*******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.**********
…TUESDAY JUNE 14 2022 12:11 AM EDT...
See Area of Interest #6 below for more information on the broad area of low pressure materializing in the southern Caribbean Sea… Central America… and far eastern Pacific.
Elsewhere… a pair of cold fronts to enter the Atlantic basin from the continental United States may kick off a tropical disturbance as follows:
(1) A shortwave upper trough currently over the northern US plains and longwave upper trough will work together to drive a cold front into the western Atlantic by 48 hours. The potential for a tropical disturbance along the tail end of this front… at a location offshore of the southeastern US… remains possible as wind shear is expected to be low due to the approach of the current upper ridge developing over the US.
(2) The amplified upper trough currently over the northwestern US will drive the current western US frontal system into the western Atlantic by day 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… The broad area of low pressure across the southern Caribbean Sea… Central America … and far eastern Pacific and its thunderstorms remains supported by the outflow of a tropical upper ridge in the region and a pair of surface tropical waves of low pressure… one at 90W longitude and another at 82.5W. To the north of this disturbance is a lengthy axis of cold core upper vorticity… and by 48+ 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.
The eastern tropical wave is producing a thunderstorm cluster in the vicinity of 12N-80W which is slightly south of the previous forecast track… and so my updated one in the outlook below is nudged south accordingly for the short-term. The track forecast for the possible Caribbean spin-up is stalled at 24 to 48 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 manifested on the southeast side of the forecast northwestern lobe of upper vorticity. Models are in agreement on a largely northward swing in track between 48 and 72 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 lobe to the northwest. Models then agree on a more westward track after 72 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 remain at 30%… slightly lower than the NHC’s recently raised 40% as of this writing. I have not raised the peak odds due to the less organized appearance of the thunderstorm bands in the region which have lost their spiral banding from 24 hours ago. The short-term odds through 48 hours are also lowered into the 0% to 5% range due to the disorganization… and also possible wind shear to be induced by the close proximity of the northwestern upper vorticity lobe. As the upper vorticity then weakens and enhances the upper outflow… odds are ramped up to a 20% to 30% range at 72 to 96 hours… with a trim down to 20% by 120 hours due to increased land interaction with Belize. 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 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 15)… 0% chance of tropical cyclone formation (just offshore of southern Nicaragua near 12N-82.5W)
IOH 48 Hr Outlook (0000Z Jun 16)… 5% chance of tropical cyclone formation (just offshore of southern Nicaragua near 12N-82.5W)
IOH 72 Hr Outlook (0000Z Jun 17)… 20% chance of tropical cyclone formation (just offshore northern Nicaragua near 14.5N-83W)
IOH 96 Hr Outlook (0000Z Jun 18)… 30% chance of tropical cyclone formation (offshore of Honduras near 16.2N-85.2W)
IOH 120 Hr Outlook (0000Z Jun 19)…20% chance of tropical cyclone formation (northern Belize near 17.5N-88.8W)
...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… weak tropical low becomes defined by 84 hours on the coast of Nicaragua while a better-defined tropical low in the eastern Pacific is in progress near 9.8N-88.5W… through 108 hours the two tropical lows merge over the Honduras/Guatemala border… merged circulation moves quickly west-northwest into the Bay of Campeche by 144 hours
1200Z ECMWF Model Run...
** For area of interest #6… no development shown
1800Z GFS Model Run...
** For area of interest #6… compact tropical low becomes defined in the southern Caribbean Sea offshore of the Nicaragua/Costa Rica border at 21 hours and while generally stationary becomes a compact tropical cyclone at 63 hours… northward motion develops which takes the compact tropical cyclone just offshore of the Nicaragua/Honduras border at 90 hours… track turns west-northwest which takes the tropical cyclone to the waters offshore of northern Belize at 120 hours.
1200Z NAVGEM Model Run...
** For area of interest #6… at 48 hours tropical low becomes defined in the southern Caribbean Sea near 10.2N-80.5W… northward motion develops which takes the tropical low just offshore of the Nicaragua/Honduras border at 96 hours where it becomes a tropical cyclone… track turns west-northwest which takes the tropical cyclone to the waters offshore of the Yucatan peninsula east coast near 18N-85W at 120 hours.
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