MY 2020 ATLANTIC HURRICANE SEASON BIRDSEYE VIEW POST #173
*******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 NOVEMBER 7 2020 10:05 PM EDT...
See Tropical Storm Eta section below for the only active tropical cyclone in the Atlantic basin. See area of interest section below for the open central Atlantic disturbance being currently monitored in the NHC 5-day tropical weather outlook.
TROPICAL STORM ETA...See special update #172A posted on the home page of this site for technical information on Eta. Forecast below is an updated version of the forecast from the special update...but with another upward adjustment in intensity due to recent strengthening and also due to the current strength of the thunderstorms in Eta’s circulation.
*The Cayman Islands have already seen tropical storm conditions...conditions will quickly improve as Eta moves away
*Central Cuba will see strong tropical storm conditions tonight...time to prepare is over
*The western Bahamas will see tropical storm conditions by tomorrow morning...preparations must be finished tonight!
*Interests in south Florida and Florida Keys will see tropical storm or hurricane force conditions by tomorrow night and into Monday. Tomorrow is the last day to prepare! When in public...wearing a mask and frequent hand sanitizing will protect you from the COVID-19 virus. If you live in an area prone to coastal storm surge impacts...think of a family/friend residence or a hotel you can relocate to in case you may have to do so in the coming days...as a public storm shelter may not be as ideal in controlling your exposure to COVID-19.
*Interests in the northern Florida peninsula should gather storm preparation supplies early as Eta has a high chance of moving across the region as a tropical storm on Wednesday. This is to avoid last minute shopping crowds amid the COVID-19 outbreak. Also see previous bulletin for other advice related to preparing for Eta during the outbreak.
0 Hr Position (0000Z Nov 8)...65 mph maximum sustained wind tropical storm centered just north of the Cayman Islands at 20.7N-79.9W
IOH 24 Hr Forecast (0000Z Nov 9)...80 mph maximum sustained wind hurricane centered just west of Andros Island of the western Bahamas at 24.2N-79.2W
IOH 48 Hr Forecast (0000Z Nov 10)...80 mph maximum sustained wind hurricane centered over the southwestern Florida peninsula coast at 25.4N-80.7W
IOH 72 Hr Forecast (0000Z Nov 11)...80 mph maximum sustained wind hurricane centered over the eastern Gulf of Mexico at 26.7N-84.5W
IOH 96 Hr Forecast (0000Z Nov 12)...65 mph maximum sustained wind tropical storm centered offshore of the northwest Florida peninsula coast at 28.2N-83.8W
IOH 120 Hr Forecast (0000Z Nov 13)...35 mph maximum sustained wind tropical depression centered inland over southeastern Georgia at 31N-82W
AREA OF INTEREST #1...A surface low pressure has formed in the open central Atlantic near 26N-51W with the support of the eastern divergence zone of an upper trough fragment that has been left behind in the region. As a deep-layered ridge amplifies over the eastern United States and western Atlantic...this upper trough fragment and current upper trough exiting eastern Canada will merge together and amplify while shifting into the eastern Atlantic...giving an opportunity for the current central Atlantic surface low pressure to strengthen. However given that the merged upper trough is forecast to be elongated southwest-to-northeast...it will produce southwesterly shear across the surface low and also make the surface low elongated without a well-defined center as the supporting upper divergence zone of the upper trough will be elongated in this configuration. Therefore not forecasting above-zero odds of subtropical cyclone formation at this time despite the introduction of this disturbance into the NHC 5-day tropical weather outlook over the last day.
IOH 24 Hr Outlook (0000Z Nov 9)...0% chance of subtropical cyclone formation (central Atlantic near 26N-50W)
IOH 48 Hr Outlook (0000Z Nov 10)...0% chance of subtropical cyclone formation (central Atlantic near 26N-45W)
IOH 72 Hr Outlook (0000Z Nov 11)...0% chance of subtropical cyclone formation (central Atlantic near 29N-40W)
IOH 96 Hr Outlook (0000Z Nov 12)...0% chance of subtropical cyclone formation (eastern Atlantic near 31N-35W)
IOH 120 Hr Outlook (0000Z Nov 13)...0% chance of subtropical cyclone formation (south of the Azores and west of the Canary Islands near 32.5N-25W)
...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 Tropical Storm Eta...crosses central Cuba at 42 hours...turns northwest and passes over the Florida Keys at 54 hours as a strengthening tropical storm...reaches southeast Gulf of Mexico at 22.5N-87.5W at 84 hours...drifts very slowly northeast thru 120 hours while becoming a hurricane still located in the southeastern Gulf of Mexico. For area of interest #1...broad surface low forms near 25N-51W at 42 hours...becomes elongated near 26N-42.5W at 72 hours...elongated circulation reaches waters southwest of the Azores near 35N-31W at 120 hours. Elsewhere...tropical wave currently at 55W longitude organizes into a broad tropical low pressure in south-central Caribbean Sea near 13.5N-75W at 150 hours...possible tropical cyclone formation suggested in longer range.
0000Z ECMWF Model Run...For Tropical Storm Eta...strengthens while passing just northwest or Grand Cayman Island at 24 hours...crosses western Cuba by 48 hours...after passing just southwest of the Florida Keys strengthens into a hurricane near 25N-85W by 72 hours...drifts northward to 27N-86W by 120 hours. For area of interest #1...broad surface low forms near 27.5N-47.5W at 48 hours...becomes elongated near 30N-40W at 72 hours...elongated circulation reaches 31N-32W at 120 hours.
1200Z GFS Model Run... For Tropical Storm Eta...crosses central Cuba as a strong tropical storm at 18 hours...crosses Florida Keys as a hurricane at 42 hours...reaches 26N-96W at 90 hours...drifts slowly eastward toward waters offshore of the southwest Florida coast through 120 hours. For area of interest #1...elongated surface low forms near 28.5N-46W at 42 hours...northeast part of elongated circulation becomes a tight consolidated circulation centered just southeast of the Azores near 36N-25W...consolidated center stays stationary through 120 hours.
0600Z NAVGEM Model Run...For Tropical Storm Eta...passes over Cayman Islands at 18 hours...passes over central Cuba by 36 hours...curves northwestward into southeast Florida by 54 hours while strengthening into a strong tropical storm...reaches northeast Gulf of Mexico by 66 hours...while performing a counter-clockwise loop turn over the eastern Gulf of Mexico becomes a hurricane by 90 hours...while drifting northeast makes landfall on northwest coast of Florida peninsula at 102 hours...reaches northeast Florida coast after weakening to a tropical storm at 120 hours. For area of interest #1...surface low forms near 27.5N-47.5W at 30 hours...surface low becomes stronger but also elongated as it reaches 31.5N-30W at 120 hours. Elsewhere...tropical wave currently at 55W longitude organizes into a broad tropical low pressure in the eastern Caribbean Sea by 114 hours...in long range drifts northeastward towards Puerto Rico.