*******Note that forecast 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 OCTOBER 7 2022 3:38 AM EDT...
Tropical Depression Twelve in the eastern tropical Atlantic has weakened to a remnant trough of low pressure... see remnants of twelve section below for more information. Elsewhere... the next tropical depression... thirteen... has formed while crossing the Paraguana and Guajira peninsula regions of northwestern Venezuela and northern Colombia. This system has potential to bring significant hurricane impacts to the east coast of Nicaragua by Sunday... with what remains of this system potentially spreading impacts into southern Honduras... El Salvador... and southern Guatemala through day five. See tropical depression thirteen section below for additional information on this developing situation.
TROPICAL DEPRESSION TWELVE (RECENTLY DOWNGRADED TO REMNANTS OF TWELVE)...The tropical depression in the eastern tropical Atlantic has moved closer to the nearby upper vortex and associated shearing upper southwesterly winds to the northwest. The shear has made it challenging for the depression to fire thunderstorms over its swirl center... as a result the depression has succumbed and was downgraded to a remnant trough of low pressure at 11 PM EDT. Over the next 120 hours... the current eastern North America upper trough... followed by an additional second upper trough to quickly follow behind from central Canada... are expected to sweep into the western Atlantic with the eastern divergence zone of the troughs weakening the Atlantic surface ridge. Therefore if the remnants of the depression survives it passage beneath the nearby upper vortex to the northwest... the remnants will continue west-northwest into the open central Atlantic and toward the aforementioned Atlantic surface ridge weakness. At this location... the remnants could make a comeback beneath the southwest side of the central Atlantic upper ridge where shear is lower and upper outflow is higher... or alternatively make a comeback as a subtropical disturbance enhanced by the eastern divergence zone of the western Atlantic upper troughing... particularly if the upper troughing becomes amplified enough as to not excessively shear the remnants. None of the models have returned to showing the remnants making a comeback... and it is not guaranteed in the short-term the remnants will survive its current encounter with the nearby upper vortex. Therefore this is my planned final statement on this system on this blog. However should models return in showing the remnants re-developing... or if observations during future updates warrant... I will re-introduce the remnants of this system as an area of interest on this blog as needed.
AREA OF INTEREST #35 (RECENTLY UPGRADED TO TROPICAL DEPRESSION THIRTEEN)...The vigorous tropical wave of low pressure which recently crossed the ABC Islands (Aruba Bonaire and Curacao)... northwestern Venezuela... and south-central edge of the Caribbean Sea was upgraded to potential tropical cyclone thirteen by the NHC at 11 AM EDT Thursday as their were concerns about the wave developing tropical storm force winds before establishing a well-defined center... thus allowing for the issuance of a tropical storm warning for the Guajira peninsula of Colombia. As of 11 PM EDT... the NHC cited a better defined spin developing on doppler radar from the ABC Islands... and combined with additional data from aircraft reconnaissance upgraded this system to tropical depression thirteen as the better-defined center moved into the Paraguana peninsula of northwestern Venezuela. The thunderstorm mass which contains the rotating center of the depression is already spreading into the Guajira peninsula and adjacent far northern parts of Colombia. Meanwhile the surrounding sprawling thunderstorm clusters that previously reached well south into Venezuela have fizzled... another indication that this system is consolidating into a compact tropical cyclone beneath the remaining thunderstorm mass. Outer skeletal northern bands of activity to the north of the thunderstorm mass and over water are also signs that a tropical cyclone has formed... and all systems are a go for tropical depression thirteen to mature into a stronger tropical cyclone once it clears northern Colombia and reaches the more open south-central Caribbean water.
The depression is west of my previous forecast track... and my updated one is adjusted accordingly. The surface ridge weakness associated with the current northwestern Atlantic frontal low is closing as the frontal low continues lifting northeastward and away... meanwhile the western convergence zone of the current eastern North America upper trough is building a strong surface ridge that will soon roll into the United States from Canada. This ridge will keep this system on a steady westward heading toward and then into Nicaragua by 48 and 72 hours. Afterwards an amplified western Canada upper trough is expected to support a sprawling frontal cyclone that will weaken the west side of the steering surface ridge... therefore by days 4 and 5 the westward track of this system is expected to slow down and bend more north. This will result in this system moving into western Central America and southeastern Mexico... or alternatively hug the eastern Pacific coastline from El Salvador to southeastern Mexico. Because this system is launching its westward heading at the southern latitude of 12N... my track forecast currently opts for the more south eastern Pacific long-range scenario. Regarding intensity... it appears the strong thunderstorm activity of this system has generated enough latent heat to build a southeastern Caribbean upper anticyclone. If this upper anticyclone is maintained... which could very well be the case as this system is maintaining a strong thunderstorm mass... it may be able to ward off some of the effects of northerly shear to be induced by the northern Caribbean upper ridge axis. Therefore my current intensity forecast starts off similar to the NHC's 11 PM EDT advisory as this system first needs to recover from land interaction with northern Colombia... followed by a higher strengthening rate than shown by the NHC while en route to Nicaragua. I currently expect this system to peak as a top-end category 1 or category 2 hurricane between 48 and 72 hours for its Nicaragua landfall. I did not project a higher intensity than this at this time as I still anticipate a little bit of northerly shear. Due to this potential landfall intensity along the current and expected brisk westward track... I also forecast this system to maintain its tropical cyclone status while heading into the eastern Pacific. If this ends up being the case... this system will retain its Atlantic name in the eastern Pacific and therefore I will continue forecasting this system should any crossover into the eastern Pacific occur. For the eastern Pacific part of my forecast track... this system will remain under the low shear/upper outflow of tropical upper ridging and be over warm waters. However I show only a cautious gradual strengthening rate due to the uncertainty regarding how much land interaction this system will be experiencing... with a further south track leading to less interaction and a more northern track increasing land interaction.
