11am SUNDAY UPDATE — Hurricane Watch in Florida.
Dorian has become Category 5 with sustained winds near 180 mph, the strongest hurricane in modern records in the northwest Bahamas! Catastrophic conditions now in the Abacos Islands. Grand Bahama Island (Freeport) Sunday night and Monday.
*Florida: Hurricane Watch and Storm Surge Watch from Broward/Palm Beach County line up to Volusia/Brevard County line. Tropical Storm Watch for Lake Okeechobee. A Storm Surge Watch means the possibility of life-threatening inundation, from rising water moving inland from the coastline, during the next 48 hours.
Dorian has grown larger in size and should move closer to Florida, late Monday through Tuesday night. Hurricane-force winds extend outward up to 45 miles from the center, and tropical storm-force winds extend outward up to 140 miles.
One other tidbit I found very interesting about Hurricane Dorian: Watched National Hurricane Center veteran Dr. Ed Rappaport on TV, late Saturday night. He noted they were more sure of Dorian’s intensity than its track, when that’s usually the other way around!
Graphics automatically updated below. New article after 5pm ET.
The National Hurricane Center’s Saturday 5pm headline: ‘Severe Hurricane Dorian expected to hit portions of the northwestern Bahamas hard on Sunday’
Florida may be avoiding a catastrophic run-in with powerful Hurricane Dorian but at 5pm Saturday, the National Hurricane Center issued a Tropical Storm Watch for about 130 miles of the state’s east coast — and the severe impact may be starting in the Bahamas.
Dorian is a Category 4 hurricane with sustained winds near 150 mph, and gusts even higher.
It’s about 350 miles east of West Palm Beach and moving toward the west near 8 mph, which is even slower than it had been, meaning a prolonged time of high wind and heavy rain over a particular area.
And that’s going to continue for now, according to the National Hurricane Center.
“A slower westward motion should continue for the next day or two, followed by a gradual turn toward the northwest. On this track, the core of Dorian should move near or over portions of the northwestern Bahamas on Sunday, and move closer to the Florida east coast, late Monday through Tuesday.”
But many questions remain:
- Will it hit Florida?
- If so, then where?
- If not, then how close will it get?
- And where would be the closest place to Dorian?
Remember not to focus on the exact track since typical forecast errors at day 4 are about 155 miles, and at day 5, about 205 miles.
The National Hurricane Center doesn’t know yet, but the map above shows Dorian’s hurricane-force winds (75+ mph, in maroon) extend outward up to 30 miles from the center, and tropical storm-force winds (39 to 74 mph, in orange) extend outward up to 105 miles.
Keeping that in mind, the Tropical Storm Watch is in effect from Deerfield Beach to Sebastian Inlet, which means tropical storm conditions are possible, generally within 48 hours. In this case, they’re expected Monday, even if the eye of the storm is 100 miles away.
Deerfield Beach is the northernmost city in Broward County, and between Fort Lauderdale and West Palm Beach. About two hours up I-95, Sebastian Inlet separates Indian River County — which is in the Tropical Storm Watch — from Brevard County, home of the Kennedy Space Center, which is not.
That doesn’t mean other parts of Florida won’t escape Dorian.
The National Hurricane Center is warning,
“Given that the area of tropical storm force winds could expand, and taking into account the uncertainty in the track forecast … Interests elsewhere in southern and central Florida should continue to monitor the progress of Dorian. Additional watches may be required” for more of the east coast, Saturday night or Sunday.
“The uncertainty in the track is high while the hurricane is moving slowly across the northwestern Bahamas and near the east coast of Florida. Any deviation of Dorian’s core to the left would result in an increase in the winds along the east coast of Florida.”
Again, focus on the entire cone, rather than just the line running through the middle, because it considers the experts’ and computer models’ growing margin of error for the center of the storm.
But the severe impact is starting in the northwestern Bahamas, where winds should reach tropical storm strength Saturday night, and hurricane conditions by Sunday.
There won’t be relief from wind speed.
The National Hurricane Center says,
“Some fluctuations in intensity are likely, but Dorian is expected to remain a powerful hurricane during the next few days.”
