A slowly-developing area of showers and thunderstorms over the far southern Bay of Campeche is expected to bring the risk of flooding to a portion of the already water-logged Gulf coast this weekend.
The National Hurricane Center says there is a high potential of the disturbance becoming a depression or named storm late Thursday or Friday. So far, the system has moved little. It is expected to move northward beginning on Thursday in between two ridges of high pressure, one over the Southwestern U.S. and the other over the western Caribbean and South Florida.
Strong upper-level winds and dry air on the disturbance's western flank should prevent this system from rapidly strengthening. Instead, abundant moisture on the eastern side of the circulation is likely to bring locally heavy rainfall a portion of the Gulf coast, particularly from Louisiana eastward to the Florida Panhandle.
Forecasts from NOAA's Weather Prediction Center indicate to 5 to 10 inches of rain may fall in these areas, with locally higher amounts. Above normal rain has been observed this spring along this section of the Gulf, and sections of coastal Louisiana and Mississippi have received more than double their average rainfall since the start of March.
Rain from the developing system may start as soon as Friday, but is likely to be heaviest Friday night into Saturday. Heavy rain may spread from Georgia into the Carolinas on Sunday or Monday before the remnant circulation of the storm departs on Tuesday.
Expires at 8:00am on Thursday June 17th, 2021
Monday was a busy day for forecasters at the National Hurricane Center. There were three systems of interest in the tropical Atlantic basin, but only one that is of particular interest to Floridians.
Chances of tropical development continued to increase in the southern Gulf of Mexico, where forecasters believe a tropical depression or storm may form by the end of the week.
Regardless of its tropical classification, the center of the system is more likely to move toward the coasts of Texas or Louisiana. However, indirect impacts such as heavy rain and high seas could affect sections of Florida's Gulf Coast this weekend.
Here is the latest tropical outlook from the National Hurricane Center...
Tropical Depression Two formed east of North Carolina Tuesday morning, then later that evening strengthened into Tropical Storm Bill.
DEPRESSION STILL PRODUCING HEAVY RAINS WITH POSSIBLE FLASH
FLOODS OVER MUCH OF THE SOUTHEASTERN UNITED STATES
1. Claudette is expected to produce heavy rainfall and flash flooding across eastern portions of the Florida Panhandle, North Florida, and southern Georgia today, and into the Carolinas through Monday morning. Flash, urban, and small stream flooding impacts are possible across these areas.
2. A few tornadoes are possible today across parts of Georgia and the Carolinas.
3. Tropical storm conditions are expected along portions of theNorth Carolina coast late tonight and Monday, where a Tropical StormWarning is in effect. Tropical storm conditions are possible innortheastern South Carolina tonight and Monday, where a TropicalStorm Watch is in effect.
CHANGES WITH THIS ADVISORY: None. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Warning is in effect for...
- Little River Inlet to Duck, North Carolina
- Pamlico and Albemarle Sounds A Tropical Storm Watch is in effect for...
- South Santee River, South Carolina to Little River Inlet A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area, in this case within 24 to 36 hours. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, in this case within the next 24 to 36 hours. Interests elsewhere across the Carolinas should monitor the progress of this system. For storm information specific to your area, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office.
Key messages for Claudette can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT3, WMO header WTNT43 KNHC, and on the web at www.hurricanes.gov/graphics_at3.shtml?key_messages. RAINFALL: Claudette is expected to produce additional rainfall totals of 2 to 4 inches with isolated maximum totals of 6 inches across the eastern portions of the Florida Panhandle into North Florida, southern Georgia, central and coastal South Carolina into eastern North Carolina through Monday morning. Flash, urban and small stream flooding impacts, as well as new and renewed minor river flooding are possible across these areas. Storm total rainfall of 5 to 10 inches with isolated 15 inch amounts was observed in southeast Louisiana, southern Mississippi, southern Alabama, and the western Florida panhandle. For the latest rainfall reports and wind gusts associated with Claudette, see the companion storm summary at WBCSCCNS3 with the WMO header ACUS43 KWBC or at the following link: https://www.wpc.ncep.noaa.gov/discussions/nfdscc3.html STORM SURGE: The combination of storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water could reach the following heights above ground somewhere in the indicated areas if the peak surge occurs at the time of high tide... NC/VA Border to Cape Lookout, NC...13 ft Cape Lookout, NC to Little River Inlet, SC...12 ft Surgerelated flooding depends on the relative timing of the surge and the tidal cycle, and can vary greatly over short distances. For information specific to your area, please see products issued by your local National Weather Service forecast office. WIND: Tropical storm conditions are expected to begin in the warning area late tonight or early Monday. Tropical storm conditions are possible in the watch area tonight and Monday. TORNADOES: A few tornadoes are possible today across parts of Georgia and the Carolinas.
