Category: Tropical Weather

Almost a week after producing Tropical Storm conditions across the Windward Islands, and four days after weakening to a tropical wave, Harvey has regenerated into a tropical storm over the Bay of Campeche. Now, it’s setting it sights on Texas.

As of 12am EDT Thursday, Tropical Storm Harvey was centered about 440 miles southeast of Port Mansfield, Texas with maximum sustained winds near 40 mph. Harvey was drifting toward the northwest at 2 mph. A hurricane watch is in effect for the coast of Texas from Port Mansfield, to San Luis Pass. Tropical Storm Watches have also been issued from Port Mansfield southward to Boca de Catan, Mexico, and from San Luis Pass northward to High Island, Texas. A Storm Surge Watch is also in effect from Port Mansfield to High Island.

Current indications are that Harvey should head northwestward while strengthening over the next day or two. Harvey should be approaching the Lower or Middle Texas coast on Friday. With warm water and low wind shear, there is a chance that Harvey could rapidly intensify on Thursday, and could make landfall as a hurricane.

Once Harvey makes landfall, it will start to slow down and its movement could become erratic as there will be little in the way of upper-level wind flow to steer the storm. Many models are now showing a turn towards the west or southwest for a day or two, others show the storm nearly stationary once inland, and still others have the storm drift off towards the east or northeast after landfall. There’s also the chance that Harvey stalls before moving inland. The exact track that Harvey takes will have a huge impact on the region for obvious reasons.

While wind and storm surge are obviously threats to Texas, especially along the coast near where Harvey makes landfall, by far, the bigger threat at this point is flooding from heavy rainfall. The slow movement once inland means that heavy rain will continue across portions of the region for several days, leading to widespread, severe flooding, especially across parts of south and southeast Texas.

Some models, such as the one above, are showing the possibility for 10-20 or more inches of rain across parts of the area over the next week. Some models are showing extreme totals of 30-40 or more inches during the same time frame. while these numbers seem unbelievable, they wouldn’t be unprecedented. Hurricanes that move out of the Gulf of Mexico are usually loaded with tropical moisture and if they are moving slow enough, can produce several months worth of rainfall in a matter of days. In 1978, Tropical Storm Amelia dropped 48 inches of rain on Media, Texas. This is the most rainfall recorded from a single storm anywhere in the United States. Just one year later, Tropical Storm Claudette made landfall near the Texas/Louisiana border. In Alvin, Texas, just west of Houston,  a total of 42 inches of rain was recorded in just 24-hours. This set a new record for 24-hour rainfall in the contiguous United States. More recently, in 2001, Tropical Storm Allison produced 20-40 inches of rain on portions of southeastern Texas and Louisiana.

Meanwhile, a trough of low pressure is drifting across Florida this evening. This system will produce heavy rain across portions of the Sunshine State over the next few days, which could lead to some localized flooding. Once it drifts back into the Atlantic, it will need to be watched for signs of development. While the most likely track for the system, if it develops at all, is to head northeastward out into the open Atlantic, there are some models that show the potential for the system to impact portions of the East Coast early next week.

At this time yesterday, we thought we had a pretty good idea of what to expect for the forecast for Hurricane Matthew. Then the midday models started rolling in, and we started scratching our heads. Instead of coming close to Florida and then heading up the coast, passing south and east of New England, the models started doing some wacky things. First, one of them had it menace the Southeast, then do a big loop back into the Bahamas before hitting Florida again in a much-weakened state. Then, another model did something similar. “It’s just two outliers” is what we thought, the rest still bring it up the coast. We were still fairly confident in our forecast. Then, the GFS model came out around midnight and chaos ensued.

At that point, our forecast went right out the window. What seemed like an anomaly from one or two models, was quickly becoming the consensus. The GFS model, which had been very consistent with a track up the East Coast, suddenly changed gears, and had Matthew threaten Florida and the Bahamas not once, but twice, once from the southeast, then again from the northeast and east. Oh, it still brought Matthew up the coast, bringing rain and gusty winds to parts of New England for the weekend, but now it was doing it NEXT weekend, not this weekend.

