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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 #30

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


...FRIDAY JUNE 12 2020 3:39 PM EDT...

See area of interest section below for tropical wave that has recently entered the eastern Caribbean Sea. Elsewhere...an upper trough fragment in the north Atlantic is forecast to dive south and amplify into a cold core upper vortex over or just east of the Azores in 48 hours while cut-off by the robust longwave upper ridge that has just entered the west Atlantic from North America. Today's ECMWF and GFS model runs agree that this could result in the associated surface frontal low pressure potentially strengthening into a consolidated frontal cyclone. The ECMWF and GFS also show that the upper ridge could now become strong enough to keep the upper vortex and surface cyclone separated from the larger western Europe upper vortex and at a further south position in the waters south of the Azores after 48 hours...where water temperatures are 20 to 21 deg C. The upper vortex maybe cold enough for the surface cyclone to acquire thunderstorms and tropical characteristics at these water temperatures. However not declaring an area of interest at the present time. Waiting to see if the GFS/ECMWF consensus perists...and also if the NAVGEM and/or CMC models also converge with that consensus as they do not show as consolidated of a surface circulation...and the CMC still shows the surface circulation and upper vortex quickly shifting east while merging with the larger western Europe upper vortex.


AREA OF INTEREST #1...The once vigorous tropical wave just east of the southern Lesser Antilles has crossed the islands and entered the eastern Caribbean Sea while considerably weakening due to the shearing effects of upper westerly winds and dry saharan air surging in from the east unfavorable for tropical development. In the longer range...the upper ridge that has recently entered the west Atlantic will push the northwest Caribbean upper vortex repsonsible for the shearing upper winds westward and away...eventually merging with the south side of the upper trough over eastern North America...a pattern that will reduce the shear as the tropical wave moves toward the central Caribbean Sea (shear will also be lowered over the adjacent Bahamas region). To the north...the surface cold front associated with the eastern North American upper trough and the remnants of the broad frontal low currently in the central Atlatnic are expected to congeal together...creating enough of a surface ridge weakness to draw any surface low pressure generated by the tropical wave on a west-northwest to northwest track toward the northern Caribbean Islands and perhaps toward the Bahamas. Therefore despite a drop in wind shear...I keeps odds of development at 0% thru 72 hours due to land interaction. I finally show a 5% chance of development at 96 hours over the Bahamas where land interaction effects are less severe...with such low odds due to my uncertainty as to whether or not this tropical wave will ever produce a surface low pressure area at this location in the long range...so far none of the models have shown such a solution. My odds are back to 0% by 120 hours as there will be enough surface ridging to the north that tries to impart a westward angle in track...taking this potential disturbance into shearing upper southwesterly winds generated by the eastern North America upper trough as the trough finally move eastward toward the Atlantic.

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

IOH 24 Hr Outlook (1200Z Jun 13)...0% chance of tropical cyclone formation (eastern Caribbean Sea south of Puerto Rico near 16.5N-66.5W)

IOH 48 Hr Outlook (1200Z Jun 14)...0% chance of tropical cyclone formation (over the Dominican Repubic near 18.5N-72W)

IOH 72 Hr Outlook (1200Z Jun 15)...0% chance of tropical cyclone formation (over northeast coast of Cuba near 20.5N-76W)

IOH 96 Hr Outlook (1200Z Jun 16)...5% chance of tropical cyclone formation (central Bahamas near 24N-76W)

IOH 120 Hr Outlook (1200Z Jun 17)...0% chance of tropical cyclone formation (just northeast of the western Bahamas near 27N-77W)


...COMPUTER MODEL SUMMARY...

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


0000Z CMC Model Run...For area of interest #1...no tropical cyclone formation shown. Elsewhere...new frontal low pressure in northeastern Atlantic dives south to a position just east-northeast of the Azores by 48 hours...cyclonically loops beneath its supporting cut-off upper vortex and arrives into the Azores by 72 hours...begins drifting eastward away from the Azores at 96+ hours while weakening...opens into a surface trough by 114 hours.


0000Z ECMWF Model Run...For area of interest #1...no tropical cyclone formation shown. Elsewhere...new frontal low pressure in northeastern Atlantic dives south to a position just northeast of the Azores by 48 hours...consolidates and strengthens while cylonically looping beneath its supporting cut-off upper vortex and arrives into the Azores on this path by 72 hours and to a position southwest of the Azores by 96 hours...begins drifting east-southeast away from the Azores at 120+ hours while weakening in the long range.


0600Z GFS Model Run...For area of interest #1...no tropical cyclone formation shown. Elsewhere...new frontal low pressure in northeastern Atlantic dives south to a position just northeast of the Azores by 30 hours...cylonically loops beneath its supporting cut-off upper vortex and arrives into the Azores on this path by 48 hours...consolidates and strengthens just southwest of the Azores by 60 hours...begins drifting westward to a position southwest of the Azores and weakens by 96 hours...begins drifting eastward in the waters south of the Azores at 120+ hours.


0000Z NAVGEM Model Run...For area of interest #1...no tropical cyclone formation shown. Elsewhere...new frontal low pressure in northeastern Atlantic dives south to a position just northeast of the Azores by 36 hours...cylonically loops beneath its supporting cut-off upper vortex and arrives into the Azores on this path by 60 hours...makes a second cyclonic loop over and just south of the Azores between 60 and 90 hours...weakens to a surface trough just southeast of the Azores just after 120 hours.

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