Skip Navigation Links
NOAA NOAA United States Department of Commerce

Tropical Depression EIGHTEEN-E


ZCZC MIATCDEP3 ALL
TTAA00 KNHC DDHHMM

TROPICAL DEPRESSION EIGHTEEN-E DISCUSSION NUMBER   2
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP182014
200 PM PDT WED SEP 24 2014

Deep convection formed closer to the center of the depression late
this morning, but recent satellite imagery suggests that strong
upper-level winds are beginning to cause a separation between the
center and the convection once again.  Dvorak intensity estimates
were unchanged at 1800 UTC and a recent ASCAT pass indicated
maximum winds of around 30 kt.  Strong upper-level northeasterly
winds are expected to prevent significant strengthening during the
next 12 to 24 hours, however the depression could become a low-end
tropical storm during this time.  The shear is forecast to decrease
late Thursday and Friday, which should allow for some modest
strengthening before the cyclone moves into less favorable
thermodynamic conditions late in the period.  The updated NHC
intensity forecast is similar to the previous advisory and is again
close to the SHIPS guidance.

The initial motion estimate is 280/12, a little more westward than
estimated earlier today.  The model guidance indicates that the
cyclone should turn west-northwestward and continue on that general
heading during the next several days, to the south of a mid-level
ridge over northern Mexico.  Later in the period, the cyclone
should turn northwestward as a weakness in the ridge develops along
115W.  The GFS continues to show a slightly stronger cyclone
turning northward, while the ECMWF takes a weaker system westward.
The NHC track lies between these solutions and is close to the
multi-model consensus.  The updated track is a little west of
the previous advisory, primarily due to the more southward and
westward initial position.


FORECAST POSITIONS AND MAX WINDS

INIT  24/2100Z 15.1N 106.8W   30 KT  35 MPH
 12H  25/0600Z 15.7N 108.4W   30 KT  35 MPH
 24H  25/1800Z 16.7N 110.5W   35 KT  40 MPH
 36H  26/0600Z 17.7N 112.3W   35 KT  40 MPH
 48H  26/1800Z 18.5N 114.1W   40 KT  45 MPH
 72H  27/1800Z 19.7N 116.0W   45 KT  50 MPH
 96H  28/1800Z 20.5N 116.8W   45 KT  50 MPH
120H  29/1800Z 21.5N 117.0W   40 KT  45 MPH

$$
Forecaster Brown

NNNN