09.02.19

Tracking the Tropics—September 2, 2019

Posted in Commentary, Storm History, Storm Facts, GWC News, Hurricane Intensity, Hurricane Records, Tracking the Tropics at 9:28 pm by gmachos

Labor Day 2019 is a day that history repeated itself in the Atlantic Tropics. Actually it was on Sunday, but again, another Labor Day was overshadowed by the impact and the threat for more impacts from Hurricane Dorian. It was on this date some 84 years ago, another monster storm was devastating the Florida Keys, the Labor Day Hurricane of 1935.

THIS DAY IN HURRICANEVILLE HISTORY

The storm had winds of 185 mph and gusts well over 200 mph. It was a small yet powerful storm that went through the Florida Straits and into the Keys. The monster hurricane destroyed the Overseas Railroad, a brainchild of Florida businessman, Henry Flagler, and left many World War I Veterans that were working on the railroad. The railroad, which linked the Florida Keys with mainland Florida, was then replaced by the U.S. 1 highway, now the only route out of the Keys.

It was the first Category Five Hurricane to make landfall in the continental United States. Only three other storms: Camille (1969), Andrew (1992), and Michael (2018) have ever done that, and Andrew and Michael were re-evaluated and re-categorized as Cat 5 storms in 2002 and 2019. For a very long time, the storm held the mark for the lowest pressure ever recorded in the Western Hemisphere for 53 years until Hurricane Gilbert surpassed it in September 1988.

Wilma would then surpass the mark made by Gilbert in the wild hurricane season of 2005. In almost the same location as Gilbert near the Yucatan Peninsula, Wilma’s pressure ended up at 882 millibars as it became the fifth Category Five Hurricane that season. Andrew followed a similar path as the Labor Day Hurricane did, but was just a bit further to the north as it made landfall in Homestead in Southern Dade County, Florida.

A LOOK AROUND IN THE ATLANTIC

Dorian is dominating the scene in the Atlantic. However, believe it or not, there are four disturbances being watched throughout the basin from the coast of Africa to the South Central Gulf. The most immediate concern outside of Dorian is located in the South Central Gulf of Mexico. A tropical depression could emerge from this over the next several days. Currently, the chance for development within the next 48 hours is 60 percent, and that probability will increase to 70 percent in five days.

The next feature that needs the most attention, although it is still a long ways out is in the Eastern Atlantic. What the NHC calls an elongated area of low pressure is located several hundred miles west of the Cape Verde Islands. This system is in the prime area of development during the peak of the Atlantic Hurricane Season, and has an 80 percent potential of becoming a tropical cyclone of some kind over the next 48 hours, and a 90 percent chance over the next 5 days.

Further to the east in Western Africa, another wave is about to depart into the Eastern Atlantic, and there is already a 50 percent chance of development into a depression over the next five days. So, the tropical pipeline appears to be firing up just in time for the statistical peak of the Atlantic Hurricane Season, which occurs on September 10th. Finally, there is another area of disturbed weather several hundred miles to the south-southeast of Bermuda, which has about a 30 percent chance of formation from 48 hours to 5 days out.

I plan to have another update to the blog on Hurricane Dorian sometime during the day on Tuesday. I also may discuss the severe weather and heavy surf that dominated my Labor Day Weekend trip to Long Beach Island.

Hurricane Dorian—More Thoughts

Posted in Storm Track, Commentary, Storm Facts, Storm Preparation, GWC News, Storm Warning, Storm Safety, Hurricane Intensity, Tracking the Tropics at 3:14 pm by gmachos

On this early Tuesday afternoon, Dorian has basically grinded to a halt in its forward motion while its winds have decreased some 35 miles per hour from its peak on Sunday afternoon. The storm is still a high end Category Four Hurricane with 150 mph winds and a minimum central pressure of 938 millibars, or 27.70 inches of Hg.

The Northwestern Bahamas have been absolutely pounded as the storm as slowed and its eye crawls across the backbone of Grand Bahama Island towards Freeport. There are outer rain bands currently affecting Eastern Florida. All 67 counties in the Sunshine State are under a State of Emergency while portions of Georgia, South Carolina, and North Carolina are under a State of Emergency as well.

