top of page
Home: Text

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 

Home: Text
Home: Blog2
Search
Writer's pictureNCHurricane2009

MY 2024 ATLANTIC HURRICANE SEASON BIRDSEYE VIEW POST #65

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


...UPDATE...MONDAY AUGUST 12 2024 3:45 PM EDT...

The organizing tropical wave of low pressure... tagged as area of interest #17 in this blog post and Potential Tropical Cyclone Five by the National Hurricane Center... appears to be consolidating a better-defined center to the northwest of previous forecasts. The more west position means tropical storm conditions will arrive tomorrow instead of Wednesday for the northeastern Caribbean Islands... and tropical storm force winds and heavy rainfall will now reach as far west as Puerto Rico in addition to coastal surf. The northern Lesser Antilles... Virgin Islands... and Puerto Rico are under a tropical storm warning as of this writing... and should rush preparations for tropical storm conditions to completion by tomorrow morning.


...MONDAY AUGUST 12 2024 12:50 AM EDT...

See areas of interest #16 section below for a final update on the surface trough of low pressure now in the southwestern Gulf of Mexico whose potential for development has ended as upper winds are switching to a less conducive configuration. See area of interest #17 section below for an update on the large and continuously organizing tropical wave of low pressure which has recently entered the central tropical Atlantic... slated to head for the northeastern Caribbean Islands by Wednesday most likely as a tropical storm and then possibly towards Bermuda by Friday as a potentially strong hurricane.


Further east... a large tropical wave of low pressure which emerged from the west coast of Africa on Saturday is currently in the eastern tropical Atlantic with its maxium area of spin over the Republic of Cabo Verde Islands... however thunderstorms are limited to an area well south of the spin as the wave has ingested dry Saharan air and this wave is not forecas to develop. Satellite imagery over Africa (https://www.goes.noaa.gov/FULLDISK/GMIR.JPG) shows another similarly large wave is over western Africa... however none of the models develop it when it emerges into the eastern tropical Atlantic in 3+ days perhaps while also forecasting this wave to ingest dry Saharan air.


AREA OF INTEREST #16... The surface trough of low pressure currently in the southwestern Gulf of Mexico is expected to continue northwest toward the Texas/Mexico border region in the next 24 hours while rounding the southwest side of the current central North America surface ridge. During this time the current suppressing northern Gulf of Mexico upper vorticity is expected to roll southwest into this disturbance while pushed by the ongoing southern US upper ridge... therefore time has ran out for this disturbance to become a tropical cyclone and this will be my final statement on this area of interest on this blog. Regarding impact to land areas... the most recent satellite frames show the band of thunderstorms that was in progress on the northwest side of this system for much of Sunday has decayed... therefore the potential for rainfall across northern Veracruz and Tamaulipas may already be ending.

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

IOH 24 Hr Outlook (1800Z Aug 12)... 0% chance of tropical cyclone formation (western Gulf of Mexico just southeast of the Texas/Mexico near 25N-97W)

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

Not in the official outlook


AREA OF INTEREST #17 (POTENTIAL TROPICAL CYCLONE FIVE)... The large tropical wave of low pressure that was previously in the eastern tropical Atlantic is now in the central tropical Atlantic. After previously having a northwest-southeast tilted envelope over the last couple of days… today the wave appears to have consolidated into a more circular but still large tropical low with the prior southeastern circulation featuring curved thunderstorm bands merging with the dry northwestern circulation that was wrapped in Saharan dust. Tropical development has slowed for now as the remainder thunderstorm bands have become broken while the system has ingested dry Saharan air… however the system is still well-organized… has high computer model support showing development… and appears to have a good future ahead of it with a favorable upper wind outlook and warm sea-surface temperatures along its forecast track. Therefore tropical cyclone formation within the next five days appears imminent… and I have transitioned to showing a specific track and intensity forecast for the expected tropical cyclone instead of showing probabilities of cyclone formation. The NHC as of 5 PM EDT has begun to issue advisories on this system under the title of potential tropical cyclone five (the fifth system of the 2024 Atlantic Hurricane Season the NHC has issued advisories on)… in order to issue tropical storm watches/warnings ahead of time for the northeastern Caribbean islands.


Forecast track in the next 24 hours has a northward tilt in the west angle as satellite animation was still suggesting the prior southeastern circulation… mentioned in the prior paragraph… was gaining a more north position while finishing its merger with the northwestern circulation. Through 96 hours the west-northwest track continues toward a western Atlantic surface ridge weakness to be induced by the divergence zone of the current eastern Canada upper vortex… when the vortex later shifts into the Atlantic as a trough whose eastern divergence zone lowers surface pressures and opens the weakness. By 120 hours a complete north-northeast turn into the weakness and upper trough is shown. Regarding the upper-level wind outlook… much of the cut-off upper vorticity to the northwest has revolved away from this system while pushed by the current North Atlantic upper ridge. Relatively lower pressures on the south side of the upper ridge will result in an inverted upper trough to the east of this area of interest… with this area of interest staying under a favorable upper anticyclone (low shear and supporting outflow) in between the upper vorticity to the northwest and inverted upper trough through 96 hours. During this time this system does not walk into increased shear associated with the northwestern upper vorticity as the cool-core vorticity also ends up dissipating by 96 hours from prolonged isolation from high-latitude cold air. By 120 hours this system curves north-northeast into the southwesterly flow ahead of the aforementioned upper trough with two scenarios possible… (1) the upper southwesterly flow enhances the northern outflow of this system which would also help with its strengthening… or (2) the upper trough ends up being close enough to this system to begin shearing it. My intensity forecast is similar to the NHC… calling for gradual development at first due to the dry Saharan air… then more rapid intensification after 48 hours as this system reaches the western part of the Atlantic basin where dry Saharan air concentrations tend to be lower. I currently agree with the NHC in not showing intensity higher than a top-end category 2 by day 5… especially since it’s uncertain if shear will be present by day 5 as noted above. However should this system develop a well-defined center and strong thunderstorm core earlier… will have to bump up the intensity forecast in future updates and possibly call for a major hurricane peak (category 3+).


