000
WTPZ41 KNHC 302039
TCDEP1

Tropical Storm Narda Discussion Number  10
NWS National Hurricane Center Miami FL       EP162019
300 PM MDT Mon Sep 30 2019

A couple of microwave passes that arrived shortly after the release
of the previous advisory showed that Narda had become better
organized this morning.  The imagery revealed well-defined banding
and a mid-level eye feature that was located just offshore the coast
of mainland Mexico.  The latest Dvorak satellite intensity estimates
from TAFB and SAB are 45 and 55 kt, respectively.  Recent ASCAT data
supported an intensity on the lower end of this range, therefore the
advisory wind speed has been set at 45 kt. A 10-minute average wind
of 32 kt with a gust to 43 kt was reported at Mazatlan late this
morning as the center of Narda passed nearby. Since the center is so
close to the coast, little additional strengthening is expected.  By
late tonight or early Tuesday, Narda is likely to move just inland
along the coast and weakening should begin by that time.  The system
is forecast to become a remnant low within a couple of days and
dissipate over northwestern Mexico shortly thereafter.  Weakening
and dissipation could occur much sooner if Narda moves to the right
of the current NHC forecast track.

Narda continues to move quickly northwestward or 325/14 kt, around
the southwestern periphery of a large mid-level anticyclone.  There
has been no change to the track forecast reasoning as Narda should
continue heading northwestward along the northwestern coast of
mainland Mexico. The track guidance is in somewhat better agreement
this cycle, and the NHC forecast is in best agreement with the 1200
UTC ECMWF model, and is essentially an update of the previous
forecast.

The main threat posed by Narda continues to be very heavy rainfall,
due to large amounts of moisture being advected northward and
northeastward over Mexico on the eastern side of the cyclone's
circulation.  These rains, which could total as much as 15 inches in
a few locations, will result in life-threatening flash floods and
mudslides.


FORECAST POSITIONS AND MAX WINDS

INIT  30/2100Z 24.0N 107.4W   45 KT  50 MPH
 12H  01/0600Z 25.4N 108.7W   45 KT  50 MPH
 24H  01/1800Z 26.9N 109.8W   35 KT  40 MPH...INLAND
 36H  02/0600Z 28.2N 110.8W   30 KT  35 MPH...INLAND
 48H  02/1800Z 29.4N 111.6W   25 KT  30 MPH...POST-TROP/REMNT LOW
 72H  03/1800Z...DISSIPATED

$$
Forecaster Brown