Not all of the models are showing this loop, but as you can see in the image above, there are several that do now. Before we get into what we think might happen, we’ll get into what is causing this peculiar forecast. Looking at the upper atmosphere this morning, we see a trough of low pressure across much of the West, and a ridge of high pressure in the East. There’s also a pretty strong jet stream moving into the West Coast and into the Rockies, before it makes a sharp left turn in the Mississippi Valley.

As this trough of low pressure moves eastward, the models had been projecting that it would strengthen and sharpen up, in effect “capturing” Matthew as the trough neared the East Coast. The southerly winds ahead of the trough would drive Matthew northward or northeastward, and bring it up the coast. Instead, the models are now showing that this trough will actually weaken as it moves eastward, and flatten out. As a result, high pressure will build back in, blocking Matthew from moving northward. This would turn Matthew back towards the south and let it mill around in the Bahamas. Not all of the models are showing this scenario. Some still have the trough just strong enough to draw Matthew northward enough that the westerly winds of the jet stream are able to push it out to sea once it gets up towards the Carolinas.

This leads us to more questions. If Matthew does not get pulled north and head out to sea, then what does its future hold? Some models have it loop around, back into the Bahamas, then back towards Florida before turning northeast and heading up the coast again next week. Another one sends it back into Florida as a much weaker tropical storm, then across the state and into the Gulf of Mexico where it eventually weakens and dissipates. At this point, we’re back to “wait and see” mode.

What we do know is this: There are hurricane warnings in effect for much of Florida and the Bahamas. Hurricane Matthew is still a Category 3 storm with top winds near 120 mph this afternoon. It is going to move through the Bahamas over the next 24 hours, and then come dangerously close to the Atlantic coast of Florida, with landfall a possibility, but not definite. It will likely head northward, bringing gusty winds and heavy rain to much of eastern Florida, southeastern Georgia, South Carolina, and southeastern North Carolina over the next few days. After that? That’s a really good question that we just can’t answer right now.

Hurricane Matthew rapidly intensified from a Category 1 Hurricane to a Category 5 Hurricane in the southern Caribbean today, making it the first Category 5 Hurricane in the Atlantic since Hurricane Felix in 2007. While the track for the next couple of days is fairly certain, there’s plenty of uncertainty in what Matthew will do beyond the weekend.

Here are the things that we do know: As of 11pm EDT on Friday, Matthew was a Category 5 Hurricane on the Saffir-Simpson scale, with maximum sustained winds of 160 mph.The storm was centered anout 440 miles southeast of Kingston Jamaica, and was moving towards the west at 7 mph. A Hurricane Watch remains in effect for Jamaica while a Tropical Storm Watch is in effect for Haiti from the southern border with the Dominican Republic to Port-au-Prince. A Tropical Storm Warning also remains in effect for the coast of Colombia from the Colombia/Venezuela border to Riohacha.

Matthew passed just north of the ABC Islands (Aruba, Bonaire, Curacao) and northern South America earlier on Friday, which is a fairly rare occurrence. There were a few wind gusts to near tropical storm force in Aruba and Bonaire early Friday, but for the most part, it’s just been a breezy and cloudy day in an area that usually is sunny and warm. When Matthew crossed the island of Martinique a few nights ago, it produced sustained winds of 40 mph and a gust to 60 mph at the airport in St. Pierre, with reports of gusts of up to 89 mph on the island. There were several reports of damage across the island.

Now that we’ve gone over what we know, here’s what we are fairly sure about: Matthew should turn more towards the northwest and eventually north this weekend as a powerful hurricane, with some fluctuations in intensity, as is normally the case with strong storms. Unfortunately, Matthew is expected to pass very close to Jamaica on Monday. It may even make landfall on the island. Even a glancing blow will likely result in widespread damage across the island. After that, Matthew should continue northward, and it will pass very near or over extreme western Haiti or eastern Cuba before heading into the Bahamas. Some slight weakening is possible due to interaction with the land areas, but Matthew should still be a strong hurricane (Category 2 or 3) when it enters the Bahamas.

