*******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.**********
...TUESDAY JUNE 1 2021 10:40 AM EDT...
Today marks the first official day of the 2021 Atlantic Hurricane Season. As such...I have begun issuing daily birdseye view posts on the Atlantic tropics. See area of interest #1 section below for remarks on the upper-level disturbance currently located offshore of south Florida and over the western Bahamas. It is quiet elsewhere in the Atlantic tropics.
AREA OF INTEREST #1...The south end of the current northwestern Atlantic upper trough has become cut-off into a western Atlantic upper vortex located offshore of south Florida due to the strength of the current eastern US deep-layer ridge. The eastern divergence zone of the upper vortex is producing showers and thunderstorms over the western Bahamas and adjacent waters. At the surface is the tail end of the of the cold front associated with the upper trough...which has recently decayed into a surface trough of low pressure with the loss of air mass contrasts. The surface trough is also being currently supported by the eastern divergence zone of the upper vortex.
Forecast track for the surface trough of low pressure is for it to edge westward toward the Florida peninsula as the surface layer of the eastern US deep-layer ridge is bridging with the Atlantic subtropical surface ridge...with a northward bend in track shown by 48 hours as the eastern US deep-layer ridge becomes eroded by the current central US upper trough. The central US upper trough is expected to knock the upper layer of the deep-layered ridge southeastward and directly over the surface trough...which may provide an opportunity for continued low shear and upper outflow supportive of thunderstorms and possible tropical development. My odds that this system becomes a tropical depression before moving ashore on the Florida peninsula is at a low 10% given the current lack of computer model support and with the thunderstorm intensity on colorized infrared satellite being lower compared to yesterday afternoon/evening. Should this system maintain showers/thunderstorms over the next day or so...enhanced rainfall will continue over the western Bahamas and spread into the Florida peninsula from the east coast.
******Infohurricanes.com outlook. Visit hurricanes.gov (hurricanes dot gov) for official outlook***********
IOH 24 Hr Outlook (1200Z Jun 2)...10% chance of tropical cyclone formation (offshore of southern Florida and just southwest of Grand Bahama Island near 26N-79W)
IOH 48 Hr Outlook (1200Z Jun 3)...0% chance of tropical cyclone formation (Florida peninsula near 27.5N-82W)
...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 area of interest #1...surface trough makes landfall over northeast Florida and coastal Georgia at 42 hours without developing.
0000Z ECMWF Model Run...For area of interest #1...surface trough shown to dissipate in next 24 hours.
0600Z GFS Model Run...For area of interest #1...surface trough moves into Florida Peninsula in the next 12 hours without developing.
0600Z NAVGEM Model Run...For area of interest #1...surface trough moves into Florida Peninsula in the next 18 hours without developing.