Official Discussion issued by the National Hurricane Center

Jose (AL122017) DATA RELEASED: 9/5/2017 11:00:00 AM UTC

Copy of official data

Tropical Storm Jose Discussion Number   1
NWS National Hurricane Center Miami FL       AL122017
1100 AM AST Tue Sep 05 2017

Deep convection associated with the disturbance in the central
Atlantic has become more organized overnight.  Banding features
are starting to develop as seen in the first-light visible pictures
from the GOES and METEOSAT imagery.  Additionally, the ASCAT
scatterometers sampled the system at 1140Z and 1234Z, showing that a
well-defined - though slightly elongated - center had formed.  The
maximum believable winds from ASCAT were 35 kt.  Thus advisories
are being started on Tropical Storm Jose, the 10th named storm of
the Atlantic season.

With no history on the center location, the motion is estimated to
be west-northwest at 11 kt.  Jose should move toward the west or
west-northwest for the next three to four days at a slightly faster
rate of forward speed as it moves south of the deep-layer
Azores-Bermuda high.  In about four to five days, Jose should turn
toward the northwest and slow as it reaches the southwestern
periphery of the high.  The model guidance is in good agreement
with this scenario and the official forecast is based upon a blend
of the ECMWF-GFS-UKMET deterministic and ensemble model output.

The environment in which Jose is located in appears to be quite
conducive for development for the next three days as the SSTs are
very warm, the vertical shear is very low, and there is abundant
mid-level moisture.  By days four and five, however, the vertical
shear may increase in part due to the outflow from Hurricane Irma to
its west.  Thus the official intensity forecast show steady
intensification until day three, then remains flat through day
five.  This forecast is based upon the IVCN multi-model consensus
technique, but has the usual - large - uncertainties at the long
forecast range.

The ASCAT observations indicate that the tropical-storm-force winds
extend out about 40 nm from the center in the southeastern
quadrant.  The official size forecast suggests a gradual increase in
size, based upon the RVCN multi-model consensus approach.


FORECAST POSITIONS AND MAX WINDS

INIT  05/1500Z 12.3N  39.1W   35 KT  40 MPH
12H  06/0000Z 12.8N  40.8W   40 KT  45 MPH
24H  06/1200Z 13.4N  43.4W   50 KT  60 MPH
36H  07/0000Z 13.9N  46.2W   60 KT  70 MPH
48H  07/1200Z 14.4N  49.2W   70 KT  80 MPH
72H  08/1200Z 16.0N  55.0W   90 KT 105 MPH
96H  09/1200Z 18.5N  59.0W   90 KT 105 MPH
120H  10/1200Z 21.5N  62.5W   90 KT 105 MPH

$$
Forecaster Landsea