At 1100 AM EDT (1500 UTC), the center of Tropical Depression Claudette was located near latitude 33.8 North, longitude 84.2 West. The depression is moving toward the eastnortheast near 17 mph (28 km/h). An eastnortheastward to northeastward motion with some increase in forward speed is expected over the next couple of days. On the forecast track, the system should continue to move across portions of the southeastern U.S. through tonight, move over the coast of North Carolina into the western Atlantic Ocean on Monday, and pass near or just south of Nova Scotia on Tuesday. Maximum sustained winds remain near 30 mph (45 km/h) with higher gusts. Some restrengthening is expected tonight, and Claudette is forecast to become a tropical storm again late tonight or early Monday over eastern North Carolina. Further strengthening is possible over the western Atlantic Ocean through early Tuesday. Claudette is expected to become a posttropical cyclone by late Tuesday. The estimated minimum central pressure from surface observations is 1009 mb (29.80 inches).
Surface observations and visible satellite imagery show that the center of Claudette is moving across central Georgia this morning. Although the deep convection near the center has waned overnight, loose convective bands are evident over portions of North and South Carolina, and to the southeast of the center across southeastern Georgia and northern Florida. There have been a few wind reports of 20-23 kt along the coast of Georgia and South Carolina within the past couple of hours, with the higher reports occurring at some elevated towers. The initial wind speed is maintained at 25 kt, but the strongest winds are well removed from the center and occurring mainly over water. Claudette is beginning to accelerate east-northeastward with an initial motion estimate of 070/15 kt. There has been no change to the track forecast reasoning. Claudette should continue to accelerate east-northeastward ahead of a mid-tropospheric trough moving into the central United States. The center of the cyclone should be near the coast of North Carolina Monday morning, and then pass well offshore the Mid-Atlantic coast Monday afternoon and Monday night. The track guidance remains in very good agreement and the updated NHC forecast is very close to the previous official foreast. As the large circulation of Claudette moves off of the southeastern United States coast later today and tonight, winds will increase along and offshore of the coast, and the system is expected to regain tropical-storm status by Monday morning. Additional re-strengthening is foreast on Monday and Monday night while the cyclone moves over the warmer waters of the Gulf Stream. After that time, the system is expected to quickly transition to an extratropical cyclone, and the global models show the post-tropical cyclone opening up into a trough of low pressure by Wednesday morning. The NHC intensity forecast is a blend of the various intensity aids and the modest deepening indicated by the global models.
Tropical Storm Bill is not a threat to the United States and is likely to dissipate by Thursday or Friday as it races across the cooler waters of the North Atlantic.
The third system of interest is in an area not typical for June tropical cyclone formation.
A strong tropical wave has emerged off the west coast of Africa and a limited window of opportunity for development in the next few days as it moves across the central Atlantic Ocean. Thereafter, conditions are expected to be less favorable for continued strengthening as it moves closer to the Lesser Antilles next week.
Expires at 2:00pm on Tuesday June 15th, 2021
A tropical system may form in the southern Gulf of Mexico this week, but current forecast data suggests it is unlikely to be a significant threat to Florida.
A broad area of low pressure over the Bay of Campeche became slightly better organized Sunday, and forecasters at the National Hurricane Center now give it a "medium chance" of become a tropical depression or storm in the next five days. Little change in the environment surrounding the disturbance is expected through Tuesday, but thereafter a tropical wave moving across the Yucatan Peninsula could enhance nearby thunderstorm activity and be the catalyst to cyclone development.