Regarding impacts to land areas:
(1) Heavy rainfall with flash flooding potential and gusty winds will continue over far northwestern Venezuela and northern Colombia... especially the Guajira peninsula... for the rest of the morning hours. Weather conditions will improve by the afternoon and evening as this system continues westward and away.
(2) I recommend that interests along the east coast of Nicaragua begin preparing for potentially severe hurricane force wind and coastal storm surge to arrive by Sunday morning. Inland areas in central Nicaragua should also prepare for tropical storm force winds with some damage potential to arrive by Sunday evening. Heavy rainfall with flash flooding and mudslide potential is another hazard to consider.
(3) There is potential for heavy rainfall... with flash flood potential... to spread across southern Honduras... El Salvador... and southern Guatemala by early next week. Gusty winds along coastal El Salvador and the south-facing eastern Pacific coast of Guatemala cannot be ruled out... especially if this system crosses over into the eastern Pacific while maintaining tropical cyclone status.
******Infohurricanes.com forecast. Visit hurricanes.gov (hurricanes dot gov) for official forecast***********
0 Hr Position (0000Z Oct 7)...35 mph maximum sustained wind tropical depression centered over the Paraguana Peninsula of northwestern Venezuela at 11.9N-69.8W
IOH 24 Hr Forecast (0000Z Oct 8)...50 mph maximum sustained wind tropical storm centered in the south-central Caribbean Sea at 12N-75W
IOH 48 Hr Forecast (0000Z Oct 9)...85 mph maximum sustained wind hurricane centered east of Nicaragua at 12N-80W
IOH 72 Hr Forecast (0000Z Oct 10)...65 mph maximum sustained wind tropical storm centered over central Nicaragua at 12N-85W
IOH 96 Hr Forecast (0000Z Oct 11)...40 mph maximum sustained wind tropical storm centered in the eastern Pacific just offshore of El Salvador at 12.5N-89W
IOH 120 Hr Forecast (0000Z Oct 12)...50 mph maximum sustained wind tropical storm centered in the eastern Pacific just offshore of the Guatemala/Mexico border at 14N-92.5W
...COMPUTER MODEL SUMMARY...
Source...Florida State University Experimental Forecast Tropical Cyclone Genesis Potential Fields (http://moe.met.fsu.edu/tcgengifs/)
1200Z (Oct 6) CMC Model Run...
**For Tropical Depression Twelve... becomes a remnant trough near 18N-36W at 6 hours
**For area of interest #35... tropical cyclone formation suggested just offshore of the Guajira peninsula west coast at 30 hours... makes landfall on the northern Nicaragua coast at 84 hours as a potential hurricane after which time the landfall weakens it to a remnant low... remnant low located over the Guatemala/Mexico border at 120 hours.
1200Z (Oct 6) ECMWF Model Run...
**For Tropical Depression Twelve... initialized as a remnant trough at 0 hours
**For area of interest #35... tropical cyclone formation suggested just offshore of the Guajira peninsula west coast at 24 hours... makes landfall on the central Nicaragua coast at 72 hours as a compact hurricane after which time the landfall weakens it to a remnant low... remnant low located in the eastern Pacific offshore of Guatemala at 120 hours.
1800Z (Oct 6) GFS Model Run...
**For Tropical Depression Twelve... weakens to a remnant trough near 18N-37W at 9 hours
**For area of interest #35... tropical cyclone formation suggested over the Guajira peninsula at 18 hours... makes landfall on the north coast of Nicaragua at 66 hours as a top-end tropical storm after which time the landfall weakens it to a remnant low... remnant low located over the Guatemala/Mexico border at 120 hours.
1800Z (Oct 6) NAVGEM Model Run...
**For Tropical Depression Twelve... initialized as a remnant trough at 0 hours
**For area of interest #35... tropical cyclone formation suggested near 13.8N-74.5W at 30 hours... makes landfall on the northeast coast of 78 hours after which time it moves westward along the coast... shifts more northwest in track into western Caribbean waters at 90 hours... makes landfall over northern Belize at 102 hours... after crossing the Campeche province of Mexico the tropical cyclone enters the eastern Bay of Campeche at 120 hours.
**Tropical wave currently over central Africa emerges from west coast of Africa at 120 hours... organizes into a tropical low near 11N-19W at 132 hours... tropical cyclone formation suggested near 10.5N-24W at 168 hours.
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