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 2022 ATLANTIC HURRICANE SEASON BIRDSEYE VIEW POST #20

*******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 3 2022 12:38 AM EDT...

A broad tropical low pressure system spanning the northeastern Yucatan peninsula and the western Caribbean Sea is expected to lift northeast. There is a high chance of this system bringing tropical storm conditions to western Cuba… south Florida… and the western Bahamas from now through this weekend. Tropical storm conditions are possible for Bermuda early next week if this system can remain intact under the forecast heightened levels of wind shear. See area of Interest #4 section below for more details. Elsewhere… the surface trough currently northeast of the western Bahamas has not developed further… see area of Interest #5 section below for details.


New to this site this year… I will be sequentially numbering up areas of interest for possible Atlantic tropical development. In this scheme… will reset back to #1 at the start of next year (January 2023). The current two areas of interest in this blog post are designated #4 and #5 as I designated the first three of this year earlier this month (in previous birdseye view posts on the home page). This scheme is to reduce confusion as Atlantic tropical activity increases during the peak of the hurricane season… when multiple simultaneous areas of interest begin and end which previously required shuffling around the area of interest numbers from update to update.


AREA OF INTEREST 4 (POTENTIAL TROPICAL CYCLONE ONE)…Regarding the tropical low pressure system near the northeast coast of the Yucatan peninsula and western Caribbean Sea… the CIMSS 850 mb vorticity product (http://tropic.ssec.wisc.edu/real-time/windmain.php?basin=atlantic&sat=wg8&prod=vor&zoom=&time=) shows the dominant low-level spin is still absorbing low-level vorticity to the west… which has recently orbited to the southwest side of the dominant spin. Because the absorption is not complete… we still have an oblong circulation instead of a circular one and hence the NHC has designated this system as a potential tropical cyclone instead of a tropical cyclone (tropical depression or storm).


A few features are expected to steer this tropical system northeast… (1) In the high-latitudes the current central Canadian frontal cyclone and upper vortex is currently blocked from moving east due to a northeast Canada upper ridge recently propped up by the warm sector of the frontal cyclone. However a chunk of the upper vortex is expected to slip past the south side of this upper ridge and create a northwest Atlantic frontal low whose surface ridge weakness will help attract this tropical system northeastward… (2) in the low-latitudes the axis of nearby upper vorticity to the north will create a northeast push in the upper layers of the atmosphere. By 96 to 120 hours the shortwave upper trough just offshore of California will arrive near this tropical system and re-enforce the low-latitude axis of upper vorticity. At the end of the 5-day forecast period the steering pattern is expected to shift as a result of the stalled Central Canadian upper vortex. The current frontal cyclone below the upper vortex is decaying… however by day 5 the eastern divergence zone of the upper vortex will have birthed another frontal cyclone whose warm sector will build an upper ridge over the northwest Atlantic. In turn the amplifying northwest Atlantic upper ridge will amplify the low-latitude upper vorticity axis into a cut-off upper vortex… with the east side of this upper vortex hooking the track of this tropical system more northward. A final note regarding the track forecast … my updated one in the outlook below continues to generally follow the GFS which remains on the southern side of the model consensus. I have not selected the more northern forecast tracks seen in the other models as it will be harder for development further north due to higher levels of shear in association with the low-latitude upper vorticity axis.

Due to the improved concentration and organization of the thunderstorms near the current dominant low-level spin… I have raised odds of tropical cyclone formation to 90% since special update #19A… matching the NHC’s high odds in their latest tropical weather outlook. I have not done a tropical cyclone formation forecast with intensity projections as there is still a chance that this system does not become a tropical cyclone for two reason… (1) the high shear levels to be induced by the low-latitude axis of upper vorticity… (2) as this system begins to accelerate northeast while chasing the northwest Atlantic surface ridge weakness mentioned in the previous paragraph… that might help reduce the shear as the direction of travel would be aligned with the direction of the shearing upper winds. However this system may still suffer from an elongated structure that would technically not count it as a tropical cyclone as cyclones by scientific definition require a circular structure with a well-defined center. The elongation is possible as the supportive upper divergence region of the low-latitude upper vorticity axis will also be elongated. By 120 hours water temps below 26 deg C along the forecast track will end tropical development potential… hence tropical development odds at that time are lowered to 0%.


