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 2021 ATLANTIC HURRICANE SEASON BIRDSEYE VIEW POST #67

*******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 AUGUST 1 2021 11:15 PM EDT...

Satellite image as of 2350Z. 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 line are in the NHC 2-day tropical weather outlook:

NHC TAFB Surface Analysis 1200Z:

GFS Model Upper-Level Winds 1200Z:


The stalled surface frontal boundary currently positioned across the western Atlantic has produced strong thunderstorm clusters over the North Carolina coast and offshore waters over the last several hours. Over the next 48 hours…the cold front currently over the eastern US will soon overrun the stalled front and potentially re-enforce the thunderstorm activity. In addition upper ridging over the western Atlantic with low shear and upper outflow is forecast to persist…therefore an area of interest for tropical development may emerge offshore of the eastern US within the next couple of days.


Elsewhere…conditions in the low-latitudes of the tropical Atlantic will soon return to a more favorable state as the upward-motion phase of the Madden Julian Oscillation (MJO) is shifting east into the Atlantic basin (https://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/mjo.shtml). As of late…the more reliable GFS and ECMWF models agree that the tropical wave of low pressure currently in the eastern Atlantic near 20W longitude and another wave to emerge from Western Africa in 4 to 5 days may each evolve into a low pressure spin…perhaps while aided by the MJO's arrival and also the outflow and divergence of the eastern tropical Atlantic upper ridge axis. Although the tropical wave currently at 20W would likely struggle to develop as its north side is currently embedded in dry Saharan air…similar solutions among the global models over the last few days is a signal that an area of interest may emerge in the eastern tropical Atlantic in the coming days.

...COMPUTER MODEL SUMMARY...

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

1200Z CMC Model Run...no tropical cyclone formation shown in the Atlantic basin for the next seven days (168 hours)

1200Z ECMWF Model Run...

**For tropical wave of low pressure currently at 20W longitude…strengthening low pressure spin shown to develop near 12.5N-25W at 48 hours…low pressure spin dissipates at 72 hours

**Vigorous tropical wave of low pressure forecast to emerge from west Africa at 120 hours…develops low pressure spin near 10.5N-30W at 168 hours.


1800Z GFS Model Run...

** For tropical wave of low pressure currently at 20W longitude…leaves behind a low pressure spin just southeast of the Republic of Cabo Verde Islands at 33 hours…thru 60 hours the low pressure spin moves into the islands while orbiting the large circulation of the remainder of the wave off to the west…the low pressure spin dissipates shortly thereafter.

**Vigorous tropical wave of low pressure forecast to emerge from west Africa at 96 hours…develops into a low pressure spin near 10.5N-20W at 105 hours…low pressure spin reaches 12.5N-35W at 168 hours.

1200Z NAVGEM Model Run... no tropical cyclone formation shown in the Atlantic basin for the next seven days (168 hours)

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