At the moment of equinox, the Earth’s axis leans neither toward or away from the sun — a parity that produces a nearly equal day and night.
“For us in the Northern Hemisphere, the sun is rising later now, and nightfall comes sooner,” said Deborah Byrd, editor-in-chief of the online magazine Earth and Sky. “We’re enjoying the cooler days of autumn.”
But in South Florida, the onset of fall-like temperatures is still at least a month away.
The average daytime high in West Palm Beach doesn’t dip below 85 degrees until Oct. 20, with overnight lows remaining in the 70s until Oct. 27 when the normal finally dips to 69 degrees.
And even then, the difference between the warmest and coldest periods of the year in South Florida can be just 25 degrees, according to the book Florida Weather, which was co-authored by Florida Climatologist David Zierden.
This week, the difference between the daytime high and overnight low in West Palm Beach was just 12 degrees with Monday reaching a searing 91 degrees and this morning bottoming out at an unofficial 79 degrees.
An area of high pressure over the state should keep the temperatures above normal into the weekend. The normal high this time of year in West Palm Beach is 88 degrees, with a normal overnight low of 75 degrees.
An unusual summer weather pattern cracked open South Florida’s sky Sunday, spearing Palm Beach County with more than 2,500 lighting strikes in two hours and detonating storms along pools of rain-cooled air.
Fed from above by sub-freezing temperatures whipped into the state by a plunging jet stream, and gorging on sticky daytime highs that peaked at 94 degrees in West Palm Beach, the rapid-fire storms temporarily cut electricity to as many as 12,000 homes.
“It was like a tropical storm was hitting, it was huge,” said Theo Hayes, who lives near the Intracoastal in West Palm Beach. “The rain got to the point where I couldn’t see Palm Beach Island. It was weird, but that’s Florida weather.”
Meteorologists with the National Weather Service in Miami said the pattern that emboldened Sunday’s storms will be in place again Tuesday with an upper-level area of low pressure over the Gulf of Mexico sending in westerly winds to battle afternoon sea breezes.
Storms similar to Sunday’s focused their ire south on Monday, hitting mostly in Miami-Dade County. But a 70 percent chance of showers is in Tuesday’s forecast for West Palm Beach, with another round of widespread thunderstorms possible, according to meteorologists at the South Florida Water Management District.
Catron said the persistent showers that lasted from Mother’s Day through Memorial Day were tough on a business that depends on landscapers and homeowners being able to work outside. Keeping plants from sitting in puddles of water for days was also a chore.
“I had two pumps going and we wasted a lot of time pulling plants out of flooded areas,” Catron said. “It just wasn’t a fun time.”
The National Centers for Environmental Information are part of the National Oceanic and Atmospheric Administration. Their monthly climate reports are gathered by averaging observations from individual weather gauges nationwide – both automated and from volunteer observers. Crouch said because it’s known how rain spreads on average from place to place, the centers are able to interpolate statewide measurements back 124 years.
While May was notably wet for Florida, Crouch said there’s no rainfall trend statewide in terms of looking for clues that point to climate change.
Colin Zarzycki, a scientist with the National Center for Atmospheric Research in Boulder, Colo., said that while a warmer atmosphere can hold more water vapor making for heavier rains, it’s wrong to pin a single month’s record on global warming.
“It’s not fair to say that having the wettest May on record is due to climate change, but having events like that is consistent with climate change,” Zarzycki said. “We would expect these records to get broken more frequently as the climate changes, that’s the direction we are going.”
Crouch said May’s warmth nationwide, which broke the record set during the dust bowl era of 1934, does represent a long term warming trend.
According to the NCEI, the average May temperature across the U.S. was 65.4 degrees last month, 5.2 degrees warmer than average. Nationwide, there were more than 8,590 daily warm temperature records broken or tied in May. That’s 18 times more than the 460 cold temperature record set during the month.
“May was definitely contributing to the trend,” Crouch said.
Florida’s average temperature in May was 76.1 degrees, compared to the warmest May in 2010 which averaged 78.5 degrees.
Last month’s showers and cloudiness contributed to Florida’s lower average temperature.
