Storm Strengthens, Makes Turn Toward Mid-Atlantic Coast, And Picks Up Speed
Upon waking up this morning, I could hear the winds picking up. The pressure had dropped to 29.38 inches of Hg, or about 995 millibars. However, that was a drop of nearly a half an inch since yesterday morning. The bigger news awaited me as I got to my computer and got on the internet. Sandy had strengthened. Winds had increased to 85 miles per hour while the barometric pressure had dropped to 946 millibars, or 27.94 inches of Hg. The storm had tightened up much like a figure skater does when he or she pulls in her arms. Hurricane force winds still extended some 175 miles from the eye while tropical storm force winds only reached out about 485 miles after being at 520 miles on Sunday.
Over the next few hours on Monday morning, another couple ingredients with Sandy began to come into play. The storm began to make its westerly turn toward the coast, and pick up in forward speed. So basically, we have a strengthening storm that is now moving toward the Mid-Atlantic coast as predicted, and is picking up in forward speed. The thing you don’t want to hear when trying to evacuate ahead of a hurricane is a strengthening storm that is moving faster. As of the 8:00 AM Advisory from the National Hurricane Center, Sandy was located about 265 miles to the Southeast of Atlantic City, New Jersey. Now moving to the North-Northwest at 20 miles per hour, we are anticipating a landfall sometime within the next 13 hours.
A record surge is expected in places such as New York Harbor, Sandy Hook, and other locations along the Jersey Shore. The forecast is calling for a surge between 6 to 11 feet in New York Harbor, Raritan Bay, and Long Island Sound. If the storm hits within the next 13 hours, it will make an impact around the time of high tide, which is already enhanced by the presence of the full moon. You couldn’t ask for worse timing. Another thing to keep in mind with the surge along the Jersey Shore, Raritan Bay, New York Harbor, and Long Island Sound, and that is the fact that the coastline of New Jersey and New York meet at right angle, which will help funnel in the water to New York City, and Northeastern New Jersey. Winds are expected to gust between 60 and 80 miles per hour, and the National Hurricane Center has indicated that Sandy could strengthen to 90 miles per hour.
The worst of the weather is expected to begin around mid-afternoon, or about 2:00 to 3:00 PM EDT. Winds, which are already gusting between 30 and 50 miles per hour, are expected to ramp up significantly at that time along with the rain. Here in South Plainfield, the pressure has fallen further to 29.21 inches of Hg, or about 989 millibars. Already about a quarter of an inch has fallen from the storm. Winds have been steady at 20 miles per hour with gusts to 40 miles per hour. Oh, by the way, if you are in the Great Lakes region, you’re not going to be immune from this storm with cold air being pulled down, the storm is expected to bring snow to parts of the Appalachians including West Virginia and Western Virginia.
You know this is a different animal when a tropical system is going to bring snow on its western flank.
Storm’s Track And Strength Much Different Than Irene Was
Hours away from what could be an historic landfall along the Jersey Shore, Hurricane Sandy is expected to be a devastating storm. However, there are those around the Garden State and neighboring states that think it would be as bad. They will ride it out just like they did with Irene. There is just one problem with that, and that is Sandy is a much different animal than Irene was.
The storm’s track, size, momentum, and intensity is expected to be much different than Hurricane Irene was when it came up the coast. Differences between the two storms range from minimum central pressure, storm surge levels, and maximum sustained winds. Here is a breakdown of how Sandy is a much different threat than Irene.
Sandy’s projected track is going to be much different than Irene’s was. Normally, tropical storms and hurricanes run along the East Coast of the United States, and don’t directly impact New Jersey. Irene was a rare exception last year with two landfalls near Cape May and Little Egg Harbor. However, the bulk of the Garden State remained on the western side of the storm, which is traditionally not as strong due to the counterclockwise flow around the low.
