Tropical Storm RENE Advisory Tue Sep 08

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Tropical Storm Rene Discussion Number   5
NWS National Hurricane Center Miami FL       AL182020
800 AM CVT Tue Sep 08 2020

While Rene continues to have a well-defined circulation, satellite
imagery indicates that the associated convection remains poorly
organized.  Various subjective and objective satellite intensity
estimates are in the 30-35 kt range.  Based on these, along with a
28 kt observation from Sal/GVAC, the initial intensity remains a
possible generous 35 kt.

The initial motion is westward or 280/13 kt.  There is no change
in the track forecast philosophy, as a westward motion is expected
today, followed by a west-northwestward motion through Thursday as
Rene rounds the southwestern periphery of a deep-layer subtropical
ridge. On days 4 and 5, the cyclone is forecast to move more slowly
northwestward to north-northwestward through a weakness in the
aforementioned ridge.  The track guidance has shifted a little
eastward after 72 h, and the new track forecast is also nudged
eastward during that time.  Other than that, the new forecast track
is similar to the previous track.

It is unclear why the convection is currently so poorly organized,
although land interaction with the Cabo Verde Islands is a
possibility.  Conditions generally appear favorable for
strengthening during the next three days or so, and much of the
intensity guidance forecasts Rene to become a hurricane in 2-3 days
time even though the water temperatures gradually decrease along
the forecast track.  After 72 h, Rene is expected to reach both
warmer water and strong westerly shear, with the latter expected to
cause the storm to weaken.  The new intensity forecast has only
minor tweaks from the previous forecast and follows the trend of
the intensity guidance.


Key Messages:

1. Rene is expected to produce tropical storm conditions across
portions of the Cabo Verde Islands today.  A Tropical Storm Warning
is in effect for those islands.

2. Rene will bring locally heavy rainfall to portions of the Cabo
Verde Islands today.


FORECAST POSITIONS AND MAX WINDS

INIT  08/0900Z 16.4N  24.9W   35 KT  40 MPH
 12H  08/1800Z 16.7N  26.9W   35 KT  40 MPH
 24H  09/0600Z 17.1N  29.5W   45 KT  50 MPH
 36H  09/1800Z 17.9N  32.1W   55 KT  65 MPH
 48H  10/0600Z 18.8N  34.7W   65 KT  75 MPH
 60H  10/1800Z 19.8N  37.1W   70 KT  80 MPH
 72H  11/0600Z 21.0N  39.0W   70 KT  80 MPH
 96H  12/0600Z 24.5N  42.0W   65 KT  75 MPH
120H  13/0600Z 28.6N  42.9W   55 KT  65 MPH

$$
Forecaster Beven