Now paraphrasing, a life-threatening storm surge will raise water levels by as much as 10 to 15 feet above normal tide levels in areas of the Abaco Islands and Grand Bahama Island (Freeport). Near the coasts, the surge will be accompanied by large and destructive waves.
The northwestern Bahamas should expect 10 to 15 inches of rain, with isolated areas getting 25 inches. The rain could cause life-threatening flash floods.
The Bahamas issued a Hurricane Warning at this time Friday for the northwestern islands, including the Abacos, Berry Islands, Bimini, Eleuthera, Grand Bahama Island, and New Providence (Nassau). There’s also a Hurricane Watch for Andros Island.
A Hurricane Warning means hurricane conditions are expected somewhere within the warning area. A warning is typically issued 36 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous. Preparations to protect life and property should be rushed to completion.
A Hurricane Watch means hurricane conditions are possible within the watch area. A watch is typically issued 48 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous.
At the beach, swells will begin to affect the east-facing shores of the Bahamas, Florida, and up into Georgia and the Carolinas during the next few days. The waves are likely to cause life-threatening surf and rip current conditions.
Areas near the shore in the southeastern U.S. are expected to get 4 to 8 inches of rain, with isolated areas getting 12 inches.
East central Florida remains under the threat of direct impacts from Dorian. Preparations should be completed Sunday.
“Dorian will be a major hurricane of Category 3 or 4 intensity as it makes its closest approach to east central Florida.”
People “along the Treasure Coast should prepare for tropical storm conditions arriving prior to sunrise on Monday. Farther north, tropical storm conditions are forecast to arrive in Brevard County by Monday night, and Volusia County (Daytona Beach) by Tuesday.”
“Along the coast, large battering waves and increasing surf will begin to impact the beaches Sunday with an increasing risk for major beach erosion and coastal flooding during the times of high tides Sunday morning around 10am, Sunday night around 10:30pm, around noon on Monday, and Monday evening around 11pm. … Elevated water levels with high surf and wind driven piling of water along the coast will cause moderate to severe erosion of dunes and the risk of coastal flooding.”
“Gusts to tropical storm-force will be possible across interior areas, especially in passing squalls, as Dorian makes its nearest approach to central Florida early next week.”
Check your hurricane plan and emergency supplies kit. If you live in a place particularly vulnerable to flooding, plan to move to safe shelter on higher ground. If ordered to evacuate, do so immediately.
For southeast Florida, due to Dorian’s close proximity,
“Small shifts in the track of the hurricane would bring big changes in expected impacts.”
“Regardless of the eventual track of Dorian, significant marine and beach impacts are expected along the entire southeast Florida coast. A prolonged period of strong winds over the Atlantic coastal waters will cause very hazardous seas, rough surf, and beach erosion through the middle of the week. Coastal flooding is also possible in vulnerable locations along the east coast each day through the middle of the week, particularly during the times of high tide.”
In both areas, prepare for:
- Some damage to roofing and siding materials, along with damage to porches, awnings, carports, and sheds.
- Several large trees snapped or uprooted. Several fences and roadway signs blown over.
- Scattered power and communications outages.
Severe #HurricaneDorian, seen in this “sandwich loop” from NOAA’s #GOESEast, is heading for the northwestern #Bahamas where the Cat. 4 storm is expected to bring life-threatening storm surge and devastating winds. Latest updates from the @NHC_Atlantic: https://t.co/cJtAELwt0H pic.twitter.com/D4jMyuYkWb— NOAA Satellites (@NOAASatellites) August 31, 2019
Hurricane Dorian is the only thing looking good right now, according to the National Hurricane Center.
“Dorian’s satellite presentation continues to be outstanding. The eye has remained very distinct and is surrounded by a ring of very deep convection.”
Dorian is forecast to move over a deep layer of very warm waters, and with low wind shear along the hurricane’s path, there could actually be some additional strengthening possible during the next day or so.
More likely will be fluctuations in intensity due to eyewall replacement cycles that are considered difficult to predict.
