Tropical Storm Noel strengthens after hitting Cuba

Tropical Storm Noel strengthened as it began to head toward Florida and the Bahamas on Wednesday after drenching Cuba and killing at least 61 people with surging floodwaters and mudslides in the Dominican Republic and Haiti.

The death toll from days of downpours in the Dominican Republic, in particular, begun to climb as emergency workers fanned out to bring aid to towns and villages cut off by raging rivers and inundated by chest-high floods.

Forty-one people were confirmed dead and another 33 were missing while at least 25,540 people were homeless and 6,300 homes had been destroyed, said Luis Luna Paulino, head of the Dominican Republic's emergency operations center.

Forecasters projected the storm would veer northeast over the Bahamas on Thursday, away from Florida and well clear of U.S. oil and gas installations in the Gulf of Mexico.

Hurricane forecast out day before season's start

FORT COLLINS, Colo. — With the 2007 Atlantic hurricane season a few hours away, researcher William Gray released his newest forecast Thursday still showing an expectation for 17 named storms and nine hurricanes, five of them intense.

Gray, based at Colorado State University, described it as a very active season. He said there was a 74 percent chance of a major hurricane making landfall somewhere on the U.S. coast.

There is a 50 percent chance of a major hurricane making landfall on the East Coast, including the Florida Peninsula, according to the new forecast; the long-term average is 31 percent.
The chance of a major hurricane hitting the Gulf Coast between the Florida Panhandle and Brownsville, Texas, is 49 percent; the long-term average is 30 percent. There is also an above-average chance of a major hurricane making landfall in the Caribbean, according to the forecast.

Thursday's forecast was largely unchanged from Gray's last forecast, released in early April.

"We expect an above-average hurricane season," said Phil Klotzbach, a member of Gray's team and lead author of the forecast.

The Atlantic hurricane season, which runs from June 1 to Nov. 30, averages 9.6 named storms, 5.9 hurricanes and 2.3 intense hurricanes per year.

There were 10 named Atlantic storms last year and five hurricanes, two of them major. None of the hurricanes hit the U.S. Atlantic coast.

The devastating 2005 season set a record with 28 named storms, 15 of them hurricanes. Four hurricanes hit the U.S. coast, the worst among them Katrina, which devastated parts of the Gulf Coast.

NOAA predicts above normal 2007 Atlantic Hurricane season

13 to 17 Named Storms Predicted

May 22, 2007 — Experts at the NOAA Climate Prediction Center are projecting a 75 percent chance that the Atlantic Hurricane Season will be above normal this year—showing the ongoing active hurricane era remains strong. With the start of the hurricane season upon us, NOAA recommends those in hurricane-prone regions to begin their preparation plans.

"For the 2007 Atlantic hurricane season, NOAA scientists predict 13 to 17 named storms, with seven to 10 becoming hurricanes, of which three to five could become major hurricanes of Category 3 strength or higher," said retired Navy Vice Adm. Conrad C. Lautenbacher, Ph.D., undersecretary of commerce for oceans and atmosphere and NOAA administrator. An average Atlantic hurricane season brings 11 named storms, with six becoming hurricanes, including two major hurricanes.

Climate patterns responsible for the expected above normal 2007 hurricane activity continue to be the ongoing multi-decadal signal (the set of ocean and atmospheric conditions that spawn increased Atlantic hurricane activity), warmer-than-normal sea surface temperatures in the Atlantic Ocean and the El Niño/La Niña cycle.

Last year, seasonal hurricane predictions proved to be too high when an unexpected El Niño rapidly developed and created a hostile environment for Atlantic storms to form and strengthen. When storms did develop, steering currents kept most of them over the open water and away from land.

