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 2021 ATLANTIC HURRICANE SEASON BIRDSEYE VIEW POST #4 (Weekend Edition)

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


...SATURDAY MAY 22 2021 3:24 PM EDT...

Satellite image as of 1600Z. 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:

Welcome to what I call my “weekend edition” posts...where I put together the entire post on using only mobile phone tools instead of a laptop computer. This will allow me to execute these posts while on the go during weekend activities.


Subtropical Storm Ana forms in the waters just northeast of Bermuda....making this the seventh Atlantic Hurricane Season in a row where the first storm forms before June 1st! See Ana section below for additional details. Elsewhere...the tropical low pressure over the western Gulf of Mexico has made landfall over Texas and is not expected to develop...see area of interest #1 section below for additional details.


SUBTROPICAL STORM ANA...As expected...the western Atlantic surface frontal low pressure last night was able to develop enough central shower and thunderstorm activity to be classified as Subtropical Storm Ana...thanks to the aid of instability provided by the cold upper-level temps of the overhead upper vortex despite Ana being over lukewarm 20 deg C water. The NHC began advisories on Ana at 5 AM EDT today.


My forecast track is nudged westward due to Ana’s current position relative to the last forecast. In the next 48 hours...the frontal system/upper trough over eastern Canada will break through the deep-layer ridge and turn Ana and the upper vortex east-northeast. Models agree that the incoming Canadian front will absorb Ana at 48 hours...and my updated forecast also shows this.


I have again lowered the intensity forecast and no longer show transition to fully tropical status as Ana is nearing the slightly warmer 22 deg C south edge of the Gulf Steam waters and yet has less thunderstorms than when it formed this morning. Their may not be as much instability in place as I previously thought...perhaps from dry air caused by the western convergence zone of the upper vortex.


For Bermuda...expect coastal sea swells to remain this weekend until Ana pulls away to the east-northeast.

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

0 Hr Position (1800Z May 22)...45 mph maximum sustained wind subtropical storm centered northeast of Bermuda at 34.3N-63W

IOH 24 Hr Forecast (1800Z May 23)...45 mph maximum sustained wind subtropical storm centered at 35N-60.5W

IOH 48 Hr Forecast (1800Z May 24)...Absorbed by cold front near 36N-55.5W)


AREA OF INTEREST #1...The tropical surface low pressure disturbance in the western Gulf of Mexico has made landfall over Texas while steered by the west side of the deep-layer ridge dominating the region. It has been recently removed from the NHC outlook as of 2 PM EDT as it is not expected to develop due to landfall. The upper vorticity that helped trigger this disturbance Thursday evening is parked over eastern Mexico...producing trailing acitivity over the western/central Gulf of Mexico with its eastern divergence zone. However there are no signs of organization in this activity. This is my final statement on this system on this blog.

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