After three days, with cooler water and increasing shear, gradual weakening is expected,
“but Dorian will remain a dangerous hurricane through five days.”
There’s a ridge of high pressure north of the hurricane that’s steering it. In about a day or two, most of the global models shift it eastward, and deepen a trough over the eastern U.S.
That should have Dorian drifting northwest and north-northwest while over the northwestern Bahamas and near Florida.
After that time, the hurricane should begin to move a little faster northward and eventually toward the northeast by the end of the five-day forecast period — and that pretty much parallels the southeast U.S. coastline.
CATEGORY 3 HURRICANE: Marks a “major” hurricane. Maximum sustained winds of 111-129 mph. Devastating damage will occur. Well-built framed homes may incur major damage or removal of roof decking and gable ends. Many trees will be snapped or uprooted, blocking numerous roads. Electricity and water will be unavailable for several days to weeks after the storm passes.
CATEGORY 4 HURRICANE: Maximum sustained winds of 130-156 mph. Catastrophic damage will occur. Well-built framed homes can sustain severe damage with loss of most of the roof structure and/or some exterior walls. Most trees will be snapped or uprooted and power poles downed. Fallen trees and power poles will isolate residential areas. Power outages will last weeks to possibly months. Most of the area will be uninhabitable for weeks or months.
CATEGORY 5 HURRICANE: The worst level possible. Maximum sustained winds of 157+ mph. Catastrophic damage will occur. A high percentage of framed homes will be destroyed, with total roof failure and wall collapse. Fallen trees and power poles will isolate residential areas. Power outages will last for weeks to possibly months. Most of the area will be uninhabitable for weeks or months.
This page should update on its own, like ThePhillyFiles weather page, so keep returning to see changes. The National Hurricane Center often begins advisories with a list of what has changed since the previous one.
Full advisories come every six hours (5am, 11am, 5pm and 11pm using Eastern Daylight Time) and intermediate advisories come every three hours in between (8am, 2pm, 8pm, 2am). There will be more advisories if Dorian threatens landfall in the U.S.
Monitor the progress of Dorian and make sure to have your hurricane plan in place. That means keeping a week’s worth of the basic items you’d need on hand throughout every hurricane season (June 1 through Nov. 30).
Keep scrolling down for tweets and now podcasts from the National Hurricane Center, plus more graphics.
Continuing Coverage: Hurricane Dorian
- Hurricane Dorian off the Carolinas, Tropical Storm Warnings in New England Thurs., Sept. 5, 2019
- Hurricane Dorian off Georgia, Tropical Storm Watch extended to Delaware Wed., Sept. 4, 2019
- More watches, warnings for Florida and up the coast for Hurricane Dorian Tues., Sept. 3, 2019
- Hurricane Dorian to get ‘dangerously close’ to Florida, then other states Mon., Sept. 2, 2019
- Hurricane Dorian’s strength, size means ‘hit or miss’ matters little for Florida Sun, Sept. 1, 2019
- Center of Hurricane Dorian more likely to turn before hitting Florida Sat., Aug. 31, 2019
- Hurricane Warning for part of Bahamas as ‘extremely dangerous’ Dorian heads toward Florida Fri., Aug. 30, 2019
- Hurricane Dorian to intensify, be ‘extremely dangerous’ in Florida Thurs., Aug. 29, 2019
- Hurricane Dorian expected to intensify, threaten Florida as a Category 3 Wed., Aug. 28, 2019
- The latest: Tropical Storm Dorian Tues., Aug. 27, 2019
The latest on Hurricane Dorian:
The National Hurricane Center is now providing audio briefings (podcasts) when the media pool is activated by the NHC Public Affairs Officer. That usually happens when a Hurricane Watch is initiated for part of the U.S. coastline. The audio briefings will provide the latest information regarding the hurricane threat and its expected impacts.
- 4 hurricanes in 6 weeks? It happened to one state in 2004. (Hint: I was there, reporting on them all, and also the following year, when the National Hurricane Center ran out of letters for storm names, and used six from the Greek alphabet.)
- Wikipedia: 2004 Atlantic hurricane season
- Wikipedia: 2005 Atlantic hurricane season