Heat and humidity will dog South Florida through the weekend but the gooey high temperatures may be just below the threshold needed to trigger heat advisories, National Weather Service meteorologists said.
Daytime highs in West Palm Beach are forecast to reach above 90 degrees through Monday with overnight lows near 80 degrees. The heat index, or "feels like" temperature, will likely reach into the triple digits.
NWS meteorologist Anthony Reynes said he doesn't believe heat index temperatures in Palm Beach County will meet heat advisory levels, but it's possible. For Palm Beach County, a heat advisory is issued if the NWS expects the heat index temperatures to reach 108 or higher for at least two hours. An excessive heat warning is issued when the heat index is forecast to reach 113 or higher for at least two hours.
"It's going to be close," Reynes said on Friday afternoon. "We are not going for an advisory at this time, but will continue to monitor the forecast trends. Still, we will be highlighting that it will be warm, with heat index values in the 100 to 105 range."
A heat advisory was in effect for all of South Florida through 8 p.m. Friday with heat index temperatures forecast to reach up to 110 degrees in Palm Beach, Broward and Miami-Dade counties. As of 2 p.m., West Palm Beach had experienced a 105 heat index temperature, with Naples hitting 109 and a gauge at Fort Lauderdale Executive Airport measuring 106.
The normal high temperature for West Palm Beach this time of year is 90 degrees with an overnight low of 76 degrees.
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A mid-level area of high pressure parked over the southeast United States can be blamed for the persistent heat and humidity, forecasters said. "The resilient southeastern ridge will hold through the extended period, locking us in our own tropical bubble of sorts," NWS Miami meteorologists wrote in their discussion.
Rain chances Saturday are forecast to be 30% in the afternoon, decreasing to 10% in the evening. Sunday's rain chances are up to 40% during the day and 30% in the evening. Afternoon thunderstorms are possible both days.
Beryl makes landfall near Tulum, Mexico, in the Yucatan Peninsula
In the tropics, Beryl made landfall Friday as a 110-mph Category 2 storm at about 6 a.m. near Tulum, Mexico.
Beryl quickly weakened to a tropical storm, but is forecast to regain hurricane status Sunday in the Gulf of Mexico before making landfall Monday as a Category 1 storm somewhere between extreme northeast Mexico through western Louisiana.
National Hurricane Center forecasters noted that Beryl could strengthen beyond the current prediction if wind shear lightens in the Gulf of Mexico, and they noted that the average error in forecast track at three days out is around 100 miles.
"It remains too soon to pinpoint where the greatest impacts will be," wrote NHC senior hurricane specialist Jack Beven in the 11 a.m. forecast Friday. "However, watches for portions of northeastern Mexico and South Texas will likely be required later today."
The hurricane center said Friday that no additional tropical activity is expected over the next seven days.
The heat advisory thresholds have changed
The NWS announced last month that Broward County would join Miami-Dade County in an experimental program that starts advisories at a lower threshold level. In those two counties, an advisory is issued if heat index temperatures of 105 or higher are expected for at least two hours. An excessive heat warning is issued if the heat index is expected to reach 110 or higher for at least two hours.
Robert Molleda, meteorologist in charge at the NWS Miami office, said the changes were made at the request of the counties and align better with "local climatology" as well as recent health data that shows people get sick from temperatures lower than the current thresholds.
He said Palm Beach County may be included in the lower thresholds if it requests it and after an assessment this summer of how the alerts are issued in Broward and Miami-Dade.
What is a heat advisory?
A heat advisory means people sensitive to warm temperatures should take precautions to avoid heat illness, including staying hydrated and seeking breaks if working or playing outside. Signs of heat exhaustion or heat stroke include symptoms such as muscle cramps, excessive sweating, throbbing headache, passing out, confusion and seizures.
An excessive heat warning, the highest alert level on a four-tier scale, means everyone needs to take precautions to stay safe in the heat because "you may become seriously ill or even die," the NWS says.
Tips to beat the heat
Tips for keeping safe during excessively hot weather from the American Red Cross:
∎ If you suspect heat injury, call for help.
∎ Children and the elderly are among the most vulnerable.
∎ Try not to work outside in the hottest part of the day; if you must work in the heat, slow down.
∎ When outdoors, take frequent breaks in the shade.
∎ Drink plenty of water.
∎ If you wait until you feel thirsty, you're already getting dehydrated.
∎ Don't drink beverages containing caffeine or alcohol (sodas or beer). They interfere with the body’s temperature-regulating mechanisms.
∎ Sweating is the body’s mechanism for cooling. If you stop sweating, call for help.
Sunscreen advice
∎ Wear sunscreen every day, even if you're only going from house to car and car to office.
∎ Look for broad-spectrum UVA and UVB protection. The key ingredients? Titanium dioxide, zinc oxide or Parsol 1789. And never dip below SPF 15.
∎ Protect the oft-neglected eyelids, earlobes and lips. Women develop fewer skin cancers on their lips than men do because they enjoy the physical protection of lipstick.
∎ Cover up your kids. Children especially need sunblock — two-thirds of sun damage happens before the age of 15. But don't put sunscreen on babies under 6 months of age; keep them out of direct sunlight.
∎ Replace your sunscreen annually. Unopened, sunscreen has a shelf life of up to three years. Once opened, the SPF starts breaking down. It's a good idea to buy new products at the beginning of each summer.
∎ Complete all outdoor activities before 10 a.m. or start them after 4 p.m. to avoid the sun at its strongest.
∎ Get to know your skin. Practice self-exams to familiarize yourself with your own landscape. That way, you can more easily notice mole changes such as growing, bleeding or crusting. Have a skin cancer-related checkup, including a complete skin examination as recommended by theAmerican Cancer Societyevery three years for people between 20 and 40 years of age, and every year for anyone 40 and older.
Kimberly Milleris a journalist for The Palm Beach Post, part of the USA Today Network of Florida. She coversreal estate and how growth affects South Florida's environment. Subscribe toThe Dirtfor a weekly real estate roundup. If you have news tips, please send them tokmiller@pbpost.com.Help support our local journalism: Subscribe today.
