Category: Tropical Weather

The peak of hurricane season in the Atlantic occurs around September 10 on average. As we rapidly approach that date, the Atlantic is starting to get active, with two named systems right now.

The biggest threat this afternoon is Tropical Storm Gordon. As of midday Tuesday, Gordon was centered about 130 miles south-southeast of Mobile, Alabama, moving towards the northwest at 15 mph. Maximum sustained winds were near 65 mph, and some additional strengthening is possible. Gordon could become a hurricane before making landfall along the Mississippi or Alabama coastline tonight Hurricane and Tropical Storm Warnings are in effect for much of the north-central Gulf Coast, with a Storm Surge Warning also in effect for parts of the area.

While storm surge flooding and strong winds are threats with Gordon, heavy rain will be a more prolonged threat to the region. Once Gordon makes landfall it will slow down as it moves into the Deep South and Mississippi Valley. This will keep the heavy rain threat going for a few days. Rainfall totals of 3-6 inches, with localized totals to 10 inches or more could result in flooding across much of the region. By Friday, as the system continues to drift northward, an approaching cold front will pick up the system, and send it off towards the Ohio Valley and Great Lakes.

Meanwhile, in the Central Atlantic Ocean, Florence has become the third hurricane of the season. As of midday Tuesday, Florence was about midway between the Lesser Antilles and Cape Verde Islands, moving toward the west-northwest at 12 mph. Florence has maximum sustained winds near 75 mph, but the current forecast calls for Florence to weaken a bit over the next few days before regaining a little strength. Florence should continue in a general northwestward track through the week, remaining over open water. After that, things may get a little complicated.

The steering currents in the central Atlantic Ocean are forecast to weaken later this week, making the future track of Florence uncertain once we get into the weekend. The more likely case is what usually happens, an approaching trough of low pressure picks up Florence and it curves northward and eventually harmlessly out to sea. However, if that trough is not strong enough to grab Florence, it could meander around for a while or start to drift westward as a ridge of high pressure builds back in to the north. While Florence would still likely head out to sea eventually, this scenario would imply a potential threat to the East Coast later next week. We won’t know which scenario is more likely until we get to this weekend at the earliest.

Even farther to the east, a developing low pressure system is passing south of the Cape Verde Islands today. It is expected to continue on a general west to west-northwest track over open waters for the next several days. Conditions are favorable for development, and the system could become a tropical depression later this week. It is still a week away from impacting any land areas, if it were to even get that far.

In the Pacific, Hurricane Olivia will strengthen a bit more over the next day or two as it continues to move away from Mexico and into the open waters of the Eastern Pacific. Hurricane Norman, however, is the system getting attention in that part of the world.

As of Tuesday morning, Norman was centered about 750 miles east of Hilo, Hawaii, moving toward the west at 17 mph. Maximum sustained winds were near 85 mph. Norman is expected to maintain its current strength for another day or two before a weakening trend begins. The system is expected to turn more toward the northwest later this week, passing safely east and north of Hawaii towards the end of the week. It will send some rough surf towards the islands, but that should be the only impact as the region continues to recover from Hurricane Lane.

Officially, hurricane season in the Atlantic Basin starts on June 1 and ends on November 30. In recent years, Mother Nature has not adhered to that calendar, and it appears as though she won’t this year either.

A cluster of thunderstorms centered over the Yucatan Peninsula and northwestern Caribbean Sea has been slowly organizing over the past several days. Conditions should be favorable for the system to continue to organize as it heads northward into the Gulf of Mexico over the next day or two. The system could become a tropical depression over the Memorial Day Weekend while slowly moving across the Gulf of Mexico.

Most of the forecast models are in good agreement that the system should continue northward toward the central Gulf Coast, with slow but steady strengthening expected. If it reaches tropical storm strength, it would be given the name Alberto.

While gusty winds and storm surge are threats near where the system makes landfall, but far, the bigger threats are heavy rain and flooding. The shield of heavy rain will extend far from the center, bringing heavy rain to much of the Southeast and the Gulf Coast during the Memorial Day Weekend. Widespread totals of 2-5 inches are expected, with localized totals in excess of 10 inches possible in some areas. Flood watches have already been issued for parts of the region, and more are expected to be issued in the coming days.