Unfortunately, Sandy’s track will be much different and unprecedented, which could cause a lot of trouble. Right now, Sandy is moving to the Northeast, parallel to the Mid-Atlantic coast. However, there is a blocking pattern in place with an area of high pressure to the northeast of Sandy, which will prevent it from escaping into the Atlantic. On top of that, there is a cold front moving in from the west that will also pull the storm in. In response, Sandy will make a left turn into the Jersey Shore anywhere from Toms River south to Atlantic City.
What this projected landfall along the Jersey Shore means is that a lot of the Garden State including my hometown of South Plainfield in Middlesex County will face the storm’s notorious right front, or northeast quadrant. This is the part of the storm that has the strongest winds and roughest weather.
Storm Strength And Momentum
The strength of both Sandy and Irene are pretty much the same if you are looking at just the maximum sustained winds. Irene ended up being a tropical storm upon landfall with 70 mile per hour winds. Sandy currently has winds of 75 miles per hour, and could further strengthen to 80 mile per hour winds by landfall. However, Sandy is a much deeper storm in the sense that its pressure is very low than a typical Category One Hurricane.
Similar to Hurricane Isaac, which affected Louisiana back in August, Sandy is not your typical minimal hurricane with a minimum central pressure currently at 950 millibars, or 28.05 inches of Hg. This is crucial because remember there is a high pressure system to the north, and that is creating a very strong pressure gradient with the hurricane. A pressure gradient is a difference in pressure over a particular distance. The pressure gradient will also add to the wind while the low pressure itself will also help stir up the tide levels slightly.
Another difference between Sandy and Irene is the momentum each had prior to landfall. If you recall, Irene limped her way to the finish line last August thanks to the entrainment of dry air into the system. Irene was a ragged storm just hanging on to hurricane strength by the time it made land in Jersey. On the other hand, Sandy has been not only able to maintain its strength, it has also been able to deepen with a drop of 10 millibars in pressure alone on Sunday. It should be further energized when it moves across the Gulf Stream, and morphs into a hybrid storm as forecast.
Irene was a very large storm in its own right with tropical storm force winds stretching another 300 plus miles beyond the hurricane force winds. Compared to Sandy though, it is much smaller storm. As of the most recent advisory on Sunday night, Hurricane Sandy had hurricane force winds extending some 175 miles while tropical storm force winds extend some 520 miles.
What that means is that Sandy is about 1,000 miles wide. The storm is the second largest tropical cyclone in the Atlantic since 1988. Hurricane Igor, which occurred during the 2010 Atlantic Hurricane Season, is the largest in the last 25 years. Hurricane Gilbert was the vast Atlantic storm in 1988 when it was as big as the state of Texas after making landfall in the Yucatan and coming ashore again near Matamoros, Mexico.
The size is important because that will play a role in determining the duration of the rough weather conditions. It will also cover a broader area. The entire state will feel winds of 60 to 80 miles per hour at the height of the storm. Conditions will be felt as far west as Ohio and Indiana.
One Final Note
Besides the heavy rain, wind, waves, and storm surge being stirred up in the Mid-Atlantic from the Delmarva to New England, this system will also be unique in the sense that it will help produce heavy snowfall in Southwestern Virginia, West Virginia, Eastern Tennesse, and Western North Carolina along the Appalachian Mountains. In terms of its size, scope, power, and variety of weather, Sandy could equal and even surpass Superstorm ‘93.
Storm Appears To Be Trying To Form An Eye; Pressure Falls Five Millibars This Morning
Hurricaneville continues to monitor Tropical Storm Isaac as it moves through the Gulf of Mexico. The storm has had a long history of teasing the experts and the rest of us by having flare ups during the course of its day only to level off, and even in some cases wane. Isaac has been battling dry air throughout most of its lifetime. Most recently, the dry air is being fed into the storm from an upper level low over the Yucatan Peninsula.
