*******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 AUGUST 22 2022 6:05 AM EDT...
As the tropical Atlantic continues its generally calm pace... keeping an eye on a pair of tropical waves of low pressure currently present in the eastern Atlantic/western Africa region:
(1) See area of interest #20 section below for an update on the large tropical wave currently over western Africa
(2) See area of interest #21 section below for an update on the tropical low pressure located west of the Republic of Cabo Verde Islands
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 areas of interest in this blog post are designated #20 and #21 as I designated the other nineteen 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 #20...The large tropical wave of low pressure that continues to make its way westward across western Africa has continued to become less organized. Specifically all of its thunderstorm activity has collapsed... leaving behind a broad area of cloudiness on the wave's west side that is currently nearing the west coast of Africa. Despite these observations... their remains long range computer model support showing this wave developing once it later moves into and across the eastern and central tropical Atlantic. Also potentially favoring this tropical wave is the widespread tropical upper ridge with favorable low wind shear and upper outflow that has been dominating the region... which is expected to persist. Also noting that the additional disturbance to the west... tagged as area of interest #21 on this blog... is making some effort at moistening out the dry saharan air in the eastern tropical Atlantic. Despite these positive observations and ongoing computer model support... I have not raised odds of tropical cyclone formation for this tropical wave above 10% due to the ongoing disorganization of the tropical wave. There is also no guarantee that this wave will escape ingesting dry Saharan air... this has been a recurring theme in this region of the Atlantic basin this season that has been contributing to the ongoing drought of Atlantic tropical cyclones. Note that while I still have 10% development odds by day 5...I have also lowered short-term odds of development to the ongoing absence of thunderstorm activity currently associated with this wave.
******Infohurricanes.com outlook. Visit hurricanes.gov (hurricanes dot gov) for official outlook***********
IOH 24 Hr Outlook (0000Z Aug 23)...0% chance of tropical cyclone formation (just offshore of the west coast of Africa near 12N-17W)
IOH 48 Hr Outlook (0000Z Aug 24)...0% chance of tropical cyclone formation (south-southeast of the Republic of Cabo Verde Islands near 12.5N-22W)
IOH 72 Hr Outlook (0000Z Aug 25)...5% chance of tropical cyclone formation (eastern tropical Atlantic near 12.8N-27W)
IOH 96 Hr Outlook (0000Z Aug 26)...10% chance of tropical cyclone formation (eastern tropical Atlantic near 13.1N-32W)
IOH 120 Hr Outlook (0000Z Aug 27)...10% chance of tropical cyclone formation (eastern tropical Atlantic near 13.5N-37W)
AREA OF INTEREST #21...The tropical low pressure area that was passing through the Republic of Cabo Verde Islands this past weekend is now located west of the islands. For much of Sunday it appeared the tropical low had given up while it continued to ingest dry Saharan air. However as of this morning thunderstorm activity has developed northwest of and next to the observed center of rotation... and as a result I have not dropped odds of tropical cyclone formation to 0%. Also noting that this tropical low is now located in a break between two patches of dry Saharan air which may explain some of its recovery this morning... one batch to the north that extends to northwestern Africa... and a batch to the west that presents itself as an east-west band of beige tint in true-color visible satellite imagery. However as of this update I have not raised odds of development above 5% either while weighing the following negative factors:
(1) For the next three days... the tropical low will continue west over lukewarm 26 deg C waters that are marginally favorable for development. The tropical low will reach warmer waters by 4+ days
(2) As the tropical low reaches warmer waters... there is some potential for an increase in westerly vertical shear as the current north Atlantic upper trough is expected to deposit cut-off upper vorticity that migrates southward toward the central tropical Atlantic.
(3) Computer model support showing this tropical low developing decreased by late Sunday.
In future updates... will consider raising shorter-term odds of tropical cyclone formation should the current levels of thunderstorm activity persist. However odds of development in the longer-range will likely remain on the low side due to the above-mentioned possiblity of westerly wind shear developing. In the outlook below... small adjustments are made to the forecast track based on the current position of the tropical low. By day 5 a slight northward angle develops in the westward track as this system begins to round the southwest side of the Atlantic surface ridge.
******Infohurricanes.com outlook. Visit hurricanes.gov (hurricanes dot gov) for official outlook***********
IOH 24 Hr Outlook (0000Z Aug 23)...5% chance of tropical cyclone formation (eastern tropical Atlantic near 16N-32.5W)
IOH 48 Hr Outlook (0000Z Aug 24)...5% chance of tropical cyclone formation (eastern tropical Atlantic near 16N-37.5W)
IOH 72 Hr Outlook (0000Z Aug 25)...5% chance of tropical cyclone formation (central tropical Atlantic near 16N-42.5W)
IOH 96 Hr Outlook (0000Z Aug 26)...5% chance of tropical cyclone formation (central tropical Atlantic near 16N-47.5W)
IOH 120 Hr Outlook (0000Z Aug 27)...5% chance of tropical cyclone formation (central tropical Atlantic near 17N-52W)
...COMPUTER MODEL SUMMARY...
Source...Florida State University Experimental Forecast Tropical Cyclone Genesis Potential Fields (http://moe.met.fsu.edu/tcgengifs/)
1200Z (Aug 21) CMC Model Run...
**For area of interest #20...no development shown
**For area of interest #21...no development shown
1200Z (Aug 21) ECMWF Model Run...
**For area of interest #20...tropical wave departs western Africa within next 48 hours... organizes into a tropical low centered just southwest of the Republic of Cabo Verde Islands at 120 hours... tropical low located at 13N-33.5W at 168 hours.
**For area of interest #21...no development shown
1800Z (Aug 21) GFS Model Run...
**For area of interest #20...tropical wave departs western Africa within next 48 hours... by 105 hours organizes into a large tropical low just south of the Republic of Cabo Verde Islands featuirng a southern tight center at 10N-24.5W... tight center swings northwest while revolving around the periphery of the large tropical low and reaches 16N-29W at 138 hours... tight center gradually intensifies into a tropical cyclone and reaches 15N-36W at 168 hours.
**For area of interest #21...no development shown
1800Z (Aug 21) NAVGEM Model Run...
**For area of interest #20...no development shown
**For area of interest #21...tropical low remains defined while continuing westward across the eastern and central tropical Atlantic... arriving to 16N-46W at 168 hours.
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