Last year, the hyperactive season got off to a very early start when Tropical Storm Arlene formed in the central Atlantic on April 19. The 2016 season got an even earlier start when Hurricane Alex formed on January 14 and Tropical Storm Bonnie developed on May 27. In 2015, Tropical Storm Ana formed on May 8, and made landfall near Myrtle Beach, South Carolina on May 10, the earliest landfalling storm on record in the United States. Based on data from 1966-2009, the first named storm in the Atlantic doesn’t normally develop until July 9 and the first hurricane doesn’t develop until August 10.

An early start is not always a harbinger of what the season will bring. NOAA issued their seasonal hurricane outlook on Thursday, and it calls for a 35 percent change for an above normal season, a 40 percent chance for a normal season, and a 25 percent chance for a below normal season. An average season consists of 12 named storms, of which 6 become hurricanes and 3 become major hurricanes. The 2017 season consisted of 17 named storms, of which 10 became hurricanes and 6 were major hurricanes. These storms produced an estimated $280 billion in damage, making 2017 the costliest season on record. Many parts of the Caribbean, as well as Texas and Florida are still struggling to recover from direct hits by Hurricanes Harvey, Irma, and Maria.

We’re in the peak of hurricane season now, and as you’d expect, the tropics are getting active, with two tropical storms and a hurricane in the Atlantic, but the biggest threat to land is not the one that’s been advertised for the past few days.

With Irma dissipating over land a few days ago, Jose was the only active tropical system in the Atlantic for a few days, and thus grabbed most of the attention while it was completing a small loop a few hundred miles east of the Bahamas. It weakened to a tropical storm, but has since restrengthened into a hurricane. As of 5pm Saturday, it was centered a little less than 500 miles south-southeast of Cape Hatteras, NC with maximum sustained winds near 80 mph. It was moving towards the north at about 6 mph. The forecast for Jose for the next 48 hours is fairly easy. It will continue to head northward around the edge of a large high pressure area. While it remains over very warm water, there is still plenty of wind shear aloft, and the wind shear will counteract the warm water, preventing much, if any, additional intensification. It will produce rough seas for much of the western Atlantic, and also create a high risk of rip currents from New England to the Carolinas.

By Tuesday, Jose will start to move over colder waters as it passes north of the Gulf Stream, so it should start to weaken. At the same time, it will start to encounter westerly winds aloft, which will turn it more towards the northeast and eventually east. On this track, the center should pass about 100 to 150 miles south and east of Cape Cod as a weakening tropical storm. By this point, the storm may not even be completely tropical any more, and starting the transition into an extratropical system. It will pass close enough to bring gusty winds and some rainfall into southeastern portions of New England, but the impacts will be similar to a fall nor’easter across the region. The biggest impacts will be across Cape Cod, where some wind gusts in excess of 60 mph are possible. Coastal flooding will also be an issue, as tides are running high this week with the New Moon on Wednesday. Rainfall totals of 1-3 inches and locally heavier shouldn’t cause any flooding issues, and will actually be beneficial, as some parts of the region have been dry lately, with some drought conditions starting to reappear.

Well out in the Atlantic is Tropical Storm Lee. As of 5pm Saturday, Lee was centered about 720 miles west-southwest of the Cape Verde Islands, moving towards the west at 10 mph. Lee has maximum sustained winds near 40 mph. Lee is expected to continue on a general west to west-northwest track for the next few days. While some modest strengthening is possible over the next day or two, the long-term outlook is for Lee to weaken by early next week, and probably dissipate over the open waters of the central Atlantic, well away from any land areas.

While Jose has been grabbing the headlines, and Lee remains weak, Tropical Storm Maria has formed east of the Lesser Antilles, and this storm will likely grab most of the attention over the next few days, especially after Jose starts to move away from the East Coast.

Tropical Storm Maria formed Saturday afternoon east of the Lesser Antilles. As of 5pm Saturday, it was centered about 620 miles east-southeast of the Lesser Antilles, moving towards the west at 20 mph. Maximum sustained winds are near 50 mph, and additional strengthening is expected. Maria could become a hurricane on Sunday. A hurricane watch has already been issued for the islands of Antigua, Barbuda, St. Kitts, Nevis, and Montserrat, with a tropical storm watch in effect for the islands of St. Lucia, Martinique, Guadeloupe, Dominica, Barbados, St. Vincent, and the Grenadines. Additional watches and warnings are likely to be issued tonight and Sunday.