Now, the part that nobody knows with any certainty right now – what happens after Matthew gets into the Bahamas. This is the big question, and a lot of it has to do with what the upper-level pattern looks like. A trough of low pressure will be starting to move out of the Northeast while another one moves into the Great Plains. In between, a ridge of high pressure will be moving into the East. Exactly how quickly these features move eastward will determine which way Matthew goes.

As you can see from the images above, there are dozens of possibilities as to where Matthew might go. Based on the most recent model runs, a track through the Bahamas and then northward off the Carolinas is the most likely outcome, but there are still some models that have the storm stall in the Bahamas or even drift closer to Florida or even possibly into the Gulf of Mexico. Once it gets up towards the Carolinas, there are even more possibilities to consider. The storm could continue up the coast and threaten the Northeast. It could start to turn northeastward and threaten Atlantic Canada. It could turn more east-northeastward and head harmlessly out to sea. At this point, there isn’t really one scenario that stands out as more likely than any of the others.

At this point, we really have to wait and see how the pattern evolves before we’ll have a better idea as to what Matthew is going to do.  So, if you are along the East Coast or have plans along the East Coast later next week, keep an eye on Matthew’s progress if you have plans for that time frame.

The peak of hurricane season is normally a 6-week period from late August until late September. This year is no exception. We currently have five active tropical systems that we’re tracking, and more may be on the way. Of the five that are currently out there, all of them are a threat to some land areas, four of them to parts of the United States.

We’ll start in the Central Pacific where Hurricane Madeline is bearing down on parts of the Hawaiian Islands. As of 8am HST Tuesday, Hurricane Madeline was centered about 415 miles east of Hilo, Hawaii, moving towards the west at 10 mph. Maximum sustained winds are near 120 mph, making Madeline a Category 3 Hurricane on the Saffir-Simpson Scale.  A Hurricane Watch and Tropical Storm Warning have been issued for the Big Island of Hawaii, and a Tropical Storm Watch has been issued for Maui County, including the islands of Maui, Molokai, and Lanai. The current forecast calls for Madeline to pass just south of the Big Island with some weakening expected. Madeline should pass close enough to Hawaii to bring strong winds and heavy rain to some of the southernmost islands. Rainfall totals of 5-10 inches and locally heavier are possible, especially in the windward sides of the islands. Rough surf will pound most of the islands for the next several days.

Next up is Hurricane Lester, which was centered about 1350 miles east of Hilo, Hawaii at midday, moving toward the west at 14 mph. Lester has top winds near 120 mph, is expected to steadily weaken over the next few days while continuing in a general westward direction. While Lester is not a threat to land for the next few days, that could change by the end of the week. The current track calls for Lester to gradually turn more towards the west-northwest and northwest by Friday and Saturday, passing a little north of the Hawaiian Islands. While this track would likely spare the islands from most of the wind and rain, if Lester makes that turn a bit later, it would pass a lot closer to the islands. Residents of Hawaii should make sure to keep tabs on Lester’s progress once Madeline moves away from the region.

In the Atlantic, Hurricane Gaston is the strongest of the three active storms, but also the one that is farthest from land at the moment. as of midday Tuesday, Gaston was centered about 700 miles east of Bermuda, moving towards the east-northeast at 8 mph. Gaston has maximum sustained winds near 105 mph, but is expected to start to steadily weaken over the next few days. A track towards the east-northeast or northeast is expected to continue for the rest of the weak. On this track, Gaston may move right through the Azores as a weakening hurricane or strong tropical storm towards the end of the week.

Closer to the mainland we find Tropical Depression Eight. The storm was centered about 70 miles south of Cape Hatteras, North Carolina early Tuesday afternoon and was nearly stationary. Maximum sustained winds are near 35 mph. A slow drift toward the north is expected tonight and Wednesday, with some strengthening possible as the storm moves over the warm waters of the Gulf Stream. A Tropical Storm Warning is in effect for the coast of North Carolina from Cape Lookout to Oregon Inlet. Wins gusts to 30-40 mph and locally heavy rainfall are expected over the Outer Banks of North Carolina tonight and Wednesday. After that, the system should start to head out into the Atlantic and dissipate by later in the week.

