Sunday, September 10, 2017

A Hurricane of Anticipation: General Update on Irma Including Radar Imagery, Advisories, Bryan Norcross Statement -- and the Missing Ocean

**This entry was posted September 10, 2017.**

The Sun peers just above the top of the clouds of the inner eyewall of Hurricane Irma on September 6, 2017 in a photo captured by the U.S. Air Force Reserve 53d Weather Reconnaissance Squadron (the "Hurricane Hunters").

This was right around when the storm was at its most intense -- a monster category 5 with maximum sustained winds of 185MPH -- and the "stadium effect" is just an astonishing site. Other in-the-eye images of Hurricane Irma from the 53d WRS twitter feed are available here.

OK, it's time for a comprehensive Hurricane Irma update ...

NOAA-NASA satellite GOES-16 geocolor image of Hurricane Irma passing the eastern end of Cuba at about 8:00AM EDT on Sept. 8, 2017. For an explanation of what is meant by "geocolor," see here.


The 11PM EDT stats for Irma are as follows:

Location: 23.5N 81.0W or about 30 miles (50 km) NNE of Varadero, Cuba or 90 miles (145 km) SE of Key West, Florida.

Maximum Sustained Winds: 120 MPH (195 km/h)

Movement: NW or 305 degrees at 6 MPH (9 km/h)

Minimum Pressure: 933mb (27.55" Hg)

As you can see, the hurricane is significantly weaker than it was in my last update. This is due to the hurricane's interaction with Cuba -- with the eye itself grazing the northern shore of the island -- the hurricane (of course) weakened considerably, at least in terms of maximum sustained winds -- dropping from 165MPH to 120MPH.

The subtropical ridge over the Atlantic was strong enough that it kept the storm from recurving directly into Miami -- meaning Miami-Dade should avoid widespread devastation. Yes, that's a good thing.


Drone footage of nearly abandoned Miami Beach, Fla., ahead of Hurricane Irma, September 9, 2017.


Of note, the evacuation from Miami and Miami-Dade have resulted in those cities being temporarily practically abandoned. Here is a New York Times article featuring an embedded 90-second video of footage taken by a drone flying along and over the streets of Miami Beach this morning showing a nearly deserted city. Here are some frame grabs from that drone footage:

Drone footage of nearly abandoned Miami Beach, Fla., ahead of Hurricane Irma, September 9, 2017.


Drone footage of nearly abandoned Miami Beach, Fla., ahead of Hurricane Irma, September 9, 2017.


The Baker Act refers to the 72-hour period in which a person with a suspected mental illness (as defined) is viewed as being a danger to him/her self or others. This includes negligent to self -- as in, riding out a category 5 hurricane outside.

Wanna bet some ACLU fucktard will "swing into action" and take up a case against the city for this?? Always proudly defending the wrong thing.

Caption from CBS News online article: In this frame made from video on Fri., Sept. 8, 2017, an official in Miami speaks with homeless people about moving to shelters ahead of powerful Hurricane Irma.


Ron Book, Chairman of the Miami-Dade County Homeless Trust, who is overseeing this effort, had the following to say on the matter in two different interviews -- one to the Miami Herald and another to AP:

"No one's ever tried this before. But I'm not going to be the mayor of Houston. I'm not going to tell people to take a Sharpie and write their names on their arm."

"I am not going to sign suicide notes for people who are homeless in my community. I am just not going to do it. That's why you have a Baker Act. It's there to protect those who can't otherwise protect themselves."

Amen, brother.

NWS composite radar mosaic for the Southeastern U.S., looped 2218 - 2328UTC September 9, 2017.


Anyway, back to the topic at hand ...

Hurricane Irma is beginning a long-awaited northward turn in response to having reached the western flank of aforementioned ridge. The tropical cyclone is forecasted by all the models (including to the GFS and European operational ones and most of their ensembles) to turn to the northwest or north-northwestward as it comes under the influence of an upper level trough over the eastern United States.

NWS composite radar mosaic for the Southeastern U.S., looped 0108 - 0218UTC September 10, 2017.


Irma is forecasted to move over the Florida Keys -- quite possibly, Key West itself -- by dawn tomorrow (Sunday) and then push north-northwestward along the Gulf coast of the Florida peninsula, threatening the Tampa / St. Petersburg area with a high-impact hurricane. The storm could intensify over the next 24 to 48 hours with maximum sustained winds reaching 140MPH -- a category 4 storm -- before crossing the Florida coast for good and riding up the peninsula.

The actual landfall location on the Florida peninsula will be somewhere between Everglades National Park (southwest side) and Sarasota.

NHC Advisory 44 information graphic for Hurricane Irma issued 11PM EDT September 9, 2017 showing the most likely track and cone of uncertainty out to day 5.


A word about the intensity forecasts: The GFS and the NAM models have repeatedly insisted on intensifying Irma as it approaches Florida. The GFS intensities have been way overdone (showing central minimum pressures in the 885-mb range). Model forecasts of tropical cyclones remain problematic.

