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 

 
 
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MY 2020 ATLANTIC HURRICANE SEASON BIRDSEYE VIEW POST #35

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


...WEDNESDAY JUNE 17 2020 3:15 PM EDT...

See area of interest sections below for all areas that are being monitored or were recently monitored for tropical cyclone development by the National Hurricane Center and I. Elsewhere...the configuration of the Madden Julian Oscillation (MJO) favorble for tropical cyclone activity appears to be shifting eastward toward the eastern Pacific and western Atlantic regions (https://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/mjo.shtml). It also appears computer models by next week show a large upper ridge building over the eastern Pacific and western Gulf of Mexico region which would favor tropical development...with the GFS favoring development in the eastern Pacific and CMC and NAVGEM favoring development toward the western Gulf of Mexico region of the Atlantic basin...therefore maybe watching this area for development next week.

AREA OF INTEREST #1...The southeastern divergence zone of a cut-off upper vortex over the southeastern United States is supporting a surface cold front extending from the low pressure center over coastal North Carolina (area of interest #2)...and also an area of cloudiness and thunderstorms to the northeast out ahead of the front and moving toward Bermuda. Watching to see if a more concentrated disturbance...perhaps of tropical nature...develops with the support of the upper vortex's divergence zone as it eventually moves offshore into the northwest Atlantic...and/or develops with the support of anticyclonic outflow beneath western Atlantic upper ridging being generated by the warm southerly surface flow out ahead of the front. Based on the large area of cloudiness already moving toward Bermuda and increasing model support that shows a weak surface low pressure developing over or near Bermuda in the short-term...I have adjusted my short-term forecast points in the updated outlook below eastward closer to Bermuda...but still located west of Bermuda. Vertical wind shear values unfavorable to tropical development will be on the lower side due to the circular shape of the upper vortex as it moves into the northwest Atlantic...and due to the amplified nature of the western Atlantic upper ridging to be located just east of the upper vortex. However I keep odds of development at 0% during much of the forecast period except at 72 and 96 hours when the forecast points pass over a warm swath of Gulf stream waters. However my peak odds of development remain a ta very low 5% due to the lackluster computer model support...with only the GFS developing a bonafide surface low pressure at the present time.

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

IOH 24 Hr Outlook (1200Z Jun 18)...0% chance of tropical cyclone formation (western Atlantic near 29N-74W)

IOH 48 Hr Outlook (1200Z Jun 19)...0% chance of tropical cyclone formation (west of Bermuda near 33N-69W)

IOH 72 Hr Outlook (1200Z Jun 20)...5% chance of tropical cyclone formation (northwestern Atlantic near 36N-68W)

IOH 96 Hr Outlook (1200Z Jun 21)...5% chance of tropical cyclone formation(northwestern Atlantic near 38N-66W)

IOH 120 Hr Outlook (1200Z Jun 22)...0% chance of tropical cyclone formation (south of Nova Scotia near 41N-62.5W)


AREA OF INTEREST #2...The surface frontal low pressure that was offshore of the southeastern United States this morning made landfall near Cape Lookout North Carolina while swinging north-northeastward around the east side of the cut-off upper vortex over the southeastern United States that has been supporting this feature with its eastern divergence zone. With the GFS still showing the upper vortex drifting northward in the next 24 hours...I expect a more northwestward track of the surface frontal low pressure into Virginia as it whirls toward the center of the upper vortex in its post-mature phase...where it should disspate beneath the core of the upper vortex where there is a lack of divergence. Therefore subtropical cyclone formation is not expected and this feature has been removed from the National Hurricane Center tropical weather outlook. A strip of counties that have been under a persistent heavy rain band from northeastern North Carolina to southwestern Virginia are under flood warnings...see the National Weather Service (www.weather.gov) for more information. Once the water levels in the affected areas subside...notable impacts from this system will be over. This is my final statement on this weather system on this blog.

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

IOH 24 Hr Outlook (1200Z Jun 18)...0% chance of subtropical cyclone formation (Virginia near 37.5N-77.5W)


AREA OF INTEREST #3...Over the last 24 hours...the National Hurricane Center in their tropical weather outlook has mentioned a tropical wave of low pressure which has produced two rounds of showers and thunderstorms...one yesterday afternoon that had some rotation while supported by lower shear and upper outflow from tropical upper ridging...and a second this morning and early afternoon spreading into Trinidad and northeastern Venezuela while supported by the upper divergence zone of a persistent western Atlantic upper vortex that has recently been streteched into an upper trough by an upper ridge building in the western Atlantic. Tropical cyclone development however is not expected due to unfavorable atmospheric conditions that lie ahead...specifically southwesterly wind shear generated by the upper trough...followed by a zone of upper convergence and sinking air in the eastern Caribbean Sea being generated by the northerly flow behind the upper trough and on the southeast side of the upper ridge. This is my final statement on this tropical wave on this blog as the tropical wave has been removed from the National Hurricane Center tropical weather outlook as of 2 PM EDT.

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

IOH 24 Hr Outlook (1200Z Jun 18)...0% chance of subtropical cyclone formation (Just offshore of Venezuela north coast near 11N-65W)


...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...but surface low formation over Bermuda forecasted at 36 hours...shifts east-northeastward and opens into a surface trough at 60W longitude. For area of interest #2...moves surface low northwestward into Virignia where it dissipates by 42 hours. For area of interest #3...no tropical cyclone formation shown.


0000Z ECMWF Model Run...For area of interest #1...no tropical cyclone formation shown. For area of interest #2...shows surface low swing westward and dissipating over western North Carolina by 48 hours. For area of interest #3...no tropical cyclone formation shown.


0600Z GFS Model Run...For area of interest #1...weak surface low pressure area shown to form just south of Bermuda at 24 hours...drifting slowly northward to a position over Bermuda by 60 hours...relocating northwestward into the northwest Atlantic near 37N-67.5W at 96 hours while strengthening...located south of Nova Scotia near 41N-65W at 120 hours. For area of interst #2...shows surface low dissipate over the North Carolina/Virginia border by 24 hours. For area of interest #3...no tropical cyclone formation shown.


0600Z NAVGEM Model Run...For area of interest #1...no tropical cyclone formation shown...but a weak surface low shown briefly in the vicinity of Bermuda in 48 hours. For area of interst #2...shows surface low dissipate over the North Carolina/Virginia border by 24 hours. For area of interest #3...no tropical cyclone formation shown.

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