BIRDSEYE VIEW POSTS

Since 2012 on the Weather Underground (www.wunderground.com) 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 via Disqus on Weather Underground at www.wunderground.com/cat6. You can see my Disqus feed at this link for my latest comments. Feel free to reply to me with your disqus account or e-mail at IOHurricanes@outlook.com 

 
 
Search
  • NCHurricane2009

MY 2020 ATLANTIC HURRICANE SEASON BIRDSEYE VIEW POST #46

*******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 JUNE 28 2020 5:44 PM EDT...

See area of interest sections below for areas in the tropical Atlantic being monitored for tropical cyclone development by the National Hurricane Center.


AREA OF INTEREST #1...A tropical wave of low pressure in the eastern tropical Atlantic...now heading into the central tropical Atlantic...continues to show some signs of defined rotation on satellite. Even though southeasterly flow on the east side of the rotation appears to have kinked the dry saharan air locally northward and away...the shower and thunderstorms activity has diminished likely from the effects of the dry air. And because there is no computer model support showing development...I have lowered odds of tropical cyclone formation to 0% despite the tropical wave finally being introduced into the National Hurricane Center tropical weather outlook and despite the tropical wave being below a cell of tropical upper ridging that is keeping wind shear low and upper outflow that is otherwise favorable for development high. During or just after 72 hours...conditions will become even less favorable for development as the tropical wave nears westerly shearing winds induced by the ongoing central Atlantic upper vorticity. On a final note...I have adjusted the forecast points my updated outlook below further north as the rotation apperas to be further north around 13 or 14N latitude...which I think is another negagtive for development as this puts the rotation closer to the dry saharan air layer.

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

IOH 24 Hr Outlook (1800Z Jun 29)...0% chance of tropical cyclone formation (tropical Atlantic near 14N-45W)

IOH 48 Hr Outlook (1800Z Jun 30)...0% chance of tropical cyclone formation (tropical Atlantic near 15N-52W)

IOH 72 Hr Outlook (1800Z Jul 1)...0% chance of tropical cyclone formation (east of the Lesser Antilles near 16N-57.5W)


AREA OF INTEREST #2...A shortwave upper trough that was over the north-central United States has merged with a persistent upper vortex over eastern Canada...and the surface cold front it has been supporting has arrived into the northeastern United States with showers and thunderstorms firing ahead of the front over Tennessee...North Carolina...and Virginia. While continuing to be driven by the upper vortex...the front will soon arrive into the northwestern Atlantic. The computer models consensus is that the dominant low pressure along the front in the coming days will be a non-tropical feature along the front to develop over southeastern Canada...to be supported by the eastern divergence zone of the upper vortex and also from an upper trough from northern Canada that later dives southeastward around the currently developing central North America upper ridge. However yesterday's 0000Z ECMWF and todays 1200Z CMC suggest another surface low pressure could form further south either along or ahead of the front and west-northwest or northwest of Bermuda...perhaps with the aid of the outflow of the upper ridging in the western Atlantic as a tropical feature. Because the National Hurricane Center has introduced this frontal zone into their 5-day tropical weather outlook...I have marked it as an area of interest today. Forecast points in the outlook below are based on the initial formation of a second low pressure center west-northwest of Bermuda at 48 hours as the 1200Z CMC suggested...which is agreement with where the GFS places an upper divergence maximum between the upper vortex and western Atlantic upper ridge during that time. I only have non-zero odds of development at 72 hours when the possible surface low shifts northeastward to the maximum temps of the warm Gulf stream waters in the region...but I keeps those odds very low at 5% due to lack of majority model support showing the existence of a surface low to begin with...and also due to possible southwesterly wind shear from the east side of the upper vortex should the western Atlantic upper ridge fail to sufficiently cover the surface low. Odds of development are dropped back to 0% by 96 hours due to arrival to cooler waters.

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

IOH 24 Hr Outlook (1800Z Jun 29)...0% chance of tropical cyclone formation (coastal southeastern Virginia near 36.5N-76W)

IOH 48 Hr Outlook (1800Z Jun 30)...0% chance of tropical cyclone formation (west-northwest of Bermuda near 34.5N-69W)

IOH 72 Hr Outlook (1800Z Jul 1)...5% chance of tropical cyclone formation (northwestern Atlantic near 38N-66W)

IOH 96 Hr Outlook (1800Z Jul 2)...0% chance of tropical cyclone formation (northwestern Atlantic near 42N-57.5W)


...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...no tropical cyclone formation shown. For area of interest #2...northeastern US front swings into west Atlantic by 24 hours...weak low pressure along or ahead of front west-northwest of Bermuda near 34.5N-69W by 54 hours that tracks north-northeastward and loses its identity near 40.5N-63W by 84 hours.


1200Z ECMWF Model Run...For area of interest #1...no tropical cyclone formation shown. For area of interest #2...northeastern US front swings into west Atlantic by 24 hours...no well-defined low pressure along front till 120 hours when a strengthening frontal low forms between Nova Scotia and Newfoundland and ejects rapidly east-northeastward into the open north Atlantic after that time.


1200Z GFS Model Run...For area of interest #1...no tropical cyclone formation shown. For area of interest #2...northeastern US front swings into west Atlantic by 24 hours...no well-defined low pressure along front till 120 hours when a strengthening frontal low forms between Nova Scotia and Newfoundland and drifts slowly east-northeastward to a position east of Newfoundland by 162 hours.


1200Z NAVGEM Model Run...For area of interest #1...weak low pressure develops along tropical wave near 15N-44W by 24 hours...dissipating neaar 17.5N-52.5W by 54 hours. For area of interest #2...northeastern US front swings into west Atlantic by 24 hours...no well-defined low pressure along front till 96 hours when a strengthening frontal low forms over the southeastern Canada mainland...drifting eastward into the waters east of Newfounland by 120 hours.

0 views

©2020 by Info On Hurricanes.

 

Questions? Comments? Send to me on IOHurricanes@outlook.com