MY 2025 ATLANTIC HURRICANE SEASON BIRDSEYE VIEW POST #58

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

...FRIDAY AUGUST 15 2025 1:45 AM EDT...

The Atlantic tropics remain active with the ongoing tropical storm in the open central Atlantic occurring alongside two other concurrent areas of interest:

(1) See Tropical Storm Erin section below for more information on the tropical storm... the tropical storm is expected to strengthen into the first hurricane of the 2025 Atlantic season within the next 24 hours and bring surf to the shores of the northeastern Caribbean Islands... Bermuda... the Bahamas... and United States southeast coast through day 5. Interests in Bermuda should monitor the progress of Erin carefully as more direct impacts such as gusty winds and heavy rainfall are possible during the middle of next week.

(2) Sea area of interest #18 section below for more information on the tropical disturbance currently approaching northeastern Mexico and southern Texas from the southwestern Gulf of America.

(3) See area of interest #19 section below for more information on a possible north Atlantic deep-layer cyclone that could acquire tropical characteristics in the days ahead.

Elsewhere in the Atlantic basin... the tropical wave of low pressure that Tropical Storm Erin formed within a few days ago has merged with the tropical wave that has recently moved into the waters southwest of the Republic of Cabo Verde Islands. Satellite imagery also suggests another tropical wave is currently moving offshore from Africa... and another large wave is forecast to depart Africa in about 4 days. There is potential for the waves to merge into a lengthy surface trough spanning the central and eastern tropical Atlantic. Will watch for the development of well-defined rotations within the possible surface trough in the days ahead and declare new areas of interest in future updates as needed.

TROPICAL STORM ERIN... The tropical storm in the central tropical Atlantic has begun to bend increasingly north in track while approaching the west extent of the steering Atlantic surface ridge. Most of the strengthening in the last 48 hours has occurred today instead of Wednesday coinciding with the timeframe that Erin reached lower concentrations of dry Saharan air. Observing the strong thunderstorm activity is lopsided to the southwest of center... around sunset time true color visible satellite showed the unmistakable beige tint of the dry Saharan air band just to the northeast. These observations taken together suggests Erin is still affected by dry Saharan air... therefore forecasting brisk strengthening but not above category 1 hurricane status over the next 24 hours. The surface layer steering forecast has not changed much as the surface frontal system currently approaching from the northeastern US and eastern Canada will create a ridge weakness that curves Erin north with time. The upper layer forecast has seen notable changes in the last 48 hours that means a stronger hurricane and more westward track. Regarding the tropical latitude upper vorticity band to the northwest... it is already further west than previous model projections which delays the northward deflection of Erin's track and reduces the upper outflow suppression/ southerly shear this feature imparts. Between 24 and 48 hours I do lower the intensification rate as Erin encounters the shear during its initial interaction with the tropical latitude upper vorticity band. By 72 hours what remains of the cool-core tropical latitude upper vorticity band becomes a distant upper vortex over Florida due to its prolonged isolation from high-latitude cold air... ending its effect on steering and allowing for Erin's intensification. Despite this the track still is largely northward by 72+ hours due to the western Atlantic surface ridge weakness associated with the tail end of the aforementioned surface front. For the timeframe that is currently 5+ days away... models still show enough upstream upper ridging that cuts off the tail of the frontal system's upper trough into a mid-latitude east-west band of upper vorticity around 35N latitude. However as noted in the area of interest #19 discussion below... the upper trough is now forecast to gain more amplitude alongside the next upper trough currently over western Canada such that the two fuse into a bi-polar upper vortex who pulls away the eastern part of the mid-latitude upper vorticity band... meanwhile the western part of the mid-latitude upper vorticity band remains distant over North Carolina/ Tennessee. The break in the mid-latitude upper vorticity band means less upper westerly upper flow in Erin's vicinity through day 5... translating to less shear that allows for Erin to become/ remain strong through that time and also re-enforces the westward-adjusted forecast track that brings Erin southwest of Bermuda instead of due south of Bermuda. The models are computing a strong enough frontal cyclone over Newfoundland by day 5 whose southward cold air transport helps bring the western center of the cold core bi-polar upper vortex closer to Erin... which translates to a long range track closer to Bermuda than the United States east coast and then an eventual northeast turn for the 5+ day window. For intensity... in this update I do not currently forecast anything above a lower-end category 4 as it is uncertain if Erin could undergo inner core changes such as an eye wall replacement cycle that holds back further intensification... or has a delay in going into an eye wall replacement cycle that would allow for an even higher intensity.