The potential tropical development, identified by meteorologists as Invest 92, is not an immediate or significant threat to Florida at this time. Long range forecast data suggests the system would be steered north and not northeast, placing the Texas and Louisiana coastlines more at risk of direct impacts. However, in this scenario, an abundance of tropical moisture on the system's east side has the potential of reaching the Sunshine State by the end of the week, and indirect tropical impacts such as heavy rain and high seas could not be ruled out.
Elsewhere in the tropics, a disturbance off the coast of South Carolina was also identified by the National Hurricane Center in their Sunday afternoon tropical outlook. It was referred to as a "non-tropical" area of low pressure with only a "low chance" of gradual tropical development as it moved away from the United States.
June is a relatively quiet month in the tropics when compared to the busier months of August, September and October. However, it's not uncommon for tropical storms to form in both regions identified for possible development in the coming days. The next named storm of the 2021 Atlantic Hurricane Season would acquire the name Bill. The first storm of the year, Tropical Storm Ana, was a preseason development that developed near Bermuda on May 22.
Expires at 2:00pm on Tuesday June 15th, 2021
The National Hurricane Center continues to monitor the southwest Caribbean Sea for the first time in the young 2021 Season for possible tropical development.
It gives an area near the coast of Nicaragua and Costa Rica a low chance of development, where an area of low pressure is expected to form Thursday or Friday. The latest outlook says gradual development is possible after the area of low pressure forms, toward next weekend.
An atmospheric wave that tends to increase the number of showers and thunderstorms is forecast to move eastward from the eastern Pacific into the Caribbean and Atlantic Ocean Basins late this week into next week. It is this wave that has a small chance of spawning a tropical cyclone in the Caribbean, but it is too soon to be certain.
June is often a quiet month in the tropics compared to the active months of August, September, and October. However, the southwest Caribbean is a climatologically-favored area for tropical development in June if an area of disturbed weather develops there.
Expires at 2:00pm on Wednesday June 9th, 2021
An area of disturbed weather south of Cuba has an increasing chance of developing into the season’s next tropical depression this weekend, increasing the flood risk across parts of South Florida.
Images from satellite were showing a better-defined system, with heavier showers and thunderstorms over the central and western Caribbean Sea Friday morning. Computer models have been hinting at tropical development in this area for more than a week, but have been inconsistent in timing the organization of this system. The increasing organization of the disturbance prompted the National Hurricane Center to increase the chances of development to 60% as of their mid-morning Friday update.
Days of easterly winds have been producing bands of heavy rainfall over portions of South Florida, where soils are already saturated. An analysis of gauge and radar data show that much of the Gold and Treasure coast areas have seen rainfall between 150 and 250 percent of average over the past 30 days. The forecast for 3 to 6 inches of additional rain in some areas this weekend is the reason why Flood Watches are in effect.
lol The forecast track and intensity of the disturbance is highly uncertain because it is in its formative stage. For much of the season, global computer models have done a poor job forecasting what meteorologists call the “genesis” (or formation) of tropical cyclones. The overall steering pattern may draw moisture northward from this disturbance into South Florida this weekend, but there is a good chance the core of the disturbance could stay in the Caribbean until early next week. Another cold front over the United States may pick this system up into the eastern or central Gulf of Mexico some time next week, but interests in Florida are encouraged to monitor forecasts this weekend as changes are likely.
Expires at 6:00pm on Saturday October 24th, 2020
Localized flooding will continue to be possible across portions of South Florida through Thursday, thanks to tropical moisture being funneled in by a disturbance south of Cuba.
A Flood Watch continues through at least Wednesday evening for coastal and metro areas of Miami-Dade, Broward and Palm Beach counties.
Forecasters at the National Hurricane Center says the disturbance south of Cuba has a “low chance” of tropical development in the next five days as it moves east of Florida and toward the Bahamas. At the present time, this disturbance does not pose an immediate or significant tropical threat to the State of Florida. However the presence of nearby tropical moisture could enhance rainfall rates in portions of South Florida over the coming days, or until the system moves farther away from the Sunshine State.
