BIRDSEYE VIEW POSTS

Since 2012 on the Weather Underground (www.wunderground.com) 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 via Disqus on Weather Underground at www.wunderground.com/cat6. You can see my Disqus feed at this link for my latest comments. Feel free to reply to me with your disqus account or e-mail at IOHurricanes@outlook.com 

 
 
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MY 2020 ATLANTIC HURRICANE SEASON BIRDSEYE VIEW POST #18

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


...SUNDAY MAY 31 2020 7:30 PM EDT...

As the official start of the 2020 Atlantic Hurricane Season is tomorrow...will now be doing daily birdseye view posts on the Atlantic tropics till the end of the Atlantic Hurricane Season on November 30...with interruptions to daily updates only occurring from personal vacations...etc. See area of interest section below for all areas of potential tropical development in the Atlantic basin over the next few days.


AREA OF INTEREST #1...In the next 24 hours...the western Atlantic surface low pressure and its parent upper vortex located east of Bermuda will become absorbed by the much larger upper trough and surface cold front approaching from eastern North America. This is my final statement on this feature as subtropiacal cyclone formation here will no longer be possible.

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

IOH 24 Hr Outlook (1200Z Jun 1)...0% chance of subtropical cyclone formation (western Atlantic near 35N-57.5W)


AREA OF INTEREST #2...In the last 24 hours...tropical depression 2-E in the eastern Pacific strengthened into Tropical Storm Amanda...then Amanda made landfall in Guatemala while drawn northward into the surface pressure falls induced by the sprawling upper ridge/outflow over Central America. This upper ridge has only recently been able to expand northward from the eastern Pacific into Central America as the upper vortex that is currently over northern Mexico recently shifted westward and out of the way. Surface pressure falls to the north of Amanda have also been triggered by the upper divergence zone on the east side of the northern Mexico upper vortex...and this divergence zone is also repsonsible for the widespread thunderstorms that have been ongoing in the western Gulf of Mexico. Due to the activity in the western Gulf and the latest suite of computer model runs...have shifted the focus for Atlantic side tropical cyclone potential westward toward the Bay of Campeche/western Gulf of Mexico. The consensus among the NAVGEM...Euro (ECMWF)...and GFS models suggests that in the short term (by 48 hours) either the remnant low of Amanda will emerge into the Bay of Campeche and redevelop as an Atlantic tropical cyclone...or that Amanda will lose its identity within the larger field of surface pressure falls and that a second tight spin will occur in the Bay of Campeche. Because of the above-mentioned strong model agreement...I have greater than 50% odds of tropical cyclone formation in the Bay of Campeche in 48 to 72 hours. The model agreement also shows that whatever develops in the Bay of Campeche slides westward and southwestward into southeastern Mexico in between 48 to 72 hours...likely the steering influence of the surface ridge currently over eastern North America and the remainder of the broad surface low pressure field which would be located to the southeast. With this forecast track philosophy...I drop the odds of development by 96+ hours due to increased land interaction with southeastern Mexico as well as less favorable upper winds as the northern Mexico upper vortex shifts back east into the Gulf of Mexico...due to the eventual eastward shift of the adjacent western North America upper ridge. At 120+ hours...all long range model solutions at this time suggest that the upper vortex will slide back west into Mexico yet again as the western North America upper ridge builds a fully closed anticyclone further north that would push the upper vortex back west...with whatever is left of the broad surface low pressure area shifting east...northeastward...then northward across the Gulf of Mexico while transitioning into a system supported by the eastern divergence of the upper vortex. This could mean another round of potential tropical cyclone activity in the heart of the Gulf of Mexico in the long range.

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

IOH 24 Hr Outlook (1200Z Jun 1)...0% chance of tropical cyclone formation (inland northwest Guatemala/Mexico border near 17.5N-91W)

IOH 48 Hr Outlook (1200Z Jun 2)...60% chance of tropical cyclone formation (eastern Bay of Campeche just offshore of Mexico near 19N-92W)

IOH 72 Hr Outlook (1200Z Jun 3)...60% chance of tropical cyclone formation (central Bay of Campeche just offshore of Mexico near 18.5N-94W)

IOH 96 Hr Outlook (1800Z Jun 4)...30% chance of tropical cyclone formation (just inland of Mexico's Bay of Campeche coast near 18N-95W)

IOH 120 Hr Outlook (1800Z Jun 5)...10% chance of tropical cyclone formation (along Mexico's Bay of Campeche coast near 18N-94W)


