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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 2020 ATLANTIC HURRICANE SEASON BIRDSEYE VIEW POST #55

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


...TUESDAY JULY 7 2020 7:54 PM EDT...


Tropical Storm Edouard has transitioned into a remnant frontal low pressure in the open North Atlantic...see Edouard section below for details and final statement on Eduoard. See area of interest sections below for other areas being monitored for tropical cyclone development.


REMNANTS OF EDOUARD...While accelerating east-northeastward into cooler open north Atlantic waters and losing its thunderstorms...Tropical Storm Edouard within the last day has finally transitioned into a remnant frontal low pressure supported by the eastern divergence zone of the upper trough moving across the western Atlantic. The remnant low pressure in 48 hours will reach the British Isles of western Europe...then reach Denmark and the southern Scandinavian regions in 72 hours...while moving in tandem with an expected north fracture of the upper trough (the remainder of the trough will become stuck against the upper ridging that has recenlty amplified into the north Atlantic). This is my final statement on the remnants of Edouard on this blog as it is no longer a tropical feature.


AREA OF INTEREST #1...For the broad surface low pressure over the southeastern United States..surface observations and radar animation showed that the well-defined spiral that moved into southwestern Georgia yesterday moved northeastward between Macon and Atlanta as of this morning. Although there have been curved thunderstorm bands to the east of this location across South Carolina...this morning's surface observations did not show a closed circulation here. This indicates that the thunderstorm activity has become sheared east of the closed circulation as the surface low has transitioned into a feature supported by the eastern divergence zone of upper vorticity over the eastern United States. The closed circulation as of late has continued east-northeast into the northern Georgia/South Carolina border with the thunderstorm bands remaining sheared off to the east. A track to the northeast is expected to generally continue from the steering influence of the western periphery of the Atlantic surface subtropical ridge during the forecast period. Given that the closed circulation has become less defined on radar...which may give an opportunity for a new one to form closer to the Carolina coast or offshore within the thunderstorm bands...and that the latest model consensus suggest that the surface low will be on the South Carolina coast in the next day or so...I have raised my odds of tropical cyclone formation from 10% to 20%. But my forecast track remains further north...suggesting that the current closed circulation will make its way to the northern Outer Banks of North Carolina in 48 hours instead of reforming further southeast. If indeed a reformation occurs...then I will be raising odds of development and adjust the forecast track accordingly. By 72+ hours...this system will be moving over cooler waters just offshore of the northeatern United States...likely transitioning into a non-tropical system supported by the eastern divergence zone of the remainder of the western Canada upper vorticity to manifest itself as an approaching upper trough (meanwhile the current upper trough that ejected from the western Canada upper vortex...currenlty over central North America...will pass to the north of this disturbance without much interaction with it). Therefore I drop odds of tropical cyclone development to 0% by this time.

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

IOH 24 Hr Outlook (1800Z Jul 8)...0% chance of tropical cyclone formation (eastern North Carolina/South Carolina border near 34.5N-79W)

IOH 48 Hr Outlook (1800Z Jul 9)...20% chance of tropical cyclone formation (northern Outer Banks of North Carolina near 36N-76W)

IOH 72 Hr Outlook (1800Z Jul 10)...0% chance of tropical cyclone formation (just southeast of New Jersey near 38.5N-74W)


AREA OF INTEREST #2...The vigorous tropical wave of low pressure in the central tropical Atlantic is currently crossign the Lesser Antilles...but the heaviest thunderstorm activity to the west of the wave axis has already crossed the islands into the northeastern Caribbean Sea. The tropical wave has become disorganized...likely the effects of dry saharan air...as the wave has been in an otherwise favorable environment of low shear and upper outflow beneath upper ridging. Therefore tropical cyclone formation is no longer expected from this disturbance before upper winds become less favorable when upper vorticity over the Bahamas shifts southward over the tropical wave. This is my final statement on this disturbance on this blog.

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

IOH 24 Hr Outlook (1800Z Jul 8)...0% chance of tropical cyclone formation (eastern Caribbean Sea near 15N-66W)


...COMPUTER MODEL SUMMARY...

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


1200Z CMC Model Run...For area of interest #1...surface low reaches the South Carolina coast in 24 hours...reaches New Jersey in 90 hours...loses its identity shortly after that time within frontal system currently approaching from the north-central United States. For area of interest #2...no tropical cyclone formation shown.


1200Z ECMWF Model Run...For area of interest #1...surface low reaches the South Carolina coast in 24 hours...approaches landfall at Long Island New York in 96 hours...loses its identity over Maine within frontal system currently approaching from the north-central United States by 120 hours. For area of interest #2...no tropical cyclone formation shown.


1200Z GFS Model Run...For area of interest #1...surface low reaches the South Carolina coast in between 36 and 42 hours...reaches New Jersey coast in 84 hours...loses its identity over Maine within frontal system currently approaching from the north-central United States by 102 hours. For area of interest #2...no tropical cyclone formation shown.


1200Z NAVGEM Model Run...For area of interest #1...surface low pressure reaches northern South Carolina coast in 24 hours...approaches landfall at Long Island New York in 90 hours...loses its identity over the Gulf of Saint Lawrence west of Newfoundland in 126 hours within frontal system currently approaching from the north-central United States. For area of interest #2...no tropical cyclone formation shown.

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