"There is some uncertainty this year as to whether or not La Niña will form, and if it does how strong it will be," said Gerry Bell, Ph.D., lead seasonal hurricane forecaster at the NOAA Climate Prediction Center. "The Climate Prediction Center is indicating that La Niña could form in the next one to three months. If La Niña develops, storm activity will likely be in the upper end of the predicted range, or perhaps even higher depending on how strong La Niña becomes. Even if La Niña does not develop, the conditions associated with the ongoing active hurricane era still favor an above-normal season."

Bell also noted that pre-season storms, such as Subtropical Storm Andrea in early May, are not an indicator of the hurricane season ahead. "With or without Andrea, NOAA's forecast is for an above normal season."

"With expectations for an active season, it is critically important that people who live in East and Gulf coastal areas as well as the Caribbean be prepared," said Bill Proenza, NOAA National Hurricane Center director. "Now is the time to update your hurricane plan, not when the storm is bearing down on you."

The Atlantic hurricane season runs from June 1 through November 30, with peak activity occurring August through October. The NOAA Climate Prediction Center will issue an updated seasonal forecast in August just prior to the historical peak of the season.

The Atlantic Hurricane Seasonal Outlook is an official forecast product of the NOAA Climate Prediction Center. Instituted in 1998, this outlook is produced in collaboration with NOAA scientists at the NOAA Climate Prediction Center, NOAA National Hurricane Center, NOAA Hurricane Research Division and the NOAA Hydrometeorological Prediction Center. The NOAA National Hurricane Center has hurricane forecasting responsibilities for the Atlantic as well as the East Pacific basins. The NOAA Climate Prediction Center, NOAA National Hurricane Center and the NOAA Hydrometeorological Prediction Center are three of the NOAA National Weather Service's nine NOAA National Centers for Environmental Prediction, which provides the United States with first alerts of weather, climate, ocean and space weather events.

NOAA, an agency of the U.S. Commerce Department, is celebrating 200 years of science and service to the nation. From the establishment of the Survey of the Coast in 1807 by Thomas Jefferson to the formation of the Weather Bureau and the Commission of Fish and Fisheries in the 1870s, much of America's scientific heritage is rooted in NOAA. NOAA is dedicated to enhancing economic security and national safety through the prediction and research of weather and climate-related events and information service delivery for transportation, and by providing environmental stewardship of the nation's coastal and marine resources. Through the emerging Global Earth Observation System of Systems (GEOSS), NOAA is working with its federal partners, more than 60 countries and the European Commission to develop a global monitoring network that is as integrated as the planet it observes, predicts and protects.

Eye Of The Hurricane Reveals A New Power Source

Science Daily — In the eye of a furious hurricane, the weather is often quite calm and sunny. But new NASA research is providing clues about how the seemingly subtle movement of air within and around this region provides energy to keep this central "powerhouse" functioning.

Using computer simulations and observations of 1998's Hurricane Bonnie in southern North Carolina, scientists were able to get a detailed view of pockets of swirling, warm humid air moving from the eye of the storm to the ring of strong thunderstorms in the eyewall that contributed to the intensification of the hurricane.

The findings suggest that the flow of air parcels between the eye and eye wall - largely believed trivial in the past - is a key element in hurricane intensity and that there's more to consider than just the classic "in-up-and-out" flow pattern. The classic pattern says as air parcels flow "in" to the hurricane's circulation, they rise "up," form precipitating clouds and transport warm air to the upper atmosphere before moving "out" into surrounding environmental air.

"Our results improve understanding of the mechanisms that play significant roles in hurricane intensity," said Scott Braun, research meteorologist at NASA's Goddard Space Flight Center, Greenbelt, Md. "The spinning flow of air parcels - or vortices - in the eye can carry very warm, moist eye air into the eyewall that acts as a turbocharger for the hurricane heat engine." The research appears in the June 2007 issue of the American Meteorological Society's Journal of the Atmospheric Sciences.