Expires at 12:00pm on Thursday October 22nd, 2020
A cold front will pass through the northern half of Florida this weekend, while attention turns to the Caribbean early next week for possible tropical development.
The high pressure system which has been responsible for the recent warm, dry weather is expected to move east and allow a cold front to move into the Florida Panhandle Friday. The front will then move into North Florida Friday night, before slowing to a crawl across central and south Florida on Saturday and Sunday respectively.
A sharp temperature gradient will develop across the peninsula Saturday, and a strong northeast flow behind the front will create rough surf and minor coastal flooding along the Atlantic Coast.
A shower or isolated thunderstorm is possible ahead of the cold front, but limited moisture will keep rain chances low in most areas through Saturday. Showers are more likely across south and east Florida Sunday thanks to a strengthening onshore flow bringing more moisture into the area.
Cooler and drier air will follow the passage of the front, dropping temperatures near or slightly below average for at least a day across the panhandle and portions of North Florida. Morning lows will fall into the 60s north of the I-4 corridor Saturday, and afternoon highs will only rebound to the upper 70s and lower 80s. Near-normal temperatures are expected across South Florida where the front will have less of an impact.
All eyes will then turn to the tropics early next week, where a disturbance in the southwestern Caribbean Sea has the potential to develop. The National Hurricane Center outlined the area as having a "low chance" of becoming a tropical depression or storm in the next two to five days. Environmental conditions are then expected to become more favorable for development and long range forecast models suggest the system might move toward the north or northeast by late next week.
Hurricane season officially ends November 30th, but South Florida is generally more vulnerable to cyclones during the month of October. Storms typically develop this time of year in the Caribbean and off the Southeast coast of the United States, often giving residents little time to prepare due to the proximity to land.
Expires at 8:00am on Saturday October 17th, 2020
Flooding rains along portions of Florida’s Treasure and Gold Coasts are poised to move up the peninsula this weekend.
A cold front which brought cooler, drier air to much of central and north Florida earlier in the week has stalled over south Florida. Deep tropical moisture high in the atmosphere, partially tied to newly-formed Tropical Depression 25 in the western Caribbean, is expected to gradually develop northward over the upcoming weekend.
The National Weather Service has continued Flood Watches into the weekend for both the Treasure and Gold Coasts. Many areas in Martin and St. Lucie counties have had more than 9 inches of rain over the past several days, and an additional 2 to 4 inches are possible through Friday night. This new rain may cause flooding of urban areas and exacerbate existing flooding in areas that are already saturated.
Farther north, widespread rainfall of 1 to 3 inches is becoming more likely toward the I-4 corridor, beginning on Saturday and lasting into Saturday night and Sunday. Locally higher totals exceeding 3 inches are possible, if not likely, according to forecasters at NOAA’s Weather Prediction Center. Heavy rain could expand as far north as the First Coast, Gainesville, and Lake City on Sunday, but there is more uncertainty in the threat of flooding in these areas because of dry air that is firmly entrenched in those areas.
Moisture high in the atmosphere from Tropical Depression 25 is likely to enhance rainfall over the Florida Peninsula. However, the latest forecast track from The National Hurricane Center takes the depression westward toward Mexico’s Yucatan Peninsula on Saturday and then farther west into the southwestern Gulf of Mexico early next week. If this track holds, the state of Florida would not experience direct effects from this tropical system.
Much of the Florida Panhandle is likely to stay dry over the upcoming weekend as high pressure nosing southward from the Appalachians maintains greater control over the weather in that part of the state.
Two tropical waves have the potential to develop in the Caribbean by this weekend, and one of them could be of particular interest to Florida next week.
The active pace of the record-breaking 2020 Atlantic Hurricane Season came to a standstill last week, giving coastal residents a brief sigh of relief. However, meteorologists anticipate that the basin could enter into another active period later this week as the final active month of the hurricane season approaches.