Whether or not this system becomes elongated or circular… it has potential to strengthen due to the aforementioned upper divergence of the upper vorticity axis and anticyclonic outflow of the tropical upper ridge to be located ahead of the upper vorticity. In an elongated state… note that this system may bring tropical storm conditions and remain classified by the NHC as a potential tropical cyclone (PTC) in order to continue tropical storm watches/warnings. Whether we have PTC or tropical storm status… the following is the expected timing for possible gusty winds… heavy rain… and coastal sea swells in the days ahead:

(1) For now through Saturday: western Cuba... south Florida and the Florida Keys. Now is the time to prepare quickly. Western Cuba should be finishing preparations now. South Florida and the FlorIda Keys should be done preparing by tomorrow afternoon.

(2) For Sunday: the western Bahamas... prepare now. Preparations must be done by early Saturday.

(3) Conditions in the northeastern Yucatan should improve going forward as this system is expected to track northeast and away.

(4) This system could approach the vicinity of Bermuda after this weekend. Tropical storm conditions are possible if this system remains intact under the wind shear

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

IOH 24 Hr Outlook (1800Z Jun 3)... 90% chance of tropical cyclone formation (north coast of Cuba’s west tip near 22.5N-84W)

IOH 48 Hr Outlook (1800Z Jun 4)... 90% chance of tropical cyclone formation (just offshore of southeast Florida near 25N-80W)

IOH 72 Hr Outlook (1800Z Jun 5)... 90% chance of tropical cyclone formation (northeast of the western Bahamas near 27N-76W)

IOH 96 Hr Outlook (1800Z Jun 6)... 90% chance of tropical cyclone formation (western Atlantic near 29N-70W)

IOH 120 Hr Outlook (1800Z Jun 7)… 0% chance of tropical cyclone formation (just east of Bermuda near 32N-64W)


AREA OF INTEREST 5… Despite a relaxation of shear over the surface trough of low pressure northeast of the Bahamas… caused by the weakening of the upper vorticity in the area… the shower and thunderstorm activity in the region has remained displaced to the east. A careful study of upper winds shows the upper vorticity became stacked over the surface trough… and with a lack of divergence directly beneath the core of the upper vorticity showers and thunderstorms could not fire directly over the surface trough. After spending a short time being a closed surface low… as of 0000Z this system is downgraded back to a surface trough on the NHC TAFB surface analysis… and conditions for the surface trough are about to become more hostile. This is due to wind shear ramping back up in the next 24 hours as upper westerly flow increases with the eventual approach of a chunk of the current central Canada upper vortex. Therefore tropical cyclone formation is not anticipated… this is my final statement on this area of interest on this blog.

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

IOH 24 Hr Outlook (1800Z Jun 3)…0% chance of tropical cyclone formation (west-southwest of Bermuda near 30N-68.5W)


...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 #4... crosses central Florida peninsula at 54 hours with an elongated structure… elongated low pressure proceeds to strengthen with the SW-NE oriented axis of the circulation passing just northwest of Bermuda at 108 hours… by 126 hours the elongated circulation transitions into a cold front featuring a frontal low near 39.5N-50W

**For area of interest #5... surface low moves across Bermuda at 42 hours… weakens to a surface trough crossing 59W longitude by 66 hours


1200Z ECMWF Model Run...

**For area of interest #4... by 24 hours organizes into a large tropical depression in the southern Gulf of Mexico centered at 22.5N-87.5W… as a tropical storm crosses the central Florida peninsula between 48 and 72 hours… while gaining additional strength and size passes just north of Bermuda at 120 hours.

**For area of interest #5... surface low weakens to a trough just southeast of Bermuda at 48 hours.


1800Z GFS Model Run...

**For area of interest #4… through 45 hours the current consolidated center degenerates into multiple centers while system moves northeast across the southeastern Gulf of Mexico and south Florida… by 51 hours one of the eastern centers strengthens into a compact tropical cyclone located just north of the western Bahamas… tropical cyclone moves across Bermuda at 108 hours and is located just east of Bermuda at 120 hours while weakening.

**For area of interest #5… surface low weakens to a trough just east of Bermuda at 42 hours.


1200Z NAVGEM Model Run...

** For area of interest #4… develops into a large tropical depression centered over the northeast corner of the Yucatan peninsula at 30 hours… through 66 hours crosses the central Florida peninsula while strengthening to a tropical storm… gains additional strength and size while passing offshore of the southeast US and reaches a position midway between North Carolina and Bermuda at 120 hours

**For area of interest #5... surface low weakens to a trough just west of Bermuda at 24 hours.

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