"While the 'in-up-and out' pattern has been the prevailing paradigm for the past five decades, when you closely examine intense hurricanes it's apparent that a second family of moist air parcels often travels from the border of the eyewall to the eye, where it picks up moisture from the ocean surface," said co-author Michael Montgomery, professor of meteorology at the U.S. Naval Postgraduate School, Monterey, Calif. "These moisture-enriched air parcels then rather quickly return to the main eyewall and collectively raise the heat content of the lower eyewall cloud, similar to increasing the octane level in auto fuel."

The researchers analyzed thousands of virtual particles to track the movement of air between the eye and eyewall, and between the eyewall and its outside environment. To uncover the impact of these particles on storm intensity, they used a simulation of Hurricane Bonnie from a sophisticated computer model and data gathered during the NASA Convection and Moisture Experiment (CAMEX).

The simulation has also helped to explain the formation of deep "hot towers" observed in Bonnie and many other hurricanes by NASA's Tropical Rainfall Measuring Mission (TRMM) satellite. TRMM carries the first and only space-based precipitation radar that allows researchers to peer through clouds and get a 3-D view of storm structure. It captured a particularly deep hot tower in Bonnie as the storm intensified several days before striking North Carolina.

Hot towers are deep, thick clouds that reach to the top of the troposphere, the lowest layer of the atmosphere, usually about ten miles high in the tropics. The updrafts within these "towers" act like express elevators, accelerating the movement of energy that boosts hurricane strength, and are called "hot" because of the large amount of latent heat they release as water vapor is condensed into cloud droplets. Deep hot towers in the eyewall are usually associated with a strengthening storm.

In previous research, Braun, Montgomery, and Zhaoxia Pu of the University of Utah, Salt Lake City, found a direct relationship between these deep hot towers and the intense vortices inside the eye. "The vortices were shown to be especially crucial in providing the focus and lift needed for hot tower formation and add insight into when and where hot towers will develop in storms," said Braun. The study was published in the January 2006 CAMEX special issue of the Journal of the Atmospheric Sciences.

Vortices are created in response to the rapid change in wind speed from the fierce eyewall to the calm eye. Near the surface, air spiraling inward collides with these vortices to force air up, forming updrafts. Strong updrafts in the eyewall carry moisture much higher than normal and help create hot towers.

The current study suggests that in addition to providing lift, these vortices also feed high energy air from the low-level eye into the eyewall, boosting the strength of the updrafts. This transfer of energy allows the storm to remain stronger than expected, particularly when encountering weakening influences, including cooler ocean water temperatures and wind shear, the change in the direction and speed of winds with altitude.

"This discovery may help explain why strong storms can remain intense for several hours or longer after encountering conditions that usually bring weakening," said Montgomery. "Ongoing research will add to our understanding of the dynamics associated with storm intensity so that we can pinpoint the variables and processes that must be represented in numerical models to improve intensity forecasts."

When hurricane Bonnie finally began to lose strength a couple days before landfall, a significant amount of air in the eyewall was traced back - not to the eye - but to the middle levels of the atmosphere away from the storm. This inflow was caused by wind shear and brought much cooler, drier environmental air into Bonnie's circulation, acting like an anti-fuel to reduce energy in the storm and weaken its strong winds.

Despite these and other recent advances in understanding the internal workings of hurricanes, forecasting their intensity is still a significant challenge.

"Most of today's computer models that aid forecasters cannot sufficiently account for the extremely complex processes within hurricanes, and model performance is strongly dependent on the information they are given on the structure of a storm," said Braun. "We also typically only see small parts of a storm at a given time. That is why it is important to combine data from field experiments such as CAMEX with data from TRMM and other satellites. As observing technologies and models improve, so too will forecasts."

Note: This story has been adapted from a news release issued by NASA/Goddard Space Flight Center.

Atlantic's 1st named storm forms early

The first named storm of the year formed Wednesday off the southeastern U.S. coast, more than three weeks before the official start of the Atlantic hurricane season, forecasters said.

Subtropical Storm Andrea had top sustained winds around 45 mph Wednesday morning and didn't appear to be much of a threat, the National Hurricane Center in Miami said. Still, a tropical storm watch was issued for parts of Georgia and Florida, meaning tropical storm conditions are possible within 36 hours.

