El Niño and La Niña are climate phenomena that originate in the equatorial Pacific Ocean. These phenomena can have wide-ranging effects on weather around the world.
Never occurring simultaneously and sometimes not at all, El Niño and La Niña are the opposite phases of the El Niño-Southern Oscillation, or ENSO. ENSO describes the fluctuation of two elements, temperature and pressure.
The temperature component of ENSO refers to ocean water temperature. When sea-surface temperatures are above average by about 1 degree Fahrenheit or more, El Niño can develop. When temperatures are below average, La Niña can form. When temperatures are at or near average neither develops. This is called ENSO-neutral.
The air pressure component refers to the difference in air pressure between the western and eastern parts of the equatorial Pacific. Scientists use readings from Darwin, on the north-central coast of Australia, and from Tahiti, more than 5,000 miles to the east. When the pressure is lower than normal in Tahiti and higher than normal in Darwin, conditions favor the development of El Niño. When the opposite occurs, La Niña may develop.
The two components, temperature and pressure, are strongly related, and conditions of both must be right for either El Niño or La Niña to form. For example, if sea-surface temperatures favor El Niño but air pressure conditions do not, El Niño will not develop.
Scientists are not sure exactly what starts the process. But from time to time, air pressure conditions change over the equatorial Pacific, affecting the trade winds, which normally blow from east to west. The winds act on the surface of the water pushing it along. If the trade winds strengthen, as occurs during La Niña, more warm water is pushed westward. And in the eastern Pacific cold, deep water rises-up to replace it. If the trade winds weaken, as happens during El Niño, less water moves westward and less cold water rises, and the central and eastern Pacific warm up more than usual.
A huge mass of warm water in the ocean transfers a lot of heat high into the atmosphere through convection. Convection is when warm, moist air rises from the sea surface and forms storms. The heat in turn affects atmospheric circulation, both in the north-south direction and east-west.
The location of the convection is important. In El Niño, because the warm water stays in the eastern Pacific, the convection occurs there. In La Niña, the eastern Pacific stays colder, and the convection occurs much farther to the west.
The changes in atmospheric circulation can result in changes in weather in various parts of the world, what meteorologists call teleconnections. Much of this is related to the position of the jet stream, the high-altitude winds that sweep across the planet from west to east.
In El Niño, the jet stream tends to shift to the south. That can bring rain and cooler conditions to much of the Southern United States, and warmer conditions to parts of the North. Elsewhere, El Niño can create warm, dry conditions in Asia, Australia and the Indian subcontinent. Parts of Africa and South America can be affected as well.
In La Niña, the jet stream shifts northward. That can lead to warm and dry conditions in the Southern United States, and cooler, wetter weather in parts of the North, especially the Pacific Northwest. Parts of Australia and Asia can be wetter than normal.
In the U.S., the National Oceanic and Atmospheric Administration (NOAA) declares when an El Niño or La Niña event begins. Weather forecasters will talk about how a developing El Niño, for example, may bring a wetter, or perhaps a drier, winter. Or they may describe how an established La Niña is making for a more active hurricane season. It’s important to note that these are just typical effects. El Niño and La Niña sometimes don’t follow the expected patterns. Also, strength matters and a strong El Niño, as measured by how high sea-surface temperatures are above normal, will have greater effect.
How do El Niño and La Niña effect the Atlantic Hurricane season? The chances for the continental U.S. and the Caribbean Islands to experience a hurricane substantially increase during La Niña and decrease during El Niño.
El Niño produces stronger westerly winds at upper levels of the atmosphere across the tropical Atlantic. This increases the vertical wind shear, basically shearing the tops from developing storms before a healthy circulation can form. El Niño events generally suppress Atlantic hurricane activity so fewer hurricanes than normal form in the Atlantic during August to October, the peak of Atlantic hurricane season.
During La Niña, westerly winds high in the atmosphere weaken. This results in an expanded area of low vertical wind shear, allowing more Atlantic hurricanes to develop. La Niña not only increases the number of hurricanes that develop but may allow stronger hurricanes to form.
El Niño and La Niña also influence where Atlantic hurricanes develop. During La Niña, more hurricanes form in the deep Tropics from weather disturbances that originate over North Africa. These systems have a much greater likelihood of becoming major hurricanes, and of eventually reaching the U.S. and the Caribbean Islands.
Although hurricanes occur more often during La Niña episodes, significant tropical weather events have occurred during the neutral phase. For example, the record shattering 2005 hurricane season that included Katrina and Rita occurred during the neutral phase. And in 1992, Hurricane Andrew, the most destructive United States hurricane of record, made landfall along the Gulf coast during a neutral phase of the El Niño-Southern Oscillation.
