Category: Tropical Weather

As the climatological peak of the 2015 Hurricane Season draws closer, things are starting to get more active in the Atlantic.

At 11am, Tropical Storm Danny was upgraded to a hurricane with top winds near 75 mph. Danny was located about 1100 miles east of the Lesser Antilles and heading towards the west-northwest at 12 mph. The future of Danny is still a bit uncertain. It should continue to head on a west-northwesterly heading for the next few days, likely reaching the Lesser Antilles late Sunday or early Monday. How strong it will be at that time is the big question. The official forecast from the National Hurricane Center calls for Danny to cross the Antilles as a hurricane, then weaken to a tropical storm as it nears Puerto Rico and the Virgin Islands. However, many of the computer models are indicating that Danny weaken back to a tropical storm before reaching the islands, and several have it degenerating to a tropical wave shortly after moving into the Caribbean.

Meanwhile, an area of disturbed weather southwest of Bermuda is producing shower and thunderstorm activity this afternoon. Conditions are favorable for the system to gradually acquire some tropical or sub-tropical characteristics over the next few days. Most indications are that it should remain over open waters, but it could increase the surf along the East Coast through the weekend.

In the Pacific, Tropical Depression 3-C has formed about 700 miles southeast of Hilo, Hawaii. The forecast for the depression is steady strengthening while continuing on a general northwesterly course for the next day or two. The storm

should start to turn more towards the north, and could threaten portions of the Hawaiian Islands this weekend or early next week. While the system will likely become a tropical storm (and given the name Kilo), how strong it eventually gets is a question mark. Some models keep it just a tropical storm, while many of them to strengthen it into a hurricane. Residents of the 50th state should keep a close eye on this system’s progress over the next few days.

Farther to the west, there are twin typhoons in the Western Pacific. The more immediate concern is Typhoon Goni. As of midday Wednesday (EDT), Goni was located just northeast of the northern tip of the Philippines with top winds of 135 mph, and was moving towards the west at 7 mph. Goni is expected to make a turn towards the north later today and eventually northeast over the enxt few days. This would bring Goni east of Taiwan, but also heading right towards southwestern Japan. Some of the islands east of Taiwan and south of Japana, including Okinawa, could be directly in the path of the storm.

Farther east is Super Typhoon Atsani. Atsani has top winds near 150 mph and is located about 450 miles southeast of Tokyo, moving northwest at 10 mph. Atsani is expected to turn more toward the north and northeast, heading out into the open Pacific while steadily weakening.

There are a few other areas of disturbed weather being monitored for development, including a system in the eastern Pacific about 1000 miles southwest of the southern tip of Baja California and another Atlantic tropical wave just emerging from the coast of Africa. With the climatological peak of hurricane season still a few weeks away, conditions should remain active for a while.

The 2015 hurricane season has been rather slow thus far in the Atlantic, but things are starting to get a bit more active.

Tropical Depression 4 formed on Tuesday, and quickly became Tropical Storm Danny by Tuesday evening. As of midday Wednesday, Danny had top sustained winds of 50 mph and was located about 1400 miles east of the Lesser Antilles, heading westward at 12 mph. Most indications are that Danny should continue on a general west to west-northwest track for the next few days while steadily strengthening. Danny could become a hurricane later this week, and could start to threaten the Lesser Antilles by late this weekend or early next week. There is still a great amount of uncertainty in the track and intensity forecast, however, so residents of the islands in the eastern and northeastern Caribbean should keep a close eye on the storm for the next several days.

While tropical systems often produce wind damage and coastal flooding, there is one aspect of this storm that could actually be good news for parts of the Caribbean – heavy rainfall. With the tropics remaining quiet this year, the lack of thunderstorm activity has resulted in a severe drought across portions of Puerto Rico and the Virgin Islands. In St. Croix, USVI, only 7.31 inches of rain has fallen since January 1, which is 11.38 inches below normal. San Juan, PR has only received 20.73 inches of rain in 2015, which is 10.34 inches below normal. Too much rain in a short period of time will result in flooding, even with the ongoing drought, but residents of the region will likely take every drop they can get right now.

