*******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 JUNE 13 2022 1:46 AM EDT...
See Area of Interest #6 below for more information on the gyre of low pressure currently developing in the southern Caribbean Sea and parts of Central America. Elsewhere… upper vorticity over western Canada is separating from the current upper vortex making landfall on the west coast of Canada. This upper vorticity is expected to deliver a shortwave upper trough that travels from the northern US plains in 12 hours to the mid-Atlantic US coastal region by 48 hours. The shortwave upper trough will tag team with the current eastern Canada upper trough to drive a surface cold front into the western Atlantic in 2 to 3 days. The potential for tropical development along the tail end of this front… at a location offshore of the southeastern US… at this time appears possible as wind shear is expected to be low due to the approach of the current upper ridge developing over the US. However at this time I have not added this frontal system as an area of interest for tropical development as models have stopped showing such a solution over the last couple of days.
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… A broad area of spin and scattered thunderstorms is currently present across the southern Caribbean Sea… Nicaragua… and Costa Rica. This area of disturbed weather is being supported by the outflow of a tropical upper ridge in the region and a pair of surface tropical waves of low pressure… one at 87.5W longitude and another at 77.5W. To the north of this disturbance is a lengthy axis of cold core upper vorticity… and by 72+ hours the upper air pattern is forecast to become more conducive for tropical development of this disturbance 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. The western of the two aforementioned tropical waves will likely spin up into a far eastern Pacific disturbance located offshore of either western Nicaragua… El Salvador… or Guatemala… 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. Meanwhile the eastern tropical wave will likely spin up into a southern or western Caribbean disturbance… and as of 2 PM EDT Sunday the NHC began issuing probability outlooks for Caribbean tropical cyclone formation in their tropical weather outlook product. With this… this marks the sixth area of Interest I have monitored for Atlantic tropical development on this blog this year.
Declaring an area of interest in the Caribbean seems reasonable as the NAVGEM and CMC models have recently joined in the GFS in showing Caribbean side development in addition to far eastern Pacific development. The ECMWF is the only hold out among the major global models while only showing eastern Pacific development. The track forecast for the possible Caribbean spin-up in the outlook below initially shows a west track across the southern Caribbean in association with the current westward-tracking tropical wave at 77.5W longitude. The track is then paused at 48 to 72 hours as the upper atmosphere just east of Nicaragua will be the most favored for surface low pressure spin-up as an upper divergence maximum forms between the northwestern and northeastern lobes of upper vorticity. Models are in agreement on a largely northward swing in track between 72 and 96 hours… which makes sense due to a myriad of factors including potential fujiwhara interaction with the twin 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 the western US… and the influence of the upper vorticity to the northwest. Models then agree on a more westward track between 96 and 120 hours… which is possible if the fujiwhara interaction with the eastern Pacific twin is ended if the Caribbean spin absorbs it… and also possible 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 are 30%… slightly higher than the NHC’s 20% as of this writing… due to increasing computer model support showing Caribbean-side development. The odds are initially at a low 0% to 10% for the next 72 hours as a well-defined Caribbean surface low pressure spin is not yet in progress… which will be a prerequisite needed before tropical cyclone formation can happen. Odds are ramped up to 20% to 30% by 96 and 120 hours as the upper air pattern improves with the fracturing of the nearby upper vorticity into two lobes. Even at 30%… odds are still on the low side as we are waiting to see if the models continue to support Caribbean side development… and it is possible that any Caribbean-side development becomes impeded by too much competition for surface inflow and upper outflow with the forecast eastern Pacific twin disturbance or too much land interaction with Nicaragua and Honduras should the Caribbean and eastern Pacific twin disturbances merge over land.
Regarding impacts to land areas:
(1) Regardless of tropical cyclone formation or not… heavy rains are possible this week across Panama… Costa Rica… Honduras… Nicaragua… El Salvador… Guatemala… and Belize. Any excess rains can result in flash flooding or mudslides.
(2) Interests on the west coast of Nicaragua… and south coasts of Honduras… El Salvador… and Guatemala should be aware of possible eastern Pacific tropical cyclone activity this week 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 should be aware of possible Caribbean tropical cyclone activity 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 14)… 0% chance of tropical cyclone formation (southern Caribbean near 12.5N-80W)
IOH 48 Hr Outlook (0000Z Jun 15)… 10% chance of tropical cyclone formation (just offshore of Nicaragua near 12.5N-82.5W)
IOH 72 Hr Outlook (0000Z Jun 16)… 10% chance of tropical cyclone formation (just offshore of Nicaragua near 12.5N-82.5W)
IOH 96 Hr Outlook (0000Z Jun 17)… 20% chance of tropical cyclone formation (just offshore of the Nicaragua/Honduras border near 15N-83W)
IOH 120 Hr Outlook (0000Z Jun 18)… 30% chance of tropical cyclone formation (offshore of Honduras near 16.2N-85.2W)
...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 #6… Central American gyre of low pressure becomes defined by 114 hours with one tight eastern Pacific center just offshore of western Nicaragua and one Caribbean center just offshore of northern Honduras… Caribbean center makes landfall in the northeastern Yucatan peninsula at 132 hours
1200Z ECMWF Model Run...
** For area of interest #6… no development shown
1800Z GFS Model Run...
** For area of interest #6… southern Caribbean low pressure becomes defined just offshore of Costa Rica and southern Nicaragua at 63 hours… while stationary it becomes a tropical cyclone at 72 hours… northward motion develops which takes the compact and strengthening tropical cyclone just offshore of the Nicaragua/Honduras border at 102 hours… track turns west-northwest which takes the strong tropical cyclone to the waters just offshore of northeastern Honduras at 120 hours.
1200Z NAVGEM Model Run...
** For area of interest #6… at 60 hours tropical low becomes defined in southern Caribbean just north of Panama near 10.5N-80.5W… becomes a tropical cyclone just east of southern Nicaragua at 96 hours… northward motion develops which takes the strengthening tropical cyclone just offshore of the Nicaragua/Honduras border at 114 hours… tropical cyclone makes landfall in the northeastern Yucatan peninsula at 162 hours.