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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 2024 ATLANTIC HURRICANE SEASON BIRDSEYE VIEW POST #77

Updated: Aug 27

*******Note that forecast 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.*********


...TUESDAY AUGUST 27 2024 10:20 PM EDT...

Surface and upper air charts have now been added to the satellite image associated with this post. The charts were not originally included in this update to allow the update to be released in a timely manner.


The following are recent events this evening across the Atlantic tropics... will have more information on each situation during my next full update on the Atlantic tropics scheduled for tomorrow morning:

(1) In the central Gulf of Mexico... scattered showers and thunderstorms have recently increased in association with the eastern divergence zone of the upper vortex over Texas... however the CIMSS 850 mb vorticity product (https://tropic.ssec.wisc.edu/real-time/windmain.php?&basin=atlantic&sat=wg8&prod=vor&zoom=&time=) shows no low-level low pressure spin has developed so far to declare an area of interest for tropical development.

(2) A large tropical wave of low pressure emerged from the coast of Mauritania on August 19... since then the north side of the tropical wave separated from the rest of the wave as a surface trough of low pressure that has continued west across the mid-latitudes of the Atlantic. Since yesterday the surface trough appeared to evolve into a surface low... and as of this evening the small surface low pressure swirl while located southeast of Bermuda has seen an increase in thunderstorm bursts while interacting with the boosting divergence zone of the upper trough that has recently dived into the northwest Atlantic from eastern Canada. Will make an assessment in my next full update as to whether or not this feature needs to be upgraded to an area of interest for tropical development.

(3) The eastern Atlantic tropical wave... tagged as area of interest #19 in this update... has recently seen an increase in thunderstorms. Should these trends continue... an increase in tropical cyclone formation odds maybe warranted by my next full update.


...MONDAY AUGUST 26 2024 11:55 PM EDT...

Satellite image from 2320Z earlier this evening… the disturbance that is tagged area of interest #18 in this blog post is circled in yellow while the disturbance tagged area of interest #19 is circled in green:

The disturbance that was crossing south Florida on Sunday has dissipated… see area of interest #18 section below for more information. As such the potential for tropical development in the Atlantic basin has switched  eastward away from this area and toward the tropical waters between Africa and the Lesser Antilles where the tropical wave of low pressure now in the eastern tropical Atlantic may develop in the days ahead… see area of interest #19 section below for more information. In addition… satellite imagery suggests another vigorous tropical wave of low pressure which has recently moved into west Africa from central Africa… will watch to see if this wave also becomes an area of interest in future updates as it potentially takes advantage of the expanding tropical upper ridge axis that area of interest #19 is currently forecast to take advantage of.


AREA OF INTEREST #18... The weak tropical disturbance that moved into south Florida on Sunday produced thunderstorms in the region by Sunday evening… however by Monday morning the thunderstorms dissipated and there were no signs of rotation in the remaining clouds over south Florida nor eastern Gulf of Mexico. Therefore the disturbance has dissipated before getting the chance to take advantage of the low shear/outflow environment setting up beneath the core of the current central Gulf of Mexico upper ridge. With the disturbance dissipated… this is my final statement on this area of interest on this blog.


AREA OF INTEREST #19 The surface tropical wave of low pressure that entered the eastern tropical Atlantic from western Africa over the weekend suffered from a combo of ingestion of dry Saharan air and upper outflow suppression from a wave of upper vorticity that descended southward from the mid-latitudes of the eastern Atlantic. However models are beginning to pick up on an increasingly favorable upper wind pattern in the days ahead where a tropical upper ridge (environment of low shear and upper outflow) expands over the surface tropical wave… in the wake of the overhead wave of upper vorticity which is expected to accelerate west and away while pushed by the current mid-latitude central Atlantic upper ridge. Because of the emerging model consensus developing the surface tropical wave… the surface wave has been introduced into the NHC tropical weather outlook as of 8 PM EDT… and is the nineteenth area of interest tracked on this site this year. I agree with the NHC in starting with low peak odds of tropical cyclone formation of 20% to ensure the current model consensus holds and to wait for signs of organization… which the wave currently lacks… before issuing higher odds. Weighting the 20% odds toward the longer term.. with 0% in the shorter term… is also a reflection of the currently disorganized wave which will need time to organize. Noting the track forecast by day 5 has an increased north slant as the surface wave catches up to the wave of upper vorticity to the west… which could allow the upper vorticity to pull the surface system more north… especially if the surface system begins to become a stronger/taller tropical cyclone.

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

IOH 24 Hr Outlook (0000Z Aug 28)... 0% chance of tropical cyclone formation (eastern tropical Atlantic near 11.5N-30W)

IOH 48 Hr Outlook (0000Z Aug 29)… 0% chance of tropical cyclone formation (eastern tropical Atlantic near 11.8N-35W)

IOH 72 Hr Outlook (0000Z Aug 30)… 5% chance of tropical cyclone formation (central tropical Atlantic near 12N-40W)

IOH 96 Hr Outlook (0000Z Aug 31)… 10% chance of tropical cyclone formation (central tropical Atlantic near 13.5N-44W)

IOH 120 Hr Outlook (0000Z Sep 1)… 20% chance of tropical cyclone formation (central tropical Atlantic near 15N-47W)

*****National Hurricane Center (hurricanes.gov) official outlook as of 8 PM 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 26) CMC Model Run...

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

**For area of interest #19… Current east Atlantic tropical wave evolves into a tropical low near 17.5N-55W at 156 hours


1200Z (Aug 26) ECMWF Model Run...

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

**For area of interest #19… Current east Atlantic tropical wave evolves into a tropical low near 13.5N-47.5W at 132 hours… tropical low reaches 15N-56W by 168 hours


1800Z (Aug 26) GFS Model Run...

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

**For area of interest #19… Current east Atlantic tropical wave evolves into a tropical low near 11.5N-36W at 69 hours… tropical cyclone formation suggested near 13.5N-55.5W by 168 hours


1200Z (Aug 26) NAVGEM Model Run...

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

**For area of interest #19… Current east Atlantic tropical wave evolves into a tropical low near 12.5N-40W at 114 hours… subsequently becomes stationary at this location while tugged by large tropical wave approaching from the east

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