atlantic Ocean side.

The maximum sustained winds of Irma on Saturday morning were 130 mph, with higher gusts.

All of the Keys are under a storm surge warning, along with all of the South Florida coastal lines. Surges of five to 10 feet above ground over portions of the Keys probable, according to the weather service. Those estimates take into account that the storm surges may occur at high tide—which exacerbate the depth.

Storm surges in the upper Keys were expected to begin on Saturday morning, functioning like waves that continuously accumulate, moving inland. As Irma’s eye moves near the Keys, counter-clockwise motion winds will cause surges from the west in the lower Keys.

Along the immediate coast, a combination of onshore winds and large waves will cause the deepest water, according to the weather service. Surge-related flooding also depends on the tides.

In addition to storm surges while Irma passes through, 10 to 20 inches of rain are expected in the Florida Keys through Tuesday night. In some areas, rainfall could be 25 inches.

By 8 a.m. Saturday, Irma was 193 miles southeast of Key West moving at 12 mph. It is expected to make landfall in the Keys Saturday night and into Sunday morning.

Four last resort shelters were still open Saturday morning, with no services available. Those include:

▪ Coral Shores High School (89951 Overseas Highway, Plantation Key)

▪ Marathon High School (350 Sombrero Road, Marathon)

▪ Sugarloaf Middle School (225 Crane Boulevard, Sugarloaf Key)

▪ Key West High School (2100 Flagler Avenue, Key West)

Miami Herald staff staff writer Chuck Rabin contributed to this report.