MY 2025 ATLANTIC HURRICANE SEASON BIRDSEYE VIEW POST #37

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

...MONDAY JULY 14 2025 6:15 PM EDT...

For the mid-latitudes of the Atlantic basin:

(1) URGENT - See area of interest #9 section below for the tropical low offshore of the southeastern United States which has become better organized offshore of east-central Florida... interest in east-central Florida should monitor the progress of this feature for possible additional development overnight. This feature is forecast to cross the Florida peninsula and then angle increasingly north toward the coastal regions of the Florida panhandle... Alabama... and Mississippi... bringing heavy rain with flash flooding potential and possibly other impacts depending on how much development occurs in the days ahead.

(2) An additional surface low developed overnight in the northwestern Atlantic near 39N-65W under the eastern divergence zone of a small upper vortex left behind by the current north Atlantic upper trough (this is a vortex different than the vortex that helped to trigger area of interest #9). The upper vortex has since retrograded southwest and away from the new surface low... and the surface low is becoming increasingly tucked under warm core anticyclonic upper ridging with low shear and upper outflow potential which is being aided by the warm southerly flow ahead of the current east Canada frontal low. Moreover the surface low is parked at the north wall of warm Gulf stream waters. However tropical development of this surface low is not expected as it will soon be pushed north into cooler waters by the west side of the current northwest Atlantic surface ridge.

For the tropical latitudes of the Atlantic basin... tropical development continues to be precluded by surges of dry Saharan air. Furthermore upper-level winds are unfavorable for tropical development across the Caribbean and Bay of Campeche due to upper westerly shearing winds on the south side of a band of upper vorticity in the region.

AREA OF INTEREST #9... The tropical low pressure offshore of the southeastern United States continues to be supported by split flow upper divergence between the southwest side of a small retrograding upper vortex and southeast side of an upper anticyclonic ridge over the southeastern United States. Overnight I did not do a special update on this feature as the thunderstorm activity pulsed down. Today the tropical low has re-developed thunderstorm activity... the most organized that it has had since birth... and it appears to have relocated even further south (to 29N-78.5W). The southward relocation is probably due to the latest positioning of the split flow upper divergence zone which is continually shifting south due to the southwestward retrogression of the small upper vortex. The upper vortex is blocking northern outflow and hence preventing thunderstorms in the northern half of the surface circulation. The ongoing thunderstorms and associated latent heat release generated warm core upper outflow to the south may be contributing to the southward relocation of the tropical surface low in the most recent hours... as the outflow is contributing to dropping surface pressures... and if current trends continue the tropical low will likely relocate to 28.5N latitude by tonight. Water vapor satellite suggests a fully closed upper vortex with a circular area of dryness just north of the tropical surface low... however at the 200 mb layer the data being fed into the models shows the upper vortex has weakened to an inverted upper trough (see 200 mb GFS model upper wind map in the above birdseye view chart). The most recent water vapor satellite animation suggests the cool core inverted upper trough may be deflecting more west toward southern Georgia instead of overtopping the tropical low thanks to the thunderstorm latent heat release... in which case an ongoing canopy of thunderstorms may be able to develop a full-fledged warm core upper anticyclone over the tropical low in between the fading southern Georgia inverted upper trough and current western Gulf of America upper vortex. This is different than for example today's 1200Z GFS model run which had the inverted upper trough sliding overtop the tropical low and Florida... then merging with the current western Gulf of America upper vortex with such a merger continually suppressing upper outflow over the tropical low. As such the GFS run and the other suite of model runs in the computer model summary section below may have not been well-initialized with the current events being seen with the tropical low... and I have raised my odds of tropical cyclone formation to 50% for tonight/ early tomorrow... before the tropical low moves west into Florida.