"We're not looking at this system strengthening significantly," said Richard Pasch, a senior hurricane specialist at the center. "We're not viewing this as a major threat."

At 11 a.m. EDT, Andrea was centered about 140 miles southeast of Savannah, Ga., and about 150 miles northeast of Daytona Beach. The storm was moving west at about 3 mph.

Forecasters said no significant rain from the storm was expected to fall over land through at least Thursday morning. But wind-driven waves have been causing beach erosion in South Carolina, Georgia and Florida and the ocean has lapped at beachfront homes and condominiums.

Subtropical systems are hybrid weather formations that are usually weaker than hurricanes and tropical storms. They are kind of a half-breed, sharing characteristics of tropical systems, which get their power from warm ocean water at their centers, and more typical bad weather that forms when warm and cold fronts collide, Pasch said.

Forecasters said Andrea has the warm center characteristic of tropical storms but its core is not particularly well defined. In addition, its winds are farther out from the center than they would be in a tropical storm.

Typically about one subtropical storm forms each year, but they often turn into tropical storms. That doesn't appear to be the case with Andrea, senior hurricane specialist Jack Beven said. It only has a small area of warmer water to draw energy from and is also facing dry winds.

He said it wasn't unusual for the storm to form in May, outside the hurricane season that starts June 1 and end Nov. 30.

"What we call the hurricane season is a totally manmade creation. Nature doesn't always pay attention to that," Beven said.

Eighteen tropical storms and four hurricanes have been recorded in that month since 1851, and none of the hurricanes made landfall in the U.S. The earliest hurricane to strike the U.S. was Alma in northwest Florida on June 9, 1966.

Private and university forecasters have predicted that the 2007 season will be especially active, producing up to 17 tropical storms and hurricanes and a "well above average" possibility of at least one striking the U.S. The federal government plans to release its predictions May 22.

The Atlantic basin has been in a busy period for hurricanes since 1995. Some federal forecasters believe this is part of a natural cycle. But the Intergovernmental Panel on Climate Change, a U.N.-sponsored group, says global warming caused by humans has led to an increase in stronger hurricanes.

Florida in the Bull’s Eye this Hurricane Season

"We’re in for a Rough Year," Says AccuWeather.com’s Bastardi

(State College, PA - May 8, 2007) - AccuWeather.com Chief Hurricane Forecaster Joe Bastardi and his team expect this season’s hurricanes and tropical storms to pose a far greater threat to lives and property than last year’s, with significantly more storms striking the US.

In the AccuWeather.com 2007 Hurricane Season Forecast released today, Bastardi warns that six or seven storms will strike the US coast. This includes the possibility of multiple strikes by the same storm, such as the way Hurricanes Andrew and Katrina – both extreme examples – struck Florida before later striking the US Gulf Coast. The majority of these landfalls are projected for the Gulf Coast from the mouth of the Mississippi River to Cape Hatteras, NC, with the center of the bull’s eye on Florida.

AccuWeather.com forecasts 13 or 14 total storms in the Atlantic Basin, with three or more likely to be major hurricanes of Category 3 or greater.

Bastardi, who in March of last year correctly forecast that the Gulf Coast would get "minimal" attention by that season’s hurricanes, said that this year’s indicators all point to the Gulf being at much higher risk for destructive tropical weather than last year. Said Bastardi, "The highest area of risk has swung southwest from the Atlantic to Florida and the eastern and central Gulf Coast regions. In past years that exhibited the same climatological patterns we expect this season, these areas were the main target of Atlantic hurricanes and tropical storms". Said Bastardi, "The highest area of risk has swung southwest from the Atlantic to Florida and the eastern and central Gulf Coast regions. In past years that exhibited the same climatological patterns we expect this season, these areas were the main target of Atlantic hurricanes and tropical storms".

