Thursday, September 29, 2016

Matthew Becomes the Fifth Hurricane of the 2016 Atlantic Hurricane Season; Jamaica, Hispañola, Cuba, Bahamas Threat

September 29,2016
Hurricane Matthew became the fifth hurricane of the 2016 Atlantic hurricane season early Thursday afternoon, and poses a danger to Jamaica, parts of Hispañola, eastern Cuba, and the Bahamas early next week. It's potential U.S. impact later next week still remains unclear.
(MORE: Hurricane Central)
Matthew was located 150 miles north-northeast of Curaçao, as of Thursday evening.

Current Storm Status
A Hurricane Hunters reconnaissance mission early Thursday afternoon measured flight-level winds a few thousand feet above the sea of just over 85 mph northeast of the center of circulation, and a dropsonde just 2,100 feet above the surface sampled winds of 94 mph, prompting the upgrade to hurricane status.
A tropical storm watch continues for Aruba, Bonaire, Curaçao and the northern coast of Colombia. Winds of 40 mph or greater are possible in the "ABC Islands" beginning later Thursday, and in northern Colombia on Friday.

Current Watches/Warnings
Radar from Meteo France shows the heaviest rain has ended, but a few bands of rain are still lingering over parts of the Lesser Antilles, but will slowly diminish the remainder of Thursday.
George F.L. Charles Airport on St. Lucia picked up 9.21 inches of rain Wednesday. On the south side of the island, Hewanorra Int'l Airport picked up 13.19 inches of rain in just 12 hours from 8 p.m. Wednesday through 8 a.m. Thursday, according to the Antigua Met Service.
A wind gust to 89 mph was reported in St. Pierre, Martinique, Wednesday evening. Some stations are elevated at 50 to 100 feet. Sustained winds of 39 mph were reported on the island of Barbados.

The 'Caribbean Right Turn'

Matthew is currently experiencing some wind shear provided by southwest winds several thousand feet above the surface, which has blown convection away from its center of circulation.

Current Satellite, Wind Shear
This wind shear may temporarily pump the brakes on any significant intensification of Matthew the next day or so. However, convection wrapping around the previously-exposed center may fend off the shear.
First up, given the southern track, outer bands of rain and winds to tropical storm force are possible in the typically drier "ABC Islands" – Aruba, Bonaire and Curaçao – as well as parts of coastal Venezuela and Colombia Thursday through early Saturday.
Beyond that, uncertainty is still considerable on the critical details of this system.
(MORE: Just Because It's Fall Doesn't Mean We Shouldn't Pay Attention to the Tropics)
Over the next couple of days, Matthew should continue to move west as it rides the southern periphery of the Bermuda high.
Sometime this weekend, Matthew should make its long-anticipated northwest or northward turn in the Caribbean Sea, as the system reaches the southwestern edge of the Bermuda high.
The critical details regarding when exactly that turn is made, how sharp it is, and Matthew's intensity at that time will dictate the impacts for Jamaica, Hispañola, and eastern Cuba.
Unfortunately, there is still some important forecast uncertainty regarding those important details, which is common for a tropical cyclone forecast several days out.
(MORE: Facts/Myths About the Hurricane Cones of Uncertainty)
For now, impacts could begin in Jamaica and Hispañola (particularly Haiti) as soon as Sunday night, and in eastern Cuba as soon as Monday.
In addition, there is uncertainty regarding Matthew's intensity as it nears those locations. Matthew may be stronger than the current forecast.

Projected Path and Intensity
Beyond that, Matthew is likely to begin impacting parts of the central or southeast Bahamas by Tuesday.
(FLASHBACK: Hurricane Joaquin 2015)

U.S. Threat?

Beyond that, it is still too soon to determine which parts of the U.S. may be in danger next week.
Ensemble forecast guidance includes scenarios where Matthew moves north, then northeast remaining well off the East Coast, but also includes tracks into the Gulf of Mexico next week.
(MORE: Why Long-Range Model Forecasts For the Tropics Can't Often Be Trusted)
The track will depend, in part, on the steering currents in the atmosphere.
  • If high pressure aloft is stronger near or over the Eastern U.S., that may steer Matthew closer to some part of the U.S.
     
  • Conversely, if a southward dip in the jet stream is in play over some part of the Eastern U.S., that could help deflect Matthew to the east.
For now, ensemble forecast guidance is lessening the threat of a Gulf of Mexico track, but it is still too far out to rule out an East Coast threat later next week.
There is also considerable uncertainty on how fast Matthew moves.
Even if Matthew stays sufficiently off the East Coast, a threat of dangerous swells, coastal flooding, and beach erosion is likely to be in play along parts of the Eastern Seaboard.
Colorado State University tropical scientist, Dr. Phil Klotzbach noted 60 percent of landfalling U.S. hurricanes from September 27 and beyond since 1900 have occurred in Florida. However, while lower probability, there have been landfalls this late in the season as far west as the Texas Gulf Coast.
Typical October named storm origin locations and tracks.
For now, all interests in the Caribbean Sea, Gulf of Mexico, Bahamas and U.S. East Coast should continue to monitor the progress of Matthew. Check back with us frequently at weather.com for any important forecast updates.
Now is a good time to make sure you're prepared before the storm. Are you #HurricaneStrong?
MORE: Atlantic Category 5 Hurricanes

No comments:

Post a Comment