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 2022 ATLANTIC HURRICANE SEASON BIRDSEYE VIEW POST #66

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


...SATURDAY AUGUST 6 2022 4:02 AM EDT...

The outflow of a tropical upper ridge over the southern Caribbean sea has been supporting rounds of showers and thunderstorms over the last few days. However a tropical disturbance has not formed below the upper ridge... and the potential for a disturbance to develop here is dwindling as the tropical upper ridge is expected to soon shift west into the Central American landmass. The westward shift of the upper ridge is anticipated due to the west shift of upper vorticity currently at 55W longitude into the Caribbean... as that upper vorticity gets pushed around the current mid-latitude western Atlantic upper ridge.


Elsewhere... the usually reliable GFS and ECMWF computer models over the last 24 hours have begun to suggest that a tropical wave of low pressure currently over western Africa could develop as it moves into the eastern tropical Atlantic in the days ahead. The National Hurricane Center has added this tropical wave to their 5-day tropical weather outlook as of 2 AM EDT. See area of interest #14 section below for more information.


New to this site this year... I will be sequentially numbering up areas of interest for possible Atlantic tropical development. In this scheme... will reset back to #1 at the start of next year (January 2023). The current area of interest in this blog post is designated #14 as I designated the other thirteen of this year in previous birdseye view posts on the home page. This scheme is to reduce confusion as Atlantic tropical activity increases during the peak of the hurricane season... when multiple simultaneous areas of interest begin and end which previously required shuffling around the area of interest numbers from update to update.


AREA OF INTEREST #14...Satellite image of the western Africa tropical wave of interest taken at 0300Z:

Based on the above satellite image... as of 0300Z their appears to be two closely spaced tropical waves of low pressure in the far eastern Atlantic/western Africa region. The western of the two appears as a faint swirl in the low clouds at a location just east of the Republic of Cabo Verde Islands while the eastern of the two waves appears as a faint swirl in the low clouds over southwestern Mauritania near 14N-10W. Both waves feature limited thunderstorm activity scattered in nature at present due to the dry saharan air layer lurking just to the north. Within the last 24 hours...recent runs of the GFS and ECMWF have quickly latched onto the eastern of the two waves as an area of interest of tropical development... and the National Hurricane Center (NHC) has added this wave to their tropical weather outlook product as of 2 AM EDT. This now marks the fourteenth Atlantic tropical area of interest I have tracked on this blog this year.


Within the next five days... the tropical wave of interest is expected to continue generally west into and across the eastern tropical Atlantic at a typical 5W longitude per day pace while steered by the vast Atlantic surface ridge. Upper-level winds are favorable for development as the wave will be under an equally vast tropical upper ridge with low shear and upper outflow. However going against the tropical wave are the following two factors:

(1) The tropical Atlantic remains under the suppressing sinking motion phase of the Madden Julian Oscillation (MJO) (https://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/mjo.shtml).

(2) The tropical wave is currently at a further north location... at 14N latitude. This may expose the wave to the dry saharan air layer lurking to the north...and more mild east-central Atlantic water temperatures once it moves offshore of western Africa.

Regarding the second unfavorable factor... the GFS does suggests the tropical wave will establish a tightening center of spin in the more favorable thermodynamic conditions to the south (warmer waters... less dry saharan air). Interestingly... the ECMWF is gung-ho about developing this tropical wave while maintaining a further north center of spin around 14N latitude. My track forecast below splits the difference between the two models... only suggesting a slight southward reformation of the center of spin over the next five days. Given the models have only recently shown this wave developing and the above two unfavorable factors... waiting to see if these model solutions persist before raising odds of tropical cyclone formation. However given the currently strong development signal in the usually reliable GFS and ECMWF models by days 4 and 5... I think odds above 10% are warranted by day 5. Therefore I am in agreement with the NHC's 20% odds of development by day 5.

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

IOH 24 Hr Outlook (0600Z Aug 7)... 0% chance of tropical cyclone formation (western Africa near 14N-15W)

IOH 48 Hr Outlook (0600Z Aug 8)... 0% chance of tropical cyclone formation (eastern tropical Atlantic near 14N-20W)

IOH 72 Hr Outlook (0600Z Aug 9)...5% chance of tropical cyclone formation (just southwest of the Republic of Cabo Verde Islands near 13.5N-25W)

IOH 96 Hr Outlook (0600Z Aug 10)...10% chance of tropical cyclone formation (eastern tropical Atlantic near 13.5N-30W)

IOH 120 Hr Outlook (0600Z Aug 11)...20% chance of tropical cyclone formation (eastern tropical Atlantic near 13.5N-35W)


...COMPUTER MODEL SUMMARY...

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


1200Z (Aug 5) CMC Model Run...

**For area of interest #14...tropical wave of interest emerges from west coast of Africa at 66 hours...briefly establishes a low pressure center that passes just south of the Republic of Cabo Verde Islands from 78 to 90 hours... after losing its low pressure center the wave passes 39W longitude at 132 hours.

**Vigorous tropical wave emerges from west coast of Africa at 144 hours while featuring a low pressure center just offshore of Mauritania... low pressure center located just east of the Republic of Cabo Verde Islands at 168 hours.


1200Z (Aug 5) ECMWF Model Run...

**For area of interest #14...tropical wave of interest emerges from west coast of Africa just before 48 hours... rapid tropical cyclone formation suggested near 14N-33.5W at 96 hours...tropical cyclone located at 15N-37.5W at 120 hours.


0000Z (Aug 6) GFS Model Run...

**For area of interest #14...tropical wave of interest emerges from west coast of Africa and crosses 20W longitude just offshore by 69 hours... establishes a tropical low near 11.2N-25W at 75 hours... tropical cyclone formation suggested at 93 hours near 11.2N-29.5W... located near 14N-35W at 120 hours as a compact potential hurricane.


1800Z (Aug 5) NAVGEM Model Run...

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

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