On Monday morning, however, there appear to be signs of intensification finally taking place in the storm. The latest radar imagery courtesy of the Weather Channel is showing an eye trying to form in the circulation. In addition, the 8:00 AM Advisory from the National Hurricane Center indicates a pressure drop to 988 millibars. Less than twelve hours ago, the pressure had increased to 993 millibars. Could this be another tease by the storm. All depends on how much moisture can begin to get into the southern side of the circulation.
The storm is now within optimal conditions for strengthening with the warm waters in the Gulf of Mexico ranging between 85 and 87 degrees, which is well above the required 80 degrees for intensification. In addition, upper level winds are relatively light. The problem for Isaac has been that it has not been able to form a well defined core, and get that rapid intensification engine going because it has been constantly plagued by the dry air. Since the storm has not been able to strengthen into a hurricane, the NHC’s latest forecast discussion (5:00 AM EDT on August 27th) has backed off its projection of a Category Two storm by landfall.
Will Isaac get its act together this time? This is the question of the day for those tracking the storm.
Storm Could Get As Strong As Category Two At Landfall Along Northern Gulf Coast
On Sunday, Tropical Storm Isaac spent the entire day lashing South Florida and the Keys with its 60 to 65 mile per hour winds. Fortunately, forecasts that called for the storm to become a hurricane prior to moving through the Florida Keys didn’t come to pass. Now, Isaac is moving into the Gulf of Mexico with no land masses to interact with prior to making a landfall along the Northern Gulf coast by the middle of the week.
Since it has been in the Eastern Caribbean, Isaac has struggled to get its act together. Battling dry air, an upper level low in the Western Caribbean and Yucatan Peninsula, and the rugged terrain of Hispaniola and Cuba, the vast storm system has not been able to get strong enough to become the season’s fourth hurricane. Much of the precipitation has been staying to the north of the center of circulation as the upper low is pushing dry air into the southern side of the storm. As a result, the storm is asymmetric in shape.
With Isaac moving into the Southeastern Gulf, shower and thunderstorm activity has increased on the northern side. If the upper level low over the Yucatan can move away from the storm, there will be plenty of warm water and optimal upper level conditions for intensification. The National Hurricane Center has been indicating in their forecast discussions that Isaac could strengthen to a Category Two Hurricane on the Saffir-Simpson Scale with 100 mile per hour winds by the time it makes landfall.
Another trend that has been developing is a more westward forecast track with the storm. Late last week and into this weekend, the models had been indicating an impact further to the east along the Northeastern Gulf from the Florida Panhandle southward to places such as Tampa along the West Coast of Florida. Little by little though the track has been shifting to the left. Now, the storm could make landfall anywhere along the Northern Gulf coast from Louisiana to the Florida Panhandle. The timing of the landfall appears to be some time mid-week, which would be ironic for New Orleans, which was impacted by Hurricane Katrina seven years to the day on Wednesday.
Currently, Isaac is located about 60 miles Southwest of Key West, Florida, or about 530 miles to the Southeast of the Mouth of the Mississippi River. The storm is moving to the West-Northwest at 15 miles per hour, and has maximum sustained winds of 65 miles per hour. Winds are gusting to near hurricane force. Barometric pressure has fallen some 9 millibars in the past 20 hours to 991 millibars or 29.26 inches of Hg, and the winds have increased five miles per hour from earlier in the day. Isaac is a large storm with tropical storm force winds extending some 200 miles from the center of circulation. The size of the storm is a big concern for forecasters since Isaac’s vast circulation will likely create high seas, storm surge, and waves along the coast prior to coming ashore.
Taking a look at the watches and warnings, a Hurricane Warning is out for the North Central Gulf coast from Morgan City, Louisiana eastward to Destin, Florida including New Orleans, Lake Pontchartrain, and Lake Murepas. A Hurricane Watch is in effect from east of Destin, Florida to Indian Pass, Florida. Tropical Storm Warnings are in effect along the Florida Peninsula from Sebastian Inlet southward on the East Coast and from Tarpon Springs southward on the West Coast, the Florida Keys including the Dry Tortugas and Florida Bay, Lake Okeechobee, and from east of Destin, Florida to the Suwanee River.
