National Hurricane Center sees high chances for a tropical storm to develop just offshore over next few days
Even though a potential tropical disturbance is drifting across Florida, partly sunny skies are forecast across much of Central Florida Saturday, with occasional storms and showers that could bring brief periods of heavy rain.
On Saturday morning, that weak, but broad area of low pressure had moved partially inland, centered south of Lake Okeechobee but drifting across much of the southern half of Florida and the Bahamas, National Weather Service forecasters said. The low pressure area is forecast to drift northward overnight then move back out into the Atlantic Ocean by Sunday somewhere near Brevard County.
Once the system moves off the coast and back into the Atlantic, National Hurricane Center forecasters say conditions will be favorable for development of a tropical or subtropical depression. They put the chances at 70% over 48 hours and 90% over the next five days.
An Air Force Reserve Hurricane Hunter is scheduled to investigate the system on Saturday if necessary, but if the system’s center remains inland, that flight could be canceled and another flight could be dispatched on Sunday.
Isolated light showers moved ashore overnight in Volusia and Brevard counties on Friday and Friday night and the system also whipped up a group of storms that triggered a short flood advisory Saturday morning in Palm Beach County.
Locally rain chances range from 30% on Saturday and 50% on Sunday to 70% on Monday. Rainfall totals, which could be up to 5 inches, will depend on where any persistent bands of heavy rain set up across the state as the system moves northward.
Forecasters told Volusia County 1-3 inches of rainfall was possible with the system, with as much as 4 inches in isolated locations, said Jim Judge, the county’s emergency management director.
Fortunately for Floridians, most of the rain and convection associated with the wave is to the east of the center, and any storms that do move over the state are forecast to move quickly.
Slightly more than a half-inch of rain had fallen in Daytona Beach on Friday, bringing the total for the month so far to 7.54, nearly 3 inches above normal. The plentiful rainfall in Volusia County and counties to the south has raised water levels in the St. Johns River to near flood stage in Geneva.
In Northeast Florida, including Flagler County, the Weather Service office in Jacksonville said the storm is not expected to bring significant impacts. It is forecast to bring a higher potential for rip currents and higher seas.
Once the storm moves offshore, it’s not likely to become a hurricane, said Brian McNoldy, a senior research associate at the University of Miami’s Rosenstiel School of Marine & Atmospheric Science.
“Although there is a slim chance it becomes a hurricane at some point, that would be well off the US east coast as it’s zipping northeast on Tuesday-Thursday,” McNoldy said Friday afternoon. “Parts of the mid-Atlantic and northeast may experience some rough surf and coastal erosion/flooding, but nothing they’re not used to from average Nor’easters.”
Also on Friday, on social media, McNoldy cautioned about the drawbacks to the easy accessibility of the computer forecasting plots commonly called spaghetti models.
“I wish they were not shown to the public,” said McNoldy. “Unless you know what those various 4-letter acronyms are and could describe them in some detail, you shouldn’t be looking at them.”
“It’s not that they should be secretive, it’s that they represent very different things yet are presented as equals,” he said. The Hurricane Center specialists use those models in collaboration with other more complex models that aren’t publicly available to make their forecasts.
The spaghetti models are likely to come up again soon as this week kicked off the traditional period of higher storm activity. A third system was far east and moving westward in the hurricane conveyor belt for this time of year, about 950 miles east-southeast of the Windward Islands. The Center said that system is likely to become a storm over the next 48 hours to 5 days.
The first one of the systems to become a named storm would be called Dorian. After that, the next name up in the rotation for 2019 names is Erin.