Drier air and higher pressure aloft favor a quiet week of weather across the Sunshine State. And despite three areas of interest being monitored for possible tropical development, strong winds aloft will prevent them from becoming threats over the next five days.
The first disturbance of note was an area of low pressure located just east of North Carolina, referred to by meteorologists as Invest 92L. In their 8 pm Tropical Outlook, the National Hurricane Center said dry air and strong upper-level winds are likely to prevent it from acquiring tropical characteristics as it moves away from the United States this week.
The circulation around 92L, has allowed this drier air aloft to move all the way into Florida. This will effectively reduce or eliminate rain chances across most of the state for several days. The only exception will be spotty and brief showers that form from an onshore east-northeasterly flow along the eastern half of the peninsula each afternoon. Rain chances will be highest where low-level moisture is the greatest, which is projected to be mostly in east-central and southeast Florida. Otherwise, a generally dry and comfortable weather pattern is in the forecast for most of the upcoming work week statewide.
Two other disturbances have been identified as having "low chances" of tropical development, but are likely to also encounter inhibiting conditions. One was located south of Puerto Rico, and the other a few hundred miles east of the Lesser Antilles. While brief tropical development remains possible, their eventual outcome will likely be doomed by the same vast area of strong winds aloft covering much of the Southeast, western Atlantic, and the Caribbean.
The peak of the 2021 Atlantic Hurricane Season has passed, but Florida is still susceptible to landfalling tropical systems this time of year. However, long-range forecast data suggests the deterrent factors that are present now - namely the dry air and high amounts of wind shear - are likely to be around through at least the next 10 days. Nonetheless, tropical storms or hurricanes have and still could impact the United States in late October and through much of November.
Two days of heavy rain prompted flood watches and warnings across the northern third of Florida this weekend. The heavy rain risk will shift south this week, while the tropics stay active but non-threatening.
Three to five inches of rain has been observed or radar estimated across inland areas of north and central Florida since Friday, and isolated amounts over three inches have also been noted in the Panhandle. The tropical moisture responsible for the weekend washout is forecast to shift east and south in the coming days, enhancing the daily shower and thunderstorm activity across central and south Florida by midweek. Localized flooding will be possible where storms repeatedly produce heavy rain over the same areas multiple days in a row.
The greatest coverage and intensity of Monday's storm activity will be across northeast and central sections of the peninsula, where a southwesterly wind enhances storm coverage along the Atlantic sea breeze by late afternoon. The heaviest downpours are likely Monday near or east of I-75 from Lake City to The Villages, then along and north of the I-4 corridor from Lakeland to Orlando, and up I-95 from Daytona Beach to Jacksonville. Elsewhere across Florida, showers are possible in the morning hours closer to the Gulf Coast, with spotty thunderstorms expected across inland areas by afternoon.
On Tuesday and Wednesday, the axis of heavier afternoon and evening rains will spread southeast to include the Space Coast, the Treasure Coast and portions of South Florida. Meanwhile, a shift in the winds will allow drier air to work its way into the northern half of Florida, effectively limiting afternoon sea breeze activity to only a few brief and spotty showers near and north of I-4. This trend is likely to continue through Friday, and may even be reinforced by the approach of a true fall front moving into the northern third of the state.
In the tropics, two new tropical storms formed over the weekend in the Atlantic Ocean. Neither are expected to be a threat to the United States. Tropical Storm Peter was located 350 miles east of the northern Leeward Islands Sunday evening, while Tropical Storm Rose was 370 miles south of the Cabo Verde Islands. Both storms are forecast to move more north than west and stay over the open waters of the Atlantic in the next five days.
Two other areas of disturbed weather were also being monitored for possible development by the National Hurricane Center Sunday evening. The remnant circulation and moisture from Odette was moving south of Newfoundland and had a "low" chance of reacquiring tropical characteristics. The second area noted was a tropical wave expected to move into the eastern Atlantic Ocean from Africa, where forecasters say it has a "medium" chance of developing into a tropical depression or storm by Friday. Neither of these disturbances poses a threat to land through over at least the next seven days.
Expires at 10:00pm on Monday September 20th, 2021
Ida's heavy rain that began Sunday in the western Panhandle continues Tuesday and is expected to push into more of North and Central Florida on Wednesday.
Flash Flood Watches were in effect from Marianna to Panama City and westward to Pensacola today, where another 2 to 5 inches of rain are forecast. Isolated amounts of 5 to 7 inches are possible near the strongest, most persistent rain bands. The heaviest rain is likely Tuesday morning in the western Panhandle, but is likely to continue through much of the day over the eastern Panhandle and Florida's Big Bend, including Tallahassee.