“The rainy pattern started and it persisted with very little interruption through the end of the month,” said Robert Molleda, warning coordination meteorologist with the National Weather Service in Miami. “We tapped into this deep moisture and it really didn’t break.”
A pattern “eerily similar” to what Florida experienced in May is setting up in the Gulf of Mexico, said Alex Wallace, an on-camera meteorologist with The Weather Channel.
A deep dip in the southern branch of the jet stream is again poised to pump tropical moisture into the Sunshine State.
“It’s just the cycle this time of year,” Wallace said. “It’s the rainy season.”
According to EarthSky.org, the asteroid was first located by the Catalina Sky Survey in Arizona on Nov. 30, 2010.
“They didn’t have enough observations to track its orbit fully and so predict its return,” wrote Eddie Irizarry in a blog on EarthSky.org. “On May 8, almost eight years later, astronomers discovered an asteroid and gave it the temporary designation Zj99C60.”
But then they realized it was the same asteroid they had discovered in 2010 returning.
Meteorologists at the National Weather Service in Miami said a “very prolonged period of high rain chances” is possible, which could help alleviate some of the moderate to severe drought in portions of South Florida.
The Weather Prediction Center says there is a marginal threat for excessive rainfall Saturday morning into Sunday along the coasts of Broward and Miami Dade counties where the tropical flow will most heavily focus. A marginal risk means there is between a 5 and 10 chance that rainfall could cause flash flooding.
Temperatures will remain seasonally normal with highs this weekend in the low to mid 80s and overnight temperatures in the low 70s at the coast, but cooler inland.
Earlier this week, the heavy rain was forecast to start on Friday, but has since pushed back to Saturday. Timing depends somewhat on the formation of a weak low in the crook of Florida’s big bend area that will suck in tropical moisture.
AccuWeather is forecasting Saturday to be more of a mixed bag, but agrees with the NWS forecast for heavy rain Sunday.
The Weather Channel also agrees it will be a wet weekend.
The National Weather Service in Miami has designated May 15 through Oct. 15 as the permanent dates for the rainyseason, fixing the days similar to the set time frame given for hurricane season.
Robert Molleda, the warning coordination meteorologist with the NWS in Miami, announced the change Thursday, saying it will help increase awareness of what can be the most dangerous time of year for weather in South Florida.
“We get most of our rainfall and all the associated hazards — lightning, flooding, tornadoes, severe thunderstorms — during this time,” he said. “I think we can use it as a way to get everyone ready for the rainyseason similar to the way we get ready for hurricane season.”
In the past, the rainyseason was determined by looking at dew point temperatures, sea surface temperatures and an established pattern of rainfall typical to the rainyseason — at least three consecutive days.
With the potent winter up north finally giving way to more spring-like weather, Tuesday’s cool front may be the last before the rainy season starts in May.
But it was a memorable one.
Four reports of hail in Martin County were recorded by the Storm Prediction Center, including ice chunks the size of quarters in Tequesta. The National Weather Service in Miami also said a trained weather spotter saw hail in Atlantis and Lantana. Video from Jupiter Inlet shows pea-sized hail bouncing off a balcony.
“I’ve been living in this town 50 years and I’ve seen hail before, but I’ve never seen as much hail as I did yesterday,” said Tom Knapp, who lives just north of County Line Road in Tequesta. “You could have gotten a sled and slid down my front lawn there was so much hail.”
The following videos were taken by Knapp’s son, also named Tom, near the Jupiter Inlet. They show small hail and a palm tree that is smoking after being struck by lightning.
Lake Worth received the highest amount of rain at 3.16 inches, with Boynton Beach as runner up with 2.7 inches.
Most of coastal Palm Beach County got just 0.53 inches of rain in March, which was 3.03 inches less than what’s normal for the month, according to the South Florida Water Management District.
Before Tuesday’s rain, coastal Palm Beach County was down nearly 4 inches since Jan. 1, with the 16 county region overseen by the South Florida Water Management District at an average 3.92-inch deficit.
The storms were particularly strong because they hit near peak warming of the day with a very cool upper atmosphere.
