MY 2025 ATLANTIC HURRICANE SEASON BIRDSEYE VIEW POST #26

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

...UPDATE...SUNDAY JUNE 29 2025 12:40 PM EDT...

Infrared (left) and visible (right) satellite imagery of Tropical Storm Barry as of 1601Z. The visible image is marked with red-dashed lines showing the increasingly-defined banding features that are confirming the recent aircraft recon center fixes... the center is marked with red crosshairs:

Tropical depression two in the western Bay of Campeche has become Tropical Storm Barry as of 11 AM EDT... but it was not easy for it due to disrupting southwesterly shear imparted by the small upper vortex that was over northern Mexico. The upper vortex is making its northeast escape toward southern Texas and beyond as the central US upper ridge has shifted east and out of the way to allow for the upper vortex to move around it. During the overnight the shear was causing thunderstorm tops with no cyclonic curvature to zoom from west-to-east on nighttime infrared satellite imagery... making it hard to spot the surface spin underneath... and aircraft recon was also struggling to find a closed circulation. After sunrise aircraft recon finally found a northwestward-moving closed surface center with sufficient strength to declare Tropical Storm Barry... and as of 11 AM EDT Barry had 40 mph maximum sustained winds while centered at 20.4N-96.2W with 1006 mb minimum surface pressure. It is still hard to spot the aircraft recon center fix on infrared satellite... and even visible satellite had the same issue until 1600Z as increasingly defined banding features confirmed the recon fix. The increased northward angle is more than I forecasted in my full update from 12:45 AM EDT below... the current angle will bring the center onshore in northern Veracruz later today rather than central Veracruz. Barry is still a weak/ shallow tropical cyclone and so it is unlikely the increased northward angle is due to coupling with the upper southwesterlies... the 11 AM EDT NHC advisory discussion also states Barry is being steered by the surface/ low-level ridge that is relocating southwestward from the eastern US into the northern Gulf of America. Perhaps the west extent of the relocating ridge is not quiet enough to prevent the increased north angle... and also noting the CIMSS 850 mb vorticity product (https://tropic.ssec.wisc.edu/real-time/windmain.php?basin=atlantic&sat=wg8&prod=vor&zoom=&time=) and 0600Z NHC TAFB surface analysis shows the eastern divergence zone of the small upper vortex moving into Texas has created a surface trough of low pressure offshore of northeastern Mexico which perhaps helped Barry make a more northward turn.

Increasing impacts to a swath of east-central and northeastern Mexico is expected through later today as follows... heavy rainfall with flash flooding potential across central and northern Veracruz... all of Tamaulipas instead of just the southern areas due to the increased north angle in track... and neighboring inland provinces to the west. The corridor of expected gusty winds and coastal surf is narrowed to northern Veracruz due to the latest track angle.

...SUNDAY JUNE 29 2025 12:45 AM EDT...

See tropical depression two section below for an update on the active tropical system in the Bay of Campeche tracking west-northwest toward Veracruz.

Elsewhere noting the following vigorous tropical waves of low pressure in the Atlantic basin as follows:

(1) A tropical wave of low pressure has recently crossed the Lesser Antilles islands and is now entering the eastern Caribbean... but not before producing a concentrated area of thunderstorms over the central and northern islands. The ability for the wave to produce thunderstorms has been enhanced by a channel of poleward upper outflow between a westward-retrograding upper vortex in the western Atlantic and central to eastern tropical Atlantic upper ridge which has been allowed to expand as the regional cool-core upper vorticity string along 25N latitude has been weakening while isolated from high-latitude cold air. However tropical development is not occurring as the western Atlantic upper vortex is producing excess southerly shear... and this will continue for the next 48 hours as the upper vortex and surface tropical wave continue west in tandem. The north side of the tropical wave may produce squalls of thunderstorms across the Virgin Islands... Puerto Rico... and Hispaniola (Haiti and the Dominican Republic) in the short-term. After 48 hours... the upper vortex turns northwest and settles over the northwestern Bahamas and waters offshore of the southeastern US while gravitated toward an upper trough moving into eastern North America... with the upper vortex also weakening from its prolonged isolation from high-latitude cold air. This may give an opportunity for the tropical wave to produce another area of disturbed weather in anticyclonic outflow to the south of the weakening upper vortex as the wave approaches Central America by day 4... however none of the models at this time show development of the wave in the longer range.

