LATE MONDAY UPDATE: At least 5 percent probabilities of tropical storm force winds spread through the entire Florida peninsula Monday night, reaching 30-50 percent in South Florida over the next five days. (Credit: NHC)
ORIGINAL POST: A stunning shift to the southwest for the Hurricane Irma forecast have put the Florida Keys in play for impacts late this week.
Needless to say, this has been an evolving forecast and major changes can and have been taking place every six hours, with new information coming out of the National Hurricane Center. Forecast model runs have moved west and south over the past several days.
Early Monday morning, the Keys were in a 10 percent probability bracket for tropical storm force winds by late Friday or early Saturday morning, and that 10 percent edged up into southeastern Florida as well. The 20 percent probability bracket was just off-shore and a 40 percent bracket was moving into Andros Island in the Bahamas.
Monday’s major forecast models showed Irma skirting the coast of Cuba and then making a sharp right turn into the Keys and the Florida peninsula. NOAA’s GFS had the storm moving over Havana and then into the Keys before riding up the state as a blockbuster hurricane.
The European (ECMWF) had Irma making the sharp right turn sooner, moving off the coast of Cuba and plowing north just off Florida’s East Coast. The Canadian model (CMC) favored the GFS track, although it kept the storm off the coast of Cuba. The Navy model (NAVGEM) also pulled it into the Florida peninsula from the south.
Expect more adjustments from the models — meteorologists said the , but as the weekend approaches, forecasts will begin consolidating.
The NHC’s Robbie Berg said in the agency’s early morning analysis: “Remarkably, the track models are very tightly clustered through day 5, which increases the confidence in the westward shift of the latest NHC forecast.”
Track errors at five days out are about 225 miles on average, Berg noted, and he reminded readers that strong winds and heavy rain extend “well away” from the center.
A NOAA Hurricane Hunter aircraft investigating Irma reported at 8 a.m. that winds had increased to 120 mph with higher gusts, and the hurricane-force winds extended 30 miles from the center. Tropical storm-force winds extended 140 miles from the center.
“Additional strengthening is forecast through Tuesday night,” the NHC said.
Late Monday forecast tracks for Hurricane Irma. (Credit: SFWMD)