By tonight (Friday night) and through the early part of the weekend Erin is expected to bring surf to the northeastern Caribbean Islands. By the late part of the weekend and into early next week surf likely reaches the shores of Bermuda... the Bahamas... and southeastern United States. Interests in Bermuda should monitor Erin very closely as the hurricane could pass close enough to bring more direct impacts such as gusty winds and heavy rainfall by the middle part of next week.

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

0 Hr Position (0000Z Aug 15)... 70 mph maximum sustained wind tropical storm centered in the central tropical Atlantic at 16.9N-51.9W

IOH 24 Hr Forecast (0000Z Aug 16)... 90 mph maximum sustained wind hurricane centered east-northeast of the northern Lesser Antilles at 18N-57.5W

IOH 48 Hr Forecast (0000Z Aug 17)... 95 mph maximum sustained wind hurricane centered just north of the northern Lesser Antilles at 20N-62W

IOH 72 Hr Forecast (0000Z Aug 18)... 115 mph maximum sustained wind major hurricane centered north-northeast of Puerto Rico at 22N-65.5W

IOH 96 Hr Forecast (0000Z Aug 19)... 135 mph maximum sustained wind major hurricane centered in the western Atlantic at 24N-67.5W

IOH 120 Hr Forecast (0000Z Aug 20)... 135 mph maximum sustained wind major hurricane centered southwest of Bermuda at 27.5N-68.8W

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

Peak Strength (0000Z Aug 18)... 130 mph maximum sustained wind major hurricane centered in the western Atlantic at 22.4N-67W

5-Day Position (0000Z Aug 20)... 120 mph maximum sustained wind major hurricane centered west-southwest of Bermuda near 28N-70.4W

AREA OF INTEREST #18... The tropical wave/ surface trough of low pressure that formed over the western Caribbean 48 hours ago has since moved west-northwest across the Yucatan peninsula... then across Bay of Campeche/ southwestern Gulf of America waters while rounding the steering western Atlantic surface ridge. Although the west extent of the ridge has been expanded into the Gulf by upper convergence below the northeast side of the inverted upper trough in the region... the latest current and forecast information regarding the strength of the ridge suggests it won't be strong enough to minimize the north angle in the track... in fact the initial position of the spin maximum of the tropical wave/ surface trough is already a little north of the previous forecast and my updated one is adjusted accordingly. The thunderstorm activity associated with this system has struggled to persist due to its proximity to the aforementioned inverted upper trough which is muffling the upper outflow... however in the next 24 hours as the system nears the northeast Mexico coast the inverted upper trough arcs to the north and away while gravitated toward the current eastern US upper vorticity. I have not agreed with raising odds of tropical cyclone formation as high as the NHC has done due to the global models not showing development and while waiting to see if this system can develop more persistent thunderstorm activity... instead only raising mine slightly to 30% due to the well-defined rotation of the low clouds in satellite animation.

Regarding impact to land areas:

(1) The potential for impacts to northern Veracruz... or inland adjacent provinces to the west of northern Veracruz and Tamaulipas... has ended to the adjusted forecast track showing a more north and less west heading.

(2) Interests across Tamaulipas and southern Texas should be aware of possible heavy rainfall/ flash flooding risk from this disturbance from tonight through Saturday. Be aware of possible surf and gusty winds toward the coast in the event this system develops within the next 24 hours before the forecast landfall.