Isaac does show some signs of strengthening. However, previous attempts have ended up just being a tease. Thunderstorms would flare up for a few hours near the center of circulation, but then level off. This latest flare up has lasted some four to five hours now, and it could persist, which would be an indication of strengthening. Again, the storm’s core is lopsided due to the dry air entrainment into the system from the upper level low over the Yucatan. If the low could move further away from Isaac, less dry air would get in on the south side, and the air would moisten from the water vapor generated by the very warm waters of the Gulf (running 85 to 87 degrees).
While the forecast track is showing a more westward track to landfall along the Northern Gulf coast, there is some discrepancy between the models as to where exactly Isaac will make an impact. The European (ECMWF), UKMET, and GFS models are about 300 miles apart with the GFS taking the most western route by having the storm move over the Southwestern part of Louisiana, which is a worst case scenario for New Orleans since the city will be on the eastern side of the storm. The ECMWF is showing a landfall in Alabama, which would mean that the Big Easy would be on the western or more weaker side of the storm.
Already, the storm has left behind a toll. On the island of Hispanola, which includes Haiti and the Dominican Republic, at least 10 people are dead according to the Huffington Post. Hundreds of homes were damaged by the storm in the Dominican Republic, and many people had to brave the elements in Haiti, where most are living in tents outside Port Au-Prince following an earthquake there several years ago. The Haitian government reported a dozen homes were destroyed by the storm and some 270 were damaged.
Storm Gradually Gains Strength On Friday As It Nears Hispaniola
Tropical Storm Isaac is gradually gaining strength as it moves through the Central Caribbean toward the southwestern coast of Haiti on this Friday night. The storm, which still remains somewhat disorganized thanks to some dry air getting into its western flank, has been slowly strengthening all day today with winds increasing to 60 miles per hour by 11:00 AM EDT, and then going up to 65 miles per hour by 5:00 PM EDT.
Maximum sustained winds with Isaac remain at 65 miles per hour with gusts of minimal hurricane force. Minimum central pressure is down to 29.29 inches of Hg or 992 millibars, which is actually down two millibars from the late afternoon advisory.
The satellite imagery shows a storm that has done a bit of a 360 in the past 24 hours or so. Yesterday at this time, much of the convection was on the western side of the storm. Now, it is on the usually more stronger eastern side. There is good outflow, or exhaust from the storm except for the northwestern part, and that is where the dry air appears to be getting into the system. There has been a trough to the west of Isaac as well, and that may be contributing to the storms continued struggles. Now, it is beginning to interact with the rugged terrain of Hispaniola, which has mountains as high as 10,000 feet on the Dominican Republic side.
The interaction between these mountains and Isaac will cause orographic lifting of the tropical air to take place, and that will cause tremendous condensation and torrential rains. Streams of moisture have already been flowing into the southern portion of the Dominican Republic. Those rains and more are expected to impact Haiti, where many are still living in tents around Port Au-Prince following the deadly and devastating earthquake there several years ago. Currently, Isaac is located some 165 miles south-southwest of Santo Domingo, the capital of the Dominican Republic, or about 185 miles to the south-southeast of Port Au-Prince.
The big story is that the storm has slowed down, which also adds to the fears of significant flooding and mudslides across Haiti and the Dominican Republic. The National Hurricane Center has Isaac currently moving at 10 miles per hour, which is down from 16 miles per hour just a few hours ago. Consequently, the NHC is forecasting some 8 to 12 inches of rain for Hispaniola with some areas receiving 20 inches. Further to the west across Cuba and even Jamaica, some 4 to 8 inches are expected with isolated areas getting up to a foot of rain. Puerto Rico is still receiving rain, and could get up between 2 to 4 inches with some remote locations seeing 6 more inches.
