Matthew’s Shrieking Winds Hit Bahamas

Wednesday night was a very stormy night across the heart of The Bahamas as Hurricane Matthew churned through the center of the archipelago. The worst impacts on Wednesday night were likely being felt on Long Island, Great Exuma Island, and nearby smaller islands extending to the northwest, as Matthew moved parallel to these islands and just to the west of them. At 11 pm EDT Wednesday, winds at a personal weather station (PWS) on Staniel Cay, Exumas, located about 50 miles north-northwest of Matthew’s center, were 60 mph, gusting to 67 mph. Winds in Nassau were 17 mph, gusting to 29 mph. Two weather stations on Great Exuma Island reported much higher winds, but these stations have gone offline and so the readings may not be trustworthy: Exuma International Airport (southeast at 119 mph, gusts to 144 mph) and Moss Town (south-southeast at 107 mph, gusts to 131 mph).


Figure 1. Enhanced infrared satellite image of Hurricane Matthew as of 11:15 pm EDT Wednesday, October 6, 2016. Image credit: NOAA/NESDIS.

Intensity update: Headed back to Category 4?
Officially, Matthew’s top sustained winds were at 115 mph as of the 11 pm EDT advisory from the National Hurricane Center. This makes Matthew a low-end Category 3 storm. Matthew’s efforts to reorganize and reintensify on Wednesday afternoon and evening were been a mixed bag. Hurricane Hunters found Matthew’s eyewall partially open at times, and the top surface winds had yet to rebound significantly. On the other hand, the convective core of showers and thunderstorms surrounding Matthew’s center has intensified and expanded, and Matthew’s central pressure began dropping late Wednesday night, a sign that the enhanced convection may be helping Matthew to regain intensity. An 11:03 pm Wednesday fix from the Air Force hurricane hunters found that Matthew had finally closed off its eyewall, and the central pressure had dropped to 959 mb. In its 11 pm EDT discussion, NHC noted that Matthew’s eye--once again distinct on satellite imagery--has contracted to about 17 miles wide, another sign of strengthening. It may take until midday Thursday for any substantial drop in Matthew’s pressure to result in a stronger wind field. NHC predicts that Matthew will again hit Category 4 intensity by Thursday evening. The 00Z Thursday SHIPS model forecast gave an 11% chance that Matthew would intensify enough to become a Category 5 storm again by Thursday night.


Figure 2. NHC forecast for Matthew as of 11 PM EDT Wednesday, October 6, 2016.

Track update: Still heading for Florida coast
Matthew continues heading on a northwest track that will take it just west of New Providence Island, putting Nassau in the most intense part of the storm’s dangerous right-hand side. However, Matthew may head just far enough west to avoid the worst-case impacts for Nassau, most likely tracking over parts of Andros Island. Unlike the mountainous parts of eastern Cuba and western Haiti that took a toll on Matthew as it crossed them, Andros is a very flat island, so it should have little or no effect on the storm.

Should Matthew continue on its due-northwest track, it would come uncomfortably close to making landfall along the urban corridor from Miami to Palm Beach. Our most reliable track models insist that Matthew will begin angling just to the right before landfall, which would keep the southern part of this corridor on Matthew’s weaker side. Broward County (including Fort Lauderdale) is in a hurricane warning, while Miami-Dade County is in a tropical storm warning. The risk of dangerous impacts, including hurricane-force winds, ramps up greatly from Palm Beach northward. The most recent NHC forecast (see Figure 2 above) keeps Matthew as a Category 4 hurricane as it reaches the Melbourne area on Friday morning and a strong Category 3 by Friday evening just east of Jacksonville. The 00Z Thursday run of the GFS model agrees very closely with the official NHC track. Hurricane Warnings are now in effect from Broward County to Fernandina Beach, Florida, with a Hurricane Watch extending northward to Edisto Beach, South Carolina.

If NHC’s forecast were to prove spot-on, conditions along Florida’s central and northern Atlantic coast could easily top anything observed in many decades. As we noted this afternoon, the Melbourne area--including Kennedy Space Center--has never recorded a major hurricane. Hurricane Dora struck near St. Augustine, FL, as a Category 3 in 1965, but otherwise the Jacksonville area and its 1.5 million residents have never experienced a hurricane of this magnitude. A northward-moving “coast scraper” hurricane has the potential to cause widespread damage over an enormous swath of populated area. In general, the storm surge threat with such a storm would be less than for a perpendicular landfall, but as the Atlantic coast begins curving toward Georgia, the risk of dangerous storm surge will rise markedly, with inundations of up to 8 feet possible from Sebastian Inlet, FL, to the Georgia/South Carolina border.

The bottom line: Matthew continues to pose a potentially dire threat to much of Florida’s Atlantic coast, with major impacts likely along the Georgia coast and potentially further north.

See our previous update for more background on the various threats posed by Matthew. As always, NHC is the place to turn for official warnings, watches, and local statements.

Jeff Masters will be back with our next update on Thursday morning.

Bob Henson