Finally, we get to Tropical Depression Nine, which was centered about 340 miles west of Key West, Florida at midday Tuesday. The storm has maximum sustained winds of 35 mph, and was moving towards the west-northwest at 7 mph. The forecast for this system calls for a turn more towards the north and eventually northeast as an upper-level trough of low pressure starts to steer the system. Strengthening is expected, and the depression could become a tropical storm tonight or early Wednesday. Tropical Storm Watches will likely be issued for parts of the Gulf Coast later today or tonight. Some of the models show the possibility of the storm becoming a hurricane before making landfall along the Florida Gulf Coast later this week. Once it makes landfall, it should quickly cross the Southeast, then emerge into the Atlantic, where some re-strengthening is possible. The system will likely bring heavy rain and gusty winds to parts of the Carolinas, but beyond that its future is uncertain. Some models indicated that it will continue northeastward, out into the Atlantic, while others try to slow it down and head northward up the East Coast in a much-weakened state. Since this could have an adverse impact on the Labor Day Weekend for parts of the East Coast, anyone with interests in that region should keep an eye on the system’s progress.

Finally, a new tropical wave has emerged from the coast of Africa. This wave will cross the Cape Verde Islands tonight, then head westward across the Atlantic. Conditions are favorable for further development, and many of the forecast models show the possibility of this system strengthening over the next several days. It is still at least 5 days away from impacting the eastern Caribbean, so there is plenty of time to monitor its progress before it threatens any land areas.

As we get into the end of August, we are moving into the peak of hurricane season. As expected, the tropics have awakened, with plenty of activity to watch, but thus far, much of it remains disorganized.

Starting in the Atlantic, we have Tropical Storm Gaston. Gaston was centered about 900 miles east-southeast of Bermuda Friday evening, moving towards the northwest at 15 mph. While Gaston was briefly upgraded to a hurricane earlier in the week, it currently has maximum sustained winds of 65 mph. Conditions are favorable for Gaston to strengthen this weekend and become a hurricane once again. The storm should turn more toward the north and eventually northeast, remaining over open waters into the start of the upcoming week.

A disorganized area of showers and thunderstorms is moving across the Central Bahamas this evening. For several days, many of the forecast models have been showing the potential for this storm to develop and possibly impact Florida and/or the Gulf Coast. Despite this, the system has not developed, and conditions will be unfavorable into the weekend for any further development. Several models are still showing the potential for the system to develop once it gets into the Gulf of Mexico. Water temperatures are very warm across the Gulf, which would help to fuel any developing system. Anyone with interests in and around the Gulf Coast should keep an eye on the progress of this system.

Meanwhile, there is a weak trough of low-pressure already located in the northern Gulf of Mexico this is being watched. Upper-level conditions are not favorable for development of this system, but it will bring heavy rainfall to portions of Louisiana and Texas this weekend. This is not good news for areas that were hit hard by flooding just a few weeks ago.

Another disturbance has developed just south of Bermuda this evening. This system is expected to remain weak for the next few days while moving very little. Eventually it should start drifting westward, and some slow development is possible. This system may bring some showers and thunderstorms to Bermuda this weekend and parts of eastern North Carolina during the early part of the upcoming week, but otherwise should not have much of an impact on any land areas.

While the Atlantic is filled with potential tropical systems, the Pacific has a couple of named systems, one of which could be a threat to land.

Hurricane Lester was centered about 550 miles southwest of Cabo San Lucas, Mexico Friday evening. Lester has maximum sustained winds near 75 mph, and additional strengthening is expected.  Lester is currently moving toward the west at 9 mph, and a general westerly track is expected to continue through the weekend. Lester is not a threat to land for the next several days, however, some models are showing that it could have some impacts of Hawaii towards next weekend.