Thunderstorms produce hail if they have a particularly strong updraft that can suspend rain droplets in the freezing upper reaches of clouds. The size of the hail depends on the strength of the updraft – stronger updrafts can suspend frozen water droplets longer, allowing them to grow.
How much melt occurs as the hailstones fall to earth also impact size.
While hail is unusual in South Florida, it does happen.
Since 1976, there were 86 days in Palm Beach County where hail was reported.
What’s more rare is large hail. Since 1980, Palm Beach County has seen hail with a diameter of 1.75 inches (about golf-ball size) just 14 times, according to the National Weather Service’s Storm Events Database.
The most recent occurrence on record was on Feb. 24, 2010, when a trained weather service spotter recorded large hail west of Palm Beach International Airport during a thunderstorm that included 40 mph winds.
In late March 1996, hail damaged at least 100 vehicles at the airport and decimated a 60-acre cucumber field, according to the database.
Waterspouts were also spotted off Palm Beach County and in the Florida Keys from Tuesday’s storms.
Perched in tangles of branches woven into treetops, fuzzy heads of white down and muted orange beaks indicate the wobbly aviators are fledgling wood storks old enough to stretch their wings, but too awkward to leave the nest just yet.
Wood stork nests are a key clue in the progress of restoring Florida’s iconic river of grass, and in the past year, success rates have been something to crow about.
Buoyed by “Goldilocks” conditions of rain and drought, wood storks have turned formerly green canopied tree islands white with nests that totaled 3,894 during an annual count through summer 2017. That’s nearly double the 10-year average and the largest showing by wood storks since a banner year in 2009, according to the South Florida Water Management District.
Wood storks, which will grow to more than 3-feet tall, are the only storks breeding in the U.S., and are on the list of federally threatened species. The birds once flocked to Florida’s southern fringes, dining on bounties of freshwater fish fattened during the wet season, then corralled for easy hunting as waters receded during dry months.
Man has damaged the unique habitat balance needed by the storks, carving canals to drain South Florida for homes and agriculture. Driven farther north, the birds have suffered, nearly disappearing in the 1980s.
The National Weather Service is warning of the potential for strong to severe storms this weekend as a cold front approaches South Florida.
While scattered showers are possible for Saturday, Sunday has the highest chances for robust thunderstorms with small hail and lightning beginning in the afternoon through evening. Isolated tornadoes are also possible.
“The primary potential impacts for Sunday looks like damaging winds,” meteorologists wrote in a forecast discussion. “However, hail and even some tornadoes cannot be ruled out over South Florida for Sunday.”
A study to makeover what is probably the most maligned and misunderstood weather graphic in history is underway as federal meteorologists look to redo the hurricane cone of error – a spotlight of fear that has earned the nickname “cone of terror.”
The project, which is being conducted by the Hurricane Forecast Improvement Project, is reviewing all of the National Hurricane Center’s communication products, but the cone is taking priority.
Robbie Berg, an NHC specialist, is the informal lead of the nascent project, which is yet unnamed. He said the cone is in the top spot for study because of people’s familiarity with it, but also their chronic misuse of it.
“We know there are limitations with the cone graphic, and the concern is people think that if you’re not in it, you’re safe,” said Ed Rappaport, acting director of the National Hurricane Center. “The cone graphic is almost impossible to replace because it’s so ingrained, but make we could add to it, or introduce something that could become even more popular.”
The cone, which shows the track forecast for tropical cyclones, was discussed Tuesday at the National Hurricane Conference in Orlando during a seminar on what changes emergency managers and local weather forecasters would like to see in how hurricane information is communicated.
Some suggestions included adding a time when damaging winds will end so officials have an idea when cleanup can begin. Emergency managers said they would also like probability forecast for a storm’s potential for rapid intensification. Predicting rapid intensification is a challenge for forecasters. During the 2017 hurricane season, there were 39 incidents of rapid intensification. Seven were accurately forecast.
Rapid intensification is defined as an increase in wind speeds of 34 mph or more over a 24-hour period.
Still, the cone took center stage in Tuesday’s discussion.
