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Tropical Storm Dora Discussion Number   4
NWS National Hurricane Center Miami FL       EP042017
400 PM CDT Sun Jun 25 2017

Dora continues to exhibit well-defined convective spiral bands,
with a developing CDO.  Dvorak T-numbers from both TAFB and SAB are
3.0 so the intensity is held at 45 kt for this advisory.  The
tropical cyclone will be in a low-shear environment with
anticyclonic upper-level flow for several days.  These dynamical
factors would favor intensification.  Waters beneath Dora, however,
will begin to cool soon and the system should encounter
significantly cooler waters within 48 hours or so.  Therefore the
window of opportunity for strengthening is decreasing, especially
since the cyclone is moving a little faster than before.  The
official intensity forecast is close to the ICON consensus and still
shows Dora becoming a hurricane within 24 hours.

The latest center fixes yield a faster motion of around 300/12 kt.
A well-established subtropical ridge to the north of Dora should
produce a continued west-northwestward motion for much of the
forecast period.  By days 4 and 5 a more westward track is likely
due to the system weakening and becoming a shallow vortex.  The
official track forecast is somewhat faster than the previous one,
close to, or a little south of, the latest model consensus.

Although Dora is forecast to remain offshore, the outer bands of the
tropical cyclone could bring locally heavy rains to portions of
coastal southwestern Mexico during the day or so.

FORECAST POSITIONS AND MAX WINDS

INIT  25/2100Z 15.7N 103.0W   45 KT  50 MPH
 12H  26/0600Z 16.6N 104.7W   55 KT  65 MPH
 24H  26/1800Z 17.6N 106.7W   65 KT  75 MPH
 36H  27/0600Z 18.5N 108.6W   65 KT  75 MPH
 48H  27/1800Z 19.0N 110.4W   55 KT  65 MPH
 72H  28/1800Z 19.8N 114.0W   45 KT  50 MPH
 96H  29/1800Z 20.0N 117.5W   30 KT  35 MPH...POST-TROP/REMNT LOW
120H  30/1800Z 19.5N 120.0W   20 KT  25 MPH...POST-TROP/REMNT LOW

$$
Forecaster Pasch

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