Isolated tornadoes and strong winds from thunderstorms remain a threat over much of the Panhandle Tuesday and into the Big Bend area through Tuesday evening. Ida will continue to pull away from the state, but trailing moisture will keep heavy rain bands and thunderstorms in the forecast along the Nature Coast and eastern Big Bend areas late Tuesday night into Wednesday. Heavy rain is likely to expand southward into the I-4 corridor, including Tampa and Orlando, and eastward to Ocala, Gainesville, and Jacksonville during the day Wednesday. Pockets of flash flooding are possible anywhere near these areas.
Drier air is forecast to spread southward into much of North Florida Thursday and Friday, but Central and South Florida will still have a chance of showers and thunderstorms.
Ida is not the only tropical system in town. Tropical Storm Kate formed Monday morning, but is expected to remain over the open waters of the Atlantic well east of Bermuda through the upcoming holiday weekend. A strong tropical wave is moving off of Africa and is forecast to become the season's next depression and named storm by Wednesday. It, too, is forecast to stay over the open waters of the tropics through the weekend. Finally, an area of disturbed weather over the southwest Caribbean has a low chance of becoming a depression later this week if it can remain over the water and not move inland over Central America.
Expires at 8:00am on Wednesday September 1st, 2021
Update as of 8:30am Thursday: A new tropical depression or tropical storm is likely to form Thursday afternoon or evening over the western Caribbean. Atmospheric conditions favor strengthening once it enters the southern or western Gulf of Mexico this weekend.
For tracking purposes and to run models on the developing system, meteorologists are calling this disturbance "99L". Nearly all of the major global models bring the storm near or over western Cuba Friday evening and over the Gulf of Mexico on Saturday. The water is plenty warm enough for strengthening, but wind shear may limit its rate of intensification for another day or so. Upper-level winds in the Gulf, combined with the very warm water, will favor significant intensification over the Gulf of Mexico.
The National Hurricane Center is advising all interests along the Gulf coast from Texas to the western Florida Panhandle to monitor future forecasts for possible rain, wind, or surge impacts that could occur as soon as late Sunday.
Original story as of 9:00am Wednesday: A new tropical depression is likely to form late this week or weekend over the western Caribbean. Atmospheric conditions favor strengthening once it enters the southern or western Gulf of Mexico by Sunday.
Showers and thunderstorms associated with the tropical wave near the coast of northern Columbia are more concentrated Wednesday morning. Most of the reliable global models are forecasting the wave to become a tropical cyclone Friday or Saturday in the western Caribbean. It is likely to pass close to the Yucatan Peninsula or western Cuba during the time before entering the Gulf of Mexico later this weekend.
A ridge of high pressure is forecast to extend from Florida into Georgia and the Carolinas. Normally, a ridge in that position directs storms toward the central or western Gulf of Mexico. The warm waters of the Gulf and low wind shear strongly suggest this system will strengthen after it gets there. There are still plenty of questions regarding exactly where this storm will form and just how strong the high pressure ridge will be. These two factors will play a large role in determining where the system eventually ends up.
Emergency management professionals and meteorologists advise residents along or near the Gulf and Atlantic coasts to have a hurricane preparedness plan and kit well before a storm becomes a threat to land areas.
There are two other areas forecasters are monitoring. A trough of low pressure about 800 miles southeast of Bermuda is likely to develop into a depression or named storm over the weekend, but is likely to stay out at sea east of Bermuda through early next week. A separate tropical wave several hundred miles west-southwest of the Cabo Verde Islands has a small chance of developing over the next day or two before stronger upper-level winds arrive this weekend and likely prevent further development.
Expires at 2:00pm on Thursday August 26th, 2021
Grace is moving toward Mexico's Yucatan Peninsula and Tropical Storm Henri is spinning south of Bermuda. Neither are likely to affect the Southeast United States, but a large outbreak of Saharan dust should be more noticeable later this weekend.
A large ridge of high pressure extending from coastal South Carolina into northern and central Florida is effectively blocking Grace from moving northward like Fred did. The flow around the high will push Grace into Mexico's Yucatan Peninsula on Thursday morning as a category 1 or 2 hurricane. The high pressure ridge is expected to build westward along the U.S. Gulf Coast, which will keep Grace moving toward the west and on course for a second landfall in mainland Mexico early Saturday morning.
