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Tropical Storm Narda Discussion Number   5
NWS National Hurricane Center Miami FL       EP162019
1000 AM CDT Sun Sep 29 2019

The center of Narda either re-formed to the northwest or
accelerated its forward motion during the night, as surface
observations from Mexico and satellite imagery indicate that it is
now located along the coast of Mexico near Lazaro Cardenas.  The
initial intensity is held at 40 kt based on the Mexican
observations and little change in the satellite intensity estimates
since the last advisory.  First-light visible imagery suggests that
the cyclone's circulation is elongated east-west, with the center
located on the eastern side of the elongation.

The initial motion is a rather uncertain 325/13 kt.  Over the next
couple of days,  Narda will be steered generally northwestward along
the southwestern periphery of a large high pressure area.  After
that time, a mid- to upper-level trough approaching the northern
Baja California peninsula from the west should cause the system to
turn north-northwestward.  The new forecast track is parallel to,
but moved significantly to the right of, the previous forecast due
to the initial position and motion, and it keeps the center over
portions of western Mexico for the next 12-24 hours before bringing
the system over the southeastern and eastern portions of the Gulf of
California.

The intensity forecast is highly uncertain.  The official forecast
will follow the scenario of the previous forecast in calling for
Narda to weaken to a depression while over Mexico, and then call
for some re-intensification later in the forecast period when the
system emerges over water in a light shear environment.  However,
there are two alternative scenarios.  The most likely of these is
that the circulation dissipates as it passes over the mountains of
western Mexico, which is a distinct possibility if the system goes
as far inland as currently forecast.  The least likely is that the
center reforms offshore, which could lead to significant changes in
both the intensity and the track forecasts.

The primary threat from Narda is very heavy rainfall, which should
result in life-threatening flash flooding and mudslides over
portions of the southern coast of Mexico.  Rainfall totals of up to
15 inches are possible.


FORECAST POSITIONS AND MAX WINDS

INIT  29/1500Z 18.1N 102.1W   40 KT  45 MPH
 12H  30/0000Z 19.3N 103.6W   30 KT  35 MPH...INLAND
 24H  30/1200Z 21.5N 105.6W   25 KT  30 MPH...OVER WATER
 36H  01/0000Z 23.2N 107.3W   30 KT  35 MPH
 48H  01/1200Z 24.5N 108.6W   35 KT  40 MPH
 72H  02/1200Z 26.5N 109.9W   35 KT  40 MPH
 96H  03/1200Z 28.0N 110.5W   25 KT  30 MPH...INLAND
120H  04/1200Z...DISSIPATED

$$
Forecaster Beven

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