[Tropical] Tropical Cyclone Discussion

[EMWIN Server]

WTNT43 KNHC 201450
TCDAT3

Tropical Depression Wilfred Discussion Number   9
NWS National Hurricane Center Miami FL       AL232020
1100 AM AST Sun Sep 20 2020

First-light visible imagery of Wilfred shows a well-defined center
south of widespread - but not very well banded - deep convection.
The improved positioning this morning allows for a more confident
assessment of its movement toward the west-northwest at 17 kt.  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
slightly farther west due to the faster initial motion within 36
hours, then slightly farther east afterward based upon the TVCN
track consensus approach.

While the ASCAT scatterometer passes this morning missed Wilfred's
center, ASCAT-B observed 30 kt peak winds in its northeastern
quadrant.  This value is used as the initial intensity, consistent
with both SAB and TAFB's Dvorak classifications.

The combination of outflow from Hurricane Teddy as well as winds on
the southern side of an impinging upper-level trough are causing
about 20 kt vertical shear from the west-northwest.  This shear
should increase over the next couple of days as Wilfred gets into
closer proximity with the trough.  The strong shear and dry
mid-level humidities should continue to cause a reduction of the
deep convection and lead to the system becoming a remnant low in a
couple of days followed within another day or so by dissipation.
All statistical and dynamical intensity guidance is in agreement
with this scenario. Alternatively, Wilfred could become a remnant
low sooner, if the convection ceases later today or Monday.

FORECAST POSITIONS AND MAX WINDS

INIT  20/1500Z 15.7N  44.2W   30 KT  35 MPH
 12H  21/0000Z 16.2N  46.3W   30 KT  35 MPH
 24H  21/1200Z 16.5N  48.4W   25 KT  30 MPH
 36H  22/0000Z 16.8N  50.0W   25 KT  30 MPH
 48H  22/1200Z 17.0N  51.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
 60H  23/0000Z 17.2N  52.7W   20 KT  25 MPH...POST-TROP/REMNT LOW
 72H  23/1200Z...DISSIPATED

$$
Forecaster Landsea
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