*******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.**********
...SATURDAY AUGUST 15 2020 10:50 PM EDT...
See Tropical Storm Josephine and Kyle sections below for all active tropical cyclones in the Atlantic basin. See area of interest section below for a central Atlantic tropical wave of low pressure recently introduced into the National Hurricane Center tropical weather outlook being monitored for tropical development over the next few days. Elsewhere...another tropical wave of low pressure currently exiting western Africa is producing a large area of vigorous thunderstorms. Only the CMC computer model suggests development from this wave in the coming days. However should this tropical wave show signs of organization...I will be adding it as another area of interest for tropical development.
TROPICAL STORM JOSEPHINE...Over the last 24 hours Josephine continues to hang on to minimal tropical storm status with 40 to 45 mph maximum sustained winds despite large thunderstorm flare ups aided by the outflow of a tropical upper ridge cell in the region. This is due to disruption from westerly shear induced by the western Atlantic upper trough that Josephine is heading towards. I forecast Josephine to weaken to a remnant low pressure by 48 hours from this shear. Regarding the track forecast...I have nudged the track points northwestward due to the current position of Josephine. The track is expected to curve north as the frontal zone that Tropical Storm Kyle is merging with well to the north is weakening the west side of the Atlantic surface subtropical ridge steering Josephine. It is interesting to note that the 1200Z GFS showed the cold core western Atlantic upper trough weakening and breaking up into upper vortices around 48+ hours due to the warming provided by southerly flow ahead of the frontal system currently over the central United States. The 48 hour forecast point shown below is directly below the southwest side of one of the upper vortices...an enviroment of hostile northwesterly shear and upper convergence and so I still predict dissipation to a remnant low by that time. Will have to assess the situation later to see exactly how the western Atalntic upper trough actually ends up breaking apart...for instance if Josephine has potential to regenerate in a lower shear environment. However should any regeneration occurr...expect Josephine to continue to northward across the open western Atlantic while swept up by the aforementioned frontal system from the central United States.
******Infohurricanes.com forecast. Visit hurricanes.gov (hurricanes dot gov) for official forecast***********
0 Hr Position (1800Z Aug 15)...45 mph maximum sustained wind tropical storm centered just northeast of the northern Lesser Antilles at 20N-61.6W
IOH 24 Hr Forecast (1200Z Aug 16)...35 mph maximum sustained wind tropical depression centered north of Puerto Rico at 21N-66W
IOH 48 Hr Forecast (1200Z Aug 17)...Remnant surface low pressure centered in the western Atlantic at 25N-68.5W
TROPICAL STORM KYLE...The northwestern Atlantic tropical area of low pressure that organized in a low shear and upper outflow environment of warm upper ridging ahead of an incoming frontal zone from the eastern United States became Tropical Storm Kyle in the last 24 hours...and it is now already doubtful that Kyle is a tropical system as the frontal zone has overran the circulation and the upper trough associated with the frontal zone has strongly sheared the tropical storm's thunderstorm bursts eastward from the center...while also supporting Kyle's low pressure with its upper divergence much like a non-tropical system. Therefore expecting Kyle to be declared a non-tropical remnant frontal low shortly as it continues east-northeastward briskly across the northwestern Atlantic. I have updated my track forecast to be further to the east-northeast given the current position of Kyle compared to my previous forecast. Going forward...it appears Kyle's remnant frontal low will weaken while a much larger and more powerful frontal cyclone takes hold in the northeast Atlantic. This has to do with the evolution of the front's upper trough. Specifically the northeast part of the upper trough will amplify into a tremendous upper vortex as an eastern Canada upper ridge continues to amplify adjacent to it...producing the larger surface northeastern Atlantic frontal cyclone with its expansive eastern upper divergence zone...with this frontal cyclone likely to absorb Kyle's remnant. This is my planned final statement on Kyle as I expect it to be downgraded to a remnant non-tropical low pressure shortly.