Key West (BYX) NWS radar in standard composite mode looped 10:03PM - 10:46PM EDT September 9, 2017.


Per the 12Z European model, the forecasted wind gusts over the Florida peninsula are strong enough to cause considerable damage in places (see image farther down this entry). In fact, if the Tampa / St. Petersburg area gets a direct strike, what was feared to happen in the Miami-Dade/Fort Lauderdale area could happen instead there. 

Key West (BYX) NWS radar in standard base reflectivity mode looped 10:09PM - 10:52PM EDT September 9, 2017.


Oh, yes, I should point out that Hurricane Jose became a powerful category 4 (borderline category 5) storm and is traversing very nearly the same part of the Lesser Antilles devastated by Hurricane Irma on Sept. 5 - 6 when it was at its peak intensity with 185MPH winds. This includes Barbuda, Anguilla, and St. Martin.

As for Hurricane Jose, it is forecasted to slow down and -- per the GFS -- execute a loop over the course of several days well southeast of the Bahamas as a result of being embedded in a mid-level anticyclone. By next weekend, the hurricane could make a close approach to the U.S. Eastern Seaboard (grazing New England) and striking Nova Scotia.

However, that's way far away -- a forecast subject to numerous changes -- and I'm not going to start on that right now. One hurricane at a time.

Miami (AMX) NWS radar in standard composite mode looped 10:00PM - 10:46PM EDT September 9, 2017.


For the remainder of this entry, I would like to post an extended excerpt of Bryan Norcross's Facebook post on Saturday morning interspersed with Irma-related image (radar loops and NWS advisories).

The full post is here.

Saturday morning HURRICANE IRMA update: Irma’s assault on the State of Florida has begun. Winds are getting gusty on the southeast coast and in the Keys. The gusts will increase in surges through the morning and spread north through the day.

The center of Hurricane Irma ran into the coast of Cuba overnight resulting in some weakening of the highest winds – now down to 130 mph. While that’s not a bad thing – except for our friends along the north coast of Cuba – it doesn’t necessarily make any difference to Florida. Between Cuba and Florida, the water is extremely warm. Meanwhile the atmosphere will be conducive to Irma restrengthening.

Miami (AMX) NWS radar in standard base reflectivity mode looped 10:06PM - 10:52PM EDT September 9, 2017.


All of peninsula Florida is still expected to receive damaging hurricane-force winds. Nobody should let down their guard because of the storm’s interaction with the Cuban coast this morning. It is still a giant, tremendously dangerous storm of the type that peninsula Florida hadn’t seen since Hurricane Donna in 1960.

The forecast track for the worst of the storm is now squarely on the Lower Florida Keys and Florida’s extremely vulnerable west coast. Here’s what this means for the various parts of the state and surrounding states:

In South Florida from MIAMI TO THE PALM BEACHES, think Hurricane Wilma in terms of the wind. There will be an extended period from later today through tomorrow of strong, dangerous winds, but not the full-scale assault that would have happened if the eye had come closer. In addition, however, flooding rainfall of a foot or more, plus rising sea water – storm surge of 5 feet or more in vulnerable low-lying locations – is still possible.

US NWS weather advisories map updated 0044UTC (8:44PM EDT) September 10 (9th), 2017.


In the FLORIDA KEYS, it is a full-scale hurricane emergency. Key West is probably going to get its worst storm in modern history, and perhaps ever. Life-threatening weather conditions will overtake the Keys later today and peak tomorrow morning, although Florida Bay water will continue to rise after the center passes to the north. Ultimate hurricane protection is required for anyone remaining in the Keys. Be sure you have a solid high-elevation location to ride out the storm. The danger from rising water due to storm surge and rainfall, as well as wind, will be extreme.

NWS Forecast Office Miami - South Florida (MFL) county warning area (CWA) weather advisories
updated 8:39PM EDT September 9, 2017.


In SOUTHWEST FLORIDA -- the NAPLES-FT. MYERS-CAPE CORAL area, the potential exists for the worst hurricane in history. The core of Hurricane Irma, potentially with winds gusting over 150 mph or more, is going to come close. Buildings in Southwest Florida are not, in general, built to withstand these winds. As the peak winds approach the Gulf water will surge over the islands and the shoreline of the mainland, so it will be very difficult or impossible to move once the storm starts.

Once the eye goes by, the maximum surge – forecast to be 8 to 12 feet above the ground in low-lying areas – will move in from the Gulf. This is fast moving, destructive water. You cannot drive through it and you cannot stand in it. It will sweep buildings away. Storm surge is the deadliest hazard in a hurricane.

The water will surge miles inland in some areas – far up the Caloosahatchee River, for example – higher than you can imagine. It is critical that everyone makes it to high ground.

NWS Forecast Office Tampa Bay Area CWA weather advisories updated 8:41PM EDT September 9, 2017.