AREA OF INTEREST #3...A new surface frontal low pressure has developed in the northeastern Atlantic to the east of the Azores due to the support of a shortwave upper trough. This shortwave is part of a much larger scale longwave upper trough stretched north-to-south across the northeast Atlantic due to the strength of the deep-layered ridge currently in the north Atlantic. Model runs have varied on how to evolve the streteched northeast Atlatnic upper trough...which has implications on whether or not the aformentioned surface frotnal low pressure would consolidate or be elongated. But this morning the CMC...NAVGEM...Euro...and GFS have come into remarkable agreement that the aforementioned shortwave upper trough and southern part of the elongated northeast Atlantic longwave trough will cut-off into a circular upper vortex to the east of the Azores...in response to the north Atlantic deep-layered ridge amplifying further due to warm air adveciton ahead of what is expected to be a strong northwest Atlantic frontal cyclone to develop along the cold front currently advancing into the northwest Atlantic. The circular cut-off upper vortex will result in a circular consolidated surface frontal low pressure area that initially strengthens in the eastern divergence zone of the upper vortex...then later whirling westward toward the center of the upper vortex. The surface frotnal low will be over water temps in the 18 to 20 deg C range during teh forecast period...but because the forecast cut-off upper vortex is expected to be rather cold...measuring 1190 dekameters in height at 200 mb...I think there is potential for thundestorm activity and acquisition of subtropical characteristics with the surface frontal low. Forecast track in the outlook below is based on the GFS model presentation of the uppre vortex...first placing the surface frontal low on the east side of the upper vortex where the upper divergence to support the early phase of the frontal low will be located...then having it whirl around the north side of the upper vortex thru 72 hours as the upper vortex itself drifts southeastward. During this time the frotnal low will make its closest pass to the eastern Azores just before 72 hours...maybe even directly passing over the eastern Azores as some of the model solutions showed. At 96+ hours...the forecast track of the surface frontal low is to have it continue drifting southeastward with the upper vortex...with the southeast drift of the upper vortex caused by the northern remaining piece of the northeastern Atlantic upper trough diving southeastward around the north Atlantic upper ridge and finally catching the upper vortex. I have 20% odds of development at 48 hours due to cool waters in the upper teens of deg C...and 30% odds of development after that time due to water temps slightly warmer at 20 deg C. But my overall odds of development are on the low side due to the general rarity of any kind of tropcial development at these water temps.

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

IOH 24 Hr Outlook (1200Z Jun 1)...0% chance of subtropical cyclone formation (east of the Azores near 36N-19W)

IOH 48 Hr Outlook (1200Z Jun 2)...20% chance of subtropical cyclone formation (just east of the Azores near 37N-21W)

IOH 72 Hr Outlook (1200Z Jun 3)...30% chance of subtropical cyclone formation (just southeast of the Azores near 35N-23.5W)

IOH 96 Hr Outlook (1800Z Jun 4)...30% chance of subtropical cyclone formation (southeast of the Azores near 33N-21W)

IOH 120 Hr Outlook (1800Z Jun 5)...30% chance of subtropical cyclone formation (west of the Canary Islands near 32.5N-20W)


...COMPUTER MODEL SUMMARY...

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


0000Z CMC Model Run...Area of interest #1 absorbed by incoming frontal low pressure system from eastern North America in next 24 hours...For area of interest #2...after moving eastern Pacific Tropical Storm Amanda northward into Guatemala...has it dissipate within broader surface low pressure over southeastern Mexico and surrounding region. Suggests broad surface low pressure consolidates on west coast of Yucatan peninsula as an Atlantic-side tropical cyclone in 60 to 90 hours...with tropical cyclone intensifying will shifting northward into the Gulf of Mexico in the long range. For area of interest #3...shows frontal low pressure intensified into frontal cyclone east of the Azores in 48 to 66 hours...then has frontal cyclone drift eastward and lose its identity just north of the Canary Islands at 102 hours.


0000Z ECMWF Model Run...Area of interest #1 absorbed by incoming frontal low pressure system from eastern North America just after 24 hours...For area of interest #2...after moving eastern Pacific Tropical Storm Amanda northward into Guatemala...has it dissipate within broader surface low pressure over southeastern Mexico and surrounding region. At 48 hours...suggets consolidation of broad surface low over Bay of Campeche perhaps as a possible Atlantic-side tropical cyclone...with this feature orbiting southwestward around the remainder of the broad low pressure area into southeastern Mexico by 96 hours. In longer range...suggests remainder of broad low pressure area lifting northward across western Gulf of Mexico...but not explicity showing another Atlantic-side tropical cyclone forming again in this region. For area of interest #3...shows frontal low pressure intensified into frontal cyclone east of the Azores in 48 hours...cycloncially looping southwest into eastern Azores by 72 hours...then has frontal cyclone drift eastward and lose its identity just north of the Canary Islands at 120 hours.

1200Z GFS Model Run...Area of interest #1 absorbed by incoming frontal low pressure system from eastern North America in next 24 hours...For Area of Interest #2 eastern Paicific Tropical Storm Amanda not shown in the initialization...instead a broad surface low pressure is initially shown over southeastern Mexico and surrounding region. Suggets consolidation of broad surface low over Bay of Campeche perhaps as a possible Atlantic-side tropical cyclone in 42 hours...with this feature orbiting southwestward around the remainder of the broad low pressure area into southeastern Mexico by 72 hours. In longer range...suggests broad low pressure area eventually lifts northward into the western Gulf of Mexico while consolidating into another Atlantic-side tropical cyclone. For area of interest #3...shows frontal low pressure intensified into frontal cyclone east of the Azores in 36 hours...cycloncially looping southwest into eastern Azores by 60 hours...then has frontal cyclone drift southeastward as it gradually weakens...losing its identity over the Canary Islands at 132 hours.


0600Z NAVGEM Model Run...Area of interest #1 absorbed by incoming frontal low pressure system from eastern North America in next 24 hours...For area of interest #2...after moving eastern Pacific Tropical Storm Amanda northward into Guatemala...has it dissipate within broader surface low pressure over southeastern Mexico and surrounding region. At 42 hours...suggets consolidation of broad surface low over Bay of Campeche Mexico coast as a possible Atlantic-side tropical cyclone...with this feature drifting westward along the coast around the remainder of the broad low pressure area into southeastern Mexico through 90 hours. By 120 hours and in the longer range...has tropical cyclone drift northeastward into west coast of Yucatan peninsula...then shift north across the Gulf of Mexico as an intensfying tropical cyclone. For area of interest #3...shows frontal low pressure intensified into frontal cyclone east of the Azores in 36 hours...cycloncially looping southwest very close to eastern Azores by 66 hours...then has frontal cyclone drift eastward as it gradually weakens...eventually losing its identity north of the Canary Islands in the long range.

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