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 

  • NCHurricane2009


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


Tropical Depression Eight is now Tropical Storm Gaston with 40 mph maximum sustained winds... and as of 5 PM EDT was centered at 34.7N-44.4W. No changes to the track and intensity forecast presented below.

...TUESDAY SEPTEMBER 20 2022 11:49 AM EDT...

Visible satellite image taken of newly-formed Tropical Depression Eight located in the open central Atlantic well to the northeast of Hurricane Fiona which is currently striking the Turks and Caicos islands. Image take taken at 1450Z:

The following is a special update on what was designated area of interest #29 in birdseye view post #106 this morning... which has become tropical depression eight. Refer to birdseye view post #106 available on the home page of this site for more information on Hurricane Fiona... area of interest #30 currently approaching northeastern Venezuela... Trinidad and Tobago... and the southern Lesser Antilles... as well as information on the rest of the Atlantic tropics including other areas of interest being monitored.

TROPICAL DEPRESSION EIGHT...The surface low pressure in the open central Atlantic has continued to become better organized in a low shear and upper divergence environment on the east side of an approaching shortwave upper trough. An expanding thunderstorm cluster that developed on the northwest side of the circulation... induced by the upper divergence... has covered the swirl center of the low pressure and this system now qualifies as a tropical depression. The surface and upper layers of the atmosphere will provide conflicting steering directions over the next couple of days. At the surface a ridge is expected to build to the north of the new depression which will attempt to induce a westward push... with the ridge itself supported by the western convergence zone of the upper trough currently pivoting eastward across the north Atlantic. In the upper layers... increasing upper westerly flow as the shortwave upper trough cuts across the top of the depression will try to buckle the track of this system eastward... particularly if the depression becomes strong/tall enough to couple with the upper flow. Given the persistence of the thunderstorm flare covering the center of circulation... I expect the depression to become a moderate tropical storm in the next 24 hours which should bend more east in track while coupling with the upper flow. My intensity forecast is not quiet as high as the NHC's as of this writing as this system will reach water temps below 26 deg C at 24+ hours. In short... I currently forecast this system will weaken to a remnant low over the cooler waters between 24 and 48 hours. I expect the initial weakening to cause this system to become shallower... hence slowing down its northeast track while decoupling from the upper westerlies and feeling more steering influence from the building northern surface ridge. The slow down would then mean the circulation falls behind the upper westerly wind speed... thus exacerbating wind shear which would induce further weakening. Because my intensity forecast is lower than the NHC... I do not bring this system as far east nor as close to the Azores. After this system becomes a shallow remnant low... the southwest side of the northern surface ridge should take over and reverse the track westward and then northwestward until the remnant low dissipates.

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

0 Hr Position (1200Z Sep 20)...35 mph maximum sustained wind tropical depression centered at 32.8N-45.7W

IOH 24 Hr Forecast (1200Z Sep 21)...50 mph maximum sustained wind tropical storm centered at 37.5N-43W

IOH 48 Hr Forecast (1200Z Sep 22)...Remnant low centered at 39N-38W

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