There are a lot of watches and warnings out for this storm. Currently a Hurricane Watch is in effect for Haiti. A Tropical Storm Warning is in effect for the Dominican Republic, Haiti, the Cuban provinces of Ciego de Avila, Sanctus Spiritus, Villa Clara, Camaguey, Las Tunas, Granma, Holguin, Santiago de Cuba, and Guantanamo, Andros Island in the Bahamas, the Central Bahamas including Cat Island, The Exumas, Long Island, Rum Cay, and San Salvador, the Southeastern Bahamas including the Acklins, Crooked Island, Long Cay, the Inaguas, Mayaguana, and the Ragged Islands as well as the Turks and Caicos.
Tropical Storm Watches were first issued for the United States mainland during the 5:00 PM EDT Advisory. Now, they are in effect for the provinces of Matanzas and Cienfuegos in Cuba, Jamaica, the Northwestern Bahamas including the Abacos Islands, the Berry Islands, Bimini, Eleuthera, Grand Bahama Island, and New Providence, the Florida Keys including the Dry Tortugas, the East Coast of Florida south of Jupiter Inlet, the West Coast of Florida south of Bonita Beach, Florida Bay and Lake Okeechobee.
Looking at the most recent model runs of the GFS, GFDL, ECMWF, and HWRF, there is a general northwestward track with the GFS being the furthest east, and the ECMWRF being the furthest west but they all show an impact in South Florida, and a second landfall somewhere along the Gulf Coast.
The latest GFDL model run has Isaac moving across the southwestern coast of Haiti into the narrow channel between Hispaniola and Cuba, traveling over the spine of Cuba and impacting the Florida Keys and South Florida before moving over water again in the Gulf, and eventually making a final landfall in the Florida Panhandle.
The GFS, which actually did a fairly decent job last week of projecting that the storm would be in the general vicinity of the Eastern Caribbean at about this time, has Isaac going across southwestern Haiti, but then going further to the north into the Southeastern Bahamas and more of South Florida before exiting into the Gulf, and eventually making a second U.S. landfall in the Pensacola, Florida and Mobile Bay, Alabama area.
The ECMWF has a more western track that goes across more Cuban real estate before emerging into the Gulf and making a U.S. landfall along the Mississippi and Alabama coasts. Finally, the HWRF has a smaller storm following a similar path of the GFDL across Haiti, along the spine of Cuba and over portions of South Florida, back out into the Gulf, and making landfall in the Pensacola, Florida area.
However, those in Western Florida including Tampa where the Republican National Convention is being held, should pay close attention to the track and progress of this storm since that area is not out of the woods just yet. The cone of uncertainty has not changed much during the day on Friday, and there are still areas along the West Coast of the Sunshine State that could be impacted by this storm.
The 5:00 PM EDT forecast discussion by the NHC is still calling for Isaac not to strengthen much over the next 12 hours, and it will likely weaken as it encounters the high terrain of Hispaniola and Cuba over the next 36 hours. After that, the storm should strengthen as it enters the Florida Straits and Gulf Coast, and become a strong Category One storm with 85 mile per hour winds.
Vast Storm Battling Lots Of Dry Air And Tug Of War Between Multiple Vortices
On Tuesday afternoon after much anticipation, Tropical Depression Nine in the Western Atlantic was found by Air Force Reconnaissance aircraft to be strong enough and well organized enough to become the ninth named storm of the 2012 Atlantic Hurricane Season. Since then, things have been a struggle for Tropical Storm Isaac.
The storm, which has grown to be about the size of Texas, remains in rough shape on this late Thursday morning. Dry air to the north, west, and south of the storm has been one factor that has made it very difficult for the storm to strength. Another issue is the circulation itself, or should we say multiple circulations. As pointed out on the evening broadcasts from The Weather Channel, Isaac has had to deal with several competing vortices that are all battling to take over the storm.
