000
WTNT45 KNHC 270234
TCDAT5

TROPICAL DEPRESSION IDA DISCUSSION NUMBER  35
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL102015
1100 PM AST SAT SEP 26 2015

Deep convection again pulsed near and to the east of the center of
Ida this evening, but is now waning as shear of around 20 kt
continues over the cyclone. The most recent ASCAT missed Ida, so the
initial intensity remains 30 kt based on persistence.

The statistical models continue to suggest that Ida will intensify
later in the forecast period, while the GFS and ECMWF show the
circulation weakening and eventually elongating and dissipating by
day 5 as a front impinges on Ida from the north. The NHC forecast
continues to follow the solution of the global models given that the
cyclone is currently embedded in a dry environment with moderate
shear. It would also not be surprising if Ida were to dissipate
sooner than forecast.

The initial motion has been to the left of and slower than the
previous advisory, and is estimated at 285/04. A continued bend of
Ida's track toward the left is forecast as the shallow cyclone comes
under the influence of an amplifying low-level ridge to the north.
Much of the guidance has trended to the left and faster this cycle,
and given the change in the initial motion and the trend in the
guidance, the new NHC track is faster and about a half degree south
of the previous one. The NHC forecast is close to a blend of the GFS
and ECMWF through 48 hours and not far from the GFS after that time.

FORECAST POSITIONS AND MAX WINDS

INIT  27/0300Z 24.3N  47.4W   30 KT  35 MPH
 12H  27/1200Z 24.3N  48.0W   30 KT  35 MPH
 24H  28/0000Z 23.8N  49.1W   30 KT  35 MPH
 36H  28/1200Z 23.2N  50.8W   30 KT  35 MPH
 48H  29/0000Z 22.8N  53.2W   30 KT  35 MPH
 72H  30/0000Z 23.2N  57.4W   30 KT  35 MPH
 96H  01/0000Z 23.5N  60.5W   25 KT  30 MPH
120H  02/0000Z...DISSIPATED

$$
Forecaster Brennan