Ultimate hurricane protection is required in all of Southwest Florida. Be sure you are in an elevated location by tonight. Inside the house or building, prepare an interior hall, closet, or bathroom with as many walls between you and the outside of the building as possible. Have the food and supplies you need with you, so you don’t have to venture to other parts of the house or building during the peak of the storm.

Have mattresses handy as an extra layer of safety. Be ready to get under the mattress or use them to protect yourself from flying debris inside your house, if there is a breach of the outside wall or the roof.

Think about everything today. How are you going to entertain the kids? How are you going to take care of your pet? Take no chances. This is an extraordinarily dangerous situation.

NWS Forecast Office Melbourne CWA weather advisories updated 8:49PM EDT September 9, 2017.


Farther north on the WEST COAST OF FLORIDA – SARASOTA, TAMPA BAY, AND POINTS NORTH: The threat of deadly storm surge is real and increasing. It is essential that you get out of low-lying areas. Follow the local evacuation orders, which are still being issued.

On the current track, the wind will be fierce and damaging along the entire west coast. Review the steps listed above to stay safe if you are going to be near the eye of the storm, even well away from the water.

Along the EAST COAST OF FLORIDA, AND COASTAL GEORGIA AND SOUTH CAROLINA, there storm surge threat is very real, and it may be worse than Hurricane Matthew last year, even with Irma tracking farther west. Listen for information from your local officials and obey all evacuation orders.

NWS Forecast Office Jacksonville CWA weather advisories updated 8:41PM EDT September 9, 2017.


Elsewhere in CENTRAL AND NORTH FLORIDA – INCLUDING ORLANDO AND GAINESVILLE: Damaging hurricane force winds are expected for a long duration moving from south to north beginning late tonight (Saturday night).

Be sure you are in a sturdy building and are prepared to move to an inside hallway, closet, or bathroom during the height of the storm, which is going to go on for 12 hours or more. Have entertainment for the kids, and think about how the pets are going to go to the bathroom. Consider having a mattress handy in case a window breaks or somehow the wind gets into your house.

For all of Peninsula Florida, this is going to a long slog of weather conditions ranging from deadly to damaging to frightening to horribly uncomfortable. Millions of us will lose power. Hundreds of miles of coastline will be damaged. And some people will lose their lives.

There are still things you can do to make you life better after the storm. You'll see a list below, and a shopping list, if stores are still open in your location. Also, you’ll see Key Messages from the National Hurricane Center...

Today is the warm-up. Some dangerous conditions will begin in the southern peninsula, but tonight is when the full assault will commence. BE READY. HELP YOUR NEIGHBORS. STAY SAFE.

12Z September 9, 2017 ECMWF (Euro) run showing 6-hour maximum wind gusts across Florida Sept. 9th - 11th, 2017, as prettied up by

To be clear, I think this is the 12Z 9/9/2017 run. The CWG entry from which I got it does not specify.


OK, before ending this entry, I would like to post part of this CWG entry about an astonishing phenomenon created by Hurricane Irma -- the Atlantic Ocean water on the northwest side of Long Island in the Bahamas is literally missing, sucked out by the very low pressure in Hurricane Irma (link embedded in title):

Blurry video screenshot of the missing ocean along Long Island, the Bahamas, September 9, 2017, by Kaydi_K twitter user.


As a meteorologist, there are things you learn in textbooks that you may never see in person. You know they happen theoretically, but the chances of seeing the most extraordinary weather phenomena are slim to none.

This is one of those things — a hurricane strong enough to change the shape of an ocean.

Twitter user @Kaydi_K shared this video Saturday afternoon, and I knew right away that even though it looked as though it couldn't be possible, it was absolutely legit.

"I am in disbelief right now ..." she wrote. "This is Long Island, Bahamas and the ocean water is missing!!!"

Another blurry video screenshot of the missing ocean, Long Island, the Bahamas, September 9, 2017, by Kaydi_K twitter user.


Basically, Hurricane Irma is so strong and its pressure is so low, it’s sucking water from its surroundings into the core of the storm.

The wind on Long Island in the Bahamas is from the southeast to the northwest on Saturday. On the northwest side of the island, it would be blowing the water away from the shoreline.

Long Island, the Bahamas, September 8, 2017 -- but with the ocean missing! 


It also may be experiencing the effects of what I call the hurricane "bulge." In the center of the storm, where there is extreme low pressure, water is drawn upward. Low pressure is basically a sucking mechanism -- it sucks the air into it, and when it’s really low, it can change the shape of the surface of the ocean. As the storm draws water toward the center, it gets pulled away from the surroundings.

In any case, this isn't the sign of a tsunami. The water will return to Long Island, and it probably won't rush back with any great force. It will probably be back by Sunday afternoon.


OK, that's all for now. I'm omitting any Saturday Evening Posts or Jukebox Saturday Nights this weekend.


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