Iguana Control for Property Owners
/in News, ResidentialFrequently Asked Questions
There are a variety of options and techniques property owners can use to help reduce or eliminate nuisance-iguanas. Many of these strategies are simple and easily employed. This list of frequently asked questions will help guide you through this process.
Does LWDD provide eradication services for iguana infestations?
LWDD is a single purpose special district with the authority to provide flood control and water supply to the residents within its boundary. Tax assessments are collected for the maintenance and operation of these facilities. Iguanas typically do not interfere with LWDD’s flood control operations. However, where iguana activity is threatening significant damage to drainage infrastructure, LWDD may contract with professional wildlife managers to help control populations.
What might be attracting the iguanas to my property?
Typically, iguanas will use an area for foraging or for nesting. To prevent iguanas from entering your property consider what might attract them. Never feed iguanas – either intentionally or unintentionally. Food left outdoors will attract iguanas and can create problems for both you and your neighbors by creating dense concentrations of iguanas. Pans of cut fruit and outside pet food will attract iguanas as well as other unwanted visitors like rats and raccoons.
How can I prevent the iguanas from nesting?
You can remove protective covers including dense thickets, brush, or rock piles where iguanas congregate. Fill vacant iguana burrows with sand during the day when the animals are likely to be outside of the burrow. You do not want to fill these holes with any animals still inside.
Contrarily, some property owners have constructed artificial nesting habitats to attract iguanas. The purpose of this approach is to control reproduction. Iguanas lay their eggs in sand or mulch. By adding mulch piles or sand piles near sea walls, you can encourage iguanas to focus nesting on these controlled structures. Once eggs are deposited, they can be easily removed and then disposed of in a sealed plastic bag.
What type of landscape material can I plant to deter the iguanas?
Iguanas prefer to eat some very popular landscaping material such as: Hibiscus, Orchids, Roses, Nasturtiums, Impatiens and Purple Heart Plant. Iguanas prefer bright red, orange or yellow flowers and fruits and feed on tender leaves. Instead, plant species that are iguana-resistant, such as Milkweed, Pentas, and Citrus. Generally, plants with thick, tough, or waxy leaves will discourage iguana consumption. These types of leaves are less palatable and often difficult to digest. If the food source is removed, iguanas will be less likely to inhabit an area.
What types of exclusion techniques can I use?
Exclusion techniques can also be deployed to keep iguanas from damaging your property. Consider protecting valuable plants with cages or screen enclosures. Iguanas are excellent climbers. They may get into and on dwellings via overhanging trees. Trim overhanging branches to remove the unintentional “bridge” to buildings. Sheet metal guards on trees, palms, and dock pilings can prevent them from climbing.
Wire barriers can prevent digging on your property. In areas where iguanas burrow or dig, consider installing chicken wire fencing. This fencing should be buried several inches underground or the iguanas may dig underneath the fence.
What types of deterrent techniques can I use?
Several options can help you deter iguanas from your property. Property owners can surprise iguanas by spraying them with a water hose until they leave the area. You can also make loud noises to startle iguanas and create an unwelcome atmosphere around your property. Other techniques include hanging compact discs (CDs) near sea walls or on trees or other plants you want to protect. However, you will need to change the position of CDs on a weekly basis, so the iguanas do not become accustomed to their light reflections.
Is there an iguana repellent I can use?
While not proven, some property owners have experience success with iguana repellents. A homemade spray repellent can be made using garlic, lime juice, habanero pepper and dish soap. Iguanas loathe the smell of these ingredients and for the most part try to avoid the areas and any kind of food source that contains the smell of these ingredients. Using iguana repellents requires the need to redo the application each time it rains as the repellent will be washed away.
Where can I get professional help?
Residents are encouraged to seek professionals to remove iguanas from their property. Property owners can search the internet or phone book to locate wildlife control companies. Costs can vary depending on the extent of iguana infestation and the species of iguana that has invaded your property. Be sure to get a written quote from several service providers before contracting with a provider.
Can I kill the iguanas on my property?
Iguanas and all other wildlife are protected by anticruelty laws, and inhumane treatment of them is prohibited and punishable by state law. Inhumane treatment includes the use of poisons to kill iguanas; no poisons are legal to use on iguanas or any other reptile in Florida. Property owners that desire to kill the iguanas themselves must do so safely and humanely and follow the guideline provided by the Florida Fish and Wildlife Conservation Commission at https://myfwc.com.
Can a property owner or a professional service provider enter LWDD’s canal right-of-way to trap or provide iguana eradication services?
