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Watching the Remnants of Hurricane Irma Over Georgia

Good Evening! 

Hurricane Irma battered the Florida peninsula yesterday, first making landfall on the Florida Keys as a Category 4, then again later in the day near Naples as a Category 3. Though information is still rolling in on the extent of the damage in the state, it is pretty obvious that the entire state of Florida has been affected to some degree. After its final landfall in Florida, the storm began to expand its radius of tropical storm force winds quite a bit as the mid level system from Canada began to interact with the hurricane and started some extra-tropical processes. This only worsened the already massive storm surge that the hurricane carried with it during its long trek across the Atlantic. Places as far north as Charleston experienced storm-surge related damage, as well as power outages from Irma’s massive circulation. As is common with many intense hurricanes when they hit land, the amount of momentum that the storm had built up over the past two weeks will take some time to spin down, and that has been very evident today on radar and satellite.  If we look at radar images from the south, we can see a large area of rotation associated with the decaying low level circulation of Irma, as well as the more pronounced mid level circulation. This mid level circulation has been responsible for mixing down strong wind gusts to hurricane-force today across portions of the southeast, causing tree damage and numerous power outages.

Irma will continue to weaken over the next day or so, as it makes its way into the Tennessee River valley by Tuesday afternoon. The storm will be fully-extra-tropical (meaning that other process are sustaining the wind and convection and the storm in no longer fed by its warm-core) and quite large in nature. Showers and thunderstorms should extend all the way from Arkansas to portions of the southern Mid-Atlantic states like Virginia and Maryland. Some of the stronger showers and storms may be able to mix down some residual tropical storm strength gusts, and will also be capable of producing tropical downpours which may caused localized flooding of poor drainage areas and perhaps on roads. There is also a risk of tornadoes with any cells coming in from the feeder bands over the Atlantic. There have been some strong signatures observed over water during the past 24 hours, and a tornado watch has been issued for portions of the Southeast.

Please check with your local NWS office to stay on top of any watches or warnings that may be issued once the NHC declares the storm “post-tropical” and hands over the tracking to the folks at the Weather Prediction Center.

Hi-res Base Reflectivity imagery of the remnants of Hurricane Irma over the Southeast US

Hi-res Base Reflectivity imagery of the remnants of Hurricane Irma over the Southeast US

As Irma winds down late Tuesday and into Wednesday as the low begins to fully occlude and fill in, a warm front will progress from west to east over the Mid Atlantic states, and eventually into the Northeast. This front will begin to slow as it moves through Pennsylvania on Wednesday, due to the residual high pressure system just off the coast of the Mid Atlantic. This will cause numerous showers to form over the area, but as tropical moisture begins to fade, these showers should be on the more typical side, with steady rain and generally cloudy conditions expected.

As of right now, the most unsettled day across the eastern half of the nation appears to be on Thursday, when a little more surface heating may take place just ahead of the main area of mid level energy, and this could create a marginally unstable air mass supportive of weak thunderstorms and isolated downpours. Friday may feature more showers and possibly some thunderstorms over much of the Mid Atlantic and Northeastern states, but the overall area of coverage will depend on just how strong the mid level energy remains as it meanders over the next few days. Dry conditions may return this weekend, as an area of high pressure begins to build in from the west, which should kick the remnants of Irma out of the area and allow for more stable and clear conditions.

Evolution of the mid level remnants of Hurricane Irma over the next few days as it meanders across the eastern third of the country

Evolution of the mid level remnants of Hurricane Irma over the next few days as it meanders across the eastern third of the country

Hurricane Jose Wandering Over the Open Atlantic

Hurricane Jose is still out and about over the Atlantic, located to the north of Hispaniola and Puerto Rico. Jose has been experiencing significant wind shear due to the very rapid expansion of Irma’s outflow once it began to undergo an extra-tropical transition. Even in the face of this shear, the storm has been able to maintain hurricane intensity, and currently has winds of around 100 mph. The storm may continue to weaken as it begins to execute a very complex loop over the next few days due to a break-down of the steering currents from the remnants of Irma. This pattern is forecast to last until Friday or so, when the hurricane will once again be located just north of the Bahamas. It is at this point that the models begin to diverge significantly. Some models have the storm taking a hard right and heading out to sea, and others have Jose maintaining a more westerly motion by this weekends, which would put it uncomfortably close to the southeast US. This scenario would result in the storm also encountering more favorable conditions for re-intensification as an upper level high would be allowed to rebuild overhead.

While it is much too early to say what the overall outcome will be, there is plenty of time to watch this storm as it churns over the open waters of the Atlantic, with the only concerns being increased wave action and rip-tides. We will have more on this storm regardless if it becomes a legitimate threat to the east coast over the next few days!

Latest GOES 16 IR imagery showing Jose getting beaten up by shear from now Tropical Storm Irma's outflow (courtesy of weather.us)

Latest GOES 16 IR imagery showing Jose getting beaten up by shear from now Tropical Storm Irma’s outflow (courtesy of weather.us)

For more information and posts like this one, make sure you sign up for Premium Forecasts — where multiple detailed articles, videos, and interactives are posted each day. Also, come interact with our staff and many other weather enthusiasts at 33andrain.com!

