000
WTNT43 KNHC 082032
TCDAT3

Tropical Storm Chris Discussion Number   9
NWS National Hurricane Center Miami FL       AL032018
500 PM EDT Sun Jul 08 2018

Satellite images indicate that the cloud pattern continues to become
better organized, and T-numbers from TAFB and SAB have increased
to 3.0 on the Dvorak scale. This was confirmed by data from an Air
Force reconnaissance plane which reported flight-level winds of 51
kt on the eastern semicircle. The initial intensity is set at 45 kt
in this advisory. Chris is expected to be over a pool of warm water
for the next 2 days and embedded within an environment of low shear.
On this basis, the NHC forecast continues to call for Chris to
become a hurricane in about 36 hours. This is in agreement with the
dynamical guidance and the HCCA model consensus which strengthen
Chris to a hurricane in a couple of days. In about 4 days, Chris
will be over 13 degree C Canadian waters, and this should encourage
extratropical transition.

The steering currents have collapsed, and the cyclone has barely
moved all day. These currents are foreast to remain light, so little
motion is anticipated during the next 2 days.  A mid-level trough
forecast to swing eastward across the eastern United States will
provide enough forcing to kick Chris northeastward with increasing
forward speed over the Atlantic beyond 72 hours. The NHC forecast
continues to be in the middle of the track guidance envelope and
follows closely the corrected consensus.

FORECAST POSITIONS AND MAX WINDS

INIT  08/2100Z 32.7N  74.6W   45 KT  50 MPH
 12H  09/0600Z 32.5N  74.6W   55 KT  65 MPH
 24H  09/1800Z 32.3N  74.5W   60 KT  70 MPH
 36H  10/0600Z 32.3N  74.5W   65 KT  75 MPH
 48H  10/1800Z 33.0N  74.0W   75 KT  85 MPH
 72H  11/1800Z 36.5N  69.5W   75 KT  85 MPH
 96H  12/1800Z 43.5N  61.5W   55 KT  65 MPH
120H  13/1800Z 50.0N  52.0W   40 KT  45 MPH...POST-TROP/EXTRATROP

$$
Forecaster Avila