Good evening all!
Shower and thunderstorm activity located in the eastern and central Caribbean Sea have increased in coverage over the last few hours, and appear in the last few frames of satellite loop imagery, as if the area is trying to consolidate.
The area is associated with what the NHC is calling a tropical wave, but is depicted as a trof of low pressure on the surface analysis map, which is interacting with the Monsoon trof extending north and east of the Isthmus of Panama. The NHC has assigned a 10% probability of this area becoming a tropical cyclone during the next 48 hours, and a 20% over the next 120 hours.
The area in general is a rather large cyclonic gyre, however the particular area I am interested in is just to the south of Hispaniola. here are two areas of vorticity well established at the 850 mb level, however based on current steering, the area closest to the Isthmus should move inland.
CIMSS 850 MB VORTICITY MAP
The current wind shear map from CIMSS indicates the upper level anticyclone I had mentioned in my morning synopsis, which the GFS wind shear forecast was showing, has begun to come to fruition, and we’ll have t monitor this to see if it persists.
Analysis of the recent run of the forecast steering layers maps from the PSU e-WALL site indicate the area south of Hispaniola should move in a general westward motion over the next 12-18 hours, with a more north of west, to WNW motion thereafter.
The 18Z GFS run has dropped development of this area, however the 12Z CMC GGEM, and the FIM Experimental models still indicate development. The CMC appears to develop a strong tropical storm, to possibly a weak Category One hurricane. Both have been consistent thus far in closeness of landfall. Based on forecast steering, I still prefer the FIM Experimental track.
Based on analysis of the current wind shear and zonal shear forecast from the GFS, should this area be steered as suggested, it will meet an environment more conducive for development in about 24-30 hours from now, as the current upper level anticyclone is forecast to move north, and then move in tandem with the area of disturbed weather. Aiding this area at the moment, is an upper level low that is located over the southern GOMEX, which continues to move west. This is allowing for some ventilation where the area of concern is located.
Based on these current and forecast conditions, should they hold true for the next 48-72 hours, I am calling for further slow organization over the next 24-36 hours, with the possibility of a little steadier organization thereafter, and I would not be surprised to see this become our next INVEST over the next 24-36 hours. SHOULD this develop, I cannot at the moment rule out the probability of it making a run for CAT 1, should it just clip, or miss the Yucatan Peninsula, and slide through the uprights. My concern here being, that if upper level winds remain favorable, this will traverse and area with some extremely high TCHP, which would allow for strengthening, and should conditions be optimal, Rapid Intensification. TCHP values of 80+ will allow for R.I. if all others parameters are favorable.
I will continue to monitor this area for any significant changes.
Have a great evening!
T. F. “STORM” WALSH III
GMCS, USCG (ret)
METEOROLOGIST / HURRICANE SPECIALIST
MEMBER WEST CENTRAL FL AMS
CERTIFIED SKYWARN OFFICIAL STORM SPOTTER (advanced)