Have a great evening!

Steve Copertino

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Hurricane Irma Strengthens Again, Severe Impacts Likely in Florida

Good morning! While our weather remains calmer, we have been monitoring Hurricane Irma very closely this weekend. Irma had been moving west-northwest along the north-coast of Cuba on Saturday. This was due to a stronger sub-tropical Atlantic ridge to the north of Irma, stronger than much of the model guidance had previously indicated. Irma had also weakened from a Category 5 hurricane to a Category 3 hurricane, from more land interaction with Cuba. But Irma has now restrengthened to a Category 4 hurricane with 130mph maximum sustained winds this morning over the Florida Straits and is moving slowly northwest towards the Lower Florida Keys.

Irma is now beginning to interact with a mid-level trough over Northern Gulf of Mexico. Irma will turn even more north-northwestward today, as shortwave energy with this trough begins to phase with Irma. After moving over the Lower Florida Keys this morning, Irma’s eye will likely make landfall somewhere along the Southwest Florida coast late today or tonight. Irma’s inner core remained largely intact after leaving Cuba — and Irma just completed an eyewall replacement cycle, with the inner eyewall collapsing and the outer eyewall contracting. This has lead Irma to restrengthen again.

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Hurricane Irma Eyes Down Florida, Jose and Katia Become Life-Threatening Hurricanes

Good Evening

Since our last update, the Atlantic has racked up more records that it would take too much time to list all of them here. There have been some major changes with our storms, and unfortunately they are not welcome changes. To help get the word out about these potentially catastrophic hurricanes, we have temporarily removed our paywall. We hope everyone stays safe over the next few days during these exceptionally dangerous times.

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Starting off with the most imminent threat to land, we have Hurricane Katia, which is nearing the coast of Veracruz in Mexico. Katia has steadily organized into a hurricane with winds of 105 miles per hour, and recon will be heading into the storm shortly to get a better understanding of the storms strength before it makes landfall later this evening and into early tomorrow morning. While Katia will pose a formidable storm surge and wind threat to the immediate coast, the main threat with the storm will be the threat for life-threatening mud slides triggered by very heavy rainfall as the storm moves inland. Though the storm is relatively small, it still could produce 8-14″ of rain across portions of Mexico, which is more than enough to cause serious issues for locals.

This afternoons HWRF model showing potential rainfall accumulations over portions of Mexico during the next few days. Life-thretening mud slides will be possible as the storm moves inland (Courtesy of NOAA HRD/HWRF)

This afternoons HWRF model showing potential rainfall accumulations over portions of Mexico during the next few days. Life-threatening mud slides will be possible as the storm moves inland (Courtesy of NOAA HRD/HWRF)

Katia will likely be very close, if not over Mexico by 1am Central time, so the time the cyclone has to strengthen is very short, but it would not be all that surprising if the current reconnaissance mission found that the storm had indeed become a major hurricane. While it has little impact on the overall threats from the storm, having three active major hurricanes would be a first for the Atlantic. Regardless, Katia should rapidly weaken tonight over the high terrain of Mexico, and should degenerate into a remnant low by tomorrow evening. Overall, people in the path of Katia should be aware of rapidly deteriorating conditions as early 8pm central.

GOES 16 IR shot of hurricane Katia nearing landfall over the Mexican coastline (NASA GHCC)

GOES 16 IR shot of hurricane Katia nearing landfall over the Mexican coastline (NASA GHCC)

The next storm likely to affect land is Major Hurricane Jose. Since the last time we looked at Jose it was just a minimal hurricane. Since that time, Jose has put on a very impressive bout of intensification as it was able to hold onto the pocket of low shear just behind Hurricane Irma’s expansive outflow. An earlier recon mission into the storm found that winds have dramatically increased to 150 mph, making Jose an extremely dangerous Category 4 hurricane. With Jose acquiring 150mph winds, this marks the first time in Atlantic hurricane history that back to back storms have attained 150+mph winds. As of this evening, Jose looks rather healthy, despite the storm taking on a more sheared appearance from the aforementioned outflow of Irma. Another recon plane will be in the storm shortly to get an intensity sample, but it seems likely that the storm will at least maintain major hurricane status while it nears the islands.

IR loop of Major Hurricane Jose approaching the Leeward islands with 150 mph winds

IR loop of Major Hurricane Jose approaching the Leeward islands with 150 mph winds

Jose may come uncomfortably close to the northern Leeward islands tomorrow afternoon, the same area which Irma quite literally wiped out just a few days ago. With little infrastructure left on the islands of Barbuda and Anguilla, even sustained hurricane force winds will cause massive issues for those left on the islands. This afternoons model guidance took the storm just north of the islands, which would spare them the tight core of the storm, which is good news, but the islands may still experience very heavy squalls, intense wave action, and occasional gusts to hurricane force during the day tomorrow. As I write this, it seems that the storm is really starting to show signs of weakening a bit as the cloud tops begin to warm and the system quickly becoming lopsided, despite the eye remaining quite visible.  We will have to see if this trend continues, as this would lead to the storm possibly weakening quite a bit by the time it reaches the islands, which would be very welcome news.

