After "carving a path of destruction through the Caribbean," a path which left 90% of Barbuda "uninhabitable" and nearly a million people without power in Puerto Rico, a slightly weakened, but still devastatingly massive Category-4 Hurricane Irma is closing in on Florida. Here is the latest from the National Hurricane Center:
Irma is forecast to remain in a favorable warm water, light shear environment for the next 36-48 h. The intensity guidance shows a slow weakening during this time, but Irma is expected to remain at least a Category 4 hurricane until landfall in Florida. After landfall, a fairly quick decay in maximum winds is expected due to land interaction and increased shear, although Irma's large wind field is likely to still produce hurricane-force winds over a large area. There are two caveats to the intensity forecast. First, some additional weakening could occur during the eyewall replacement, followed by re-intensification as the cycle completes. Second, the ECMWF, UKMET, and NAVGEM forecast a track over or close to the coast of Cuba that is not currently a part of the track forecast. If this occurs, Irma could be weaker than currently forecast along the later parts of the track.
KEY MESSAGES:
1. Irma is an extremely dangerous Category 4 hurricane and will continue to bring life-threatening wind, storm surge, and rainfall hazards to the Turks and Caicos Islands and the Bahamas through Saturday. Heavy rainfall is still possible across portions of Hispaniola through today. Hurricane conditions will also spread over portions of the north coast of Cuba, especially over the adjacent Cuban Keys through Saturday.
2. Severe hurricane conditions are expected over portions of the Florida peninsula and the Florida Keys beginning Saturday night. Irma is likely to make landfall in southern Florida as a dangerous major hurricane, and bring life-threatening storm surge and wind impacts to much of the state. A Hurricane Warning is in effect for southern Florida, the Florida Keys, Lake Okeechobee, and Florida Bay, while Hurricane Watches have been issued northward into central Florida.
The NHC is currently forecasting that Irma will make its Florida landfall sometime late Saturday night or early Sunday morning as a powerful Cat-4 storm...
...packing winds of 155 mph...
FORECAST POSITIONS AND MAX WINDS
- INIT 08/0900Z 21.7N 73.8W 135 KT 155 MPH
- 12H 08/1800Z 22.1N 75.7W 135 KT 155 MPH
- 24H 09/0600Z 22.6N 77.8W 135 KT 155 MPH
- 36H 09/1800Z 23.3N 79.4W 135 KT 155 MPH
- 48H 10/0600Z 24.5N 80.4W 130 KT 150 MPH
- 72H 11/0600Z 28.0N 81.5W 90 KT 105 MPH...INLAND
- 96H 12/0600Z 33.0N 84.0W 40 KT 45 MPH...INLAND
- 120H 13/0600Z 36.0N 87.0W 25 KT 30 MPH...INLAND
...and a storm surge of up to 10 feet in the Florida Keys.
STORM SURGE: The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water is expected to reach the following HEIGHTS ABOVE GROUND if the peak surge occurs at the time of high tide...
- Jupiter Inlet to Bonita Beach, including Florida Keys...5 to 10 ft
- Bonita Beach to Venice...3 to 5 ft
- Jupiter Inlet to Sebastian Inlet...3 to 6 ft
The deepest water will occur along the immediate coast in areas of onshore winds, where the surge will be accompanied by large and destructive waves. Surge-related flooding depends on the relative timing of the surge and the tidal cycle, and can vary greatly over short distances. For information specific to your area, please see products issued by your local National Weather Service forecast office.
Meanwhile, the strong winds are expected to take a toll on Florida's power grid leaving a million or more people without power, potentially for weeks. Per Reuters:
Hurricane Irma poses a bigger menace to power supplies in Florida than Hurricane Harvey did in Texas because Irma is packing near 200 mile-per-hour winds (320 km/h) that could down power lines, close nuclear plants and threats to leave millions of homes and businesses in the dark for weeks.
Irma’s winds rival the strongest for any hurricane in history in the Atlantic, whereas Harvey’s damage came from record rainfall. Even as Houston flooded, the power stayed on for most, allowing citizens to use TV and radio to stay apprised of danger, or social media to call for help.
“When Harvey made landfall in Texas it made it fully inland and weakened pretty quickly. Irma, however, could retain much of its strength,” said Jason Setree, a meteorologist at Commodity Weather Group.