Some 10 million people are under some form of tropical advisory at this time. At this point, the storm is still forecasted to eventually turn north, but Florida is still not out of the woods yet since that turn has not yet started to happen, and it is very possible that Dorian will be much closer to Florida’s East Coast before it does turn northward. It is located about 83 miles from Cape Canaveral, Florida, and about 108 miles from Fort Lauderdale.

Hurricane Dorian is currently going through an eyewall replacement cycle, which is when an outer eyewall forms and replaces the current inner eyewall. This phase is mostly responsible for the storm’s weakening along with the long interaction with Grand Bahama Island as well as some upwelling of colder water. The eyewall replacement cycle usually results with a larger wind field as a result of the conservation of angular momentum.

While the storm is some 500 miles away from the Jersey Shore, the surf has picked up considerably in the past 12 to 18 hours at places like Ship Bottom on Long Beach Island. The surf is much rougher, and more stirred up while the wave frequency and height has increased. There is video proof of this on the GWCHurricaneville Facebook page and twitter feed. Rip tide or rip current advisories are currently in effect for the Jersey Shore through Monday night. Expect the surf and wave action to continue picking up as the storm moves further north and makes its closest approach to the Garden State.

Right now, Southern Jersey is not in the forecast track, but had been in the cone of uncertainty as of Sunday night. Places such as Long Beach Island, Atlantic City, and Cape May could still feel some impacts from Dorian as it heads further north later this week, but areas that are in more immediate danger are along the Southeast Coast from the East Coast of Florida to Southeastern Virginia. Now, let’s discuss some of the things that have been discussed over the last couple of days.

First, there was the talk about the discrepancy regarding the storm when recon detected Category 5 Hurricane winds on the Saffir-Simpson Scale, but was still listed as a Category Four. Here’s the thing: If you have an 18 wheel tractor trailer coming at you, does it really matter how fast it is going at this point? It could be going 50, 65, 70, or 100 mph, it is not really going to matter because if you get in the way of it, it is likely not going to end up well. Then, there is the heavy surf and waves here in Ocean County from Dorian.

Many will say, how is that possible? Simple. It is a ripple effect from the storm. Much like when you drop a stone in a pond. Ripples of water propagate out from where the stone is dropped. So, if you dropped a 200 pound boulder into the middle of a lake, you pretty much have what’s going on in the Atlantic as the result of Hurricane Dorian’s strength, size, and power. I will try to post another blog entry on Tuesday or so. Unfortunately, I am not able to do as much work on the blog and site due to personal commitments such as my work schedule, and other obligations.

09.01.19

Some Thoughts on Hurricane Dorian

Posted in Storm Track, Commentary, Storm Facts, Storm Preparation, Storm Warning, Storm Safety, Tracking the Tropics, Model Forecasts at 10:40 pm by gmachos

Monster Storm Slamming the Northwest Bahamas

Over the past couple weeks, I’ve been monitoring Facebook and Twitter posts, and one of the things I saw not only then, but for much of the season, was the fact that many people were again already giving up on the season as if the statistical peak of September 10th had already passed.

This mindset was similar not too long ago. In about August 2017, I had seen a post from someone on Facebook that indicated that the Atlantic Hurricane Season was a bust, and there were no signs of anything significant occurring. Within about a month, Hurricane Irma and Hurricane Maria became Category Five Storms in the Caribbean, and eventually pounded Florida and Puerto Rico.

The same thing happened a year later in the Summer of 2018, and then there was Michael, the most powerful storm to hit the Florida Panhandle, and the fourth Category Five Hurricane to make landfall in the Continental United States. The thing that amazes me is that people just don’t seem to realize how the hurricane season does not end in June and July. Rather, it is only the beginning.

Now, there are some years such as 2005 when you have storms in June and July. In that historic season, there were two Category Five Storms in just the month of July alone, Dennis and Emily. Of course, there would be several more to go in Katrina, Rita, and Wilma. But 2005 was a record shattering season. Not every big year is going to end up like that, but it also doesn’t mean that it won’t be a big season.