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

IOH 24 Hr Outlook (0000Z Aug 16)... 30% chance of tropical cyclone formation (northeastern coast of Mexico near 24.5N-98W)

IOH 48 Hr Outlook (0000Z Aug 17)... 0% chance of tropical cyclone formation (southern Texas near 27N-98.5W)

*****National Hurricane Center (hurricanes.gov) official outlook as of 8 PM EDT***********************

Formation chance through 48 hours... 50%

Formation chance through 7 days... 50%

AREA OF INTEREST #19... For the upper troughs currently over eastern and western Canada... the models have trended with a more amplified jet stream pattern where the surface frontal system associated with the western Canada trough gets strong enough to pull cold air south for a higher amplitude western Canada upper trough... and strong enough to pull warm air north to create enough warm core upper ridging that cuts-off a portion of the current eastern Canada upper trough into a vortex as that trough moves into and across the north Atlantic. Whatever energy that does not become a part of the vortex merges with the current northeast Atlantic upper vorticity. Meanwhile the eastern divergence zone of the developing north Atlantic upper vortex produces a surface frontal cyclone which then whirls below the core of the upper vortex which effectively results in a deep-layer cyclone. Because the deep-layer cyclone is forecast to be over warm 26 deg C waters in the vicinity of 40N latitude per recent GFS and CMC model runs... it could acquire tropical characteristics. The ECMWF was not quiet onboard with the GFS and CMC while having a slightly less amplified jet stream pattern... but is close enough that I have initiated a new area of interest for possible tropical development in the north Atlantic in the days ahead. This marks the nineteenth area of interest I have tracked on this site this year.

The north Atlantic deep-layer cyclone begins to move east-northeast then northeast not long after its formation as the upper trough from western Canada approaches and steers it. This shortens the amount of time over warm water and therefore my peak odds of subtropical cyclone formation are at a low 20%... the subtropical instead of tropical designation is used in the outlook below as that is the usual outcome of deep-layer cyclones that gain tropical characteristics. In the long range... per the latest model data... the upper layer of the cyclone becomes the eastern center in a bi-polar upper vortex while the amplified upper trough from western Canada becomes the western center. Note it is possible the non-tropical remnant surface layer of the cyclone arcs north toward the waters south of Greenland while caught by the bi-polar upper vortex... or it is also possible the non-tropical remnant turns east while ingested into the northeast Atlantic upper vorticity in which case the remnant weakens quickly due to the upper convergence under the west side of the upper vorticity.

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

IOH 24 Hr Outlook (0000Z Aug 16)... 0% chance of subtropical cyclone formation (northwest Atlantic near 40N-55W)

IOH 48 Hr Outlook (0000Z Aug 17)... 10% chance of subtropical cyclone formation (north Atlantic near 39N-51.5W)

IOH 72 Hr Outlook (0000Z Aug 18)... 20% chance of subtropical cyclone formation (north Atlantic near 40N-46W)

IOH 96 Hr Outlook (0000Z Aug 19)... 0% chance of subtropical cyclone formation (north Atlantic near 45N-40W)

*****National Hurricane Center (hurricanes.gov) official outlook as of 8 PM EDT***********************

Not in the official outlook

...COMPUTER MODEL SUMMARY...

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

0000Z (Aug 14) CMC Model Run...

**For Tropical Storm Erin... while passing just north of the northern Lesser Antilles... Virgin Islands... Puerto Rico through 96 hours becomes a strong hurricane... subsequently turns north and passes just west of Bermuda at 162 hours and centered just northwest of Bermuda by 168 hours

**For area of interest #18... no development shown

**For area of interest #19... Portion of large upper trough and surface frontal system currently over eastern Canada becomes a cut-off deep-layer cyclone with possible tropical characteristics near 39N-50W by 78 hours... through 102 hours moves northeast into cooler waters past 40N latitude... through 168 hours continues northeast toward the waters west of the British Isles while becoming less tropical and more elongated

**Tropical wave emerges from west coast of Africa at 102 hours... becomes a large tropical low centered over the southwestern Republic of Cabo Verde Islands at 132 hours... centroid of large tropical low positioned at 16N-33.5W at 168 hours

**Additional portion of surface frontal system currently over eastern Canada eventually becomes a small surface low with possible tropical characteristics while over the open Atlantic ocean near 34N-39.5W at 156 hours... the small surface low drifts east-northeast to 35N-36W through 168 hours

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

**For Tropical Storm Erin... similar solution to 0000Z Aug 14 CMC Model Run

**For area of interest #18... no development shown

**For area of interest #19... portion of large upper trough and surface frontal system currently over eastern Canada becomes a cut-off deep-layer cyclone with possible tropical characteristics near 39N-50W by 66 hours... through 90 hours moves northeast into cooler waters past 40N latitude... through 168 hours proceeds to take a cyclonic arc into the waters offshore of southern Greenland as a non-tropical frontal cyclone while becoming wrapped into the east side of another non-tropical frontal cyclone emerging from eastern Canada

