Tropical Depression Seven-E Forecast Discussion

000
WTPZ42 KNHC 181433
TCDEP2

Tropical Depression Seven-E Discussion Number   1
NWS National Hurricane Center Miami FL       EP072024
800 AM MST Sun Aug 18 2024

The low pressure system well south of the southern tip of the Baja 
California peninsula has now developed a well-defined center and 
sufficiently organized deep convection. These criteria indicate a 
new tropical depression has formed, the seventh one of the 2024 East 
Pacific hurricane season.  The initial intensity is set at 30 kt, 
based on a Dvorak 2.0 classification from TAFB.

Moderate easterly vertical wind shear of 15-20 kt is confining most
of the thunderstorm activity to the western half of the circulation,
and since the shear is expected to persist through tonight, only a
little strengthening seems likely in the short-term.  The shear
should lessen beginning early Monday, and the more favorable
upper-level wind environment combined with warm waters and a
relatively moist atmosphere should allow for gradual strengthening
throughout much of the week.  The NHC intensity forecast is closest
to the HCCA guidance.

The initial motion is uncertain since the system has just formed,
but the best estimate is 290/11 kt.  A high pressure ridge situated
to the system’s north should cause the cyclone to move westward to
west-northwestward at about the same speed during the next few days.
Later in the week, the models show the ridge weakening as a trough
amplifies off the west coast of the U.S., which could cause the
system to slow down.  The models are in fair agreement with the
exception of the GFS, which shows a much slower motion likely due to
the interaction with a disturbance to its west.  At this point, that
model seems unrealistic so it is being discounted for now.  The NHC
track forecast is in best agreement with the ECMWF and HCCA aids.


FORECAST POSITIONS AND MAX WINDS

INIT  18/1500Z 14.6N 110.7W   30 KT  35 MPH
 12H  19/0000Z 15.0N 112.3W   30 KT  35 MPH
 24H  19/1200Z 15.4N 114.4W   35 KT  40 MPH
 36H  20/0000Z 15.8N 116.5W   40 KT  45 MPH
 48H  20/1200Z 16.0N 118.3W   40 KT  45 MPH
 60H  21/0000Z 16.2N 120.1W   45 KT  50 MPH
 72H  21/1200Z 16.5N 121.8W   50 KT  60 MPH
 96H  22/1200Z 17.1N 124.6W   55 KT  65 MPH
120H  23/1200Z 17.9N 126.5W   60 KT  70 MPH

$$
Forecaster Cangialosi