MY 2025 ATLANTIC HURRICANE SEASON BIRDSEYE VIEW POST #20

*******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.*********

...FRIDAY JUNE 20 2025 5:45 PM EDT...

The western Atlantic tropics (western Caribbean and Bay of Campeche) and eastern Pacific tropics are expected to see a quieter phase in the short-term following the landfall and inland dissipation of tropical cyclone Erick on the south-facing Pacific coast of Mexico... and the recent dissipation of the surface trough that was following behind Erick across western Central America and southeastern Mexico (the surface trough is no longer defined by a dashed-line or by the shape of isobar contours in recent NHC TAFB surface analyses... albeit the CIMSS 850 mb vorticity product suggests there are mid-level remains of the trough across western Central America and southeastern Mexico with increasing thunderstorm activity seen in this region in more recent satellite frames toward 2000Z. The CIMSS 850 mb vorticity product can be accessed at https://tropic.ssec.wisc.edu/real-time/windmain.php?basin=atlantic&sat=wg8&prod=vor&zoom=&time=. In particular the northwest end of the mid-level remains appears to have increased spin on the CIMSS 850 mb vorticity product and visible satellite animation but an inland position over Tamaulipas and northern Veracruz... this increased spin also appears to be associated with a rapid upheaval in offshore thunderstorm squalls in the western Gulf of America over the last few hours but tropical development is not possible with the inland position of the spin maximum).

The short-term downturn in the western Atlantic and eastern Pacific tropics will be brought on by the amplification of a heat wave upper ridge across a large section of the United States... being induced by surface northward warm air transport ahead of the currently developing vigorous northwestern US surface frontal system and its supporting incoming upper trough from the northeast Pacific. This upper ridge will push the current northeastern Gulf of America upper vorticity southward... and help re-enforce the current western Atlantic upper vorticity string by pushing some of the upper vorticity from the current eastern US upper trough southward... note the southward-moving upper vorticity is already shunting the favorable upper anticyclone that was over Central America westward and away. In the longer term... 3+ days... the upper vorticity begins to weaken from prolonged isolation from high-latitude cold air as the United States heat wave upper ridge passes to the north... fostering the formation of a new Central America upper anticyclone. In particular the upper anticyclone first appears as a gap between the weakening Gulf of America upper vorticity and weakening western Atlantic upper vorticity... especially as the Gulf vorticity is first pushed westward and away by the United States upper ridge. Eventually the western Atlantic upper vorticity also proceeds west (toward day 7) once the United States upper ridge shifts east and grabs it... which will cause a westward translation of the Central America upper anticyclone but not before it promotes possible eastern Pacific and/or western Caribbean/Bay of Campeche tropical development. The NHC is already monitoring the possibility of the next eastern Pacific development in their tropical weather outlook... see outlook at hurricanes.gov as this site is focused on Atlantic basin tropical development. Meanwhile not declaring an area of interest for the Atlantic basin side (western Caribbean/ Bay of Campeche) until the global models are in better agreement on development in that area.

...COMPUTER MODEL SUMMARY...

Source...Florida State University Experimental Forecast Tropical Cyclone Genesis Potential Fields (http://moe.met.fsu.edu/tcgengifs/).

0000Z (Jun 20) CMC Model Run...

**No tropical development shown in the Atlantic basin through 7 days (168 hours)

0000Z (Jun 20) ECMWF Model Run...

**No tropical development shown in the Atlantic basin through 7 days (168 hours)

1200Z (Jun 20) GFS Model Run...

**Tropical low materializes in the south-central Caribbean east of Nicaragua at 132 hours and makes landfall on the east coast of Nicaragua by 144 hours without further development.

0600Z (Jun 20) NAVGEM Model Run...

**Tropical low materializes in the south-central Caribbean offshore of eastern Panama and northwestern Colombia by 66 hours and makes landfall on the east coast of Nicaragua by 108 hours... while moving west-northwest emerges onto the north-central Honduras coast by 138 hours and makes landfall over northern Belize by 150 hours... emerges into the southeastern Bay of Campeche at 162 hours