Eastern Pacific Basin Tropical Cyclones

Tropical Depression Three-E Forecast Discussion


466 
WTPZ43 KNHC 162056
TCDEP3

Tropical Depression Three-E Discussion Number   1
NWS National Hurricane Center Miami FL       EP032022
400 PM CDT Thu Jun 16 2022

Over the past 12 h, there has been a notable improvement on 
satellite of the convective structure with an area of low pressure 
NHC has been monitoring to the south of the coasts of El Salvador 
and Guatemala. An earlier scatterometer pass showed that the system 
had developed a well-defined center, with maximum winds between 
25-30 kt. These winds also matched a nearby ship observation in the 
northern semicircle of the system. Subsequent visible satellite 
imagery depicted convection gradually increasing near the 
circulation center, especially in a curved band on its western 
side. This improving structure is also seen well on a recently 
arriving AMSR2 microwave pass. For these reasons, the system now 
meets the criteria of a tropical cyclone, and the initial intensity 
will be set to 30 kt for this advisory.

Three-E has been making a slow cyclonic loop over the past 24 hours, 
and now appears to be drifting northward, estimated at 355/2 kt. The 
track guidance in the short-term is rather tricky, as the steering 
currents near the system appear to be light and variable, with the 
largest steering influence expected to be monsoonal flow around a 
larger-scale circulation over Central America involving another 
disturbance over the northwestern Caribbean Sea. The track guidance 
is rather spread out over the first couple of days with the ECMWF on 
the left side and GFS on right side of the track guidance envelope. 
After 36 hours, a mid-level ridge is expected to gradually build in 
to the north of the cyclone, resulting in a gradual bend westward 
and some increase in forward motion. The initial track forecast 
currently lies near the center of the track suite, close to the HFIP 
Corrected Consensus Approach (HCCA). 

Environmental conditions appear generally favorable for some 
intensification over the next day or so, with shear under 10 kt, 
high mid-level moisture, and sea-surface temperatures above 27 C. 
However, easterly shear is expected to increase after 36 hours, and 
the slow motion of the system may leave it susceptible to upwelling 
cooler waters under a fairly shallow mixed layer depth of warm 
waters in the far East Pacific. The initial intensity forecast only 
shows a peak intensity of 45 kt in 36 hours and holds the system at 
that intensity for the remainder of the period. This intensity 
forecast roughly splits the difference between higher 
statistical-dynamical guidance (SHIPS) versus lower dynamical and 
consensus aids (HMON, IVCN). Given the uncertainty in the short-term 
track of this depression, this intensity forecast is of relatively 
low confidence.


FORECAST POSITIONS AND MAX WINDS

INIT  16/2100Z 10.8N  89.9W   30 KT  35 MPH
 12H  17/0600Z 11.1N  89.9W   35 KT  40 MPH
 24H  17/1800Z 11.5N  89.9W   40 KT  45 MPH
 36H  18/0600Z 12.2N  89.9W   45 KT  50 MPH
 48H  18/1800Z 12.8N  90.3W   45 KT  50 MPH
 60H  19/0600Z 12.9N  91.0W   45 KT  50 MPH
 72H  19/1800Z 12.9N  91.8W   45 KT  50 MPH
 96H  20/1800Z 12.9N  94.5W   45 KT  50 MPH
120H  21/1800Z 12.8N  99.4W   45 KT  50 MPH

$$
Forecaster Papin




Source link