One appeared further to the south and west of the actual center while another was to the north of the storm. Thunderstorms have struggled to wrap around the circulation. To sum it all up, Isaac was literally one big mess. Since then, Isaac has reformed further south. A consequence of that appears to be a more westward track, but that will not keep it from interacting with the mountainous terrain of some of the bigger islands such as Hispaniola, which has mountains as high as 10,000 feet, and Cuba, which has mountains as high as 6,000 feet.
Moving more westward, Isaac will also be more over water and become a threat for the Central Gulf Coast states of Alabama, Mississippi, and Louisiana. Still a lot of time to watch it though, but last night, the European Model did indicate that the storm would take a more westward track into the Gulf by early next week. The GFS had indicated more of a track toward the west coast of Florida, where the Republican National Convention is scheduled to take place in Tampa. Orange futures were up five percent on Wednesday in response to the possible threat from Isaac.
As of the 11:00 AM EDT Advisory on Thursday from the National Hurricane Center, Isaac had weakened to minimal tropical storm force with maximum sustained winds of 40 miles per hour, gusts of up to 50 miles per hour, and a minimum central pressure of 1003 millibars, or 29.62 inches of Hg. Tropical storm force winds extend some 140 miles from the center. Isaac had basically remained at the same intensity all day on Wednesday with maximum sustained winds of 45 miles per hour, and a minimum central pressure of 1003 or 1004 millibars before weakening slightly overnight and this morning.
There did appear to be some signs that Isaac was going to get its act together on Wednesday night. Convection to the north of the center looked like it was trying to wrap around the center, which is an indication of intensification. However, Issac’s center reformed further south and the storm lost some strength overnight. The latest forecast discussion indicates that while the satellite imagery indicates some improvement with the system, Air Force reconnaissance still finds the system very disorganized. The intensity forecast calls for gradual intensification with Isaac becoming a hurricane within 36 hours. Sea surface temperatures and upper level winds are just right for rapid deepening, but as long as the storm’s core struggles to get organized, it will not be able to take advantage of the environment.
After Isaac becomes a hurricane, it will start interacting with land and weaken by 72 hours before moving out over water again and strengthen by 96 to 120 hours. The forecast also indicates that despite the reformation to the south, and a more westward track, Isaac could still be a problem for Florida.
Storm Weakens After Peaking Near Major Hurricane Strength
Yesterday, the Atlantic almost had its first major hurricane of the season. Hurricane Gordon, which had become a hurricane during the early part of the day, suddenly ramped up from a minimal hurricane at 2:00 PM EDT to a Category Two storm with 110 mile per hour winds at 8:00 PM EDT. It was a jump of 30 miles per hour in wind speed in just six hours, and an increase in strength from a strong tropical storm to near major hurricane in about 30 hours. Minimum central pressure dropped some 32 millibars or 0.94 inches in 39 hours.
Gordon stayed on the cusp of becoming a Category Three Hurricane on the Saffir-Simpson Scale for nine hours from Saturday evening to early Sunday morning despite the marginal sea surface temperatures of 26 degrees Celsius, or about 79 degrees Fahrenheit. However, beginning at 5:00 AM on Sunday morning, Gordon began to gradually weaken with maximum sustained winds first dropping to 105 miles per hour, then 100 miles per hour by the 11:00 AM EDT Advisory, and then 90 miles per hour by the 2:00 PM EDT Advisory.
Despite the weakening, Hurricane Gordon is still expected to remain a hurricane by the time it makes its closest approach to the Eastern Azores on Monday. As of the most recent advisory, Gordon was located some 220 miles to the Southwest of Sao Miguel Island in the Azores. In addition to undergoing some strengthening since the last time I reported on the storm yesterday, Gordon has also picked up forward speed, and is now moving to the East-Northeast at 21 miles per hour. Minimum central pressure has risen 11 millibars, or 0.32 inches to 976 millibars, or 28.82 inches of Hg (Mercury).