Meanwhile, Tropical Storm Henri (pronounced AHN-ree) has been gradually strengthening this week over the open waters of the Atlantic, south of Bermuda. A separate branch of the Bermuda high is located to the north of Henri, which will cause it to move westward through Friday. The flow between the high and a trough of low pressure over the Appalachian mountains will cause Henri to turn northward over the weekend. Henri is forecast to stay far away from the Carolina coastline; however, there is still a small chance the storm could veer toward New England late this weekend or early next week. The most probable outcome would still keep Henri offshore as a hurricane.
A large outbreak of Saharan dust several hundred miles east of the Lesser Antilles is well-defined on satellite imagery. The dry, dusty air is normally kicked off by the northern fringe of tropical waves moving from east to west across the African continent. The dust is often elevated 1 to 2 miles above the ground as it moves from east to west across the tropics. Oftentimes, the dust plume can cause a reduction in the number and intensity of tropical storms and hurricanes as it moves across the Atlantic.
The latest models that simulate aerosol movements predict that the dust could reach parts of southern Florida as soon as Sunday before spreading northward over the remainder of Florida on Monday. The dust could spread northward into parts of Georgia and the Carolinas either on Monday or Tuesday of next week, but that is a bit more uncertain. The primary impact will be colorful sunrises and sunsets as the rays of the sun refract off of the dust particles in the atmosphere.
Expires at 6:00pm on Thursday August 19th, 2021
Chances were decreasing that a tropical system will form from a weak area of low pressure approaching Northeast Florida Monday morning.
Showers from the tropical low are spreading westward into Nassau, Duval, Baker, Clay, Putnam, and St. Johns counties. These showers may be heavy for brief periods today, along with gusty winds at the coast, but the chances of a tropical depression forming are decreasing. The low is expected to move inland later Monday or Monday night over Northeast Florida and Southeast Georgia, ending the possibility of further development.
Strong storms are also expected Monday afternoon and evening across mainly inland portions of Central Florida, largely due to interactions from sea breezes as opposed to the nearby tropical area of low pressure.
Expires at 11:59pm on Monday July 26th, 2021
A frontal boundary sliding into the Southeast will begin to enhance thunderstorm activity across North Florida late Thursday and Friday, then potentially produce more widespread rain and thunder across portions of Central and South Florida Saturday and Sunday.
The storm system might also acquire tropical characteristics as it moves offshore into the Atlantic Ocean by early next week.
Thunderstorms capable of producing wind damage, small hail and waterspouts are possible just ahead of the front Thursday evening in northeast Florida, then again Friday across a large section of North and Central Florida.
The Storm Prediction Center placed a small section of Northeast Florida under a "marginal risk" (level 1 out of 5) for wind damage Thursday afternoon and evening.
Friday's afternoon and evening storms will be moving unusually fast for this time of year, with clusters of activity propagating in generally a north-to-south fashion, along with some backing to the southwest. Here are Friday's most likely arrival times for the storms in a few select cities or regions:
Lake City, Jacksonville: 4 to 7 pm
Gainesville, Ocala, Orlando: 5 to 9 pm
Space and Treasure Coasts: 6 to 10 pm
Nature Coast, Lakeland, Tampa: 7 to 11 pm
The storm coverage Saturday will be more focused in Central Florida as the front continues to slide south, although the cells likely won't be as strong or as widespread since the front will be weakening. The greatest concentration of Saturday's storm activity will be near and just south of a line from Tampa to Melbourne, sliding down into portions of South Florida by the early evening. Drier air behind the boundary will keep rain chances lower than normal Saturday across much of North Florida and in the Panhandle.
The weakening front is expected to stall across South Florida Sunday, where numerous showers and thunderstorms are also likely to develop by the afternoon and evening hours, generally speaking from Naples to Miami. Higher-than-normal rain chances will also exist Sunday in the Florida Keys, whereas much of North and Central Florida will be behind the front and largely rain-free.
The frontal boundary sagging across Florida this weekend is tied to a larger area of low pressure that is forecast to move into the Atlantic Ocean early next week, where the National Hurricane Center says there's a "low chance" it could acquire enough tropical characteristics to become a tropical depression or storm in the next five days. If this were to occur, long range forecast data suggests upper-level winds might be too strong or chaotic to allow it to become very organized. However, weak steering currents might eventually allow the system and its associated moisture to drift back in the direction of Florida later in the week.
Expires at 2:00pm on Friday July 23rd, 2021
There is an increasing chance of a tropical storm in the Caribbean this upcoming holiday weekend -- sooner than what is average in early July.