Tropical Storm Madeline could be a more immediate threat to Hawaii. Tropical Depression 14-E developed earlier on Friday about 1250 miles east-southeast of Hilo, Hawaii, and was upgraded to Tropical Storm Madeline Friday evening. Madeline has maximum sustained winds near 40 mph, and additional strengthening is expected. Madeline could become a hurricane by the end of the weekend or beginning of next week. The storm is expected to track towards the northwest this weekend before turning more towards the west. On this track, Madeline could approach the Hawaiian Islands towards midweek. Residents of the region should keep an eye on Madeline’s progress during the next few days.

In the Western Pacific, Typhoon Lionrock has been slowly meandering around south of Japan for much of the past week, but that looks like it is about to change. As of Friday evening, the storm has maximum sustained winds near 110 mph, and some additional strengthening is possible this weekend. A track toward the northeast is expected this weekend, but a turn more toward the north and eventually northwest is likely by Sunday or Monday. On this track, the typhoon would make landfall in southeastern or eastern Japan on Monday.

In the Northern Hemisphere, tropical activity normally peaks during the latter half of August and much of September. So far, it looks like 2016 will follow that pattern, as there are currently five active systems around the world, and a couple of other areas being monitored for development.

The most active area right now is the Western Pacific Ocean, where there are three active systems, a third that is dissipating in northern Vietnam, and another disturbance that could develop in the next day or two. We’ll get to the Atlantic in a bit. If you don’t care about the Pacific, then scroll down.

Tropical Storm 10W (Mindulle) is probably the most immediate threat to land. The system is located several hundred miles east of Japan, moving towards the northwest at 10 mph. Maximum sustained winds are near 50 mph, and additional strengthening is expected. Mindulle could become a typhoon this weekend. Computer model forecasts indicate a northerly track over the next few days, with landfall possible in southern Japan towards the end of the weekend or beginning of next week.

Tropical Storm 12W (Lionrock) is actually closer to the south coast of Japan right now than Tropical Storm Mindulle, but is less of a threat. Lionrock is expected to head westward to southwestward over the next few days, with some slow strengthening expected. Lionrock could threat some of the islands southwest of Japan during the early to middle portion of next week.

Elsewhere in the Western Pacific, Tropical Storm 11W (Dianmu) made landfall in northern Vietnam earlier today. The system will continue moving inland while dissipating. It will continue to bring heavy rain to parts of the region, with flooding likely. Another disturbance in the Western Pacific, located about 1000 miles southeast of Japan, is being monitored for development. The system could become a tropical depression this weekend while heading on a general northwesterly track. It could be a threat to parts of northern and eastern Japan towards the middle of next week.

In the Eastern Pacific, Tropical Storm Kay has formed. As of midday Friday, Kay had top winds near 40 mph and was passing very close to Socorro Island, off the coast of Mexico. Some slight strengthening is possible tonight and Saturday before Kay moves over colder waters and starts to weaken and eventually dissipate. Once Kay moves away from Socorro Island this afternoon and evening, it should not be a threat to any land areas.

Finally, we get to the Atlantic, where we have Tropical Storm Fiona. As of Midday Friday, Fiona was centered about 1300 miles west of the Cape Verde Islands, moving towards the west-northwest at 10 mph. Top winds are near 45 mph, but conditions are not favorable for additional strengthening. Indications are that Fiona should remain a weak system over the open waters of the Central Atlantic right through the weekend, with no threat to any land areas.

Farther to the east, a tropical wave located about 600 miles southwest of the Cape Verde Islands, is being monitored for further development. The system should remain weak through the weekend, but conditions should become favorable for development as it moves into the Central Atlantic Ocean by the beginning on next week. Many of the computer models are forecasting the system to develop into an organized tropical system during that time frame. If these forecasts are correct, the system could be a threat to the islands in the eastern and northeastern Caribbean by the middle of next week. Anyone with interests in that region should keep an eye on the system and it’s progression.