Interests in the northern Lesser Antilles and Virgin Islands should now be preparing for tropical storm force winds… heavy rain… and coastal surf to arrive by Wednesday… the potential for severe tropical cyclone impacts (such as those from a strong hurricane) have become less likely here as development paused today from dry Saharan air as noted above. Interests in Puerto Rico should also continue monitoring the progress of this system as the current forecast allows for coastal surf by Wednesday… and should a west shift occur in the forecast track heavy rains and storm force winds will become more likely. Interests in Bermuda should also watch this system as by day 5 (Friday) this system could be angling for the island as a potentially strong hurricane.

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

0 Hr Position (1800Z Aug 11)... Tropical low centered in the central tropical Atlantic at 12.5N-47.5W

IOH 24 Hr Forecast (1800Z Aug 12)... Tropical low centered east of the Lesser Antilles at 14.5N-53W

IOH 48 Hr Forecast (1800Z Aug 13)... 45 mph maximum sustained wind tropical storm centered just east of the northern Lesser Antilles at 16.5N-59W

IOH 72 Hr Forecast (1800Z Aug 14)... 65 mph maximum sustained wind tropical storm centered just southwest of Anguilla at 17.8N-63.5W

IOH 96 Hr Forecast (1800Z Aug 15)... 95 mph maximum sustained wind hurricane centered north-northwest of Puerto Rico at 22.5N-66.2W

IOH 120 Hr Forecast (1800Z Aug 16)... 110 mph maximum sustained wind hurricane centered south-southwest of Bermuda at 26N-66W

*****National Hurricane Center (hurricanes.gov) official forecast as of 5 PM EDT**************************

Landfall (1800Z Aug 13)... 50 mph maximum sustained wind tropical storm centered over the northern Lesser Antilles at 17N-62.2W

Landfall (0600Z Aug 14)... 65 mph maximum sustained wind tropical storm centered over the Virgin Islands at 18.3N-64.4W

5-Day Position (1800Z Aug 16)... 110 mph maximum sustained wind hurricane centered south-southwest of Bermuda at 27.7N-66.3W

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

Formation chance through 48 hours... 80%

Formation chance through 7 days... 90%


...COMPUTER MODEL SUMMARY...

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


0000Z (Aug 11) CMC Model Run...

**For area of interest #16... no development shown

**For area of interest #17... tropical cyclone formation suggested near 17N-55.5W at 48 hours with tropical cyclone passing just north of the northern Lesser Antilles at 72 hours... as large and potentially intense tropical cyclone moves into the waters southeast of Bermuda through 168 hours

**Tropical wave which recently emerged from western Africa passes over the Republic of Cabo Verde Islands as a broad tropical low at 18 hours... opens back to a wave shortly thereafter with no redevelopment shown in the long-range


0000Z (Aug 11) ECMWF Model Run...

**For area of interest #16... no development shown

**For area of interest #17... moves into the northern Lesser Antilles as a broad tropical low by 60 hours with tropical cyclone formation suggested just north of Puerto Rico through 84 hours as this system turns more northwest in track... strengthening tropical cyclone passes just northeast of the southeastern Bahamas by 102 hours... then as a larger and intense tropical cyclone moves north-northeast toward Bermuda through 168 hours

**Tropical wave which recently emerged from western Africa passes over the Republic of Cabo Verde Islands as a broad tropical low at 18 hours... opens back to a wave shortly thereafter with no redevelopment shown in the long-range

**Additional vigorous tropical wave of low pressure emerges from western Africa at 96 hours and passes over the Republic of Cabo Verde Islands as a broad tropical low at 156 hours


1200Z (Aug 11) GFS Model Run...

**For area of interest #16... no development shown

**For area of interest #17... tropical cyclone formation suggested just east of the northern Lesser Antilles at 45 hours and moves into the northern Lesser Antilles through 63 hours... as a high-end tropical storm its center passes over the northern Virgin Islands at 75 hours and becomes a hurricane just north of Puerto Rico at 84 hours... as a larger and potentially intense hurricane its center passes just southeast of Bermuda at 150 hours... large hurricane positioned midway between Bermuda and Nova Scotia by 168 hours

**Tropical wave which recently emerged from western Africa passes over the Republic of Cabo Verde Islands as a broad tropical low at 9 hours... opens back to a wave shortly thereafter with no redevelopment shown in the long-range

**Additional vigorous tropical wave of low pressure emerges from western Africa at 102 hours and slowly passes just south of the Republic of Cabo Verde Islands from 135 to 165 hours as a broad tropical low


0600Z (Aug 11) NAVGEM Model Run...

**For area of interest #16... no development shown

**For area of interest #17... tropical cyclone formation suggested just east of the northern Lesser Antilles at 48 hours and as a strengthening tropical storm passes just south of the Virgin Islands and Puerto Rico through 72 hours... as a strong tropical storm that curves increasingly north in track its center moves across the eastern Dominican Republic through 90 hours... continues northwest into the southeastern Bahamas through 114 hours while strengthening into a hurricane... hurricane curves north-northwest into the waters north of the Bahamas while strengthening further and reaches 27.5N-74.5W at 168 hours.

**Tropical wave which recently emerged from western Africa passes over the Republic of Cabo Verde Islands as a broad tropical low at 18 hours... opens back to a wave shortly thereafter with no redevelopment shown in the long-range

8 views0 comments

Comments


bottom of page