The tropical wave, what meteorologists are calling "97L" for tracking purposes, is located about midway between Africa and the Lesser Antilles on Wednesday. 97L is moving rapidly toward the west-northwest at about 20 mph. On this track and forward motion, it will approach the Lesser Antilles on Friday, and is likely to be situated over the northeastern Caribbean near or south of Puerto Rico and Hispaniola this weekend.
A sprawling ridge of high pressure covers the Atlantic from the South Carolina coast eastward to a position north of the developing tropical system. This will force the tropical system to move from east-southeast to west-northwest beneath the ridge at a rapid pace. Normally, weather patterns like this are predictable over long periods, so confidence is high that whatever develops in the tropical Atlantic will be in the Caribbean this weekend.
A strong trough of low pressure and cold front is forecast to move off the Southeastern coast of the United States this weekend. Most computer model simulations indicate that this trough will weaken the steering ridge. Initially, this would cause the tropical system to slow down in the central Caribbean later this weekend. The steering pattern is highly uncertain early next week and any direct interaction with the islands of Hispaniola or Cuba also complicate the forecast.
Upper-level winds are forecast to be weaker than usual over the Caribbean. Oftentimes, strong wind shear in June and July limit the number of storms that develop in the central and eastern Caribbean. The global models are forecasting much lower-than-normal wind shear late this week and weekend over the Caribbean, which would favor strengthening of the developing system.
The National Hurricane Center says interests in the Leeward and Windward Islands should monitor the progress of 97L over the coming few days. Those with interests or plans in the Caribbean this holiday weekend should factor possible tropical development into their plans also.
Expires at 11:00am on Thursday July 1st, 2021
Several inches of rain fell this week across Florida, effectively ending a short-term drought in some areas and prompting flood warnings for others. A drier pattern arrives Sunday, but more moisture is on the move next week.
Only a few weeks ago, large sections of South Florida were considered to be in a "moderate drought" according to the National Drought Mitigation Center. This has effectively been erased by several days of repeating rains over the same areas.
Farther north, too much rain has fallen in the past seven days, prompting flood warnings along the Santa Fe and St. Mary's rivers. More than six inches of water has accumulated during the week of June 20-26 across much of North Florida, near Florida's Big Bend, and along the Forgotten Coast.
Rainfall estimates have been in the 2- to 6-inch range across more than 80 percent of the state since last Sunday, with isolated totals topping six inches observed across inland areas of the peninsula near Orlando and east of Tampa. Lighter rainfall amounts were noted across rural sections of South Florida in the past seven days, where a 30-day rainfall surplus in those locations has aided in the eradication of the recent drought.
A pocket of drier air aloft is expected to move across Florida starting Sunday, offering a one or two-day break to the seemingly relentless rains. The typical brief afternoon "Florida" showers will still be possible along the sea breezes, but widespread and long-lasting activity will be on hold across most of the state through at least Monday. Thereafter, a shift in the wind pattern to be more southerly is expected to allow tropical moisture back into the atmosphere, and a rainier pattern is likely to ensue by the middle or end of the upcoming week.
The added moisture that approaches Florida later this week can be traced to a tropical wave that is moving through the Caribbean. Two other tropical waves of interest were recently noted by the National Hurricane Center for potential development, but neither are expected to be a significant or imminent threat to Florida.
Expires at 10:00am on Monday June 28th, 2021
Two robust tropical waves are moving across the Atlantic Ocean this week, with both showing at least a hint of developing. However, neither are expected to become a threat to the United States in the next five to seven days.
The first wave of interest was located a few hundred miles east of Barbados Wednesday evening, where thunderstorm activity had recently flared up. Forecasters at the National Hurricane Center (NHC) have kept chances of tropical cyclone formation very low with this wave, and say only an "increase in shower activity and gusty winds" were expected as moves across the Lesser Antilles on Friday. Upper-level are likely to be too strong for development with this wave as it moves through the Caribbean this weekend, but some of the tropical moisture associated with it may eventually reach the Gulf of Mexico next week.
A second tropical wave appeared stronger and more organized on satellite data as it was emerging off the west coast of Africa Wednesday. Long range forecast models suggest some gradual tropical development may occur with this feature as it traverses the central Atlantic Ocean over the next five days. The National Hurricane Center said there is a "medium chance" it could develop into a depression or named storm as of their Thursday morning update.
Climatologically argues against a tropical storm or hurricane originating east of the Lesser Antilles in late June, as less than 4% of them have done so since 1851. However, both disturbances this week have proven to be stronger than normal for this time of year. Tropical waves that originate over Africa tend to dissipate quickly in the central Atlantic until oceanic and atmospheric conditions become more favorable in late summer or early fall.
Expires at 2:00pm on Thursday June 24th, 2021