After the storm moves north of the islands, the eventual track of the hurricane becomes very uncertain. As Irma eventually makes landfall somewhere along the Florida peninsula, it will begin to reshape the steering currents over the western Atlantic. This could cause the storm to begin to head east and just south of Bermuda by the middle of next week. At that point, another ridge of high pressure may try to build in overhead and cause the storm to track in an erratic fashion. For this reason, we will still have to keep a weary eye on Jose over the next week or so.

This evenings HWRF model showing winds from Jose coming dangerously close to the islands devastated by Hurricane Irma

This evenings HWRF model showing winds from Jose coming dangerously close to the islands devastated by Hurricane Irma

Once again, we move onto Hurricane Irma

Irma has gone through a lengthy eyewall replacement cycle over the past day, which has allowed for the storm to weaken from its 185 mph intensity down to a 155 mph Category 4. Irma is still a very powerful hurricane, and those who think that just because the storm has weakened over the past day or so means that it will be less impactful in the long run is severely mistaken. In fact, there is some data that would suggest that the storm has begun to re-intensify just north of the Cuban coast-potentially back to Category 5 levels. This will have to be confirmed by the NHC in the coming hours.

Over the past 24 hours, the majority of the global models and their ensembles have shifted west, away from SE Florida, and now have SW Florida, and then the western coast in the direct path of this system. Additionally, radar observations show that it is almost certain that the center of Irma will make landfall on the Cuban coastline later tonight. This is a huge change from prior forecasts, and just how long the storm stays over Cuba will determine just how much the storm will weaken. As of this time it seems like Irma will make landfall on the Cuban coast early Saturday morning and could remain over land until later in the day tomorrow. Afterwards, the storm would likely be exiting into a region of extreme oceanic heat content and favorable upper level conditions. Most of the high resolution models, including the new “Deep Thunder” IBM model has Irma rapidly intensifying once it leaves the Cuban coast. I am hesitant to say that Irma will be able to intensify quickly as soon as it leaves the coast due to the fact that this is a very large storm with a very large core, and it may take some time to reorganize, depending  on how much damage is done. It is however, likely to at least regain some strength, possibly back to a high-end Category 4 as it nears Florida.

Current GOES 16 shot of Hurricane Irma with 155 mph winds just off the Cuban coast

Current GOES 16 shot of Hurricane Irma with 155 mph winds just off the Cuban coast

With regards to the track of Irma, it now seems likely that Miami will not get the brunt of the storm. Areas in SW Florida, including the Florida Keys may see the full extent of Irma on Sunday, with extremely damaging winds, deadly storm surge, and flash flooding. The models have been shifting west all day, and we may very well see more shifts this evening, but the chances are drastically increasing that the west coast of Florida will experience the worst of the storm. Those in the path will have to monitor Irma very closely over the next few days, and stay tuned for further updates as new data become available. We will have more on this developing situation tomorrow for the public.

****When making decisions, always consult the National Hurricane Center, your local National Weather Service, government officials, and local Emergency Managers.****

Latest storm-specific model tracks for Irma, showing a considerable shift away from SE FL (Courtesy of weatherbell)

Latest storm-specific model tracks for Irma, showing a considerable shift away from SE FL (Courtesy of weatherbell)

For more information and posts like this one, make sure you sign up for Premium Forecasts — where multiple detailed articles, videos, and interactives are posted each day. Also, come interact with our staff and many other weather enthusiasts at 33andrain.com!

Have a great evening!

Steve Copertino

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Major Hurricane Irma Threatens South Florida This Weekend

Good evening! Hurricane Irma remains an extremely powerful Category 5 storm, and is now moving just north of Hispaniola. It will continue to move west-northwest into the Turks and Caicos Islands later tonight. Irma is then expected to track somewhere between the Southern Bahamas and Eastern Cuba on Friday. There are still some uncertainties in its track over the next 24 hours, but we are starting to gain a model consensus on the systems eventual future. Chances are growing that Irma will be a major hurricane impacting South Florida on Sunday. Major impacts from Irma are also likely for other parts of Florida and the Southeast US.

Irma has continued to remain resilient over the last couple of days, despite encountering some mid-level shear, as well as having its inflow being disrupted by the mountains of Hispaniola. Irma has not weakened very much, as winds only have decreased from 185 mph to 175mph and pressure has remained around 921mb. Irma has remained at Category 5 strength for the longest period of time ever recorded in the Atlantic Basin. Eyewall replacement cycles that seemed to begin have just resulted in Irma’s inner eyewall merging with the outer eyewall. This is instead of the inner eyewall collapsing and the outer eyewall contracting again, which is more typical and would result in more weakening, during the cycle.

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