Meanwhile, in the Central Pacific Ocean, a tropical disturbance is gaining strength about 900 miles southeast of Hawaii. Many of the forecast models are indicating that this system should continue to strengthen, becoming a tropical

depression in the next day or two, then a tropical storm, and possibly a hurricane towards the end of the week. A track toward the northwest, in the general direction of the Big Island of Hawaii is expected. The system could impact Hawaii with gusty winds and heavy rain by the upcoming weekend.

While the Atlantic has been quiet, the Western Pacific has bee very active so far. Currently there are two large storm systems being monitored. Super Typhoon Atsani has top winds near 160 mph and is passing northeast of the Northern Mariana Islands. It will likely maintain its current strength for the next day or so before starting to weaken as it turns north and then northeast, passing out to sea well south and east of Japan.

Typhoon Goni could be a problem for parts of East and Southeast Asia. Goni currently has top winds near 130 mph and should strengthen a bit more. The current forecast has it near maximum intensity of 145 mph as it nears the northeastern tip of the Philippines. Once there, it should make a sharp turn towards the north, passing just east of Taiwan as it starts to weaken, then it may take aim at southwestern Japan.

The peak of hurricane season in the Atlantic and eastern Pacific is normally from late August into mid-to-late September. Even though it has been a fairly quiet season thus far in the Atlantic, it only takes one storm making landfall in a populated area to make it a bad season.

On October 24, 2005, Hurricane Wilma, which at one point was the strongest storm ever recorded in the Atlantic Basin, made landfall near Goodland, Florida as a Category 3 hurricane with top winds near 120 mph. Wilma was the third hurricane and second major hurricane (Category 3 or higher on the Saffir-Simpson scale) to make landfall in Florida during 2005. The previous year, a total of 4 hurricanes (3 major hurricanes) made landfall in Florida. During the same two-year period, Major Hurricanes Katrina and Rita also slammed into Louisiana.

In the 10 years since Wilma’s landfall, no hurricanes have struck Florida, and no major hurricanes have struck the United States as a whole. This 10-year lull in major hurricane landfalls is unprecedented since hurricane record-keeping began in 1851. The longest lull on record before this was a 9-year lull between August, 1860 and September, 1869. For Florida, the 10-year drought smashed the previous record of 6 years, set between 1979 and 1985.

While some may argue that the lack of landfalls is a good thing, in many ways, it’s also bad. Reports have indicated that over a million people have moved to Florida since 2005, and the vast majority of those people have likely never experienced a hurricane, let alone a major hurricane.  They may not know how to prepare for a storm that could leave them without power for a week or more. They may not know what a mandatory evacuation means or if they are in a mandatory evacuation zone. They may not know where the nearest shelter is. (For Hurricane Preparedness Tips, visit the National Hurricane Center’s Preparedness Page)

In the Northeast, the drought is even worse. While some may argue whether or not Sandy was a hurricane, it only gave New England and New York a glancing blow. The last hurricane to make landfall in New England was Hurricane Bob in 1991. The last hurricane to make landfall on Long Island was Gloria in 1985. Historically, this region gets hit by a hurricane once every 6 years, but it’s been a quarter of a century since the last one hit. That means that there is an entire generation that does not know what it means to experience a hurricane in this region. As with Florida, it’s a matter of when, not if, the next one will hit this region, and they are long overdue.

While most experts expect this to be a fairly inactive hurricane season, that does not mean the landfall drought will continue. By all accounts, 1992 was an inactive season with only 6 named storms, 4 of which became hurricanes. However, one of those hurricanes was Andrew – one of only 3 Category 5 Hurricanes ever to make landfall in the United States.

Even though the “official” start of the 2015 Atlantic Hurricane Season is on June 1, there have been many cases of tropical storms and even hurricanes that have roamed the Atlantic waters prior to that date. While the majority of these have been weak and remained offshore, there are a few notable storms in our hurricane database. At least one tropical storm has been recorded in the Atlantic Ocean every month of the year with a hurricane being observed every month except February and April. There are many reasons why tropical cyclones tend to form almost exclusively in the Summer and Autumn. Some of these factors include favorable sea surface temperatures and the northerly progression of the Intertropical Convergence Zone (ITCZ). The ITCZ is responsible for producing many of the precursor disturbances that form into tropical storms and hurricanes but travels between the Tropic of Cancer and Tropic of Capricorn as the year progresses.

