*******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.*********
...SATURDAY JUNE 22 2024 1:18 PM EDT...
The following are updates on the Atlantic tropical systems discussed in full post #23 (https://www.infohurricanes.com/post/my-2024-atlantic-hurricane-season-birdseye-view-post-23)... to cover changes with the following systems:
(1) The small tropical low pressure which made landfall at the Florida/Georgia border region overnight... which has since begun drifting northward parallel to the Georgia coast but while centered just inland... this system was tagged area of interest #6 in previous posts as it is the sixth tropical Atlantic area of interest tracked on this site this year.
(2) The low pressure gyre that formed yesterday over northwestern Central America (Belize and northern Guatemala)... which has since quickly accelerated west-northwestward across the Bay of Campeche and is already en route toward the northern Veracruz and Tamaulipas coastline of Mexico... this system was tagged area of interest #7 in previous posts as it is the seventh tropical Atlantic area of interest tracked on this site this year.
AREA OF INTEREST #6... Satellite image of the tropical low pressure swirl currently centered near but just inland of the southeastern Georgia coast... taken at 1426Z:
The small tropical low pressure swirl that approached the Florida/Georgia border region from the western Atlantic made landfall late Friday... and was not upgraded to a tropical depression as the sheared-off thunderstorm activity significantly waned. Instead of continuing west-northwest further inland... the center of this system has instead advanced northward parallel and just inland to the southeast Georgia coast. The change in the forward heading is likely due to early erosion of the steering surface ridge to the north in advance of the frontal system now quickly approaching from the central US. As such the updated forecast moves the surface low pressure swirl northward toward western South Carolina... reaching the Georgia/South Carolina border by 24 hours. This position is further away from Atlantic waters and thus tropical cyclone formation is not expected (the NHC has recently dropped odds of tropical cyclone formation to 0%).
Note that a new burst of thunderstorms fired just south of the center early this morning which brought heavy rainfall to the southeastern corner of Georgia. The burst has since waned as northerly shear continued to seperate it from the surface center... albeit there are some newer pockets of activity in the south half of the circulation and offshore of northeastern Florida. Generally speaking this system should continue to weaken inland while becoming increasingly isolated from the warm western Atlantic waters... however new bursts of thunderstorms in the south half of the circulation cannot be ruled out for the next 24 hours which could result in periods of heavy rainfall across northeast Florida... southeast Georgia... and southern South Carolina.
AREA OF INTEREST #7... Satellite image of the current Bay of Campeche tropical low pressure area now heading toward northern Veracruz and Tamaulipas... taken at 1426Z:
The area of maximum spin over northern Guatemala and Belize that developed approximately 24 hours ago has rapidly accelerated west-northwest across the Bay of Campeche and is already closing in on the northern Veracruz and Tamaulipas coastline... this has resulted in another notable westward shift in my forecast positions for this area of interest. Noting the spin of interest was along a surface trough that extended west into the Bay of Campeche... and an animation of the CIMSS 850 mb vorticity product (https://tropic.ssec.wisc.edu/real-time/windmain.php?&basin=atlantic&sat=wg8&prod=vor&zoom=&time=) suggests the maximum spin and remainder Bay of Campeche trough cyclonically orbited each other in a fujiwhara-type interaction... sending the maximum spin on a rapid west-northwest acceleration due to the steering pressure gradient between the remainder Bay of Campeche trough and steering surface ridging to the north. Recently the maximum spin and remainder Bay of Campeche trough have merged into a northwest-southeast elongated tropical low pressure offshore of northern Veracruz and Tamaulipas. Because the fujiwhara interaction has ended with the merger... and because the steering surface ridge is weakening due to the current central US frontal system... the rapid west-northwest pace of this area of interest is slowing. Noting the central US frontal system will pass too far north to recurve this area of interest northward... instead steering surface ridging recovers over the Ohio Valley region of North America through 48 hours due to convergence on the back side of the frontal system's upper trough. Therefore the maximum spin of this area of interest is forecast to continue generally west for a landfall with the Tamaulipas/Veracruz border region of Mexico in 24 to 36 hour window. Due to the current organization of this system... and the fact this system has 24 more hours in an area of light shear and upper outflow in between the upper vortex to the west now over central Mexico and east-west band of upper vorticity approaching from the northeast... for the period covering the next 24 hours I have raised my odds of tropical cyclone formation to 60% in this special update (the NHC had odds of 60% in yesterday's outlooks... and today they are adjusted to 50%). Between 24 and 48 hours outflow disruption and northerly shear increase with the arrival of the upper vorticity band from the northeast... and combined with increasing land interaction with Mexico conditions for tropical cyclone formation should be on the decline during that period.
Regardless of tropical cyclone formation or not... the main takeaway for this area of interest is that it could produce heavy rainfall with flash flooding potential across Tamaulipas... northern Veracruz... and interior areas of east-central Mexico (provinces just west of the Tamaulipas/northern Veracruz region). The flooding risk here is enhanced as Tropical Storm Alberto recently saturated the grounds in this region. Gusty winds and coastal surf are also possible for northern Veracruz and Tamaulipas.
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