On Wednesday afternoon, the National Hurricane Center outlined an area of broad showers and thunderstorms over the west-central Caribbean Sea as having a moderate chance of developing into a tropical system within the next five days. The disturbance is expected to move westward and interact with a frontal system by the end of the week, which will likely enhance thunderstorm activity and organization. Environmental conditions are then forecast to be conducive for further development over the weekend, when a tropical depression could form as the system moves towards the Yucatán Peninsula.
There is a significant amount of uncertainty regarding the development of the system and a range of scenarios for its potential track. The disturbance could drift inland over the Yucatán Peninsula and southern Mexico, become near stationary in the Bay of Campeche, or drift eastward and enter into the central Gulf of Mexico which, at that time, could threaten Gulf Coast States.
There is also another scenario that weather models are hinting at where two systems form within a few days of each other instead of just one. If this scenario plays out, one of the systems could travel westward into Central America and the second system would form east towards Cuba and likely track to the north.
Tropical cyclone genesis tends to favor the Caribbean Sea and the southern Gulf of Mexico during the month of October, bringing systems very close to land. The transition from Summer to Autumn in the northern hemisphere generally introduces cooler temperatures and stronger vertical wind shear across the open Atlantic which aids in suppressing tropical cyclone development. The Atlantic is expected to remain quiet into the end of the week as a vast area of enhanced wind shear continues to be draped over the region and extend east towards the west coast of Africa. This wind shear area could lessen by the end of the weekend which could allow more tropical cyclone development in the upcoming weeks.
Twenty storms so far this season have became the earliest on record to develop in a calendar year. Nine of those tropical cyclones have directly impacted the United States, which ties the record set in 1916. The next named tropical storm for the 2020 season would be "Gamma", the third letter in the Greek Alphabet and the second time ever to be utilized.
Expires at 6:00pm on Thursday October 1st, 2020
Tropical activity has been excessively active throughout August and September, but now a lull is expected for at least the next two weeks as the final active month of hurricane season approaches.
A strong convectively-suppressed Kelvin wave, which causes sinking air and less thunderstorm genesis, is expected to pass through the tropical Atlantic over the next 10 to 14 days. This is expected to inhibit tropical cyclone development over the open Atlantic as the month of October approaches.
Carl Schreck III of the North Carolina Institute for Climate Studies and North Carolina State University studies the effects of Kelvin waves and how they influence the development of tropical cyclones. Atmospheric Kelvin waves are tropical rainfall systems accompanied by distinctive westerly and easterly wind patterns. The waves move eastward around the planet sometimes lasting for week and can circumnavigate the tropics over the course of a month.
Schrecks’ study finds that fewer cyclones develop in the three days leading up to a Kelvin wave’s maximum rainfall, while more storms form in the three days afterward.
The National Weather Service Prediction Center notes that this brief quiet period may only last for the remainder of September before environmental conditions become favorable again for cyclogenesis, particularly in the Caribbean and the far eastern Atlantic.
During the month of October as temperatures cool in preparation for Fall and Winter, tropical activity begins to favor parts of the Caribbean and southern regions of the Gulf of Mexico, where warm sea surface temperatures and minimal vertical wind shear remain.
However, these favorable areas are much closer to land which may give coastal residents less time to be informed about an approaching tropical system and minimal time to prepare. Mid-October statistically produces a second spike in tropical cyclone activity before the season as whole begins to decline. Notable storms which formed in the month of October include: Hurricane Wilma (2005), the strongest tropical cyclone worldwide as measured by barometric pressure outside of the West Pacific; Hurricane Sandy (2012), one of the largest cyclones and the fifth costliest on record; Hurricane Michael (2018), coming ashore as a Category 5 and the tenth costliest hurricane on record; and Hurricane Opal (1995), the strongest Category 4 hurricane recorded and the third most severe landfalling cyclone in the United States based on size and intensity.
Hurricane Season concludes November 30th giving ample time for another spike in tropical activity. Once this Kelvin wave passes activity could ramp up again by mid to late October.
The Atlantic Hurricane Season has already brought a total of 20 records for earliest named storms and it may break another record for most landfalls in the United States. A total of nine cyclones have impacted the States this season, tying the 1916 season.
Expires at 8:00am on Friday September 25th, 2020