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 #61

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


...MONDAY JULY 26 2021 5:55 PM EDT...

Although the surface trough of low pressure that was north of the Caribbean Islands has dissipated... another round of thunderstorm activity has developed further north...at a location just south of Bermuda...beneath supporting upper outflow and divergence on the east end of the western Atlantic upper ridge cell expanding in the region. So far a new surface trough has not formed here...and none of the computer models forecast tropical development at this location.


Meanwhile...see area of interest #1 section below for an update on the surface low pressure that was offshore of the southeastern United States now making landfall over southeastern Georgia. Also note that the usually more reliable GFS and ECMWF computer models forecast that the cold front currently over western Canada will reach the waters offshore of the southeastern United States...with tropical development possible in the 5 to 7 day window as the tail end of the front decays beneath an offshore extension of the current United States sprawling upper ridge creating an environment of low shear and upper outflow.


AREA OF INTEREST #1...While steered by the surface ridge currently over the western Atlantic...the surface low pressure swirl offshore of northeast Florida has inched west-northwestward and made landfall over southeastern Georgia just north of the Florida/Georgia border. On the west side of the tiny surface low pressure swirl...showers and thunderstorms have developed over land and locally heavy rainfall is possible in areas inland from the northeast Florida and Georgia coast. Due to landfall...tropical development is no longer possible and I plan this to be my final statement on this system on this blog unless it continues to be mentioned in the NHC tropical weather outlook by my next update.

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

IOH 24 Hr Outlook (1800Z Jul 27)...0% chance of tropical cyclone formation (eastern Georgia/South Carolina border near 32.2N-82W)


...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...surface low dissipates over southeastern Georgia at 12 hours.


1200Z ECMWF Model Run...

**For area of interest #1...surface low dissipates over southeastern Georgia in the next 24 hours.

**Cold front currently over western Canada to reach the western Atlantic in 144 hours...multiple tropical low pressure centers develop offshore of North Carolina and north of Bermuda by 168 hours as the cold front decays.


1200Z GFS Model Run...

**For area of interest #1...surface low dissipates over southeastern Georgia at 9 hours.

**Frontal boundary currently trailing from northeast Canada frontal cyclone reaches western Atlantic over the next 48 hours...tail end of front evolves into surface low pressure offshore of the Carolinas at 69 hours while supported by a shortwave upper trough pivoting around longwave upper trough over eastern Canada...tropical development potential however reduced due to shear from the shortwave upper trough.

**Cold front currently over western Canada to reach the western Atlantic in 111 hours...tail end of front decays into a surface low pressure offshore of North Carolina from 120 to 144 hours with some tropical development potential beneath an offshore extension of warm upper ridging over the United States.


1200Z NAVGEM Model Run...

**For area of interest #1...surface low dissipates over southeastern Georgia at 6 hours.

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