Most Florida residents have not experienced a major storm since 2005, when total outages peaked around 3.6 million during Hurricane Wilma. Some of those outages lasted for weeks.
Setree compared the projected path of Irma to Hurricane Matthew in 2016, which knocked out power to about 1.2 million FPL customers in October.
“Should Irma’s worst fears be realized, our crews will likely have to completely rebuild parts of our electric system. Restoring power through repairs is measured in days; rebuilding our electric system could be measured in weeks,” FPL Chief Executive Eric Silagy said.
And, of course, panic hoarding has already set in and left store shelves empty across much of Florida.
#hurricaneirma2017 #Florida Wal-Mart pic.twitter.com/MlpyVWBDLs
— #TheResistance (@BoneKnightmare) September 6, 2017
Not surprisingly, the mad rush to evacuate has left about 40% of the gasoline stations in the Miami-Fort Lauderdale region without fuel. Floridians have turned to the Crowd-Sourced ‘Gas Buddy’ App to determine which stations still have gas.
Not surprisingly, the shuttered stores have resulted in massive gas lines with people reportedly waiting up to 90 mins for fule.
Another night of long gas lines in South Florida as people prepare for #HurricaneIrma -- LIVE in Sunrise NEXT at 11pm on @NBC6. pic.twitter.com/OvWDZ5v2Xk
— Michael Spears NBC6 (@MikeSpearsNBC6) September 7, 2017
Meanwhile, as we noted yesterday, meteorologists from Weather Underground are warning that the most devastating impacts of the storm could be felt much further north in towns along the coast of Georgia and South Carolina where the storm surge could be a catastrophic 20-28 feet high in certain areas. To put that in perspective, Hurricane Katrina in 2005 set a record for the largest storm surge ever recorded along the U.S. coast at 27.8 feet.
If Irma makes a trek up the East Coast from Miami to southern South Carolina as a Category 3 or 4 hurricane, as the models currently suggest, the portions of the coast that the eyewall touches will potentially see a massive and catastrophic storm surge, breaking all-time storm surge records and causing many billions of dollars in damage. Even areas up to a hundred miles to the north of where the center makes landfall could potentially see record storm surges. The area of most concern is the northern coast of Florida, the coast of Georgia, and the southern coast of South Carolina, due to the concave shape of the coast, which will act to funnel and concentrate the storm surge to ridiculous heights. If we look at wunderground’s storm surge maps for the U.S. East Coast, we see that in a worst-case Category 3 hurricane hitting at high tide, the storm tide (the combined effect of the storm surge and the tide) ranges from 17 – 20’ above ground along the northern coast of Florida, and 18 – 23 feet above ground along the Georgia coast. If Irma is a Cat 4, these numbers increase to 22 – 28 feet for the coast of Georgia. This is a Katrina-level storm surge, the kind that causes incredible destruction and mass casualties among those foolish enough to refuse to evacuate.
As Weather Underground notes, Savannah in Southern Georgia could see a surge of up to 23 feet if Irma strikes as a Category 3 storm. Obviously, the surge would be even larger if Irma manages to maintain Cat-4 winds.
Maximum of the "Maximum Envelope of Waters" (MOM) storm tide image for a composite maximum surge for a large suite of possible mid-strength Category 3 hurricanes (sustained winds of 120 mph) hitting at high tide (a tide level of 3.5’) along the coast of Georgia. What’s plotted here is the storm tide--the height above ground of the storm surge, plus an additional rise in case the storm hits at high tide. Empty brownish grid cells with no coloration show where no inundation is computed to occur. Inundation of 19 – 23’ will occur in a worst-case scenario along most of the coast.
Meanwhile, further north in Charleston, SC the surge could also exceed 20 feet and flood areas many miles inland from the shore.
Maximum of the "Maximum Envelope of Waters" (MOM) water depth image for a composite maximum surge for a large suite of possible mid-strength Category 3 hurricanes (sustained winds of 120 mph) hitting at high tide (a tide level of 2.5’) along the coast of South Carolina near Charleston. If Irma is a Cat 3 in South Carolina, a worst-case 17 – 21’ storm tide can occur.
All of which should make for a fairly depressing weekend of storm watching.