Maria is expected to cross the Lesser Antilles as a hurricane on Monday. It should pass farther south than Irma, which will spare the islands that were devastated from another direct hit. Once it gets past the Antilles, it will turn more towards the northwest, and head towards the Virgin Islands and Puerto Rico for Tuesday into Wednesday. It could become a strong hurricane by this point, so residents on this region, still trying to cleanup after Irma, need to play close attention to Maria.

The last few weeks have felt a lot like a Hollywood disaster movie, but not only have the disasters been real, they’re going to get worse in the next few days.

As of 11pm Friday, Hurricane Irma had regained Category 5 strength with maximum sustained winds near 160 mph. It was centered about 300 miles south-southeast of Miami, very close to the Camaguey Archipelago on the north coast of Cuba, moving towards the west at 13 mph. Hurricane Warnings and Storm Surge Warnings are in effect for most of Florida, as well as Cuba, with Hurricane Watches for much of the remainder of northern Florida. Its intensity into early Saturday will depend on how long it interacts with the Cuban coastline. Even it were to weaken a bit, it could very easily regain Category 5 status on Saturday, and will likely make landfall in Florida on Sunday as a Category 4 or 5 storm.

Irma will continue on a general west to west-northwest track early on Saturday, as it moves around the southern edge of a ridge of high pressure. At some point in the next 12-18 hours, it’ll reach the southwestern edge of that ridge and make a sharp right turn. Exactly when that turn occurs is key to determining where it will make landfall. Right now, it looks it’ll move across the Florida Keys, and then make landfall in southwestern or western Florida on Sunday. This may put cities such as Naples, Fort Myers, and possibly Tampa in the eyewall on Sunday. The current track brings the storm northward, which means that for Sunday into early Monday, the storm will head right up the west side of Florida. While it’ll be weakening once the center is inland, it should maintain hurricane strength until it gets close to the Florida/Georgia border. That means, hurricane conditions for much of the state, except possibly the Panhandle. The worst conditions will be in the eyewall, just to the right of the center. With the storm heading northward, that means east of the center. some of these locations will see sustained winds of 100-125 mph, with gusts to 150 mph. Along Florida’s heavily populated east coast, cities such as Miami, Fort Lauderdale, and West Palm Beach may be outside the eyewall, but will still see sustained winds of 60-80 mph, with gusts to 100 mph. Even places farther to the north, such as Orlando, may see wind gusts upwards of 100 mph. While flooding won’t be on the scale of Harvey, rainfall totals of 8-16 inches and locally heavier are possible across Florida, which will lead to some flooding problems. In addition, storm surge of 10-20 feet will inundate portions of southwest Florida near where it makes landfall, with lesser storm surge farther to the north and along the east coast.

While all attention has been focused on Irma, Hurricane Jose has blown up into a Category 4 hurricane in the Atlantic. As of 11pm Friday, Jose was centered a little more than 265 miles east-southeast of the Northern Leeward Islands, moving toward the west-northwest at 14 mph. Maximum sustained winds are near 155 mph, which is just below Category 5 strength. Some fluctuations in intensity are expected for the next day or two. Jose should continue towards the west-northwest for another day or so before turning more towards the northwest. Unfortunately, that track will bring Jose very close to the islands in the northern Leeward Islands. These are the same islands that Irma just devastated a couple of days ago. Hurricane Warnings have been posted for many of these islands, with Tropical Storm Watches farther south and west. The Tropical Storm Watches do not indicate that weakening is expected. They just show that those islands should be far enough from the center that they will “only” receive tropical storm conditions, and not hurricane conditions. Once Jose gets past the islands, things get a little more murky. Jose should head into the open Atlantic and start to weaken, but it will also slow down, and perhaps stall as high pressure builds in to its north. By the middle of next week, there is plenty of disagreement among the models as to where Jose will go. Some models have the high pressure area retreating, which will allow Jose to head out into the open Atlantic. Others have the high pressure area strengthening, which would send Jose westward, towards the Bahamas and possibly the East Coast. It is too early to figure out which solution is more plausible at this point. So, we may be dealing with Jose at some point again next week.

Finally, in the Gulf of Mexico we have Hurricane Katia. As of 11pm Friday, Katia was making landfall on the Mexican coastline near Tecolutla, about 115 miles northwest of Veracruz. Katia is moving toward the west-southwest at 7 mph and will continue to push farther inland overnight. After peaking earlier in the day as a Category 2 Hurricane, with top winds near 100 mph, Katia’s top winds are down to 75 mph, and it should weaken into a tropical storm overnight. Katia should rapidly weaken on Saturday as it encounters the mountainous terrain of Mexico. While this will keep wind damage confined to coastal areas, it makes the threat of flooding and mudslides even worse. Rainfall totals of 10-20 inches and locally heavier are likely in this area over the next few days.

