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BIRDSEYE VIEW POSTS

Since 2012 on the now retired Weather Underground blogs, I have been posting annotated "birdseye view" charts of the Atlantic basin, with a detailed explanation and forecasting that references the chart. From there you may know me as "NCHurricane2009." While I now do these "birdseye view" posts here, I will continue to do comments at Yale Climate Connections via Disqus where the former Weather Underground community has moved to. Feel free to reply to me there, at my Disqus feed at this link, or via e-mail at IOHurricanes@outlook.com 

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MY 2025 ATLANTIC HURRICANE SEASON BIRDSEYE VIEW POST #27

  • Writer: NCHurricane2009
    NCHurricane2009
  • Jun 30
  • 6 min read

*******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 JUNE 30 2025 3:59 PM EDT...

See remnants of Barry section below for a final update on the former western Bay of Campeche tropical cyclone which has since made landfall across east-central and northeastern Mexico. See area of interest #8 section below for more information on the area of interest the National Hurricane Center has marked in their tropical weather outlook which spans the waters offshore of the southeastern US and Florida panhandle.


Elsewhere noting the surface tropical wave of low pressure that has been traversing the eastern half of the Caribbean... after crossing the Lesser Antilles... has seen a marked decrease in its associated thunderstorms. Conditions for development of this wave are hostile due to southerly shear induced by the southeast side of the cut-off upper vortex currently over the northwestern Bahamas.


REMNANTS OF BARRY... Visible satellite image from 2001Z Sunday June 29 when Barry was at peak strength (45 mph maximum sustained winds) just before the center of circulation made landfall in far northern Veracruz:

Previous post #26 chronicles yesterday's intensification of tropical depression two in the western Bay of Campeche into Tropical Storm Barry as it made an increased turn to the north just offshore of the Mexican province of Veracruz (https://www.infohurricanes.com/post/my-2025-atlantic-hurricane-season-birdseye-view-post-26). Since then the relocation of the steering eastern US surface ridge southwestward across the northern Gulf of America forced a more westward turn... and Barry's center of circulation made landfall in far northern Veracruz but not before reaching a peak strength of 45 mph maximum sustained winds. Due to the initial pre-landfall weak strength of the tropical cyclone and rugged terrain... Barry as of 5 AM EDT early today already weakened to a remnant surface low/ trough. Despite westerly shear attempting to push Barry's thunderstorm tops into offshore western Gulf of America waters... a wave of thunderstorm cells and associated heavy rainfall was able to progress inland across Tamaulipas... northern Veracruz... and neighboring inland provinces to the west during the overnight hours following Barry's landfall. A new solid area of concentrated thunderstorms has developed in offshore western Gulf waters with the aid of split flow upper divergence between the anticyclonic flow around the upper ridge to the south and upper southwesterlies ahead of the current east Texas upper trough... and this wave of thunderstorms is progressing inland from northern Veracruz and Tamaulipas as of this writing. Therefore periods of heavy rainfall with flash flooding potential remains a concern in this region through the rest of today. This is my final statement on Barry on this blog as it is no longer a tropical cyclone.


AREA OF INTEREST #8... A surface cold front currently positioned across the central United States is being supported by the eastern divergence zone of an upper trough currently positioned over the central US/ Canada border region... the National Hurricane Center since yesterday is monitoring the potential that this surface front may promote tropical development in waters offshore of the southeastern United States or Florida panhandle in approximately 5+ days. As such this surface cold front now marks the eighth area of interest I have tracked on this site this year in regards to possible Atlantic basin tropical development.


