*******Note that forecasts and outlooks in this post are NOT the official forecast from the National Hurricane Center (NHC). They are my own detailed views on the Atlantic tropics based on current observations and latest computer model runs. As such do not make decisions based on my posts...consult news media...watches and warnings from your local weather office...and any evacuation orders issued by local governments to make the most informed and best decisions. Visit the NHC website hurricanes.gov (hurricanes dot gov) for the latest watches/warnings and official forecasts on active tropical cyclones.*********
...SATURDAY NOVEMBER 16 2024 5:30 PM EDT...
Atlantic tropical activity is winding down as the two concurrent systems that are being monitored are in their weakening phases:
(1) Tropical Storm Sara has begun to weaken while approaching Belize… see Sara section below for details.
(2) Chances for subtropical development in the far eastern Atlantic… in the vicinity of the Canary Islands and Azores... are lowering… see area of interest #50 section below for details.
TROPICAL STORM SARA… Since the last update on this site… Sara has primarily been influenced by the surface frontal system and associated upper trough that has zoomed east across the eastern US and western Atlantic. Although this system shunted the west progress of Sara… the tropical storm is west of the previous forecast while the center of circulation is offshore of northwestern Honduras instead of the previously predicted north-central Honduras position for this timeframe. Cooler drier associated with the frontal system has infiltrated the Gulf of Mexico… some of which has been ingested by Sara which has resulted in the breaking up of thunderstorm bands in the circulation. Some of the upper vorticity associated with the frontal system’s upper trough has become cut-off over the eastern Gulf of Mexico due to the force of a developing deep-layer ridge over the eastern US… and this upper vorticity has begun to impart westerly shear on Sara. The ingestion of the cooler drier air and shear has caused the tropical storm to weaken from an earlier achieved peak of 50 mph maximum sustained winds. Going forward Sara is expected to continue west then northwest across Belize and the southern Yucatan peninsula region while steered by the southwest side of the deep-layer ridge. Northwesterly shear is likely to increase across the tropical cyclone as the upper vorticity approaching from the eastern Gulf of Mexico passes just to the northeast… and Sara is likely to weaken to a tropical depression within the next 24 hours. The shear may drop just before landfall with Belize as the upper vorticity then moves away… however there won’t likely be enough time for re-strengthening before landfall.
Some rainfall returned to eastern locations such as the Cayman Islands and Jamaica due to moisture transported by the shearing upper westerlies… however rainfall should reduce again as Sara continues west and away while the shear vector also becomes more northerly which would also help push the moisture south of the area. Bands of rainfall are in progress across Honduras… El Salvador… and Guatemala were watching for possible flash flooding and mudslides. Rainfall shifts northwest into the Yucatan peninsula over the next day or so.
Gusty winds and coastal surf are possible for the coasts of northwest and Honduras and Belize until Sara weakens below storm force.
******Infohurricanes.com forecast. Visit hurricanes.gov (hurricanes dot gov) for official forecast***********
0 Hr Position (1800Z Nov 16)... 45 mph maximum sustained wind tropical storm centered just offshore of northwestern Honduras at 16.4N-87W
IOH 24 Hr Forecast (1800Z Nov 17)... 35 mph maximum sustained wind tropical depression centered over east-central Belize at 17N-88.5W
IOH 48 Hr Forecast (1800Z Nov 18)... Remnant trough located over the southwestern Yucatan peninsula near 19N-90.5W
*****National Hurricane Center (hurricanes.gov) official forecast as of 4 PM EDT*************************
36 Hr Position (0600Z Nov 18)… 30 mph maximum sustained wind dissipating remnant low centered over the western Yucatan peninsula at 18.5N-90.7W
AREA OF INTEREST #50... A deep-layer cyclone featuring ongoing bands of showers and thunderstorms has remained stalled north of the Canary Islands. Even though much of its forecast track is over waters below 26 deg C… the temps of the cyclone’s upper layer are rather cold (200 mb heights below 1176 dekameters) which is helping to generate instability and the aforementioned bands of activity. This deep-layer cyclone is expected to begin a southwest turn under the influence of the north-central Atlantic deep-layer ridge which has recently materialized… and the updated forecast track remains the same as previous but with all milestones delayed 24 hours as the deep-layer cyclone has been stalled for longer. During the southwest dive… the upper layer of the cyclone decouples with the surface layer while gravitating more east toward the high-latitude upper trough fragment currently over Greenland when it later slips down the east side of the deep-layer ridge (this fragment originated from the north fracture of the upper trough that recently entered the west Atlantic from the eastern US). This places the surface cyclone under the suppressive convergent west side of the upper layer… and the surface cyclone weakens going forward. Thus I trim down subtropical developments odds from the peak to 0% through 72 hours. In this update I lowered the peak odds to 20% as it this system has not developed a core area of thunderstorms… and time is running out for this system to do so before it weakens. Noting the Canary Islands and Azores will see coastal surf from this system regardless of subtropical status or not.