Prior to working on LWDD’s right-of-way authorization is required. Property owners and/or professional service providers should contact LWDD for authorization at 561-498-5363 or email to permits@lwdd.net.
Where can I find more information on iguana control?
Visit the Florida Fish and Wildlife Conservation Commission’s website at https://myfwc.com.
Ref: Frequently asked questions sheet was created from the Florida Fish and Wildlife Conservation Commission’s website.
Flood Control Resiliency
/in Flood Control, News, ResidentialHurricane Ian made landfall as a category 4 storm on September 28, 2022, on the west coast of Florida. This powerful storm brought with it winds of 140 mph and torrential rain. It reminds all of us at the Lake Worth Drainage District (LWDD) how important it is for public safety to have a well maintained and operating drainage system.
Effective drainage includes the free flow of water in the canal channel and unrestricted rights-of-way for regular maintenance activities as well as emergency response. Obstruction of drainage whether over the ground or within the canal channel can have devastating effects. During severe storms trees and large shrubs can topple over causing blockages in storm drains, swale areas or flood control structures. Blockages significantly increase the risk of flooding of homes, businesses and may lead to potential life-threatening events. Additionally, encroachments on the rights-of-way can severely hinder LWDD’s use of heavy equipment needed to keep residents safe during and after severe storms.
In response to the increased frequency and intensity of our hurricanes, tropical depressions, and thunderstorms, LWDD addressed flood resiliency and established the Canal Rehabilitation Program. Phase 1 of the program addresses removal of vegetative encroachments within the right-of-way and some structural encroachments that are limiting access to the canal. Phase 1 which was established in 2018 is expected to be completed in 2023.
Phase 2 of the Canal Rehabilitation program will continue to enhance LWDD’s flood control resiliency by addressing unauthorized structural encroachments, such as fences, sheds and patios, located within the canal rights-of-way which restricts maintenance access. These encroachments will be identified and prioritized for removal. Removal of the encroachments is required and is at the expense of the property owner. Dredging and reshaping of some canal channels may be performed during Phase 2 for increased function and operation of the system.
LWDD residents, both adjacent to canals and miles inland, will benefit from enhanced flood control as well as reduced cost in post-storm clean-up. Another benefit to vegetation and encroachment removal is the faster return of residential power following a storm event as an unencumbered right-of-way will facilitate utility restoration efforts.
Hurricane Ian may have passed by Palm Beach County, but it is only time until the next storm takes aim at our coast. LWDD is committed to providing the best possible flood control for our residents today and in the future.
Podcast -Tommy Strowd on Water Supply
/in Flood Control, News, ResidentialExecutive Director Tommy Strowd’s appearance on the Friends of Delray Podcast where he discusses the future of water supply in our area.
Watch Podcast
Harry Raucher Retires From Board
/in NewsHarry Raucher retired from the LWDD Board of Supervisors after serving 11 years, with 5 years as chairman. LWDD management and staff are grateful for his leadership and vision over the years. We wish Harry and his wife Barbara all the best on their new adventure. Carrie Parker Hill, a resident of Boynton Beach, was appointed interim Supervisor to complete his term which ends January 2023. Read the Board Proclamation passed on October 12, 2002, in honor of Raucher’s service below.
Proclamation In Honor Of
HARRY RAUCHER
Whereas, the Lake Worth Drainage District is a public body and political subdivision of the State of Florida, which owns rights-of-way and manages over five hundred miles of drainage canals within its jurisdictional boundary; and
Whereas, HARRY RAUCHER was appointed to the Lake Worth Drainage District Board of Supervisors on May 11, 2011, and subsequently elected by the landowners within the Lake Worth Drainage District, and has faithfully served the Lake Worth Drainage District over eleven years; and
Whereas, HARRY RAUCHER during his tenure as Board Supervisor has demonstrated extraordinary leadership and facilitated many significant accomplishments including but not limited to:
Whereas HARRY RAUCHER is retiring from service as Board Supervisor of the Lake Worth Drainage District on the October 12, 2022, and the Board of Supervisors and employees desire to honor, recognize and bestow upon HARRY RAUCHER the deserved appropriate accolades for his service.
Now, Therefore Be It Resolved, that the Board of Supervisors of the Lake Worth Drainage District, does hereby bestow special recognition to HARRY RAUCHER for his exceptional leadership and service to the Lake Worth Drainage District.
El Niño and La Niña Explained
/in Hurricanes, NewsEl Niño and La Niña are climate phenomena that originate in the equatorial Pacific Ocean. These phenomena can have wide-ranging effects on weather around the world.
