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 #79

*******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 20 2022 3:41 AM EDT...

After a long slumber... the Atlantic tropics are waking up with now multiple simultaneous areas of interest for tropical development emerging as follows:

(1) A tropical disturbance in the western Gulf of Mexico has a high chance of becoming a tropical storm later today while en-route to Tamaulipas and southern Texas... see area of interest #19 section below for more information.

(2) A currently large and vigorous tropical wave of low pressure that has spent the last 24 hours moving from interior central Africa to interior western Africa is expected to enter the eastern tropical Atlantic in three to four days. Conditions could be favorable for this tropical wave to develop once it reaches the tropical Atlantic could be favorable... see area of interest #20 section below for more information.

(3) Satellite imagery shows that a small and somewhat organized tropical low pressure area has formed tonight at a location just east-southeast of the Republic of Cabo Verde Islands. Although the small tropical low pressure is currently near widespread dry Saharan air to the north and will be tracking west over only marginally warm waters... computer model support hinting at this feature's development has increased. As of 2 AM EDT the NHC has added this feature to their tropical weather outlook... see area of interest #21 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 areas of interest in this blog post are designated #19 to #21 as I designated the other eighteen 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 #19 (POTENTIAL TROPICAL CYCLONE FOUR)...The tropical disturbance that was previously in the Bay of Campeche has turned increasingly north in its westward track... and is now making its way into the western Gulf of Mexico while slated to close in on Tamaulipas and southern Texas by Saturday night. Although the organized thunderstorm canopy weakened through midnight EDT... in recent hours the intensity of the thunderstorms is returning. Other signs that this disturbance is trying to get its act together is the 850 mb low-level vorticity (spin) trying to line up with the thunderstorm canopy on the CIMSS product... with the vorticity now just southwest of the canopy instead of being well to the south as it was 24 hours ago (http://tropic.ssec.wisc.edu/real-time/windmain.php?basin=atlantic&sat=wg8&prod=vor&zoom=&time=). The National Hurricane Center continues to assess that this disturbance has a high chance of becoming a tropical storm within the next 24 hours as it closes in on Tamaulipas and far southern Texas... and thus continues to be classified as Potential Tropical Cyclone Four in order to continue tropical storm warnings for these land areas.


Regarding the intensity forecast: Going for this disturbance is the overhead upper anticyclonic ridge featuring upper outflow...warm water temperatures... and organized thunderstorm canopy which maintains spiral cloud features and vibrant cirrus outflow clouds. Going against the disturbance is that has yet to develop a fully closed surface spin... and there is still some residual upper vorticity just to the west that is keeping the heaviest thunderstorms leaned toward the east side of the area of low-level vorticity/lowest surface pressures. Weighing both the positive and negative factors... I forecast peak strength to reach moderate tropical storm status (50 mph max sustained winds) instead of a strong tropical storm. As of the 1 AM CDT advisory the NHC has the same idea while projecting a peak strength of 45 mph maximum sustained winds. Note for 48 hours that even though the center of circulation is expected to be over land... I still forecast tropical depression status as the largely north angle in track will keep the center close enough to the Texas/Mexico coast such that offshore thunderstorm bands may still feed this system and keep it from weakening rapidly. At 72 hours the system as a whole should be tucked away further inland... and this is when I project remnant low status.


Regarding the track forecast...the previous one has performed spot on and so no changes are made in this update. The disturbance's current northwest track is expected to bend even more toward the north while the disturbance rounds the south and west sides of the Gulf of Mexico surface ridge... eventually heading toward a surface ridge weakness currently being induced by the central US frontal low pressure. By 72 hours the inland track of this system may lean more westward as the central US frontal system departs eastward... with a surface ridge building in its wake and to the north of this system.


Regarding impacts to land areas...interests in Tamaulipas and southern Texas to the south of Matagorda Bay should continue preparing for tropical storm conditions likely to arrive late Saturday afternoon or evening...as such preparations should be completed by the early afternoon at the latest. Expect heavy rainfall with flash flooding potential on both inland and coastal areas... with gusty winds and ocean swells along the coast. Although chances for tropical storm winds and gusts are lower on the southern Texas coast with the center expected to track inland... as noted in the above intensity forecast discussion this system could be initially slow to weaken post-landfall due to the center still being near the coast. Tropical storm winds and gusts on the southern Texas coast would also be more likely should this system strengthen a little more than currently forecast.

