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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 

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*******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 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 dot gov) for the latest watches/warnings and official forecasts on active tropical cyclones.**********

...SUNDAY NOVEMBER 21 2021 2:04 PM EDT...

Satellite image as of 1740Z. Areas of interest circled in yellow are not mentioned in the NHC tropical weather outlook. Areas circled in a green dashed line are in the NHC 5-day tropical weather outlook. Areas circled in a solid green are in the NHC 2-day tropical weather outlook:

NHC TAFB Surface Analysis 1200Z:

GFS Model Upper-Level Winds 1200Z:

The surface frontal cyclone centered just southwest of the Azores has not seen the development of a core of showers and thunderstorms needed for tropical development. As its supporting upper vortex becomes elongated while merging with a portion of the currently approaching northwest Atlantic upper trough… the surface cyclone is likely to become less organized and more elongated… eventually splitting into a pair of surface frontal lows over the next five days. Therefore subtropical development of this cyclone is not anticipated. The surface cyclone will continue to bring gusty winds and coastal surf to the Azores islands.

After this weekend and into mid-week… an additional surface cyclone is expected to form in the western Atlantic as yet another upper trough amplifies in response to the amplification of upstream warm core upper ridging. The incipient upper trough is currently located over central Canada. The latest model consensus has converged on a more northern solution for the position of the cut-off upper vortex to form from the amplifying upper trough… resulting in a more northern located and less tropical surface cyclone. This cyclone is likely to increase surf for the US east coast… Atlantic Canada coast… and Bermuda by the middle of this upcoming week. Gusty winds are also possible Atlantic Canada and northeast US coast.

I plan this to be my final daily birdseye view post on the Atlantic tropics for the 2021 Atlantic Hurricane Season as there are no foreseeable future tropical or subtropical developments… and the official end of the hurricane season (November 30) is approaching. Will resume daily birdseye view posts on the Atlantic tropics at the start of the next hurricane season on June 1 2022… or unless the potential for subtropical or tropical development returns to the Atlantic basin before then. For more information regarding impacts for the above-mentioned surface cyclones… refer to updates from your local weather office and news media.

On a final note… the 2021 Atlantic Hurricane Season ranks as the third-busiest on record in terms of named storms… while featuring 21 named storms. The other two busier seasons were 2005 with 27 named storms (in addition there was one unnamed subtropical Storm declared for that season’s post-season analysis)… and 2020 with 30 named storms.


Source...Florida State University Experimental Forecast Tropical Cyclone Genesis Potential Fields (

0000Z CMC Model Run...No tropical cyclone formation forecast in the Atlantic basin through 168 hours (7 days)

0000Z ECMWF Model Run... No tropical cyclone formation forecast in the Atlantic basin through 168 hours (7 days)

1200Z GFS Model Run... No tropical cyclone formation forecast in the Atlantic basin through 168 hours (7 days)

0600Z NAVGEM Model Run... No tropical cyclone formation forecast in the Atlantic basin through 168 hours (7 days)

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