*****Infohurricanes.com forecast. Visit hurricanes.gov (hurricanes dot gov) for official forecast***********
0 Hr Position (1800Z Aug 15)...50 mph maximum sustained wind tropical storm centered in the northwestern Atlantic at 39.4N-63.2W
IOH 24 Hr Forecast (1800Z Aug 16)...Remnant gale force frontal low pressure centered in the northwestern Atlantic at 42N-57.5W
AREA OF INTEREST #1...As I was putting this birdseye view post together tonight...behold yet another area of interest for tropical development has been added to the National Hurricane Center tropical weather outlook. This area of interest is a tropical wave of low pressure crossing 45W longitude...featuring some cloudiness suggesting rotation with a clump of thunderstorms just southwest of the rotation center. This tropical wave has been suppressed thus far by dry saharan air streaming from Africa. The only computer model run during the 1200Z cycle that suggested development from this tropical wave was the CMC. Therefore despite this tropical wave remaining tucked beneath a cell of upper ridging thru the forecast period (which will provide favorable low shear and upper outflow for potential tropical development)...I have only cautiously raised my odds of tropical cyclone formation thru the forecat period at this time. Regarding the forecast track...the upper trough over central North America and its associated surface cold front over the central United States are currenty forecast to pass too far north to weaken the steering Atlantic subtropical ridge. Therefore a steady west-northwest track across the Lesser Antilles and into the Caribbean Sea is expected.
******Infohurricanes.com outlook. Visit hurricanes.gov (hurricanes dot gov) for official outlook***********
IOH 24 Hr Outlook (1800Z Aug 16)...10% chance of tropical cyclone formation (tropical Atlantic near 12.5N-50W)
IOH 48 Hr Outlook (1800Z Aug 17)...15% chance of tropical cyclone formation (tropical Atlantic near 13N-55W)
IOH 72 Hr Outlook (1800Z Aug 18)...20% chance of tropical cyclone formation (Lesser Antilles near 13.5N-60W)
IOH 96 Hr Outlook (1800Z Aug 19)...25% chance of tropical cyclone formation (eastern Caribbean Sea near 14N-65W)
IOH 120 Hr Outlook (1800Z Aug 20)...30% chance of tropical cyclone formation (central Caribbean Sea near 14.5N-70W)
...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 Tropical Storm Josephine...opens into a remnant trough of low pressure just northeast of the Bahamas in 48 hours. For Tropical Storm Kyle...transitions into non tropical frontal low near 40N-60W by 24 hours...becomes absorbed by northeast Atlantic frontal cyclone while moving into the Azores in 90 hours. Elsewhere...tropical wave currently at west African coast organizes into a tropical low pressure near 13N-45W in 126 hours...tropical cyclone formation shown in long range. Tropical wave currently at 45W (new area of interest #1) organizes into a tropical low pressure just southwest of Jamaica in 126 hours...tropical cyclone formation suggested in long range,
1200Z ECMWF Model Run...For Tropical Storm Josephine..,weakens to a remnant trough just north of Puerto Rico in 24 hours. For Tropical Storm Kyle...transitions into non tropical frontal low near 41N-57.5W by 24 hours...becomes absorbed by northeast Atlantic frontal cyclone while moving just south of the Azores in 96 hours. For area of interest #1...no tropical cyclone formation shown
1200Z GFS Model Run...For Tropical Storm Josephine...opens into a remnant trough north-northwest of Puerto Rico in 36 hours. For Tropical Storm Kyle...transitions into non tropical frontal low near 40N-58.5W by 24 hours...becomes absorbed by northeast Atlantic frontal cyclone while near 44N-20W in 90 hours. For area of interest #1...no tropical cyclone formation shown
1200Z NAVGEM Model Run...For Tropical Storm Josephine...opens into a remnant trough of low pressure just southwest of Bermuda in 90 hours. For Tropical Storm Kyle...transitions into non tropical frontal low near 41N-59W by 24 hours...becomes absorbed by northeast Atlantic frontal cyclone while moving just north of the Azores in 78 hours. For area of interest #1...no tropical cyclone formation shown