******Infohurricanes.com forecast. Visit hurricanes.gov (hurricanes dot gov) for official forecast***********
IOH 24 Hr Outlook (1800Z Nov 17)… 20% chance of subtropical cyclone formation (between the Canary Islands and Azores near 35N-22W)
IOH 48 Hr Outlook (1800Z Nov 18)… 10% chance of subtropical cyclone formation (west of the Canary Islands near 32N-23W)
IOH 72 Hr Outlook (1800Z Nov 19)… 0% chance of subtropical cyclone formation (west of the southern Canary Islands near 29N-23W)
*****National Hurricane Center (hurricanes.gov) official outlook as of 1 PM EDT*************************
Not in the official outlook
...COMPUTER MODEL SUMMARY...
Source...Florida State University Experimental Forecast Tropical Cyclone Genesis Potential Fields (http://moe.met.fsu.edu/tcgengifs/).
1200Z (Nov 15) CMC Model Run...
**For Tropical Storm Sara... wobbles west-northwest into Belize through 48 hours while gradually weakening… continues west-northwest into the eastern Bay of Campeche through 72 hours while weakening further to a trough… through 114 hours the remnant low/ trough moves NNE into the western Florida panhandle… while turning ENE and reaching coast of Georgia loses identity along incoming cold front to the west by 126 hours
**For area of interest #50... deep-layer cyclone quasi-stationary north of the Canary Islands through 24 hours... afterwards moves SW while weakening and dissipates west of the southern Canary Islands by 102 hours
1200Z (Nov 16) CMC Model Run...
**For Tropical Storm Sara… makes landfall in Belize in 30 hours… continues west-northwest into the eastern Bay of Campeche through 48 hours while weakening further to a trough…shortly afterwards loses identity ahead of a cold front that enters the southwest Gulf
**For area of interest #50... moves SW while weakening and dissipates west of the southern Canary Islands by 102 hours
1200Z (Nov 15) ECMWF Model Run...
**For Tropical Storm Sara… wobbles west-northwest into Belize through 48 hours… due to land interaction weakens to a trough that enters eastern Bay of Campeche by 72 hours… shortly afterwards loses identity ahead of a cold front that enters the southwest Gulf
**For area of interest #50... deep-layer cyclone quasi-stationary north of the Canary Islands through 30 hours... afterwards moves SW while weakening and dissipates west of the southern Canary Islands by 126 hours
1200Z (Nov 16) ECMWF Model Run...
** For Tropical Storm Sara… makes landfall in Belize through 36 hours while weakening to a trough… through 90 hours while parked over the southern Yucatan peninsula loses identity to surface cold front moving across the Gulf of Mexico
**For area of interest #50... moves SW while weakening and dissipates west of the southern Canary Islands by 114 hours
1800Z (Nov 15) GFS Model Run...
**For Tropical Storm Sara... wobbles west-northwest into Belize through 45 hours while gradually weakening…continues west-northwest into the eastern Bay of Campeche through 66 hours while weakening further to a trough… shortly afterwards loses identity ahead of a cold front that enters the southwest Gulf
**For area of interest #50... deep-layer cyclone quasi-stationary north of the Canary Islands through 24 hours... afterwards moves SW while weakening and reaches waters west of the southern Canary Islands by 123 hours… the weak remnant low then turns west-northwest into the waters south of the Azores where it then loses identity to an incoming large NW Atlantic frontal cyclone by 156 hours
1200Z (Nov 16) GFS Model Run...
**For Tropical Storm Sara... makes landfall in Belize in 30 hours… continues west-northwest into the eastern Bay of Campeche through 45 hours while weakening to a trough… shortly afterwards loses identity ahead of a cold front that enters the southwest Gulf
**For area of interest #50… moves SW while weakening and dissipates west of the southern Canary Islands by 99 hours
1800Z (Nov 15) NAVGEM Model Run...
**For Tropical Storm Sara... wobbles west-northwest into Belize through 42 hours… due to land interaction weakens to a lower-end tropical cyclone that enters the eastern Bay of Campeche by 66 hours… turns NNE into the western Florida panhandle by 114 hours while re-gaining some strength… tropical cyclone then curves increasingly east into the Atlantic from the Georgia coast by 120 hours… passes just north of Bermuda while transitioning into a remnant frontal cyclone by 150 hours… frontal cyclone centered in the open central Atlantic near 38N-47.5W by 168 hours
**For area of interest #50... deep-layer cyclone quasi-stationary north of the Canary Islands through 24 hours... afterwards moves SW while weakening and dissipates west of the southern Canary Islands by 132 hours
1200Z (Nov 16) NAVGEM Model Run...
**For Tropical Storm Sara... makes landfall in Belize in 30 hours… enters the eastern Bay of Campeche as a weaker tropical cyclone by 48 hours… while curving increasingly northeast across the Gulf of Mexico makes landfall in the northern Florida peninsula by 102 hours… transitions into a remnant frontal low while passing just north of Bermuda between 126 and 132 hours… remnant frontal low races east and reaches waters SSW of Bermuda by 168 hours
**For area of interest #50... deep-layer cyclone quasi-stationary north of the Canary Islands through 24 hours... afterwards moves SW while weakening and dissipates west of the southern Canary Islands by 120 hours
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