MY 2025 ATLANTIC HURRICANE SEASON BIRDSEYE VIEW POST #6

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

...SUNDAY JUNE 1 2025 10:40 PM EDT...

The 2025 Atlantic Hurricane Season officially begins today but on a quiet note. However in the days ahead will be watching the evolution of the current large-scale eastern North America upper which may allow for tropical development in the western part of the Atlantic basin as follows:

(1) Over the next three days the strength of the current western Canada and western US warm core upper ridge will break the upper trough into three components... a northern fragment that continues quickly east across the far north Atlantic... a cut-off upper vortex over the northwestern Atlantic that will be quasi-stationary for days until the upper ridge passes by to the north... and a cut-off upper vortex over Florida (note the warm core upper ridge has already been amplified enough to initiate a central US shortwave upper trough in relatively cooler air/ lower upper air pressures to the south of the upper ridge... the Florida upper vortex materializes from this shortwave upper trough as it moves southeast toward Florida within the flow on the back side of the eastern North America upper trough).

(2) Regarding the northwestern Atlantic upper vortex... it is forecast to evolve into a deep-layer low as its eastern divergence zone initiates a surface low pressure that then whirls into the core of the upper vortex. The deep-layer low is not likely to acquire tropical characteristics as the combination of 22 deg C waters and not so cold upper air layer (200 mb heights above 1200 dekameters) will not be enough for instability needed for thunderstorms and tropical characteristics.

(3) Regarding the Florida upper vortex... models over the last 24 hours are increasingly picking up on the idea that its eastern divergence zone may initiate a surface low just offshore of the southeastern United States... because of the warm offshore waters such a feature may need to be monitored for tropical development. If model runs continue to suggest this idea into tomorrow... may initiate a new area of interest for this region and issue probabilities of tropical cyclone formation.

(4) Regarding the central Caribbean waters toward Central America... by day 7 the models suggest the cold-core Florida cut-off upper vortex will be fading due to prolonged isolation from high-latitude cold air. This would allow a central Caribbean upper ridge cell to expand to the south of the fading upper vortex... the outflow of which could trigger a central Caribbean tropical disturbance. For now the GFS model has been leading this idea... and may have to also initiate a new area of interest in the central Caribbean in the days ahead if other models come into agreement or if future satellite observations were to warrant.

...COMPUTER MODEL SUMMARY...

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

1200Z (Jun 1) CMC Model Run...

**Current upper trough over eastern North America breaks down into one upper vortex over Florida and another near 38N-60W through 84 hours... the eastern divergence zone of the Florida upper vortex produces a surface trough offshore of NE Florida by 84 hours... the weak surface trough/low loses identity through 126 hours while moving northeast ahead of next frontal system approaching from eastern US

1200Z (Jun 1) ECMWF Model Run...

**Current upper trough over eastern North America breaks down into one upper vortex over Florida and another near 39.5N-60.5W through 84 hours... the eastern divergence zone of the Florida upper vortex produces a surface trough offshore of Georgia by 96 hours which evolves into a weak surface low making landfall on the South Carolina coast by 108 hours... while moving NE along the Carolina coast the surface low loses identity ahead of next frontal system approaching from the eastern US by 132 hours

1200Z (Jun 1) GFS Model Run...

**Current upper trough over eastern North America breaks down into one upper vortex over Florida and another near 39N-61W through 69 hours... the eastern divergence zone of the Florida upper vortex produces a surface trough offshore of Georgia by 99 hours which then loses identity ahead of next frontal system approaching from the eastern US through 132 hours

**In long range Florida upper vortex weakens which allows for a tropical upper ridge cell to expand in its wake in the central Caribbean... by 168 hours the outflow of the upper ridge cell contributes to formation of a broad tropical low centered just offshore of the Nicaragua/Honduras border

1200Z (Jun 1) NAVGEM Model Run...

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