*******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 15 2022 3:06 AM EDT...
See Area of Interest #6 below for more information on the new low pressure spin in the southern Caribbean Sea.
Elsewhere… watching a pair of cold fronts to enter the Atlantic basin from the continental United States… with each front potentially kicking off a tropical disturbance as follows:
(1) A shortwave upper trough currently at the US mid-Atlantic coastal region and longwave upper trough over the northwestern Atlantic are driving a cold front into the western Atlantic. So far there are no signs of tropical development along this front as much of the thunderstorm activity that was offshore of North Carolina is now entangled with a non-tropical frontal low moving quickly east-northeastward. Will watch to see if renewed thunderstorms develop along the front’s tail end and offshore of the southeast US in the next 24 hours… which could support a tropical disturbance given the low shear and upper outflow of the approaching eastern US upper ridge.
(2) The upper vortex currently over the western US/Canada border region will drive the current western US frontal system into the western Atlantic by days 4 and 5. During this time the tail end of this frontal system is forecast to be in the northeastern Gulf of Mexico where a tropical disturbance is possible from the approach of a deep-layer ridge to the northwest which will keep wind shear low.
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 #6 as I designated the other five 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 #6… Over the last couple of days a broad surface low pressure area over Central America and adjacent waters was supported by outflow of a tropical upper ridge in the region and a passing pair of surface tropical waves. In the last 24 hours the tropical waves have each deposited a low pressure spin… one located in the far eastern tropical Pacific and the other in the southern Caribbean Sea… with the two low pressure spins becoming increasingly distinct on satellite pictures. See the NHC website hurricanes.gov (hurricanes dot gov) for more information on the far eastern Pacific low pressure as this site is dedicated to Atlantic tropical activity. Meanwhile to the north of the Caribbean low pressure spin is a lengthy axis of cold core upper vorticity… and by 24+ hours the upper air pattern is forecast to become more conducive for its development as the upper vorticity remains cut-off from high-latitude cold air… causing it to weaken and fracture into two lobes to the northeast and northwest where they will further enhance the already existing upper outflow.
In the outlook below… the track forecast for the Caribbean low pressure is stalled for the next 24 hours as the upper atmosphere just east of Nicaragua will be the most favored for low pressure development due to a zone of upper divergence to become established on the southeast side of the forecast northwestern lobe of upper vorticity. Models are in agreement on a largely northward swing in track between 24 and 48 hours… which makes sense due to a myriad of factors including potential fujiwhara interaction with the far eastern Pacific low pressure spin… a surface ridge weakness to the north caused by a frontal system to move into the eastern US from its current western US position… and the influence of the upper vorticity lobe to the northwest. Models then agree on a more westward track after 48 hours… which is possible if the fujiwhara interaction with the eastern Pacific low pressure is ended if the Caribbean low pressure absorbs it… and also expected due to the ongoing weakening of the northwestern lobe of upper vorticity and deep-layer ridge to build over the US in the wake of the departing eastern US frontal system.
Regarding probabilities of Caribbean tropical cyclone formation… my peak 5-day odds of development remain at 30%… slightly lower than the NHC’s 40% as of this writing. I have not raised the peak odds as the thunderstorm activity in the Caribbean low pressure has been on the low side… and as model support showing Caribbean development has decreased. However I have raised shorter-term odds of development (reach the 30% sooner) due to the formation of spiral banding in the cloud pattern. Later in the 5-day forecast period… the odds of development are trimmed down from the 30% peak due to increased land interaction with Belize and southeastern Mexico. With a 30% peak… odds are on the low side. This is a reflection of challenges that could go against Caribbean development… for example too much competition for surface inflow and upper outflow with the eastern Pacific low pressure or too much land interaction with Nicaragua and Honduras should the Caribbean and eastern Pacific low pressures merge over land.
Regarding impacts to land areas:
(1) Regardless of tropical cyclone formation or not… the combo of both the eastern Pacific and Caribbean low pressures may cause heavy rains later this week and into the weekend across Panama… Costa Rica… Honduras… Nicaragua… El Salvador… Guatemala… Belize… and the Mexican provinces Chiapas… Oaxaca… southern Veracruz… Tabasco… Campeche… and southern Quintana Roo. Any excess rains can result in flash flooding or mudslides.
(2) Interests on the south coasts of El Salvador… Guatemala… Chiapas… and Oaxaca should be aware of possible eastern Pacific tropical cyclone formation later this week or this weekend which would increase gusty winds and coastal sea swells. See the NHC website hurricanes.gov (hurricanes dot gov) for more information on potential eastern Pacific development as this site is dedicated to Atlantic tropical activity.
(3) Interests on the east coast of Nicaragua… north coast of Honduras… and the east coast of Belize and the Yucatan peninsula of Mexico (Quintana Roo) should be aware of possible Caribbean tropical cyclone formation later this week which would increase gusty winds and coastal sea swells.
******Infohurricanes.com outlook. Visit hurricanes.gov (hurricanes dot gov) for official outlook***********
IOH 24 Hr Outlook (0000Z Jun 16)… 10% chance of tropical cyclone formation (just offshore of southern Nicaragua near 12N-82.5W)
IOH 48 Hr Outlook (0000Z Jun 17)… 30% chance of tropical cyclone formation (just offshore northern Nicaragua near 14.5N-83W)
IOH 72 Hr Outlook (0000Z Jun 18)… 30% chance of tropical cyclone formation (offshore of Honduras near 16.2N-85.2W)
IOH 96 Hr Outlook (0000Z Jun 19)…20% chance of tropical cyclone formation (northern Belize near 17.5N-88.8W)
IOH 120 Hr Outlook (0000Z Jun 20)…10% chance of tropical cyclone formation (Bay of Campeche Mexico coast near 18.8N-92.5W)
...COMPUTER MODEL SUMMARY...
Source...Florida State University Experimental Forecast Tropical Cyclone Genesis Potential Fields (http://moe.met.fsu.edu/tcgengifs/)
1200Z (Jun 14) CMC Model Run...
** For area of interest #6… Caribbean tropical low becomes better defined after moving northwest to the waters offshore of Belize at 90 hours… after moving across the southern Yucatan peninsula enters the eastern Bay of Campeche by 120 hours.
1200Z (Jun 14) ECMWF Model Run...
** For area of interest #6… Caribbean tropical low becomes better defined after moving northwest to the waters offshore of Belize at 96 hours… after moving across the southern Yucatan peninsula enters the eastern Bay of Campeche by 120 hours.
1800Z (Jun 14) GFS Model Run...
** For area of interest #6… compact tropical low becomes defined in the southern Caribbean Sea just offshore of the Nicaragua/Costa Rica border at 15 hours… stays weak through 63 hours while tracking north along the east coast of Nicaragua… becomes better organized while moving west-northwest across the western Caribbean and becomes a weak tropical cyclone while making landfall on the east coast of the Yucatan peninsula at 90 hours… while moving across the Yucatan through 108 hours weakens to a remnant low… remnant low reaches 20.5N-92.5W in the Bay of Campeche by 120 hours while re-organizing
1200Z (Jun 14) NAVGEM Model Run...
** For area of interest #6… Caribbean tropical low becomes better defined after moving northwest into northeastern Nicaragua and eastern Honduras at 84 hours… subsequently moves west-northwest and arrives to Belize at 138 hours
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