MY 2025 ATLANTIC HURRICANE SEASON BIRDSEYE VIEW POST #51

*******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 AUGUST 3 2025 2:20 AM EDT...

The Atlantic tropics have seen an uptick in activity this weekend from a combination of satellite imagery and recent computer model data resulting in multiple new areas of interest:

(1) Along the frontal boundary currently in the northwest Atlantic... satellite imagery has shown the formation of a low pressure spin southeast of North Carolina attempting to gain tropical characteristics. This system is expected to continue east-northeast and pass north of Bermuda and is being monitored for possible tropical cyclone formation... see area of interest #13 section below for details.

(2) The National Hurricane Center has added the current tropical wave of low pressure over western Africa into their tropical weather outlook as some model runs suggest development while it moves into the central tropical Atlantic in approximately 5+ days... see area of interest #14 section below for details.

(3) In addition to the frontal low southeast of North Carolina... tagged on this site as area of interest (AOI) #13... another frontal low is positioned along the Florida/Georgia border sliding east toward offshore waters. Around sunset earlier this evening the frontal low appeared to take advantage of low shear and upper outflow associated with the ongoing upper ridge axis in the region to produce thunderstorms collocated with it. Wind shear may be low enough for the frontal low to become yet another tropical area of interest in the days ahead as the upper trough regime currently developing over eastern North America later splits into southwestern and northeastern halves... with the southwestern half staying too far west to induce shear. If it persists... the frontal low's track may become erratic and stay close to the southeastern US coast while stuck in conflicting steering between the ridge weakness associated with AOI #13 and surface ridge building to the north in the western convergence zone of the northeastern half of the upper trough split. If the frontal low continues to persist as a well-defined feature... or if another well-defined frontal low develops offshore of the southeastern US... will consider upgrading it to a tropical area of interest in future updates.

AREA OF INTEREST #13... Infrared satellite image of frontal low positioned southeast of the North Carolina Outer Banks attempting to acquire tropical characteristics... image taken 0116Z Sunday August 3:

The lengthy surface front originally generated in the divergence zone ahead of the current southwest-northeast tilted eastern Canada upper trough is now positioned across the southeastern United States and northwestern Atlantic. Satellite observations early Saturday showed a surface low pressure spin developing along the front due south of the North Carolina Outer Banks... and by 8 AM EDT Saturday was upgraded by the National Hurricane Center (in their tropical weather outlook) to an area of interest for possible tropical development. This marks the thirteenth tropical Atlantic area of interest tracked on this site this year. The well-defined frontal low has continued east and reached 33N-74W as of 0000Z earlier this evening... and suggests a system trying to acquire tropical characteristics with core thunderstorm activity and positioned just right for doing so where its poleward (northern) upper outflow is enhanced by the southwesterly jet ahead of the eastern Canada upper trough instead of being sheared by the jet. However there is some shear affecting the center of circulation as the thunderstorm core is lopsided to the east of center. Due to the potential of brisk development with the aforementioned enhanced poleward outflow... I have already started with odds of tropical cyclone at 50%... and have not gone higher as the thunderstorm core in recent satellite frames is pulsing down after reaching peak size and strength around 0100Z earlier tonight (also noting the NHC has raised odds of development from 20% as of 8 AM EDT Saturday to now 40% as of their recent 2 AM EDT update). The future track will depend on the evolution of the eastern Canada upper trough... which in the short-term leaves behind its southwestern tail. This tail quickly merges with incoming upper trough energy from central Canada and the central US to make an eastern North America upper trough which toward day 5 then splits into southwestern and northeastern halves. The question is whether this system continues east-northeast out to sea while caught in the deep-layer weakness associated with the northeastern part of the surface front and northeastern half of the upper trough split... or whether this system slows its east-northeast progress or even stalls while becoming pinned by a surface ridge to the north that builds in the western convergence zone of the northeastern half of the upper trough split. The majority of the models suggest a continuous east-northeast track out to sea while the GFS is leaning toward the slow down/ stall idea... my track forecast below splits the difference between these two ideas. The current track forecast brings this system into increasing westerly shear and by day 5 I taper down odds of tropical cyclone formation to 0%. Should this system briskly strengthen into a tropical cyclone before reaching more hostile westerly shear... it could deliver surf that reaches the shores of Bermuda by Monday.

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

IOH 24 Hr Outlook (0000Z Aug 4)... 50% chance of tropical cyclone formation (western Atlantic near 35N-69W)

IOH 48 Hr Outlook (0000Z Aug 5)... 50% chance of tropical cyclone formation (north of Bermuda near 36N-65W)

IOH 72 Hr Outlook (0000Z Aug 6)... 50% chance of tropical cyclone formation (northeast of Bermuda near 36.5N-62W)

IOH 96 Hr Outlook (0000Z Aug 7)... 30% chance of tropical cyclone formation (northwestern Atlantic near 37N-60W)

IOH 120 Hr Outlook (0000Z Aug 8)... 0% chance of tropical cyclone formation (northwestern Atlantic near 37.5N-57.5W)