While earlier global model runs were more aggressive in showing tropical development either offshore of the southeastern US or Florida panhandle... the solutions between models widely varied. More recently the models have largely backed off in showing development perhaps while depicting a more solid band of upper vorticity becoming separated from the frontal upper trough... creating a more solid area of upper winds non-conducive to tropical development over the offshore waters. My current forecast is the tail end of the surface cold front is downgraded to a surface trough of low pressure offshore of the southeastern United States in approximately 72 hours once air mass contrasts on either side of the front diminish. I currently assess the area of maximum spin (minimum surface pressure) along the trough is most likely offshore of the Carolinas due to split flow upper divergence between southwesterlies ahead of the frontal upper trough and northerlies streaming into the upper vortex now settling into the northwestern Bahamas. As the northwest Bahamas cut-off upper vortex decays due to isolation from high-latitude cold air... this could allow for an increasing gap between the frontal upper trough and cut-off upper vortex where upper anticyclonic outflow could help a surface low pressure with tropical characteristics become established along the surface trough and offshore of the Carolinas. In 4+ days upper-level conditions appear to become hostile towards tropical development in recent model data as follows... warm southerly flow ahead of an upstream surface frontal system moving across central Canada promotes an upstream warm core upper ridge across the central and eastern US... in turn the upstream upper ridge cuts off a band of upper vorticity from the frontal upper trough and sends it overtop the surface trough. Currently forecasting the surface trough on days 4 to 5 to undergo a southwest extension across north Florida and the northeastern corner of the Gulf of America due to the upper divergence at the leading edge of the incoming upper vorticity band (much like we see with the leading edge of a typical mid-latitude upper trough)... as well as split flow upper divergence at the southwest corner of the upper vorticity band between the westerlies ahead of the band and easterlies on the south side of the upstream upper ridge. I have rather low odds of tropical cyclone formation at 96 hours before the potential surface spin max offshore of the Carolinas becomes too elongated for cyclone status due to the elongated nature of the aforementioned upper divergence zone. Then by 120 hours... when the upper vorticity band overtops the surface trough and prevents upper outflow needed for thunderstorms I am forced to drop tropical development odds back to 0%.


The surface trough of interest will become quasi-stationary toward the latter part of the 5-day forecast window while sandwiched between conflicting steering surface ridges... one to the east over the Atlantic and another to the northwest over the eastern US generated by the back convergence zone of the frontal upper trough. Once the eastern US surface ridge continues into the northwest Atlantic and merges with the greater Atlantic surface ridge... the lengthy surface trough should advance back north into the southeastern US from the Florida panhandle to the Carolinas and after day 5. At this time their appears to be a rather low chance of significant weather in association with the surface trough when it moves ashore due to the band of suppressing upper vorticity mentioned in the prior paragraph.

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

IOH 24 Hr Outlook (1200Z Jul 1)... 0% chance of tropical cyclone formation (western Kentucky near 37N-88W)

IOH 48 Hr Outlook (1200Z Jul 2)... 0% chance of tropical cyclone formation (northeastern North Carolina near 36N-77.5W)

IOH 72 Hr Outlook (1200Z Jul 3)... 0% chance of tropical cyclone formation (just offshore of southeastern North Carolina near 34N-77W)

IOH 96 Hr Outlook (1200Z Jul 4)... 5% chance of tropical cyclone formation (offshore of the Carolinas near 33N-77.5W)

IOH 120 Hr Outlook (1200Z Jul 5)... 0% chance of tropical cyclone formation (offshore of the Carolinas near 33N-77.5W)

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


0000Z (Jun 30) CMC Model Run...

**For area of interest #8... no development shown


0000Z (Jun 30) ECMWF Model Run...

**For area of interest #8... no development shown


0600Z (Jun 30) GFS Model Run...

**For area of interest #8... current upper trough over the central US/Canada border reaches the northeastern US and eastern Canada by 87 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... split flow upper divergence between south side of upper trough and south side of upstream central US upper ridge allows tail end of front to evolve into a surface low just offshore of the western Florida panhandle at 96 hours... while quasi-stationary between conflicting Atlantic surface ridge to the east and passing surface ridge to the north (supported by convergent back side of the upper trough) the surface low becomes a possible tropical depression by 120 hours but is exposed to unfavorable northerly shear on the southeast side of central US upper ridge... through 168 hours the central US upper ridge pushes some upper vorticity tied to the upper trough southwest overtop the possible tropical depression with the vorticity dragging the possible depression west-southwest... the possible depression positioned just offshore of southeast Louisiana by 168 hours while weakening to a remnant low due to a lack of divergence below the upper vorticity.


0600Z (Jun 30) NAVGEM Model Run...

**For area of interest #8... no development shown

 
 
 

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