Never occurring simultaneously and sometimes not at all, El Niño and La Niña are the opposite phases of the El Niño-Southern Oscillation, or ENSO. ENSO describes the fluctuation of two elements, temperature and pressure.
The temperature component of ENSO refers to ocean water temperature. When sea-surface temperatures are above average by about 1 degree Fahrenheit or more, El Niño can develop. When temperatures are below average, La Niña can form. When temperatures are at or near average neither develops. This is called ENSO-neutral.
The air pressure component refers to the difference in air pressure between the western and eastern parts of the equatorial Pacific. Scientists use readings from Darwin, on the north-central coast of Australia, and from Tahiti, more than 5,000 miles to the east. When the pressure is lower than normal in Tahiti and higher than normal in Darwin, conditions favor the development of El Niño. When the opposite occurs, La Niña may develop.
The two components, temperature and pressure, are strongly related, and conditions of both must be right for either El Niño or La Niña to form. For example, if sea-surface temperatures favor El Niño but air pressure conditions do not, El Niño will not develop.
Scientists are not sure exactly what starts the process. But from time to time, air pressure conditions change over the equatorial Pacific, affecting the trade winds, which normally blow from east to west. The winds act on the surface of the water pushing it along. If the trade winds strengthen, as occurs during La Niña, more warm water is pushed westward. And in the eastern Pacific cold, deep water rises-up to replace it. If the trade winds weaken, as happens during El Niño, less water moves westward and less cold water rises, and the central and eastern Pacific warm up more than usual.
A huge mass of warm water in the ocean transfers a lot of heat high into the atmosphere through convection. Convection is when warm, moist air rises from the sea surface and forms storms. The heat in turn affects atmospheric circulation, both in the north-south direction and east-west.
The location of the convection is important. In El Niño, because the warm water stays in the eastern Pacific, the convection occurs there. In La Niña, the eastern Pacific stays colder, and the convection occurs much farther to the west.
The changes in atmospheric circulation can result in changes in weather in various parts of the world, what meteorologists call teleconnections. Much of this is related to the position of the jet stream, the high-altitude winds that sweep across the planet from west to east.
In El Niño, the jet stream tends to shift to the south. That can bring rain and cooler conditions to much of the Southern United States, and warmer conditions to parts of the North. Elsewhere, El Niño can create warm, dry conditions in Asia, Australia and the Indian subcontinent. Parts of Africa and South America can be affected as well.
In La Niña, the jet stream shifts northward. That can lead to warm and dry conditions in the Southern United States, and cooler, wetter weather in parts of the North, especially the Pacific Northwest. Parts of Australia and Asia can be wetter than normal.
In the U.S., the National Oceanic and Atmospheric Administration (NOAA) declares when an El Niño or La Niña event begins. Weather forecasters will talk about how a developing El Niño, for example, may bring a wetter, or perhaps a drier, winter. Or they may describe how an established La Niña is making for a more active hurricane season. It’s important to note that these are just typical effects. El Niño and La Niña sometimes don’t follow the expected patterns. Also, strength matters and a strong El Niño, as measured by how high sea-surface temperatures are above normal, will have greater effect.
How do El Niño and La Niña effect the Atlantic Hurricane season? The chances for the continental U.S. and the Caribbean Islands to experience a hurricane substantially increase during La Niña and decrease during El Niño.
El Niño produces stronger westerly winds at upper levels of the atmosphere across the tropical Atlantic. This increases the vertical wind shear, basically shearing the tops from developing storms before a healthy circulation can form. El Niño events generally suppress Atlantic hurricane activity so fewer hurricanes than normal form in the Atlantic during August to October, the peak of Atlantic hurricane season.
During La Niña, westerly winds high in the atmosphere weaken. This results in an expanded area of low vertical wind shear, allowing more Atlantic hurricanes to develop. La Niña not only increases the number of hurricanes that develop but may allow stronger hurricanes to form.
El Niño and La Niña also influence where Atlantic hurricanes develop. During La Niña, more hurricanes form in the deep Tropics from weather disturbances that originate over North Africa. These systems have a much greater likelihood of becoming major hurricanes, and of eventually reaching the U.S. and the Caribbean Islands.
Although hurricanes occur more often during La Niña episodes, significant tropical weather events have occurred during the neutral phase. For example, the record shattering 2005 hurricane season that included Katrina and Rita occurred during the neutral phase. And in 1992, Hurricane Andrew, the most destructive United States hurricane of record, made landfall along the Gulf coast during a neutral phase of the El Niño-Southern Oscillation.