000
WTNT45 KNHC 262032
TCDAT5

TROPICAL DEPRESSION IDA DISCUSSION NUMBER  34
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL102015
500 PM AST SAT SEP 26 2015

There continues to be little change associated with Ida.  A small
area of pulsing convection is lingering to the east of the exposed
low-level center.  The circulation remains well organized, however,
and mainly consists of a swirl of low-level clouds.  Earlier ASCAT
data indicated that winds were in the 25-30 kt range, and since the
cyclone has not changed much since then, the initial intensity is
held at 30 kt.

The models are quite divergent on the future intensity of Ida.  The
SHIPS model suggests that the depression could strengthen since the
shear is expected to lessen during the next 2-3 days.  Conversely,
most of the dynamical models show little, if any, strengthening
likely due in part to the abundant dry air near the cyclone.  In
fact, the latest runs of the GFS and ECMWF models show Ida's
circulation becoming elongated or degenerating into a trough within
the next few days when a frontal boundary stalls just to the north
of the system. The official forecast follows the previous couple of
advisories in maintaining Ida as a depression through the period,
however, it would not be surprising if Ida dissipates before then
like the GFS and ECMWF models suggest.

Ida is gradually turning to the left as predicted, and the latest
initial motion estimate is now 320/7 kt.  A continued turn toward
the west and then southwest is predicted during the next
couple of days as a low- to mid-level ridge builds to the north of
the cyclone. Thereafter, Ida, or its remnants, is expected to move
generally westward at a slightly faster forward speed.  Although
there remains some spread in the guidance, most of the models agree
on this general theme.  The new official track forecast is a little
faster than the previous one and remains close to the consensus
aids.

FORECAST POSITIONS AND MAX WINDS

INIT  26/2100Z 24.4N  47.1W   30 KT  35 MPH
 12H  27/0600Z 24.8N  47.7W   30 KT  35 MPH
 24H  27/1800Z 24.6N  48.5W   30 KT  35 MPH
 36H  28/0600Z 24.1N  49.6W   30 KT  35 MPH
 48H  28/1800Z 23.6N  51.4W   30 KT  35 MPH
 72H  29/1800Z 23.4N  55.8W   30 KT  35 MPH
 96H  30/1800Z 23.9N  58.9W   25 KT  30 MPH
120H  01/1800Z 24.2N  61.0W   25 KT  30 MPH

$$
Forecaster Cangialosi