"Some of those years also saw a storm break out of the pack and head up the East Coast, and we would not be surprised to see this scenario play out this year as well. Any storm that strikes north of Hatteras has increased potential to be a major one," he said.

Bastardi described the climatological patterns that he and his team expect to have an impact on this year’s hurricane season, including:

The occurrence of a weak La Niña – a formation of cooler–than–normal Pacific waters – in the wake of an El Niño at the end of last year
The current warm–water cycle that is occurring in the area of the Atlantic that is a breeding ground for hurricanes, as well as forecast precipitation and air pressure patterns expected during hurricane season
How spring is evolving across the North American continent
How summer is projected to evolve across the US
Forecasted air pressure oscillations over the Pacific, and diminished dry air over the tropical AtlanticMany of the climatological patterns currently occurring or projected for this hurricane season are similar to those of the 1930s through the 1950s, which was a period marked by frenzied hurricane activity. Cautioned AccuWeather.com Director of Forecast Operations Ken Reeves, "It is true that one of the patterns we are accounting for is the formation of a La Niña following the recent El Niño, but too often, the impact of a La Niña – or an El Niño – on a hurricane season is oversimplified. It is just one of many patterns that needs to be examined when predicting a hurricane season, and often not the most important one." Regarding the impact that the 2007 hurricane season is projected to have, Reeves said, "The heightened threat we foresee for Florida and the eastern Gulf Coast could have significant implications for the areas still recovering from the devastation wrought by the hurricanes of 2004 and 2005."

Added Reeves, "Those living farther up the East Coast should by no means let down their guard. While the threat there is lower than last year, ‘less risk’ does not mean ‘no risk.’ We expect at least one storm will threaten these areas."

Regarding the impact that this season will have on energy prices, Reeves said, "Any time you have hurricanes roaming the Gulf of Mexico, there is the possibility that energy production could be disrupted. This obviously could affect the prices consumers pay for gasoline and natural gas."

Concluded Reeves, "Overall, we will see more powerful storms across the board than we did last year. We will not get anywhere near the amount of storms that we did in 2005, but it is the intensity of the storms we do get that will be of major concern. It goes without saying that if I were living along the Gulf Coast, Florida, or the Carolinas, I would do all I could to make sure that my family and I were prepared for the possibility of a landfalling tropical storm or hurricane. This is always prudent, but it is especially so during times such as this season, when we are likely to see above-normal storm activity."

Regarding the possibility of a tropical storm or hurricane striking the Northeast, Bastardi’s 2006 forecast still holds: the region is likely be the target of a couple of storm strikes over the next ten years. "Last year the Northeast may have dodged a bullet, but unfortunately you can only be lucky for so long. As we are in a pattern similar to that of the late 1930s through the 1950s, it is important to note that during that span the Northeast was hit by major storms." Last year, Bastardi forecast that the East Coast would be far more likely than the eastern and central Gulf to see hurricane activity, and indeed, most of 2006’s ten storms tracked farther east than in 2005 – including Ernesto, which caused a half–billion dollars in damages in the region from North Carolina to New Jersey.

In summarizing what can be expected this summer, Bastardi said, "We are living in a time of climatic hardship. We’re in a cycle where weather extremes are more the norm and not the exception. One of the ways this manifests itself is in the intensity and frequency of hurricanes and tropical storms. Last year was just a breather, because the overall pattern of increased landfalls shows no sign of reversing in the near term."

Hurricane season begins June 1 and ends November 30.

An Early Start to the Season?

A strong low pressure system has formed off the East Coast of the United States. This system has developed central thunderstorm activity while remaining over the warmish waters of the Gulf Stream. Sea surface temperatures underneath the area of activity are below the usual threshold of 26C, however, upper level temperatures are cold enough that the storm could develop some tropical characteristics.

The forecast track moves it southwestward over the next few days. I'm showing the UKMET model here because it has been the most consistent and best forecast for this storm. This looks like classical subtropical development.