Tropical Cyclone Discussion

682
WTNT41 KNHC 200237
TCDAT1
 
Tropical Depression Six Discussion Number   3
NWS National Hurricane Center Miami FL       AL062026
300 AM GMT Sun Sep 20 2026

The convective organization of the depression has increased 
somewhat since the last advisory, with multiple convective bands in 
the northern semicircle. This increase is reflected in the various 
subjective and objective satellite intensity estimates now 
suggesting the cyclone has reached tropical storm strength. 
However, an ASCAT-C overpass showed maximum winds near 30 kt. Based 
mainly on that the initial intensity will remain 30 kt.  Cirrus 
cloud motion indicate that an upper-level cyclonic shear axis is 
located near or just south of the center, with very strong 
upper-level westerly flow over the southern part of the low-level 
circulation.

The initial motion is 020/4 kt.  The depression is in an area of 
weak steering currents between a low- to mid-level ridge to the 
east and a deep-layer mid-latitude trough to the northwest. During 
the next couple of days, the southern portion of this trough is 
expected to weaken, with a low- to mid-level ridge developing to 
the west and northwest of the tropical cyclone. This should result 
in the cyclone stopping its north-northeastward motion and turning 
toward the southwest. A general southwestward motion is then likely 
until the system dissipates. The track guidance has shifted a bit 
westward after 36 h, and the new forecast track is also nudged a 
bit west of the previous track.

The dynamical models are forecasting a small upper-level low to 
develop along the cyclonic shear axis near or south of the tropical 
depression during the next 12 h or so. This is likely create a less 
hostile shear environment around the depression that should allow 
some intensification. After 24 h, the models are in good agreement 
that strong upper-level northerly or northwesterly winds will move 
over the cyclone, creating strong shear and causing weakening. 
While the models forecast the shear to diminish after 48-60 h, the 
cyclone or its remnants will be in an area of dry air and 
subsidence that cause cause the convection to dissipate.  The new 
intensity forecast shows the depression becoming a tropical storm 
for a day or so, followed by weakening to a remnant low between 
60-72 h. Based on the dynamical models, the remnant low is forecast 
to weaken to a trough between 96-120 h.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  20/0300Z 33.3N  33.2W   30 KT  35 MPH
 12H  20/1200Z 33.8N  33.0W   40 KT  45 MPH
 24H  21/0000Z 34.0N  32.5W   45 KT  50 MPH
 36H  21/1200Z 33.6N  32.4W   40 KT  45 MPH
 48H  22/0000Z 32.7N  32.9W   35 KT  40 MPH
 60H  22/1200Z 31.6N  33.9W   30 KT  35 MPH
 72H  23/0000Z 30.4N  35.6W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  24/0000Z 29.0N  39.1W   20 KT  25 MPH...POST-TROP/REMNT LOW
120H  25/0000Z...DISSIPATED