Eastern Pacific Basin Tropical Cyclones

Tropical Storm Terry Forecast Discussion

WTPZ43 KNHC 072044

Tropical Storm Terry Discussion Number  14
NWS National Hurricane Center Miami FL       EP182021
300 PM CST Sun Nov 07 2021

The overall organization of the depression has become slightly
better since this morning.  Recent one-minute GOES-16 visible
satellite imagery suggests that the center is better defined and
there has been a persistent cluster of convection just southeast
of the estimated center since this morning.  Subjective Dvorak
intensity estimates from SAB and TAFB were unchanged at 30-35 kt, 
but ADT and SATCON estimates are in the 39-42 kt range.  Although a 
1410 UTC ASCAT-A overpass missed the center, it did reveal an area 
of 30-40 kt winds along the edge of the swath, however the 
strongest vectors were flagged due to rain contamination.  Given 
the recent improvement in both center definition and the persistent 
convection near that feature, the intensity is increased to 35 kt 
for this advisory.

Terry is moving just north of due west at 275/12 kt. The steering
currents ahead of the storm remains well established with a strong
deep-layer ridge located to the north.  That feature should guide 
Terry westward to west-northwestward at about 12 kt for the next
several days.  The NHC track guidance is in good agreement on the
overall scenario, but there is spread regarding the cyclone's
forward speed.  The NHC track leans closer to the slightly more 
southern and deeper GFS solution.  This is along the southern
side of the guidance envelope and fairly close to the speed of
the various consensus aids.

The storm is forecast to remain within low vertical wind shear 
conditions over the next couple of days, however it is likely to 
ingest drier and more stable air that is located just to the north. 
That stable air is expected to keep significant strengthening from 
occurring, but some limited intensification is possible during the 
next day or two.  By Tuesday night or Wednesday, environmental 
conditions are forecast become more hostile with an increase in 
vertical shear and decreasing mid-level humidity. Those factors 
should cause weakening and degeneration to a remnant low by 96 
hours.  The global models indicate that the system will open up into 
a trough along the ITCZ by day 5 and that is reflected in the 
official forecast.


INIT  07/2100Z  8.5N 102.6W   35 KT  40 MPH
 12H  08/0600Z  8.9N 104.4W   40 KT  45 MPH
 24H  08/1800Z  9.4N 106.9W   40 KT  45 MPH
 36H  09/0600Z  9.7N 109.4W   40 KT  45 MPH
 48H  09/1800Z  9.8N 111.7W   35 KT  40 MPH
 60H  10/0600Z  9.9N 114.2W   35 KT  40 MPH
 72H  10/1800Z 10.0N 116.7W   30 KT  35 MPH
 96H  11/1800Z 10.0N 121.8W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  12/1800Z...DISSIPATED

Forecaster Brown

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