Dangerous heat: A heat advisory is in effect for all of South Florida as heat index hits 109
A wave of sweltering temperatures continues to swamp South Florida with heat index, or "feels like" temperatures, expected to reach 109 degrees in West Palm Beach today and continue with triple digits into Sunday.
The National Weather Service in Miami issued a heat advisory for its entire coverage area today, which includes Palm Beach, Broward, Collier, Glades, Hendry and Miami-Dade counties, with the potential that it will be extended through the end of the weekend.
A heat advisory is issued in Palm Beach County if the heat index is forecast to reach 108 degrees or higher for at least two consecutive hours. An excessive heat warning is issued when the heat index temperatures are predicted to reach 113 degrees or higher for at least two hours.
The heat index temperature is calculated through an equation that considers ambient temperature and the amount of moisture in the air using the dew point or relative humidity. Dew point is the amount of water vapor in the air. Relative humidity is a percentage describing the amount of saturation of air.
A higher dew point makes the body's natural cooling mechanism —sweat ― less efficient.
More: Climate change triggers new Florida heat warning chart that alerts when it could be deadly outside
West Palm Beach hot weather forecast
Ambient temperatures in West Palm Beach are expected to reach a high of 94 degrees on Saturday and 93 degrees on Sunday. The normal high temperature for this time of year is 86 degrees.
"Anyone sensitive to heat should plan to avoid extended time outside, and if you are required to beoutside, take cooling breaks and stay hydrated," NWS forecasters wrote in their discussion this morning.
In the week beginning May 12, five daytime heat records were broken, including May 15's 98 degrees, which broke a 1992 record by four degrees.
Last month, the National Weather Service launched an experimental new heat risk index that it hopes will better translate the possible health complications triggered when the mercury rises to miserable levels. Like the Air Quality Index and the UV Index, the new ranking system assigns numbers to risk levels that include who is most susceptible to health problems at each level and actions that should be taken to reduce risks.
Today, the heat index had parts of Palm Beach County at its "extreme" level, which is the highest on a four-level scale. Areas at the the extreme level will experience long-duration dangerous heat with little to no overnight relief, according to the NWS.
Kimberly Miller is a journalist for The Palm Beach Post, part of the USA Today Network of Florida. She covers real estate and how growth affects South Florida's environment. Subscribe to The Dirt for a weekly real estate roundup. If you have news tips, please send them to kmiller@pbpost.com. Help support our local journalism: Subscribe today.
This article originally appeared on Palm Beach Post: Heat advisory in Palm Beach County with hot weather forecast Florida