Far to the north... an upper trough over eastern Canada is beginning its northward pivot around the east side of a polar upper vortex diving into Canada. Convergence on the back side of this upper trough is building a surface ridge over the western Great Lakes... which will soon shift east into the eastern Great Lakes while following the convergence zone of the upper trough... and this surface ridge steers the tropical low west into Florida and into the northeastern Gulf of America. During the later part of the forecast period... the southeastern divergence zone of the Canadian polar upper vortex erodes the steering surface ridge and generates a surface front slowly sagging southeast across the eastern US... turning the tropical low increasingly northwest across the northeastern Gulf and into the United States Gulf coast. The updated forecast track in my outlook below is adjusted based on the more south initial position of the tropical low... which increases the amount of time over water. And combined with the potentially more favorable upper wind pattern currently developing in water vapor satellite... discussed in the previous paragraph... I have raised my Gulf odds of tropical cyclone formation to 30%. I have not increased the Gulf odds above 30% until we see if the organized thunderstorm structure is retained during passage across the Florida peninsula... if for some reason the thunderstorms and associated latent heat release pulse down in the short-term that could allow the cool core inverted upper trough to the north and western Gulf of America upper vortex to combine and suppress this disturbance.

Regarding impact to land areas:

(1) The potential for notable impacts to southern Georgia has reduced due to the southward relocation of the tropical low.

(2) The potential for thunderstorms capable of producing flash flooding heavy rains remains across the northern Florida peninsula... and has increased for the central and southern part of the peninsula due to the southward relocation of the tropical low. Interests along the east-central Florida coast should monitor this system carefully for possible gusty winds and coastal surf by early tomorrow should tropical cyclone formation occur overnight.

(3) Interests across the United States Gulf coast... from the central and western Florida panhandle to coastal Alabama and coastal Mississippi should monitor the progress of the tropical low for possible impacts Wednesday and Thursday as there is an opening for upper winds to become favorable for development as discussed above.

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

IOH 12 Hr Outlook (0600Z Jul 15)... 50% chance of tropical cyclone formation (just offshore of northeastern Florida near 28.5N-80W)

IOH 24 Hr Outlook (1800Z Jul 15)... 0% chance of tropical cyclone formation (inland northeastern Florida near 28.5N-81.5W)

IOH 48 Hr Outlook (1800Z Jul 16)... 30% chance of tropical cyclone formation (northeastern Gulf of America near 28.5N-84W)

IOH 72 Hr Outlook (1800Z Jul 17)... 30% chance of tropical cyclone formation (just southwest of Cape San Blas Florida near 29N-85.8W)

IOH 96 Hr Outlook (1800Z Jul 18)... 0% chance of tropical cyclone formation (inland southern Alabama near 31.5N-87W)

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

Formation chance through 48 hours... 20%

Formation chance through 7 days... 30%

...COMPUTER MODEL SUMMARY...

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

1200Z (Jul 14) CMC Model Run...

**For area of interest #9... tropical low makes landfall on the northeast Florida coast just south of 30N latitude at 30 hours and re-emerges over the eastern Gulf of America by 48 hours as a broad tropical low... while moving west-northwest re-establishes a better-defined center while making landfall on the southeast Louisiana coast at 78 hours... inland remnant low continues west-northwest across southeastern Louisiana and then turns north into northern Louisiana by 120 hours... the inland remnant low dissipates shortly thereafter

0000Z (Jul 14) ECMWF Model Run...

**For area of interest #9... tropical low makes landfall on the northeast Florida coast at 29N latitude at 30 hours while a disorganized entity that lacks a well-defined center... weakens to an east-west surface trough soon after that drifts northwest into the inland section of the Florida/Georgia border by 48 hours... remnant trough dissipates soon after

1200Z (Jul 14) GFS Model Run...

**For area of interest #9... tropical low makes landfall on the northeast Florida coast at 29.5N latitude at 27 hours and re-emerges over the northeastern Gulf of America by 45 hours as a broad tropical low... the broad tropical low weakens to a surface trough that moves west-northwest into the southeast Louisiana coast by 75 hours... trough dissipates shortly after landfall

1200Z (Jul 14) NAVGEM Model Run...

**For area of interest #9... tropical low makes landfall on the Florida/Georgia border at 30 hours while becoming an increasingly broad feature... the broad tropical low continues west along the Florida panhandle coast and is centered on the western part of the panhandle coast by 48 hours... turns north into southeastern Alabama by 54 hours shortly after which time it dissipates