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

0 Hr Position (0000Z Aug 20)...Tropical low centered in the southwestern Gulf of Mexico at 21.8N-95.2W

IOH 24 Hr Forecast (0000Z Aug 21)...50 mph maximum sustained wind tropical storm making landfall on the north coast of Tamaulipas at 24.5N-97.6W

IOH 48 Hr Forecast (0000Z Aug 22)...30 mph maximum sustained wind tropical depression centered inland just north of the Texas/Mexico border at 26.5N-98.2W

IOH 72 Hr Forecast (0000Z Aug 23)...Remnant low centered inland over southern Texas at 30N-99.8W


AREA OF INTEREST #20...Satellite image of western Africa and the eastern Atlantic Ocean taken at 0300Z showing a large tropical wave of low pressure over interior western Africa being monitored for possible future development in the days ahead (area of interest #20). Also captured on the left side of the image is another new tropical low pressure area near the Republic of Cabo Verde Islands (area of interest #21):

A large and vigorous tropical wave of low pressure has been markedly well-defined in satellite pictures while sliding from interior central to western Africa in the last 24 hours. The wave features an ongoing large mass of thunderstorms and broad area of rotation. When the wave enters the eastern tropical Atlantic in three to four days... the widespread tropical upper ridge with favorable low wind shear and upper outflow that has been dominating the region is expected to persist. Therefore whether or not this wave develops hinges upon how much dry saharan air it ingests when it later enters the tropical Atlantic. Given the ongoing widespread area of thunderstorms tied to this wave and increasing computer model support at least showing this wave becoming a broad tropical low pressure spin... their appears to be a chance that this wave will repel the dry saharan air. As a result I have now tagged this tropical wave as an area of interest on this blog... now marking the twentieth Atlantic tropical area of interest I have tracked on this site this year. However my peak 5-day odds of tropical cyclone formation are only 10% at this time until we see how this wave negotiates the dry saharan air in reality. Note that this tropical wave could bring gusty winds and heavy rainfall to the Republic of Cabo Verde Islands late Tuesday through early Wednesday.

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

IOH 24 Hr Outlook (0000Z Aug 21)...0% chance of tropical cyclone formation (western Africa near 12N-7W)

IOH 48 Hr Outlook (0000Z Aug 22)...0% chance of tropical cyclone formation (western Africa near 12N-12W)

IOH 72 Hr Outlook (0000Z Aug 23)...0% chance of tropical cyclone formation (just offshore of the west coast of Africa near 12N-17W)

IOH 96 Hr Outlook (0000Z Aug 24)...5% chance of tropical cyclone formation (south-southeast of the Republic of Cabo Verde Islands near 12.5N-22W)

IOH 120 Hr Outlook (0000Z Aug 25)...10% chance of tropical cyclone formation (eastern tropical Atlantic near 12.8N-27W)


AREA OF INTEREST #21...To the west of area of interest #20...a pair of tropical waves of low pressure are in progress... a large/broad one in the eastern tropical Atlnatic whose axis is passing 30W longitude...and another in the vicinity of the west coast of Africa. In addition and over the last few short hours... satellite pictures have shown a small area of curved thunderstorm bands developing just east-southeast of the Republic of Cabo Verde Islands in the vicinity of 14N-21W. This suggests a tropical low pressure has formed in between the two aforementioned tropical waves. One could argue that this tropical low formed on the northeast side of the tropical wave at 30W... or could argue that the tropical low formed on the northwest side of the wave currently on the west coast of Africa. As of 2 AM EDT...the NHC has declared the wave on the west coast of Africa as a new area of interest. However I expect the new tropical low near the Republic of Cabo Verde Islands to become the focal point of the NHC's new area of interest... essentially merging with that wave as it leaves the west coast of Africa later today.