More importantly though, many get too caught up with the number of storms, hurricanes, and major hurricanes that are projected in the various seasonal forecasts issued by the likes of Colorado State, NOAA, The Weather Channel, etc. Remember, it only takes one. I always say how Hurricane Andrew in 1992 is a classic example of that. Andrew was the first storm of that season, and it did not really come along until the middle of August that season.

Yet, Andrew defied many odds to become the 2nd Category Five Hurricane to make landfall in the Continental United States although originally it was classified as a Category Four Hurricane when it hit Homestead, Florida. The 1992 season ended up being a below average year in terms of activity although it would later contribute to The Perfect Storm in October that year when Hurricane Grace, a Category One storm unlike the Category Five featured in the movie based on the Sebastian Junger book that came out in 2000.

Another example is the storm that Dorian is now being compared to in terms of wind power, the Labor Day Hurricane of 1935. Again this storm occurred in a season that was below average according to the data collected as of this time. Yet, the storm devastated the Florida Keys and the Overseas Railroad that linked mainland Florida with the Keys. It also left many World War I Veterans that were working on the railroad, dead. Several years later, another powerful storm came along in a below average season.

The Long Island Express of 1938 came along during another year of below average activity, but is perhaps the most powerful storm to strike Long Island and New England. It left some 600 people dead. Dorian has generated more tropical activity than the entire 1983 Atlantic Hurricane Season, but there still was Hurricane Alicia, a major hurricane that threatened the Houston and Galveston area that year. A few years earlier, there was Hurricane Allen, which had 190 mile per hour winds in the Caribbean before coming ashore in South Texas in August 1980.

The moral of all of the stories and examples of past hurricanes, is again, my important credo, “It only takes one storm to make a season regardless of how many storms, hurricanes, and major hurricanes are predicted.” There are some years, when there are a number of tropical storms, hurricanes, and major hurricanes, but not many of them make an impact in the United States. There are others such as 2004 and 2005 with numerous storms, hurricanes, and major hurricanes that do come ashore. Some of those big years like 1969, 1998, and 2004 start off very slow, and then come on very strong.

A couple weeks ago, many commemorated the 50th Anniversary of Hurricane Camille. This storm was only the third named storm of the season, and it impacted the Gulf Coast of Mississippi near Pass Christian with 180 mph winds and a 24 foot storm surge. The 1969 season would then end up with 18 named storms and 12 hurricanes. The only seasons that had more storms were 1933 and 1995, and the only season with more hurricanes was 2005.

Speaking of Camille, there is another thing that I find troubling about some of the discussions I see on social media. Many critique the forecasting of Dorian not only in terms of track, but also in terms of intensity as well. For example, there was a criticism that Dorian was named a hurricane too soon when it was about to make impacts in the Virgin Islands. Even if it was not a hurricane, it was still capable of producing torrential rains resulting in flash flooding and mudslides in the mountainous terrain of these islands.

Going back to Camille, the storm was one of the first systems that was observed with a new tool for forecasters called satellite. Forecasters such as John Hope, who later worked at the Weather Channel, Neil Frank, a future director at the National Hurricane Center, and Bob Sheets, another future director as well as Robert Simpson, the NHC director at the time, did not think Camille was that strong according to the satellite imagery that they had of it at the time. When Hurricane Hunter aircraft got into the storm, they realized that the storm was much worse than thought.

The moral of this story? Is that forecasters can only do the best they can with the tools they have available. True forecasters today have tons of tools, data, and computer power at their disposal. Never in the brief history of meteorology, which has only been around for about a little more than 100 years, have forecasters had such an abundance of information and technology available to them. Yet, there are still issues. Some models don’t work as well as others. Social media is a great way of sharing information, but it can also lead to confusion and misinformation. The public is also more informed as well due to the computer, mobile phone, and internet, and can be prone to second guess the forecaster.

