*******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.**********
…THURSDAY JUNE 23 2022 12:25 AM EDT...
See area of interest #7 section below for more information on the potential for a short-lived tropical cyclone in the open northwest Atlantic.
Elsewhere… a string of cut-off upper vorticity has settled across the Bay of Campeche… the northwestern Caribbean Sea… and western Atlantic near the northern Caribbean islands. The upper vorticity string is expected to weaken while remaining cut-off from high-latitude cold air… which would allow the tropical upper ridge currently over Central America and southern Caribbean to expand. In about 4 days split flow upper divergence could develop in the central Caribbean…. between the west side of the remaining upper vorticity to be located to the northeast and east side of the expanded tropical upper ridge. Will be watching for the possible formation of an area of interest in the central Caribbean in the days ahead.
For the eastern tropical Atlantic… the vigorous tropical wave of low pressure which has recently exited the west African coast and was passing 17.5W longitude at 18Z. The wave is showing some signs of organized thunderstorm activity. While steered westward by the current strong Atlantic deep-layered ridge… the wave will remain below a tropical upper ridge keeping wind shear low and upper outflow high. The CMC model forecasts the wave to develop while other models have dropped this solution. Will watch in the next 24 hours to see how the wave negotiates the nearby swath of dry Saharan air to the northwest or if support develops in the other models. Depending on these results… I will upgrade this tropical wave to an area of interest for tropical development in my next update.
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 area of interest in this blog post is designated #7 as I designated the other six of this year 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 #7… An environment of split flow upper divergence is developing between the west side of the current west Atlantic upper vortex and east side of the current deep-layer ridge over the United States. In this environment… a surface trough has developed over the eastern Carolinas and Virginia which as of 18Z contained a new frontal low at its north end. As of 00Z the new frontal low has descended southward into eastern North Carolina. A surface cold front incoming from the northwest… pushed by the current eastern Canada frontal low… is as of this writing producing a strong thunderstorm mass over Virginia with the aid of the upper divergence. This southward-moving thunderstorm mass is making it difficult to define surface rotation associated with the aforementioned surface trough/new frontal low in satellite animation… however the models insist a well-defined surface spin will quickly ramp up at a location offshore of the US mid-Atlantic coast in the next 24 hours.
Whatever low pressure spin develops is expected to swing east and then northeast across the northwest Atlantic while pulled around the southern and eastern edges of the cut-off upper vortex. The best opportunity for short-lived tropical cyclone formation appears to be at 36 hours… when the surface spin has had some time to be established while still being located over/near the narrow ribbon of warm Gulf Stream waters. Tropical development is not expected by 48 hours while the surface low moves into cooler waters. I assign a low 10% peak odds of tropical cyclone formation due to the narrow nature of the warm water ribbon… with a sizeable chance the surface low misses it. In addition the half of the surface low located toward the upper vortex may see upper outflow and hence thunderstorm suppression.
******Infohurricanes.com outlook. Visit hurricanes.gov (hurricanes dot gov) for official outlook***********
IOH 24 Hr Outlook (0000Z Jun 24)… 0% chance of tropical cyclone formation (western Atlantic near 34N-72.5W)
IOH 36 Hr Outlook (1200Z Jun 24)… 10% chance of tropical cyclone formation (western Atlantic near 36N-69W)
IOH 48 Hr Outlook (0000Z Jun 25)… 0% chance of tropical cyclone formation (western Atlantic near 37.5N-65W)
...COMPUTER MODEL SUMMARY...
Source...Florida State University Experimental Forecast Tropical Cyclone Genesis Potential Fields (http://moe.met.fsu.edu/tcgengifs/)
1200Z (Jun 22) CMC Model Run...
**For area of interest #7… well-defined surface center develops near 34.5N-71.5W at 30 hours… the center moves northeast and weakens to a surface trough near 40N-64W at 78 hours
**Tropical wave currently at 17.5W longitude evolves into a tropical low near 7.5N-32.5W at 72 hours… possible tropical cyclone formation near 10N-43W at 120 hours.
1200Z (Jun 22) ECMWF Model Run.…
** For area of interest #7… possible tropical cyclone formation near 33N-71.5W at 24 hours… weakens to a remnant surface trough offshore of Nova Scotia by 72 hours
1800Z (Jun 22) GFS Model Run...
** For area of interest #7… well-defined surface center develops near 33.5N-71.5W at 18 hours… moves northeast and weakens to a surface trough just offshore of Nova Scotia at 72 hours
1800Z (Jun 22) NAVGEM Model Run...
** For area of interest #7… well-defined surface center develops near 35N-72.5W at 30 hours… weakens to a surface trough near 39N-66W at 84 hours.