**Tropical wave emerges from west coast of Africa at 108 hours... becomes a large tropical low centered over the southwestern Republic of Cabo Verde Islands at 150 hours... centroid of large tropical low centered at 14N-30W at 168 hours

**Additional portion of surface frontal system currently over eastern Canada eventually becomes a small surface low with possible tropical characteristics while over the open Atlantic ocean near 36.5N-39.5W at 132 hours... continues east-northeast into the waters north of the Azores through 168 hours while losing tropical characteristics

1200Z (Aug 14) ECMWF Model Run...

**For Tropical Storm Erin... while passing just north of the northern Lesser Antilles... Virgin Islands... Puerto Rico through 72 hours becomes a strong hurricane... subsequently proceeds north-northwest in track into the waters midway between the US east coast and Bermuda through 150 hours while gaining size and becoming a potentially intense hurricane (data after 150 hours missing at above-mentioned source)

**For area of interest #18... no development shown

**For area of interest #19... upper trough associated with surface frontal system currently over eastern Canada does not quiet gain enough amplitude while crossing the Atlantic to produce a deep-layer cyclone with possible tropical characteristics

**Tropical wave emerges from west coast of Africa at 102 hours... through 150 hours becomes a large tropical low centered over the Republic of Cabo Verde Islands (data after 150 hours missing at above-mentioned source)

1800Z (Aug 14) GFS Model Run...

**For Tropical Storm Erin... while passing just north of the northern Lesser Antilles... Virgin Islands... Puerto Rico through 75 hours becomes a strong hurricane... subsequently proceeds north-northwest in track into the waters midway between the US east coast and Bermuda through 147 hours while gaining size and becoming a potentially intense hurricane... turns northeast into the waters just north of Bermuda through 168 hours while maintaining size and strength

**For area of interest #18... no development shown

**For area of interest #19... portion of large upper trough and surface frontal system currently over eastern Canada becomes a cut-off deep-layer cyclone with possible tropical characteristics near 39.5N-51.5W by 48 hours... proceeds east-northeast into the open northeastern Atlantic while becoming an increasingly non-tropical and more elongated frontal low with the weakening remnant frontal low reaching 51.2N-21.5W by 168 hours

**Through 48 hours a tropical wave emerging from west coast of Africa merges with current wave southwest of the Republic of Cabo Verde Islands to make a lengthy surface trough spanning the eastern and central tropical Atlantic... through 111 hours the surface trough proceeds west across the tropical latitudes while resembling a rather elongated WSW/ENE spin whose centroid is near 11.2N-39.5W... WSW end of the surface trough proceeds to become a WNW moving tropical low reaching 14N-52.5W through 168 hours (further development of the tropical low suggested not long after 168 hours)

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

**For Tropical Storm Erin... while passing just north of the northern Lesser Antilles... Virgin Islands... Puerto Rico through 78 hours becomes a strong hurricane... proceeds to turn increasingly north in track while gaining size with the center of the hurricane passing just west of Bermuda between 138 and 144 hours... accelerates north-northeast toward Atlantic Canada while gradually transitioning into a rather large and powerful non-tropical remnant frontal cyclone through 168 hours

**For area of interest #18... no development shown

**For area of interest #19... upper trough associated with surface frontal system currently over eastern Canada does not gain enough amplitude while crossing the Atlantic to produce a deep-layer cyclone with possible tropical characteristics

**Through 42 hours a tropical wave emerging from west coast of Africa merges with current wave southwest of the Republic of Cabo Verde Islands to make a lengthy surface trough spanning the eastern and central tropical Atlantic... a broad tropical low develops along the trough and WSW of the Republic of Cabo Verde Islands by 108 hours... the tropical low proceeds to open back to a wave while reaching 49W longitude through 168 hours

**Large tropical wave proceeds to emerge from western Africa at 144 hours while exhibiting a tropical low pressure spin centered on the west coast of Mauritania... possible tropical cyclone formation offshore of Mauritania and near 19.5N-19W at 168 hours