The government of Portugal upgraded the Tropical Storm Warning that was in effect for the Central and Eastern Azores to a Hurricane Warning for those islands yesterday afternoon. Since that time, the warning has been amended to only include the Eastern Azores. The latest forecast discussion indicates that Gordon did have a clearly defined eye, but it had begun to become less visible during the late morning hours on Sunday. Wind shear as high as 30 knots or 35 miles per hour is also beginning to take effect on the storm by giving it a more baroclinic look with a tilt toward the east.
The NHC SHIPS forecast indicates that Gordon will weaken to below tropical storm strength by late Monday morning and then became extratropical or post-tropical by the same time on Tuesday. Elsewhere in the tropics, the disturbance in the Eastern Atlantic continues to get better organized, and the NHC has upgraded the probability of formation to 70 percent over the next 48 hours.
Weather Channel Reality TV Show Focuses On Crews That Fly Into Hurricanes
Finally, a reality TV show that is actually dealing with reality! About a month or so ago, I was told by a friend of mine that the Weather Channel was going to begin broadcasting a reality TV show that dealt with the hurricane hunters, or air force reconnaissance crews that fly into tropical cyclones in both the Atlantic and Eastern Pacific.
While I have not been able to watch a full episode of Hurricane Hunters yet, I did play clips from some of them on my iPad about a week ago. I found the show to be very interesting. The episodes clearly show the different aspects of a typical day for a Hurricane Hunter crew member. These crews fly various types of missions including low level flights into tropical disturbances, dangerous flights into Eastern Pacific storms close to the mountains of Southern Mexico, and several flights into the major story of the 2011 Atlantic Hurricane Season, Hurricane Irene.
The show does a great job of detailing the various tasks of the Hurricane Hunters as well as the different types hazards that they deal with on each mission. One episode does a great job of discussing the history of the Hurricane Hunters, which dates back to the first flights into storms in the Gulf of Mexico towards the end of World War II. I’m not a big fan of reality TV although I have grown to like American Chopper on the Discovery Channel, but Hurricane Hunters on the Weather Channel has me interested.
Winds Remain At 60 Miles Per Hour For Slow Moving Storm
The Atlantic Basin continues to have a fast start to the 2012 Hurricane Season. Tropical Storm Debby, fourth storm of the season, formed on Saturday afternoon in the Gulf after a broad area of low pressure became better organized. Maximum sustained winds at that point were at 50 miles per hour.
Since then, Debby has strengthened a bit, but still hasn’t become a hurricane. As of the 4 PM CDT Advisory from the National Hurricane Center in Miami, Florida, the storm was only packing 60 mile per hour winds. The system has not intensified at all since the morning when its wind speed was bumped up.
Areas along the Gulf Coast from Western Louisiana to the Florida Panhandle had been under a Tropical Storm Watch or Warning until this afternoon. The warnings have shifted further east. Louisiana and Mississippi are no longer under any watches or warnings while the entire coast of Alabama and much of the Florida Gulf Coast and Panhandle are under an advisory.
Presently, the storm is located some 205 miles to the East-Southeast of the mouth of the Mississippi River, or 100 miles to the SSW of Appalachicola, Florida. Maximum sustained winds are again at 60 miles per hour with gusts up to 70 miles per hour. Barometric pressure is at 993 millibars, or 29.32 inches of Hg (Mercury). Debby is moving very slowly to the Northeast at 3 miles per hour. At that rate, the storm is forecast to make landfall along the Gulf Coast on Wednesday afternoon.
A Tropical Storm Warning is in effect from the Mississippi/Alabama border to the Suwanee River in Florida. A Tropical Storm Watch is in effect from south of the Suwanee River to Englewood, Florida. Looking at the latest satellite imagery courtesy of NOAA, there is definitely more organization that has taken place since Friday, but it is still evolving.
