*******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 OCTOBER 16 2019 10:38 AM EDT...
The broad tropical low pressure with showers and thunderstorms over southeastern Mexico...eastern Pacific...and Bay of Campeche has split into eastern Pacific potential tropical cyclone Seventeen-E making landfall in southeastern Oaxaca this morning...and what appears to be another developing low pressure with somewhat organized thunderstorms on the Bay of Campeche coast of Veracruz...albeit the Veracruz circulation does not appear to be fully closed due to the current dominance of Seventeen-E just to the south. This special update is to increase the short-term odds of tropical cyclone formation for the Veracruz/Bay of Campeche feature due to its current satellite presentation...and adjust the forecast track of this feature due to its current position. As such my updated forecast track in the short-term is nudged northwestward...and in the long term is adjusted northeastward as the more north position of the Veracruz/Bay of Campeche feature means it will be closer to the surface presssure falls scheduled to occur in the northeastern Gulf of Mexico due to the supportive divergence zone of a cut-off upper trough to break off from the current central US frontal system. Although I have made the short-term odds of development higher...I have nudged them downward in the longer term as the more north position exposes the disturbance to more wind shear from the passing cut-off upper trough and subsequently a much larger upper trough associated with an apporaching western US frontal system. The longer term uncertainty is also higher with this disturbance due to the more north position...as it is unclear whether or not the disturbance will lose its identity while too close other low pressure to form in the northeastern Gulf...and if so would the northeastern Gulf low pressure acquire tropical charactersitcs while making landfall in the Florida Panhandle? For now I assume this feature will remain seperate from the northeastern Gulf feature...as such by 102 hours getting caught south of the western convergence zone of the passing cut-off upper trough and associated increase in surface ridging over the southeastern US...with the surface ridging blocking eastward progress such that I show a northward hook in track into the Alabama coast. Again a reminder that the longer range outlook on this disturbance has higher than usual uncertainty until its clear how the interaction with the northeastern Gulf low pressure plays out...thus the longer-range forecast positions could change again.
******Infohurricanes.com outlook. Visit hurricanes.gov (hurricanes dot gov) for official outlook***********
IOH 6 Hr Outlook (1800Z Oct 16)...0% chance of tropical cyclone formation (coastal Veracruz near 20N-96W)
IOH 30 Hr Outlook (1800Z Oct 17)...30% chance of tropical cyclone formation (coastal Veracruz near 21.5N-97W)
IOH 54 Hr Outlook (1800Z Oct 18)....35% chance of tropical cyclone formation (western Gulf of Mexico near 23N-95W)
IOH 78 Hr Outlook (1800Z Oct 19)...25% chance of tropical cyclone formation (central Gulf of Mexico near 26N-92.5W)
IOH 102 Hr Outlook (1800Z Oct 20)...20% chance of tropical cyclone formation (coastal Alabama near 30N-88W)