Tropical Storm Rene Discussion Number  16
NWS National Hurricane Center Miami FL       AL182020
1100 PM AST Thu Sep 10 2020

Microwave satellite images from late this afternoon and evening 
shows that the center of Rene is located slightly northeast of the 
main convective mass.  This appears to be due to some easterly flow 
that is undercutting the outflow layer.  Dvorak CI numbers from 
both SAB and TAFB remain 3.0 (45 kt) but the SAB T-number has 
decreased slightly, and a recent ASCAT overpass suggests that the 
winds are not as strong as previously estimated.  The ASCAT data 
revealed peak winds of 30-35 kt, so the initial intensity has been 
adjusted to 40 kt, which could be a little generous. The 
upper-level wind pattern is expected to become favorable for 
strengthening while the cyclone moves over marginally warm sea 
surface temperatures during the next day or two.  This should allow 
for some modest strengthening during that time, but the statistical 
guidance is not as bullish as before.  Therefore the intensity 
forecast has been lowered slightly, and if strengthening does not 
occur soon additional downward adjustments to the intensity 
prediction may be needed.  By 60 h, Rene is forecast to move into 
an area of strong west-northwesterly shear, which is expected to 
weaken the cyclone during the latter portion of the forecast 
period. 

Rene continues moving west-northwestward with a motion of 290/10 
kt.  The cyclone is approaching the western periphery of a 
mid-level ridge over the eastern Atlantic and Rene is forecast to 
turn northwestward and then north-northwestward over the next few 
days.  Later in the period, a ridge is forecast to build to the 
northwest of the tropical cyclone and Rene's forward motion is 
expected to slow considerably early next week.  There is a fair 
amount of model spread by 96 and 120 h, with some of the global 
models taking Rene more northeastward during that time.  The NHC 
forecast continues to lie close to the various consensus aids, and 
indicates a fairly slow forward speed on days 3-5. 


FORECAST POSITIONS AND MAX WINDS

INIT  11/0300Z 19.3N  37.6W   40 KT  45 MPH
12H  11/1200Z 19.8N  39.1W   45 KT  50 MPH
24H  12/0000Z 20.7N  41.1W   50 KT  60 MPH
36H  12/1200Z 22.0N  43.1W   55 KT  65 MPH
48H  13/0000Z 23.7N  44.9W   60 KT  70 MPH
60H  13/1200Z 25.2N  46.1W   60 KT  70 MPH
72H  14/0000Z 26.4N  46.9W   55 KT  65 MPH
96H  15/0000Z 27.3N  47.5W   45 KT  50 MPH
120H  16/0000Z 27.5N  49.7W   40 KT  45 MPH

$$
Forecaster Brown