Tropical Storm WILFRED Advisory 9月21日

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Tropical Depression Wilfred Discussion Number  10
NWS National Hurricane Center Miami FL       AL232020
500 PM AST Sun Sep 20 2020

Wilfred is not a healthy tropical cyclone as strong vertical shear
from the combination of outflow from Hurricane Teddy as well as
winds on the southern side of a nearby upper-level trough are
impinging upon the system.  While there is substantial deep
convection, it is more linear rather than curved in appearance and
it may be more a product of forcing from the upper-level trough
rather than the tropical cyclone itself.  Dvorak classifications
from SAB and TAFB have reduced some at 18Z, though the intensity
remains a perhaps generous 30 kt.

The tropical cyclone continues to move west-northwest at a fast 17
kt clip. As the system slowly winds down, it will be increasingly
steered by the low-level flow indicating a slower movement toward
the west or west-northwest until dissipation.  The new track
forecast is similar to that from the previous advisory, except for
the final 60 hr point that does show a turn toward the northwest
based upon the TVCN and HCCA track consensus techniques.

Strong shear and dry mid-level humidities should continue to cause
a reduction in the deep convection and lead to the system becoming
a remnant low in a day or two followed shortly thereafter by
dissipation.   Most statistical and dynamical intensity guidance is
in agreement.  A plausible alternate scenario is that the small
circulation opens up into a trough and dissipation occurs sooner
than indicated below.  It is worth noting that the ECMWF model does
suggest the possibility of reformation of the system farther north
by day three.  However, this scenario is discounted at this time.

FORECAST POSITIONS AND MAX WINDS

INIT  20/2100Z 15.9N  45.8W   30 KT  35 MPH
 12H  21/0600Z 16.3N  48.0W   30 KT  35 MPH
 24H  21/1800Z 16.5N  49.9W   25 KT  30 MPH
 36H  22/0600Z 16.5N  50.8W   25 KT  30 MPH...POST-TROP/REMNT LOW
 48H  22/1800Z 16.8N  51.8W   20 KT  25 MPH...POST-TROP/REMNT LOW
 60H  23/0600Z 17.8N  52.7W   20 KT  25 MPH...DISSIPATED
 72H  23/1800Z...DISSIPATED

$$
Forecaster Landsea