Potential Tropical Cyclone Six Forecast Discussion Number 2

By | September 9, 2024

063 
WTNT41 KNHC 090232
TCDAT1

Potential Tropical Cyclone Six Discussion Number   2
NWS National Hurricane Center Miami FL       AL062024
1000 PM CDT Sun Sep 08 2024

The system is gradually becoming better organized with deep
convection increasing in coverage and intensity over the
southwestern Gulf of Mexico.  However, earlier visible satellite
imagery and aircraft data from the Air Force Hurricane Hunters
indicate that the disturbance does not have a well-defined center
and still resembles an elongated trough.  The initial intensity
remains 45 kt based on the aircraft data.  The strongest winds are
occurring on the system's west side, and are likely enhanced by the
barrier jet associated with the Sierra Madre Mountains in Mexico.

The initial motion is estimated to be 320/4 kt.  A mid-level ridge
situated over the southeastern Gulf of Mexico and western Atlantic
should steer the disturbance slowly northward or north-northwestward
through Tuesday morning, likely keeping the core of the system off
the coast of Mexico and southern Texas through that time.  By late
Tuesday, a turn to the northeast with an increase in forward speed
is forecast as the system moves in the flow between the ridge and an
approaching shortwave trough.  That motion should take the cyclone
to the Louisiana or Upper Texas coast on Wednesday.  A
north-northeastward motion is forecast after landfall when the
system merges with the trough. The NHC track forecast has been
nudged eastward toward the latest runs of the GFS and ECMWF models.
It should be noted that confidence in the track forecast is lower
than normal since the system does not have a well-defined center.

Little change in strength is expected during the next 12 to 24 hours
as it will likely take some time for the system to consolidate and
develop a well organized circulation.  Once the system is able to
close off and contract, steady strengthening is forecast as the
cyclone will be over warm waters and within a region of high
moisture and upper-level diffluence.  However, some of the models
show an increase in shear and slightly drier air affecting the
system around the time it reaches the coast.  The NHC intensity
forecast is raised from the previous one and lies roughly near the
middle of the guidance envelope.

The highest winds are expected to remain on the west side of the
system during the next day or so, but these winds should shift to
the eastern side of the circulation before the cyclone reaches the
Gulf Coast.


KEY MESSAGES:

1. The system is forecast to become a tropical storm on Monday as it
moves near the western Gulf of Mexico coast. Tropical Storm Watches
are in effect for northeastern Mexico and extreme southern Texas.

2. The system is forecast to become a hurricane before it reaches
the northwestern Gulf Coast by the middle of the week.  While it is
too soon to pinpoint the exact location and magnitude of impacts,
the potential for life-threatening storm surge and damaging winds
are increasing for portions of the Louisiana and Upper Texas
coastlines beginning Tuesday night.  Hurricane and Storm Surge
Watches will likely be issued for a portion of that area on Monday,
and residents should ensure they have their hurricane plan in
place.

3. Potential Tropical Cyclone Six is expected to bring heavy
rainfall and the risk of flash flooding from the coast of far
northeast Mexico into portions of coastal Texas and Louisiana
through Thursday.


FORECAST POSITIONS AND MAX WINDS

INIT  09/0300Z 21.9N  94.7W   45 KT  50 MPH...POTENTIAL TROP CYCLONE
 12H  09/1200Z 22.5N  95.1W   45 KT  50 MPH
 24H  10/0000Z 23.7N  95.7W   50 KT  60 MPH...TROPICAL CYCLONE
 36H  10/1200Z 25.0N  96.0W   55 KT  65 MPH
 48H  11/0000Z 26.2N  95.7W   60 KT  70 MPH
 60H  11/1200Z 28.0N  94.6W   70 KT  80 MPH
 72H  12/0000Z 29.9N  93.1W   70 KT  80 MPH...INLAND
 96H  13/0000Z 34.5N  90.7W   30 KT  35 MPH...POST-TROP/EXTRATROP
120H  14/0000Z 37.3N  89.5W   20 KT  25 MPH...POST-TROP/EXTRATROP

$$
Forecaster Cangialosi


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