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

Formation chance through 48 hours... 40%

Formation chance through 7 days... 40%

AREA OF INTEREST #14... For much of Saturday satellite imagery suggested the presence of a surface tropical wave of low pressure over western Africa whose northwest side produced thunderstorm activity over the Mali/ Mauritania border region. The National Hurricane Center has added this tropical wave into their outlook since 8 PM EDT... probably due to the usually more reliable GFS/ ECMWF model consensus suggesting possible development of the wave in 5+ days when it later reaches the central tropical Atlantic. Forecast track should be steady to the west... perhaps with a west-southwest slant in the shorter term as the steering Atlantic surface ridge reaches a peak strength under the convergence associated with the current Atlantic upper vorticity string and before the string begins to weaken and break up from its isolation with high-latitude cold air. While the upper wind profile favors development with low shear and potential for upper outflow beneath the ongoing regional upper ridge... the structure of the tropical wave is lackluster in satellite pictures and the GFS/ ECMWF model signal is weak while showing a tropical low rather than an explicit tropical cyclone. Moreover considering the ongoing of surges of dry Saharan air which has done a pretty good job in capping tropical development in the eastern and central tropical Atlantic over the last several days... so all in all keeping my peak odds of tropical cyclone formation lower than the NHC and at 10% in this update cycle.

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

IOH 24 Hr Outlook (0000Z Aug 4)... 0% chance of tropical cyclone formation (inland just east of the west Africa coast near 12.5N-16W)

IOH 48 Hr Outlook (0000Z Aug 5)... 0% chance of tropical cyclone formation (east-southeast of the Republic of Cabo Verde Islands near 12.5N-20W)

IOH 72 Hr Outlook (0000Z Aug 6)... 0% chance of tropical cyclone formation (south-southwest of the Republic of Cabo Verde Islands near 12N-25W)

IOH 96 Hr Outlook (0000Z Aug 7)... 0% chance of tropical cyclone formation (eastern tropical Atlantic near 12N-30W)

IOH 120 Hr Outlook (0000Z Aug 8)... 10% chance of tropical cyclone formation (eastern tropical Atlantic near 12N-35W)

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

Formation chance through 48 hours... 0%

Formation chance through 7 days... 20%

...COMPUTER MODEL SUMMARY...

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

1200Z (Aug 2) CMC Model Run...

**For area of interest #13... through 48 hours strengthens as an elongated surface low while passing well northwest of Bermuda which suggests a less tropical feature supported by southwesterly shearing but divergent upper wind field... strengthens further into a non-tropical frontal cyclone east-southeast of Newfoundland by 144 hours which helps it pull a portion of cool core upper vorticity to the northwest directly overhead as an upper vortex... between 144 and 168 hours the surface frontal cyclone and upper vortex stack resulting in a deep-layer cyclone that drifts east-southeast into the waters midway between Newfoundland and the Azores

**For area of interest #14... no development shown

1200Z (Aug 2) ECMWF Model Run...

**For area of interest #13... through 66 hours becomes an elongated surface low passing well northwest of Bermuda which suggests a less tropical feature supported by southwesterly shearing but divergent upper wind field... continues east-northeast across the open north Atlantic through 156 hours passing well north-northwest of the Azores while an elongated non-tropical frontal low

**For area of interest #14... tropical wave currently over western Africa enters the eastern tropical Atlantic at 36 hours... evolves into a tropical low near 18N-40W by 138 hours... tropical low continues west-northwest to 21N-45.5W through 156 hours

1800Z (Aug 2) GFS Model Run...

**For area of interest #13... through 45 hours tropical cyclone formation suggested while passing well northwest of Bermuda... through 78 hours reaches 37.5N-65.2W while becoming a more elongated less tropical feature supported by southwesterly shearing but divergent upper wind field... from 78 to 123 hours the surface low becomes quasi-stationary and weakens under the wind shear as a surface ridge builds to the north which restricts the surface low's eastward progress which in turn exacerbates the effect of the westerly shear... weak remnant low drifts east-southeast to 36N-61W through 168 hours

**For area of interest #14... tropical wave currently over western Africa enters the eastern tropical Atlantic at 36 hours... evolves into a tropical low near 11.5N-33W at 105 hours... tropical low continues west-northwest to 14N-42W through 156 hours and shortly thereafter weakens back to a tropical wave

**Tail end of surface trough/ front that area of interest (AOI) #13 is embedded within becomes a surface low near 32N-72.5W at 66 hours... between 66 and 117 hours becomes quasi-stationary then begins drifting west under conflicting steering between surface ridge to the north and ridge weakness to the northeast associated with AOI #13 and during this time becomes a tropical cyclone... while drifting west into waters south-southeast of the North Carolina Outer Banks through 129 hours rapidly intensifies into a hurricane... drifts north into the waters just east of Cape Hatteras North Carolina through 168 hours while intensifying further into an strong hurricane

**Large tropical wave emerges from west coast of Africa at 144 hours... moves across the Republic of Cabo Verde Islands through 168 hours while becoming a large tropical low

1800Z (Aug 2) NAVGEM Model Run...

**For area of interest #13... through 48 hours strengthens as an elongated surface low while passing well northwest of Bermuda which suggests a less tropical feature supported by southwesterly shearing but divergent upper wind field... strengthens into an elongated non-tropical frontal cyclone while passing southeast of Newfoundland by 120 hours which helps it pull a portion of cool core upper vorticity to the northwest directly overhead as an upper vortex... between 120 and 168 hours the surface frontal cyclone and upper vortex stack resulting in a deep-layer cyclone that moves east-southeast into a position northwest of the Azores

**For area of interest #14... no development shown