During the month of January we have seen one hurricane and one subtropical storm form. In addition, a tropical storm in 2005 and a hurricane in 1954 formed in December and lasted into the following January. One of the most unusual early season tropical cyclones was a recently discovered hurricane that developed from a non-tropical low pressure in the open Atlantic southwest of the Azores on January 1st, 1938. The storm tracked south and then southwest, an atypical storm motion in the open Atlantic, while acquiring tropical characteristics eventually becoming an 80 mph hurricane. The storm dissipated on January 6th well to the east of the Lesser Antilles with minimal impacts. Another quirky hurricane impacted parts of the Lesser Antilles in January 1955. It moved from the northeast to the southwest into the Caribbean Sea causing $600,000 in damage. Operationally, this hurricane was not recognized as a tropical cyclone until January 2nd so it was given the first name on the 1955 season list which was Alice. However, Alice actually became a tropical storm on December 30th, 1954 meaning it should have been given the next name on the 1954 list. As a result, the 1954 hurricane season officially has two storms that start with the letter A while 1955 does not have an A named storm.

February and March are far less interesting with only one tropical cyclone each. The February event formed on February 2nd, 1952 and impacted parts of Mexico, Cuba, and Florida with minimal impacts. It was a quick moving storm that quickly became extra-tropical after emerging into the Atlantic from Florida. This tropical storm was dubbed the “Groundhog Day” Storm. Moving on to March, the only tropical cyclone to exist occurred in 1908. Like Hurricane Alice, this unnamed hurricane developed northeast of the Lesser Antilles and moved towards the southwest. This hurricane had peak winds of 100mph, a Category 2 hurricane, and caused some damage to St. Bart’s though the monetary value is not known.

Tropical cyclone activity in April is also fairly rare with only one tropical storm and one subtropical storm in our database. The first storm formed in 1992 and was a short-lived subtropical cyclone that was located well to the northeast of Puerto Rico. The second and more interesting storm was Tropical Storm Ana in 2003. A non-tropical storm system formed on April 18th southwest of Bermuda. Convection began to develop around the system as it gradually acquired tropical characteristics. The storm became subtropical on April 20th while west of Bermuda and within 24 hours was considered a fully tropical system. Ana caused breezy weather and dropped over 2 inches of rainfall on Bermuda as it finally began to move off to the east. Bermuda would be the only country that would see direct impacts from Ana as a tropical cyclone but Ana would later bring breezy conditions to the Azores and rain to the United Kingdom as a post-tropical cyclone. Swells from Ana also impacted the United States and killed two when a boat capsized off of Jupiter Inlet, Florida.

The month of May has seen 24 tropical or subtropical cyclones develop since the official hurricane database began in 1851. While this number is much higher than any of the earlier months, it averages to one event every six or seven years. The last tropical cyclone to form in May was Tropical Storm Beryl in May 2012. As the name would imply, May 2012 also saw the formation of Tropical Storm Arthur about a week prior. While both storms impacted the United States, Arthur only caused minimal damage while Beryl produced $148,000 in damage and killed one person. Only three years featured two pre-season events, 1887, 1908, and 2012. The strongest pre-season hurricane was Hurricane Able which formed in May 1951. Able become a Category 3 hurricane with maximum sustained winds of 115mph. Despite its ferocity, Able stayed offshore and caused minimal damage to the United States. Prior to becoming a major hurricane off the North Carolina coast, Able did a counter-clockwise loop north of the Bahamas. A complete list of January-May subtropical storms, tropical storms, and hurricanes in included below.

While tropical storms and hurricanes do not often form during the winter and spring months in the Atlantic, a total of thirty-two events have occurred since our official database started in 1851. While the majority of these stay away from land and are weak, their genesis and track are often unusual. Research has been done to correlate early season tropical cyclones with the total number of tropical cyclones but there is no significant connection. Some seasons can start early but still have below normal activity overall (1992 is a great example) while a season with a late start can produce an above normal amount of tropical cyclones. We haven’t seen a pre-season storm in the last two years and with six weeks to go before June 1st, it has yet to be seen if Tropical Storm Ana forms during in April or May.