(2) Satellite imagery suggests a well-formed surface tropical wave of low pressure is emerging from the west coast of Africa with rotating cloudiness and thunderstorms... however colorized infrared satellite shows the wave increasingly losing thunderstorms while ingesting dry Saharan air to the northwest. Therefore development of this feature is not expected while it traverses west under the low shear environment of the recently-expanded central to eastern tropical Atlantic upper ridge.

On a final note... tropical development is possible toward day 7 (168 hours) in association with the tail end of a surface cold front that will be driven offshore from eastern North America by its associated upper trough. However the model solutions vary substantially... for example during this past 12Z to 18Z cycle the CMC had a solution of a tropical cyclone forming offshore of North Carolina which escapes northeast into open northwest Atlantic waters while gravitated toward the deep-layer ridge weakness associated with the remainder of the surface front and upper trough... whereas the GFS and ECMWF show tropical development further southwest in the waters offshore of the southeastern US or the northeastern Gulf of America. The further southwest solutions are more complex as the system could track erratically to the south of deep-layer ridging that emerges behind the upper trough... with the steering picture also complicated by cut-off upper vorticity pushed south from the upper trough and into the region by the deep-layer ridging. Westerly shear on the south side of the cut-off upper vorticity... and a lack of divergence directly below the upper vorticity... may also disrupt development potential should a tropical disturbance in fact emerge further southwest. The wide variation in model solutions are probably why no area of interest has been issued in the NHC 7-day tropical weather outlook... I also have not declared an area of interest in this update as the development potential falls after the 5-day forecast window I have for areas of interest.

TROPICAL DEPRESSION TWO... The tropical depression in the Bay of Campeche continues moving west-northwest toward central and northern Veracruz in the low-level flow between the eastern Pacific tropical low and eastern US surface ridge. Have slipped the forecast track a little more south and forecast intensity a little downward (while my previous forecast showed 45 mph max sustained wind intensity at two points... I had noted in the text that it could reach a peak above 45 in between those two points... now have a single short-lived 45 mph peak in the forecast while now assuming the intensity will not exceed 45). Some of the reasons for the south nudge in forecast track and downward nudge in the intensity include the initial position of the depression toward 19.5N latitude instead of closer to 20N... and as the depression as of this writing is not showing signs of developing further on satellite imagery while now lacking a central core of thunderstorms (instead there are bands just to the west of center... and also well north and well southeast of center). Before lifting northward and away... the northern Mexico upper vortex may also disrupt the northwestern upper outflow of this system which would help keep the intensity lower. The lower intensity projection also means odds are dropping that this system will become strong/ tall enough to couple with the upper southwesterly flow of the upper vortex before the vortex exits the region... re-enforcing the southward nudge in my updated forecast track. The low-level steering flow will keep this system on a west-northwest thru landfall and inland dissipation as the eastern US surface ridge relocates to the southwest across the northern Gulf of America while supported by the western convergence zone of the southeastern US upper vortex... especially when it later merges with the incoming western Atlantic upper vorticity which will re-enforce the upper convergence zone.

Impact to a swath of east-central Mexico is expected late this weekend into Monday as follows... heavy rainfall with flash flooding potential anticipated across central and northern Veracruz... southern Tamaulipas... and neighboring inland provinces to the west. Gusty winds and coastal surf for central and northern Veracruz is still possible as there remains time for this system to become a tropical storm before landfall. For impacts further south and southwest in association with the eastern Pacific tropical low... which is expected to turn increasingly west-northwest and parallel to the south-facing Pacific coast of Mexico while becoming stronger/taller to be guided by the upper easterlies associated with the current southwest Mexico upper ridge... refer to the National Hurricane Center site at hurricanes.gov as this site is focused on Atlantic basin systems.