Another tropical wave will emerge from the coast of Africa this weekend. Several computer models show the potential for that system to develop as it moves across the Atlantic next week, so we’ll need to keep an eye on that system over the next several days.

While Hurricane Irma is rightfully grabbing all the attention, there are two other tropical storms that could be threats to land in the coming days.

After moving across Barbuda, St. Barts, and St. Martin overnight, the eye of Hurricane Irma was moving across the British Virgin Islands early Wednesday afternoon. When Irma moved across Barbuda last night it produced sustained winds of 118 mph with a gust to 155 mph, before the anemometer failed at an automated observing station. Sustained winds of 106 mph with a gust to 131 mph were reported at Buck Island in the US Virgin Islands, while a wind gust to 113 mph was also reported this afternoon in Estate Bovoni on St. Thomas in the US Virgin Islands. Irma should continue moving west-northwestward today, with the eye passing just north of St. John and St. Thomas in the US Virgin Islands. While this places these islands in the southern eyewall, things could actually be worse. The strongest winds in the storm have been observed in the northern eyewall, which will remain over open water. Maximum sustained winds in this part of the storm are estimated to be near 185 mph, making Irma one of the strongest storms ever in the Atlantic.

Irma’s southern eyewall will likely move across northern Puerto Rico, possibly including the San Juan area. Hurricane strength winds were already moving into Culebra early Wednesday afternoon, with gusts as high as 86mph reported. In addition to the wind, heavy rain is expected across the Virgin Islands and northern Puerto Rico. Rainfall totals of 5-10 inches with locally heavier amounts, will likely produce flooding in some areas. Lesser rainfall totals are expected across St. Croix as well as southern Puerto Rico.

Once Irma moves away from Puerto Rico, the obvious question becomes “where will it go next?” Hurricane Warnings are in effect for the northern coast of the Dominican Republic and Haiti, as the storm will likely pass just north of those nations, but close enough to bring hurricane conditions to coastal locations. Hurricane Warnings are also in effect for the Southeastern Bahamas, as well as the Turks and Caicos Islands. Right now, Irma is expected to pass right across some of these islands as a Category 4 or 5 hurricane later Thursday into Friday. Beyond that, there is still a lot of uncertainty.

Hurricane Watches have been posted for eastern Cuba as well as the Central Bahamas. Irma could be impacting either location by later on Friday. For the past few days, many of the forecast models showed the potential for Irma to head west-northwestward, possibly impacting or even making landfall in northern Cuba before making a sharp right turn and heading towards southern Florida. However, since last night, many of these models have started to shift a bit, now showing that turn coming earlier, with Irma possibly making landfall in south Florida this weekend, or possibly turning even earlier, and heading northward towards the coast of Georgia or the Carolinas. At this point, it’s still too early to tell which scenario will be more plausible. Anyone with interests from North Carolina to Florida and the Bahamas should pay very close attention to Irma, and be prepared to take action on short notice.

Meanwhile, Tropical Storm Jose is nearing hurricane strength in the Central Atlantic Ocean. As of midday Wednesday, Jose was centered about 1135 miles east of the Lesser Antilles, moving towards the west-northwest at 17 mph. Maximum sustained winds are near 70 mph, and Jose will likely strengthen into a hurricane later today. Jose is expected to turn more towards the northwest while strengthening over the next few days. While the storm is currently expected to pass north and east of the Leeward Islands, it wouldn’t take much of a shift in the track to bring the storm closer to areas that got hammered by Irma last night.

We also have Tropical Storm Katia in the southwestern Gulf of Mexico. At midday Wednesday, Katia was centered about 175 miles north of Veracruz, Mexico, drifting east-southeastward at 5 mph. Katia has maximum sustained winds near 45 mph, and additional strengthening is expected. Katia should start to drift more towards the south and southwest while strengthening over the next day or two. Katia could become a hurricane before making landfall in Mexico towards the end of the week. Katia may produce heavy rain across parts of Mexico, with rainfall totals of 10 to 20 inches possible leading to flooding and mudslides across the area.