Potential Tropical Cyclone Six Discussion Number   3
NWS National Hurricane Center Miami FL       AL062024
400 AM CDT Mon Sep 09 2024

Satellite imagery shows that the disturbance is producing 
considerable deep convection with cloud tops colder than -70 deg C. 
However, the cloud pattern is still in the organizing stage with not 
much evidence of banding features at this time.  Upper-level outflow 
is becoming established over the area.  Observations from an Air 
Force reconnaissance aircraft, data buoy 42055, and a partial ASCAT 
overpass suggest that the system has not yet developed a well- 
defined center of circulation.  The intensity is held at 45 kt for 
this advisory with the assumption of some undersampling of the winds 
over the western part of the circulation.  However, this could be 
generous.

Since the center is still not well defined, the initial motion is a 
rather uncertain, but slow, 340/4 kt.  During the next day or so, 
the system is expected to move along the western side of a mid-level 
ridge over the Gulf of Mexico.  This motion should keep the core of 
the system off the coast of northeastern Mexico and southern Texas 
for the next 24-36 hours.  Then, a shortwave trough over Texas is 
expected to induce a turn toward the northeast with an increase in 
forward speed, which would take the center of the system near and 
across the northwestern or northern Gulf coast late Wednesday.  The 
official track forecast has again been nudged eastward in the 48-72 
hour period, but not quite as far east as the ECMWF and corrected 
consensus model predictions.  It should be noted that confidence in 
the track forecast is lower than normal since the system lacks a 
well-defined center. 

Since the system is still not very well-organized and lacks an inner 
core structure, only slow strengthening is expected through this 
morning.  However, the disturbance is expected to soon become better 
organized while remaining over very warm waters, with high low- to 
mid-tropospheric humidity, and low vertical shear for the next 48 
hours.  Therefore steady strengthening is likely to begin by later 
today.  This is also shown by most of the numerical guidance.  When 
the system nears landfall, the global models show increasing 
upper-level westerlies near the northwestern Gulf coast, and this 
could lead to stronger vertical wind shear over the cyclone.  
Therefore the rate of strengthening could at least level off as the 
center nears the coast.  The official intensity forecast is similar 
to the previous NHC prediction, close to the Decay-SHIPS guidance, 
and continues to show the system as a hurricane at landfall.


KEY MESSAGES:

1. The system is forecast to become a tropical storm today 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 later 
today, 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 considerable flash flooding along the coast 
of far northeast Mexico, portions of southernmost Texas, southern 
Louisiana, and southern Mississippi into Thursday morning.  A risk 
of flash and urban flooding exists across portions of the Mid-South 
from Wednesday into Friday morning.


FORECAST POSITIONS AND MAX WINDS

INIT  09/0900Z 22.2N  94.8W   45 KT  50 MPH...POTENTIAL TROP CYCLONE
12H  09/1800Z 23.0N  95.3W   45 KT  50 MPH...TROPICAL CYCLONE
24H  10/0600Z 24.1N  95.9W   55 KT  65 MPH
36H  10/1800Z 25.2N  95.7W   60 KT  70 MPH
48H  11/0600Z 26.8N  94.8W   65 KT  75 MPH
60H  11/1800Z 28.5N  93.3W   70 KT  80 MPH
72H  12/0600Z 30.7N  91.8W   50 KT  60 MPH...INLAND
96H  13/0600Z 34.9N  90.2W   30 KT  35 MPH...POST-TROPICAL
120H  14/0600Z 37.5N  89.0W   20 KT  25 MPH...POST-TROPICAL

$$
Forecaster Pasch