******Infohurricanes.com forecast. Visit hurricanes.gov (hurricanes dot gov) for official forecast***********

0 Hr Position (0000Z Jun 29)... 30 mph maximum sustained wind tropical depression moving into the western Bay of Campeche at 19.5N-94.7W

IOH 24 Hr Forecast (0000Z Jun 30)... 45 mph maximum sustained wind tropical storm centered just offshore of Veracruz at 20.5N-97W

IOH 48 Hr Forecast (0000Z Jul 1)... Dissipating remnant low centered over east-central Mexico at 21N-99W

*****National Hurricane Center (hurricanes.gov) official forecast as of 11 PM EDT***********************

Peak Strength (0000Z Jun 30)... 40 mph maximum sustained wind tropical storm centered on the northern Veracruz coast at 21.3N-97.3W

36-Hr Position (1200Z Jun 30)... 25 mph maximum sustained wind dissipating remnant low centered inland at 22.1N-98.8W

...COMPUTER MODEL SUMMARY...

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

1200Z (Jun 28) CMC Model Run...

**For tropical depression two... initialized as a central Bay of Campeche surface trough at 0 hours and as such is shown to make landfall as a weak tropical low over northern Veracruz by 30 hours... inland dissipation shortly thereafter

**Current broad upper trough over the northwestern US reaches the northeastern US and eastern Canada by 90 hours and begins to drive its surface front (supported by the eastern divergence zone of the upper trough) into offshore waters... tail end of surface front evolves into tropical low offshore of southeastern North Carolina by 132 hours due to anticyclonic upper outflow in relatively high upper air pressures between the upper trough to the north and cut-off upper vorticity to the south positioned over the Bahamas... tropical cyclone formation suggested at 138 hours south-southeast of Cape Hatteras North Carolina which moves northeast toward deep-layer ridge weakness associated with the remainder of the surface front and upper trough... despite southwesterly winds ahead of the upper trough the tropical cyclone intensifies while on a northeast speed to offset the effect of southwesterly shear and reaches 38N-64.5W by 168 hours

1200Z (Jun 28) ECMWF Model Run...

**For tropical depression two... short-term data before this system makes landfall in east-central Mexico unavailable at above-mentioned source

**Current broad upper trough over the northwestern US reaches the northeastern US and eastern Canada by 90 hours and begins to drive its surface front (supported by the eastern divergence zone of the upper trough) into offshore waters... at 168 hours tail end of surface front evolves into a tropical low offshore of northeast Florida due to split flow upper divergence between westerlies south of cut-off upper vorticity left behind by the upper trough and easterlies south of an upper ridge over the eastern US.

1800Z (Jun 28) GFS Model Run...

**For tropical depression two... initialized as a central Bay of Campeche surface trough at 0 hours and as such is shown to make landfall as a weak tropical low over northern Veracruz by 27 hours... inland dissipation shortly thereafter

**Current broad upper trough over the northwestern US reaches the northeastern US and eastern Canada by 90 hours and begins to drive its surface front (supported by the eastern divergence zone of the upper trough) into offshore northwest Atlantic waters and across the southeastern US... tail end of surface front evolves into broad tropical low just offshore of the Florida Panhandle at 135 hours... after formation the broad tropical low drifts south into the east-central Gulf while transitioning into a feature supported by upper divergence ahead of south-diving east-west band of upper vorticity left behind by the upper trough... a concentrated spot of upper divergence aids in the formation of a compact tropical cyclone within the east side of the broad low and just offshore of Tampa Bay Florida at 168 hours

1200Z (Jun 28) NAVGEM Model Run...

**For tropical depression two... curves increasingly north and makes landfall on the northeast coast of Mexico at 48 hours but without further development beforehand... turns west with inland dissipation shortly thereafter