“We know we are asking a lot of this graphic, and I’m not sure it serves us as well as we think it does,” said Nate Johnson, director of weather operations for NBC Universal-owned television stations.
While people may have grasped that the storm can go anywhere inside the cone, and 33 percent of the time outside of the cone, the second they are no longer inside the hazy white funnel, they breathe a sigh of relief – they shouldn’t.
Katie Webster, a natural hazards expert with the North Carolina Emergency Management Agency, said people dropped their guard after Hurricane Matthew’s cone of error moved away from the Carolinas in 2016.
“That’s why three days later we were rescuing people off their roof,” Webster said. “How do we convey the forecast cone is not an impact cone. The community knows the cone, but we also had 10-plus inches of rain after Matthew.”
Twenty-four people died in North Carolina from freshwater flooding during Hurricane Matthew, according to the National Hurricane Center.
The NHC and local National Weather Service forecasting offices have added multiple graphics in recent years that depict rainfall amounts, arrival time of damaging winds and storm surge heights.
But the cone, Berg said, is an “institution.” People expect to see it, they talk about it at water coolers and over dinner, they pick apart the slightest shift in its location and debate whether it means the bulls eye has moved.
It was first introduced in 2002, and has undergone three tweaks, including the use of more lively colors and a wind field circle that shows how far tropical storm, or hurricane-force winds extend. The yellow blob can stretch well outside the cone, indicating areas where damage can occur.
Still, people struggle to interpret the risks, said Bryan Norcross, a former Weather Channel hurricane expert who saved lives during 1992’s Hurricane Andrew while forecasting for a Miami TV station. In February, Norcross joined former National Hurricane Center director Max Mayfield working for an ABC affiliate that covers Fort Lauderdale and Miami.
“The way it works now is the National Hurricane Center deals out all these cards and whoever is on the receiving end has to gather up all these cards and put it into one card,” Norcross said. “My sense is a real step forward would be to have an aggregated public advisory with the key message and important graphics.”
Berg said the first step in the study will be figuring out how people use the cone graphic, including utility companies, the military, law enforcement and the average person.
He cautioned against filling it up with too many pieces of information, which may reduce the understanding rather than increase it.
“If you start layering too many hazards onto onto the graphic, people won’t know what the biggest hazard is,” Berg said. “It has to be simple.”
Near record heat will hit South Florida this week with the potential for severe weather before a cool down dumps daytime temperatures into the low 70s by the end of the week.
A low pressure system that is forecast to bring snow to the mid-Atlantic this week will also trail a stormy cold front that could bring severe thunderstorms into Florida, including Palm beach County.
Tuesday’s forecast from the Storm Prediction Center includes a marginal risk of severe weather for the northern half of Palm Beach County, escalating to a slight risk near Melbourne and an enhanced risk from about Orlando through North Florida.
But Tuesday is also expected to bring near record heat ahead of the front to South Florida where it could reach 88 degrees in West Palm Beach – four degrees short of the 1965 record for March 20 of 92 degrees.
The storminess is expected late Tuesday into early Wednesday.
“It will bear watching as this event could produce strong winds and tornadic activity over portions of the state on Tuesday evening, Tuesday night, and early Wednesday morning,” wrote National Weather Service forecasters in Miami.
But as the front leaves the state Wednesday, another push of cool and dry air will move into South Florida, leaving Palm Beach County with clear skies and below normal temperatures toward the end of the week.
Highs on Thursday and Friday will only reach into the low 70s near the coast with overnight temperatures in the low 50s. Inland areas could see lows dip into the 40s overnight.
That’s significantly different than what’s normal for this time of year when daytime highs are typically 79 degrees and overnight lows are 63 degrees.
It seems in line, however, with the roller coaster of temperature changes South Florida has experienced this month with the train of powerful winter storms rolling through the northeast.
Weather.com is calling a nor’easter “likely” beginning Tuesday. It is the fourth to hit this month with more snow, rain and possible coastal flooding for areas from Virginia to Maine.
“It will not feel like the first days of spring to those in the mid-Atlantic and New England, where a snow event is expected to unfold spanning Tuesday through Wednesday,” wrote AccuWeather meteorologist Faith Eherts.