The outflow is well defined on the eastern half of the storm. Clouds and convection are starting to wrap around the center more. However, the structure still remains ragged. The bulk of the heaviest convection is on the eastern side over Florida, which is getting pounded by rain. A Tornado Watch is in effect for the Gulf Coast of the Sunshine State as outer bands of the storm rotate through.
Portions of Florida have already received over 3 inches of rain while other locales are getting about 2 inches per hour. Forecast rain totals through Tuesday morning are calling for 4 to 6 more inches with local amounts up to a foot. Winds have ranged between 34 and 48 miles per hour from the Florida Gulf Coast to the Pandhandle. The forecast track has shifted thanks to the storm’s slow motion.
The vast circulation hasn’t made up its mind yet where it will make its landfall. A strong ridge of high pressure that has been responsible for producing tremendous heat over the Great Plains may be too far west of the storm to have a significant influence on it. A trough over the Eastern half of the country, which will help push through another cold front on Monday may be too far to the north to reel it in.
Slow Moving Storm Nearing Major Hurricane Strength
It has been a while since we’ve reported on the tropics. Not just in the Atlantic, but also in the Eastern Pacific and Western Pacific, where the bulk of activity has been taking place since the beginning of this month. We’ll have details on all of that in another blog post soon. Right now, Hurricaneville is monitoring a new threat in the Atlantic Basin.
Within the past several days, we’ve had a new named storm emerge in the Western Caribbean. Hurricane Rina first became a depression on late Sunday afternoon near the border between Nicaragua and Honduras. In the past 54 hours, the storm has exploded to the point where it is on the cusp of becoming the fourth major hurricane of the 2011 season. Rina has benefited from a rapid intensification that has taken advantage of the conducive conditions currently in the Western Caribbean.
As of this time on Monday night, Hurricane Rina was a Category One Hurricane on the Saffir-Simpson Scale with winds of 85 miles per hour. By Tuesday morning, the storm had strengthened further to a Category Two system with 100 miles per hour, and a minimal central pressure of 970 millibars, or 28.64 inches of Hg (Mercury). After going through a bit of a holding pattern during the day on Tuesday, Rina intensified to be just shy of becoming a major hurricane. Churning slowly to the West at 3 miles per hour, Rina is now located some 250 miles to the Southeast of Cozumel or 240 miles to the East-Southeast of Chetumal on the Yucatan Peninsula in Mexico.
Maximum sustained winds associated with this hurricane are now at 110 miles per hour with gusts in upwards of 130 miles per hour. Barometric pressure has fallen to 966 millibars, or 29.53 inches of Hg. Hurricane force winds extend some 30 miles from the eye while tropical storm force winds reach out some 140 miles. The eye has a diameter of 10 nautical miles. A Hurricane Warning is in effect for the East Coast of the Yucatan Peninsula from north of Punta Gruesa to Cancun. A Tropical Storm Warning is in effect from north of Chetumal to Punta Gruesa along the East Coast of the Yucatan. A Tropical Storm Watch is in effect for Belize from Belize City northward, and for the islands of Roatan and Guanaja in Honduras.
Looking at the latest forecast discussion from the National Hurricane Center, Rina is in a very favorable area for development with light wind shear at the upper levels and very warm sea surface temperatures. The storm could become a major hurricane within the next 12 to 36 hours. However, with a major trough over the Eastern United States extending into the Gulf of Mexico, Rina should begin to weaken to a Category Two storm by 48 hours. Within three days, the storm is forecast to be a Category One storm, and weaken below hurricane status by four days.
The latest forecast track shows Hurricane Rina approaching Cancun by this time Thursday night before turning to the right toward Western Cuba. Earlier on Tuesday, the GFDL model was showing Rina moving across South Florida in a track very similar to Hurricane Wilma back in 2005. However, the storm is not expected to stay that strong for long, and that will prevent the jet stream from picking up this storm, and carrying it eastward into South Florida. Hurricaneville will continue monitoring developments with this hurricane.
« Previous entries · Next entries »