MY 2025 ATLANTIC HURRICANE SEASON BIRDSEYE VIEW POST #43

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

...WEDNESDAY JULY 23 2025 7:50 PM EDT...

For the tropical latitudes of the Atlantic basin... tropical development continues to be suppressed due to ongoing upper vorticity toward the west half of the basin (bringing westerly wind shear to the south of the upper vorticity and a lack of upper divergence directly beneath). Further east... dry Saharan air continues to suppress development of the latest tropical waves of low pressure rolling off of Africa despite the improved cyclonic rotation seen with the recent waves.

For the mid-latitudes of the Atlantic basin... watching for possible development of the current eastern Gulf of America broad surface low pressure area before it makes landfall in Louisiana by Friday... see area of interest #11 section below for more information. In addition... a surface low pressure area could descend southwestward into the northern Gulf in approximately 7 days from now to become yet another tropical area of interest in this region... more details as follows:

(1) Through 60 hours the tail end of the surface cold front being generated by the eastern divergence zone of the current central Canada upper trough is driven southeast into the Carolinas by the surface ridge built in the western convergence zone of the upper trough... and through 90 hours is shown to fester over the Carolinas perhaps with the aid of upper anticyclonic outflow induced by the ongoing southeastern US upper ridge.

(2) Between 90 and 108 hours a shortwave upper trough and its associated surface front ejects east from the Great Lakes region... with the tail end of that front merging with the persistent Carolinas surface low pressure area as that front is also pushed southeast by the surface ridge induced by the back convergent side of the shortwave upper trough. At the same time a piece of energy left behind by the current northwest Atlantic upper trough is shown to revolve around the southeastern US upper ridge... reaching the northern Gulf as an inverted upper trough whose eastern convergence zone build a US Gulf coast surface ridge.

(3) From 108 to 168 hours the Carolinas surface low pressure area is coaxed southwest into the northern Gulf under the force of the US Gulf coast surface ridge... then a more sprawling and strong surface ridge descending from the US/Canada border induced by the back convergence zone of the next major upper trough to pass over Canada.

(4) This next northern Gulf surface low may then try to take advantage of outflow induced by the ongoing southeastern US upper ridge... however the upper vorticity currently near the northern Lesser Antilles is also scheduled to reach the northern Gulf as an inverted upper trough also around 168 hours. Tropical development potential will hinge on the alignment with the inverted upper trough... if for example the surface low ends up under the west side of the inverted upper trough then excess northeasterly shear would be disruptive... or alternatively if the surface low ends up under the inverted upper trough axis or east of the axis a lack of upper divergence would squash development potential. These precise details are not easy to forecast due to the usual model errors at 168 hours... therefore cannot declare a new area of interest for this scenario during this update cycle.

AREA OF INTEREST #11... A broad surface low pressure area... which is the merger between the tail end of a surface front and a surface trough ahead of the front's tail... has moved west-southwest into the eastern Gulf of America from the waters offshore of the southeastern US while steered by the current surface ridge centered over the northeast US coast. It continues to be challenging to establish a center fix for this rather broad feature... I continue to position the central area in the midst of the vacuous area that lacks cloudiness which as of 1800Z today was near 28N-85W. To the northwest of the central clear area there are thunderstorms in the vicinity of southeastern Louisiana... and to the east and southeast squalls of thunderstorms are over Florida and Cuba. Noting the National Hurricane Center finally introduced this area of interest into their tropical weather outlook since last evening... and has curiously had their center fix well east of mine. My updated forecast track in the outlook below is adjusted south due to my initial center fix relative to the previous forecast. Over the next 48 hours the steering surface ridge is re-enforced by the western convergence zone of the upper trough now ejecting from central Canada... however a gradual bend/ turn to the north eventually occurs as this disturbance rounds the southwest side of the ridge.

Regarding odds of tropical cyclone formation... the upper vortex that was over the central Bahamas is now over Cuba... and will continue west while orbiting the southeastern US upper ridge. The updated forecast track is now closer to the northwest side of the westward-moving upper vortex... which increases the potential for northeasterly shear across this disturbance. Combined with the ongoing lack of organization of the broad disturbance... I have lowered my odds of tropical cyclone formation back to 10% in this update.

Regarding impact to land areas... the broad disturbance may produce thunderstorm cells dumping periods of heavy rain (with possible flash flooding) across Florida... southern Georgia... southern Alabama... Mississippi... Louisiana... Arkansas... and eastern Texas through Friday (eastern Texas now included due to the updated forecast track). For the United States Gulf coast region from the Florida panhandle to Louisiana... the wind and coastal surf probability currently remains low due to the current low probabilities of tropical cyclone formation.

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

IOH 24 Hr Outlook (1800Z Jul 24)... 10% chance of tropical cyclone formation (offshore of southeastern Louisiana near 28N-88.8W)

IOH 48 Hr Outlook (1800Z Jul 25)... 0% chance of tropical cyclone formation (southwestern Louisiana near 31N-93W)

*****National Hurricane Center (hurricanes.gov) official outlook as of 2 PM EDT***********************

Formation chance through 48 hours... 10%

Formation chance through 7 days... 10%

...COMPUTER MODEL SUMMARY...

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

1200Z (Jul 23) CMC Model Run...

**For area of interest #11... current eastern Gulf of America broad surface low turns northwest for a landfall with south-central Louisiana at 30 hours... shortly thereafter continues north further inland and dissipates

0000Z (Jul 23) ECMWF Model Run...

**For area of interest #11... no development shown

1200Z (Jul 23) GFS Model Run...

**For area of interest #11... no development shown

1200Z (Jul 23) NAVGEM Model Run...

**For area of interest #11... current eastern Gulf of America broad surface low shifts west-northwest into southern Louisiana by 36 hours... shortly thereafter continues north further inland and dissipates