*******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 OCTOBER 10 2020 6:02 PM EDT...
See remnants of Delta section below for a final statement on the former hurricane. See area of interest sections below for other areas being monitored for tropical development.
Elsewhere...models have agreed today that the shortwave upper trough currently crossing the Great Lakes region of North America will not amplify enough to trigger possible subtropical cyclone formation in the open central Atlantic in a few days. Therefore not adding another area of interest for subtropical development.
REMNANTS OF DELTA...The upper trough over Texas/Mexico has finally been pushed eastward into Delta after making landfall in Louisiana as a hurricane...thanks to the added influence of the fast moving shortwave upper trough from western Canada that is now crossing the Great Lakes. The landfall and shear from the upper trough has weakened Delta from a hurricane to a remnant low pressure as the center moves into northwestern Mississippi. The remnant low is transitioning into a non-tropical frontal low supported by the eastern divergence zone of the upper trough. Heavy rain bands over Mississippi...Alabama....eastern Arkansas...Tennessee...and Kentucky are directly from the circulation of Delta...while the band of rain further east spreading across the Virginias and North Carolina is from the divergence zone of the Great Lakes shortwave upper trough making rainfall with moisture pulled from Delta. The remnant low of Delta does not have much of a future left...as its supporting cold core upper trough will become washed out by the warm sector of a strong frontal cyclone to develop over western North America as Delta moves into Tennessee and Kentucky over the next day or so. This is my final statement on Delta on this blog as it is no longer a tropical cyclone.
AREA OF INTEREST #1...The tropical wave of low pressure from the central Caribbean Sea is now in the western Caribbean...and despite the weakening upper vortex exiting the region while the western Atlantic upper ridge with low shear and upper outflow dominates the region...there is only a weak area of showers at the north end of the wave in the vicinity of the Cayman Islands. Perhaps then the southerly surface flow streaming into the remnant low pressure of Delta to the north is preventing this tropical wave from having its own inflow needed for thunderstorms...this is my final statement on this tropical wave on this blog.
******Infohurricanes.com outlook. Visit hurricanes.gov (hurricanes dot gov) for official outlook***********
IOH 24 Hr Outlook (1800Z Oct 11)...0% chance of tropical cyclone formation (northwestern Caribbean Sea near 19N-85W)
AREA OF INTEREST #2...The vigorous tropical wave of low pressure in the eastern tropical Atlantic has continued to produce thunderstorm activity with some signs of organization under the outflow of a tropical upper ridge as it moves into the central tropical Atlantic. In the updated outlook below I have initialized the lowest pressure of this system to be further west near 9.9N-39W where a smaller and tighter spin than yesterday appears to be present on satellite animation. Due to the better defined spin...I have raised my peak odds of tropical cyclone formation to 30%. Forecast track shows a northward angle in the westward track from a developing surface ridge weakness to the north as the eastern Canada frontal cyclone sends it main front as well as another front and its shortwave upper trough from the Great Lakes region into the central Atlantic. Southwesterly shear from the shortwave upper trough may increase as soon as 48 hours...therefore if anything develops by that time it will likely be a weak and sheared system. By 72 hours the shear should be too high for tropical development...so I end the outlook by then with 0% odds of development.
******Infohurricanes.com outlook. Visit hurricanes.gov (hurricanes dot gov) for official outlook***********
IOH 24 Hr Outlook (1800Z Oct 11)...15% chance of tropical cyclone formation (central tropical Atlantic near 10.5N-44W)
IOH 48 Hr Outlook (1800Z Oct 12)...30% chance of tropical cyclone formation (central tropical Atlantic near 11.8N-49W)
IOH 72 Hr Outlook (1800Z Oct 13)...0% chance of tropical cyclone formation (central tropical Atlantic near 14N-53W)
Satellite Image of Africa from 2100Z showing area of interest #3:
AREA OF INTEREST #3...CMC and NAVGEM models join the GFS in showing potential tropical development in the eastern tropical Atlantic from a tropical wave to emerge from western Africa...adding new area of interest. Based on the latest satellite imagery...the tropical wave of interest is over central Africa near 10N-2E...and will emerge into the eastern tropical Atlantic in 3 to 4 days where a tropical upper ridge with low shear and upper outflow will persist and may potentially aid in developing this wave. I have low 20% odds of tropical cyclone formation by day 5 at this time as the model consensus is relatively new and may change in the coming days. ******Infohurricanes.com outlook. Visit hurricanes.gov (hurricanes dot gov) for official outlook*********** IOH 24 Hr Outlook (1800Z Oct 11)...0% chance of tropical cyclone formation (western Africa near 10N-3W) IOH 48 Hr Outlook (1800Z Oct 12)... 0% chance of tropical cyclone formation (western Africa near 10N-8W) IOH 72 Hr Outlook (1800Z Oct 13)...0% chance of tropical cyclone formation (western Africa near 10N-13W) IOH 96 Hr Outlook (1800Z Oct 14)...10% chance of tropical cyclone formation (eastern tropical Atlantic near 11N-18W) IOH 120 Hr Outlook (1800Z Oct 15)...20% chance of tropical cyclone formation (eastern tropical Atlantic near 11.5N-23W)
...COMPUTER MODEL SUMMARY... Source...Florida State University Experimental Forecast Tropical Cyclone Genesis Potential Fields (http://moe.met.fsu.edu/tcgengifs/) 0000Z CMC Model Run....For areas of interest #1 and #2...no tropical cyclone formation shown. For area of interest #3...tropical wave with organized low pressure spin emerges from western Africa at 72 hours...low pressure spin opens back into a wave near 27.5W longitude at 120 hours. 0000Z ECMWF Model Run....For areas of interest #1...#2 and #3...no tropical cyclone formation shown. 1200Z GFS Model Run...For areas of interest #1 and #2...no tropical cyclone formation shown. For area of interest #3...tropical wave with organized low pressure spin emerges from western Africa at 72 hours...possible weak tropical cyclone formation as wave passes south of the Republic of Cabo Verde Islands...located at 12.5N-27.5W at 120 hours. 0600Z NAVGEM Model Run...For area of interest #1...no tropical cyclone formation shown. For area of interest #2...tropical wave organizes into a tropical low pressure spin at 10N-47W at 48 hours...tropical cyclone formation suggested at 11.5N-55W at 78 hours...located east of the Lesser Antilles at 16N-58W at 120 hours. For area of interest #3...tropical wave with organized low pressure spin emerges from western Africa at 108 hours...possible weak tropical cyclone formation suggested over the Republic of Cabo Verde Islands in the long range.