Based on recent model runs which have suggested that this tropical low could develop... expecting the wave at 30W to push the track of the tropical low on an initial northwest track... followed by a westward deflection of the track once the tropical low bumps into and gets pushed by the widespread Atlantic surface ridge. Regarding the potential for tropical cyclone formation... I have currently set development odds at a low 10% due to the tropical low's close proximity to widespread dry saharan air to the north...and also lukewarm 26 deg C waters along the forecast track which is only just enough for tropical cyclone formation. This is below the NHC's 20% odds as of this writing. Note that this tropical low could bring periods of heavy rainfall and gusty winds to the Republic of Cabo Verde Islands in the next 24 hours.

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

IOH 24 Hr Outlook (0000Z Aug 21)...10% chance of tropical cyclone formation (vicinity of Sao Tiago and Maio near 15N-23W)

IOH 48 Hr Outlook (0000Z Aug 22)...10% chance of tropical cyclone formation (just west of the Republic of Cabo Verde Islands near 16.2N-26W)

IOH 72 Hr Outlook (0000Z Aug 23)...10% chance of tropical cyclone formation (eastern tropical Atlantic near 17.2N-30.5W)

IOH 96 Hr Outlook (0000Z Aug 24)...10% chance of tropical cyclone formation (eastern tropical Atlantic near 17.5N-35.5W)

IOH 120 Hr Outlook (0000Z Aug 25)...10% chance of tropical cyclone formation (central tropical Atlantic near 17.5N-40.5W)


...COMPUTER MODEL SUMMARY...

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


1200Z (Aug 19) CMC Model Run...

**For area of interest #19...no development shown

**For area of interest #20...large tropical wave currently over western Africa emerges into the eastern tropical Atlantic at 102 hours... tropical wave organizes into a large broad tropical low centered near 12.5N-28W at 150 hours... tropical low organizes into large tropical depression centered near 14N-31W at 168 hours.

**For area of interest #21...no development shown


1200Z (Aug 19) ECMWF Model Run...

**For area of interest #19...tropical low becomes only briefly defined just offshore of the Veracruz/Tamaulipas border at 24 hours

**For area of interest #20...large tropical wave currently over western Africa emerges into the eastern tropical Atlantic at 96 hours... tropical wave organizes into a large broad tropical low centered near 13.5N-21.5W at 144 hours... center of broad tropical low located just southwest of the Republic of Cabo Verde Islands at 168 hours.

**For area of interest #21...tropical low becomes tropical depression near 18N-32.5W at 72 hours... tropical depression becomes a compact weak tropical storm which arrives to 20.2N-42.5W at 120 hours


1800Z (Aug 19) GFS Model Run...

**For area of interest #19...no development shown

**For area of interest #20...no development shown

**For area of interest #21...tropical low becomes better defined while moving into the Republic of Cabo Verde Islands at 36 hours...through 63 hours the current eastern Atlantic tropical wave swings the tropical low northwestward away from the islands after which time the Atlantic surface ridge pushes the tropical low more westward in track... tropical low reaches 18N-40W at 120 hours.

**Currently calm broad tropical wave currently passing through the Lesser Antilles becomes better defined over western Cuba at 120 hours while upper vortex currently north of the Caribbean Islands moves west-southwest to a position over the wave... as upper vortex dissipates while remaining cut-off from high-latitude cold air the wave organizes into a tropical low just north of western Cuba through 168 hours.


1800Z (Aug 19) NAVGEM Model Run...

**For area of interest #19...tropical low becomes only briefly defined just offshore of the Veracruz/Tamaulipas border at 18 hours

*For area of interest #20...large tropical wave currently over western Africa emerges into the eastern tropical Atlantic at 96 hours... the wave briefly organizes into a broad tropical low passing over the Republic of Cabo Verde Islands at 126 hours... at 168 hours the large tropical wave begins to split into a pair of low pressure spins (one near 15N-35W and a second near 12.5N-27.5W)

**For area of interest #21...tropical low becomes better defined while moving into the Republic of Cabo Verde Islands at 24 hours...through 48 hours the current eastern Atlantic tropical wave swings the tropical low north-northwestward into the waters just northeast of the islands... shortly thereafter the tropical low dissipates

**Current eastern Atlantic tropical wave develops into a tropical low near 15N-45W at 132 hours

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