000
WTNT43 KNHC 170241
TCDAT3
 
Tropical Storm Henri Discussion Number   5
NWS National Hurricane Center Miami FL       AL082021
1100 PM AST Mon Aug 16 2021
 
Bursts of deep convection continue to pulse over the southeastern 
portion of Henri's circulation.  Although the tropical cyclone is 
still being affected by dry-air entrainment and light-to-moderate 
shear, the latest subjective and objective satellite intensity 
estimates are a little higher than before, and a blend of those 
estimates yields an initial wind speed of 40 kt for this advisory. 
Henri is forecast to remain over SSTs of 28-29C throughout the 
forecast period, but the mid-level relative humidity is forecast 
to remain fairly dry, which is likely to only support gradual 
strengthening over the next day or so. After that time, a 
significant increase in northeasterly shear is anticipated, and 
that is likely to stop further strengthening. As mentioned in the 
previous advisory, given the small size of Henri, the tropical 
cyclone is likely to be more susceptible to this shear and it is 
possible that Henri weakens more than indicated below by day 3. The 
NHC intensity forecast is a blend of the various statistical aids, 
and the CTCI and HMNI models.  Less weight is again placed on the 
HWRF model, which remains quite aggressive in strengthening Henri 
over the next several days despite the expected increase in shear 
and dry mid-level environment. 

Henri is moving southwestward or 215/4 kt. The tropical storm is 
forecast to move in a counterclockwise motion over the next several 
days as it moves around a mid-tropospheric high that is forecast 
to shift eastward over the western Atlantic.  This motion should 
take Henri south of Bermuda late Tuesday or Tuesday night.  By 72 
hours, the storm is expected to reach the western extent of the 
ridge and turn northward, and then northeastward by the end of 
the forecast period.  There is still some spread in the guidance 
as to when and how sharp the turn will be.  As a result, the NHC 
track forecast is a blend of the typically reliable GFS and ECMWF 
models later in the period. 

 
FORECAST POSITIONS AND MAX WINDS
 
INIT  17/0300Z 30.7N  63.3W   40 KT  45 MPH
 12H  17/1200Z 30.5N  63.8W   45 KT  50 MPH
 24H  18/0000Z 30.4N  64.8W   50 KT  60 MPH
 36H  18/1200Z 30.3N  66.2W   50 KT  60 MPH
 48H  19/0000Z 30.3N  67.8W   50 KT  60 MPH
 60H  19/1200Z 30.5N  69.3W   50 KT  60 MPH
 72H  20/0000Z 31.3N  70.1W   45 KT  50 MPH
 96H  21/0000Z 32.8N  69.7W   45 KT  50 MPH
120H  22/0000Z 35.0N  66.5W   45 KT  50 MPH
 
$$
Forecaster Brown