MY 2023 ATLANTIC HURRICANE SEASON BIRDSEYE VIEW POST #118
*******Note that forecast 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.*********
...THURSDAY NOVEMBER 9 2023 3:59 AM EDT...
Over the next few days a tropical disturbance with development potential could emerge in the central Caribbean Sea... see area of interest #53 section below for more information. Elsewhere... no other tropical areas of interest are expected to emerge in the Atlantic basin.
AREA OF INTEREST #53... Over the next few days the following upper air pattern may cause the development of a new tropical disturbance in the central Caribbean Sea as follows:
(1) Over the next 72 hours the southern part of the current western Atlantic upper trough is forecast to become cut-off in the vicinity of the north-central Caribbean islands by amplifying upper ridging now developing over the southeastern US and western Atlantic. The southeastern divergence zone of the upper vorticity is likely to trigger showers and thunderstorms between Jamaica and northern Colombia during this time... however excess wind shear across the south side of the upper vorticity is expected to prevent tropical development in the short-term.
(2) From 96+ hours... the upper vorticity is forecast to decay and dissipate due to prolonged isolation from high-latitude cold air. This will allow for the expansion of southern Caribbean upper ridging in its wake... the outflow of which could drop surface pressures and evolve the aforementioned activity south of Jamaica into a tropical disturbance. The upper outflow environment is further aided in the long range once the upper vorticity dissiaptes... which allows the upstream upper ridging approaching from the southeastern US to merge with the southern Caribbean upper ridge. From 72 to 120 hours any disturbance that develops in the central Caribbean is likely to drift westward due to a strong surface ridge to the north that develops under the convergence zones of the current upper trough pushing into central North America... followed by the convergence zone of a second another upper trough that quickly follows behind. This second upper trough is forecast to undergo a southern and northern split in the long range as well... with the southern split to approach from the Gulf of Mexico beyond day 5. Should this tropical system become strong/tall enough... it would couple with the upper southerly flow ahead of the southern split upper trough... and a northward turn of this area of interest toward the north-central or northwestern Caribbean islands beyond day 5 cannot be ruled out.
Regarding odds of tropical cyclone formation... the GFS continues to be the most aggressive global model in showing development while the other global models have been more lax or don't show development at all. Therefore I assign a low 10% chance of tropical cyclone formation by day 5.
Over the next five days... notable impacts to land areas from this area of interest are not expected as the forecast track through that time keeps it over open central Caribbean waters.
******Infohurricanes.com outlook. Visit hurricanes.gov (hurricanes dot gov) for official outlook***********
IOH 24 Hr Outlook (0600Z Nov 10)... 0% chance of tropical cyclone formation (southeast of Jamaica near 15N-75W)
IOH 48 Hr Outlook (0600Z Nov 11)... 0% chance of tropical cyclone formation (offshore of northern Colombia near 14N-75W)
IOH 72 Hr Outlook (0600Z Nov 12)... 0% chance of tropical cyclone formation (offshore of northern Colombia near 14N-75W)
IOH 96 Hr Outlook (0600Z Nov 13)... 0% chance of tropical cyclone formation (central Caribbean near 14N-77W)
IOH 120 Hr Outlook (0600Z Nov 14)... 10% chance of tropical cyclone formation (central Caribbean near 14N-80W)
*****National Hurricane Center (hurricanes.gov) official outlook as of 1 AM 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/).
0000Z (Nov 9) CMC Model Run...
**For area of interest #53... no development shown
1200Z (Nov 8) ECMWF Model Run...
**For area of interest #53... no development shown
0000Z (Nov 9) GFS Model Run...
****For area of interest #53... broad tropical low develops in the southern Caribbean Sea near 12.5N-79.8W at 108 hours... tropical cyclone formation suggested offshore of northeastern Nicaragua near 14.5N-81W at 144 hours... strengthening tropical cyclone drifts north to toward the waters midway beween Jamiaca and Central America through 168 hours
0000Z (Nov 9) NAVGEM Model Run...
**For area of interest #53... broad tropical low develops in the central Caribbean Sea near 14.5N-80W at 144 hours... drifts north into the waters beween Jamiaca and Central America through 168 hours