Forecasting the track has improved, but only gradually on a linear scale while population growth, especially in places such as Florida, has grown exponentially. The result, a lot of people in the Sunshine State that have perhaps never really experienced a hurricane before. There was a sense of panic that I observed in Florida this week courtesy of Jim Williams live broadcast at Hurricane City on Friday night that was reminiscent of the chaos that ensued when Hurricane Floyd was off the East Coast of Florida, and lashing the Bahamas with 150 mile per hour winds in September 1999.

There was also the debate over the fact that Dorian had winds measured at Category Five intensity from reconnaissance aircraft measurements late Saturday night, and yet the advisories up and until 8:00 AM on Sunday still had the storm at a Category Four. A Category Five storm is rarified air for a tropical system, and it is also very difficult for such a system to maintain that intensity for a long period of time. Most Cat Five storms stay at that intensity for 24 hours or so, but some have lasted as long as 30 to 36 hours, or even longer. What does that mean? Perhaps the forecasters were trying to see whether the Cat Five intensity would persist. A key factor with tropical systems is their persistence.

So the forecasters might have delayed to make sure that this was a trend, and not something that just happened for a few hours, and then stopped. The NHC waited roughly about 12 hours before upgrading Dorian to a Category Five Hurricane. Then, there is the debate over the forecast track. Originally, Florida was expected to get some sort of impact from this system, especially after the system reorganized north of Puerto Rico, and did not go through the Mona Passage as originally predicted. Then, Friday into Saturday the official forecast appeared to put Florida in the clear as Dorian headed more north toward the Northwestern Bahamas.

Again, Dorian has defied many odds against it to this point. In a way, the storm is somewhat similar to Andrew in terms of surviving many obstacles only to rapidly intensify into this Category Five monster. While some did indicate that Dorian had a good chance to be a Category Four or Five storm, nobody imagined that the hurricane would become this powerful, and the strongest storm to affect the Northwestern Bahamas. It also had a minimum central pressure of 909 millibars, which was just a bit stronger than Hurricane Ivan in 2004 (910 millibars). Storms like these can make an environment of their own, and sometimes go where they want to instead of being pushed by other environmental forces. Forecasters can not always predict that.

Obviously, there is a lot of angst and concern all along the East Coast of Florida, but the Northwestern Bahamas have never seen a storm of this intensity and fury before ever on record. According to sources familiar with the Bahamas, approximately 70 percent of Abaco Islands have homes either destroyed or damaged. Grand Bahama Island including Freeport has never been hit by a Category Five Hurricane. Both of these islands have highest elevations that are only 10 to 15 feet above mean sea level, and the forecasted storm surge for those areas was supposed to be between 18 and 23 feet above normal. In addition, there are also damaging waves on top of the surge.

On top of this, the steering currents around Hurricane Dorian have broken down, or cancelled each other out, which has caused the storm to slow down. The slow motion has prolonged the devastating and catastrophic effects of the hurricane over the Northwestern Bahamas. At the same time, it does give residents along Florida’s East Coast time to prepare if the hurricane pushes further westward, and threatens to make landfall there. Dorian is expected to make a turn to the north by Tuesday, and could then threaten Georgia, South Carolina, and North Carolina as well as Florida.

States of Emergency have been declared for portions of Florida, Georgia, South Carolina, and North Carolina. The storm is expected to head north and then northeast eventually. South Jersey could feel the effects of the storm by Thursday and Friday. Forecasts for places like Ship Bottom on Long Beach Island are calling for temperatures in the low 70s with rain and wind on both of those days. Residents along Florida’s East Coast need to finalize preparations, and perhaps move westward and even south towards Miami and Dade County to stay out of the western eyewall. Dorian appears to have begun an eyewall replacement cycle, which will cause it to weaken, but also increase its wind field to conserve angular momentum.

Residents in Georgia and Carolinas need to closely monitor this dangerous situation, and get prepared if they haven’t already. Again, the slow forward speed of the storm due to breakdown in upper level steering currents does provide additional time to prepare, and get things in order in the event that evacuation orders are given. Further up the East Coast in the Mid-Atlantic and New England should periodically monitor the progress of the situation.