Tropical Cyclone Discussion
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WTPZ44 KNHC 012033

200 PM PDT WED OCT 01 2014

The area of low pressure south of Manzanillo has become better
defined today and has enough organized deep convection to be
considered a tropical cyclone. The cloud pattern consists of a
small area of central convection west of the partially exposed
low-level center and a curved band wrapping around the north and
west side of the circulation. The initial intensity of 25 kt is
based on the latest Dvorak fixes from TAFB and SAB. The structure
of the cyclone is consistent with moderate easterly shear as shown
by the SHIPS model. This shear is forecast to diminish in the next
12 to 24 hours, which should allow for some intensification while
the cyclone is moving over warm SSTs for the next couple of days.
Later in the period, the cyclone will begin moving over cooler SSTs
west of the Baja California peninsula and encounter a somewhat drier
airmass, which should lead to gradual weakening. The NHC intensity
forecast is close to the HWRF and the SHIPS model through 48 hours
and is near the SHIPS forecast after that time.

The initial motion estimate is a rather uncertain 290/07, since the
center has only recently been apparent in visible imagery. In the
short range, most of the track model guidance, with the exception
of the GFDL and the GFDL ensemble mean, shows the cyclone moving
generally west-northwestward around the southwestern periphery of a
subtropical ridge. Model spread increases markedly beyond 36 hours.
The GFS and ECMWF are well to the left showing a more westward
motion, while the aforementioned GFDL and its ensemble mean show a
northwestward and then northward motion well to the right of the
rest of the guidance. The HWRF and UKMET models are in between these
solutions, showing a northward turn around day 3. The NHC track
forecast is a little to the left of the TVCE multi-model consensus
out of respect for the GFS and ECMWF solutions, but remains well to
the right of the consensus of those models at days 3 through 5.
Given the large spread in the guidance, confidence in the details of
the track forecast late in the period, including any potential
threat to the Baja California peninsula, is lower than usual.


INIT  01/2100Z 17.3N 104.4W   25 KT  30 MPH
 12H  02/0600Z 17.8N 105.7W   30 KT  35 MPH
 24H  02/1800Z 18.5N 107.2W   35 KT  40 MPH
 36H  03/0600Z 19.2N 108.8W   40 KT  45 MPH
 48H  03/1800Z 19.7N 110.5W   50 KT  60 MPH
 72H  04/1800Z 21.0N 114.0W   55 KT  65 MPH
 96H  05/1800Z 22.5N 115.5W   50 KT  60 MPH
120H  06/1800Z 23.5N 116.0W   45 KT  50 MPH

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