Isaias, advisory 1

000
WTNT34 KNHC 062038
TCPAT4
 
BULLETIN
Tropical Depression Nine Advisory Number   1
NWS National Hurricane Center Miami FL       AL092026
400 PM CDT Tue Oct 06 2026
 
...TROPICAL DEPRESSION FORMS OVER THE GULF OF AMERICA...
...FORECAST TO STRENGTHEN QUICKLY...
 
 
SUMMARY OF 400 PM CDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...22.1N 95.6W
ABOUT 380 MI...615 KM W OF PROGRESO MEXICO
ABOUT 630 MI...1015 KM SW OF THE MOUTH OF THE MISSISSIPPI RIVER
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...E OR 90 DEGREES AT 5 MPH...7 KM/H
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES
 
 
WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.
 
Interests in the Yucatan Peninsula and the U.S. northern Gulf Coast
should closely monitor the progress of this system.
 
 
DISCUSSION AND OUTLOOK
----------------------
At 400 PM CDT (2100 UTC), the center of Tropical Depression Nine was
located near latitude 22.1 North, longitude 95.6 West. The
depression is moving toward the east near 5 mph (7 km/h) and an 
east to east-northeast motion is expected during the next couple of 
days. By Friday, a turn to the northeast is anticipated. On the 
forecast track, the depression is expected to pass to the north of 
the Yucatan Peninsula on Thursday, and approach the U.S. northern 
Gulf Coast on Friday.
 
Maximum sustained winds are near 35 mph (55 km/h) with higher gusts.
Steady strengthening is forecast, and the depression is expected to 
become a tropical storm by early Wednesday and a hurricane on 
Thursday.
 
The estimated minimum central pressure is 1007 mb (29.74 inches).
 
 
HAZARDS AFFECTING LAND
----------------------
Key messages for Tropical Depression Nine can be found in the
Tropical Cyclone Discussion under AWIPS header MIATCDAT4 and WMO
header WTNT44 KNHC.
 
RAINFALL: Tropical Depression Nine is expected to produce rainfall 
amounts of 2 to 4 inches through Thursday across coastal portions of 
the Bay of Campeche with isolated higher amounts possible in the 
states of Campeche and western Yucatan.

From Friday through the weekend, the system is expected to produce 
rainfall amounts of 3 to 6 inches, with localized totals up to 10 
inches, across the central U.S. Gulf Coast extending from 
southeastern Louisiana to the Florida Panhandle. Flash and urban 
flooding, along with isolated river flooding, will be possible. 

For a complete depiction of forecast rainfall associated with 
Tropical Depression Nine, please see the National Weather Service 
Storm Total Rainfall Graphic available at
hurricanes.gov/graphics_at4.shtml?rainqpf and the Flash Flood Risk 
graphic at hurricanes.gov/graphics_at4.shtml?ero.
 
WIND:  Gusty winds are possible in portions of the Yucatan Peninsula 
on Thursday.
 
SURF:  Swells generated by the depression are expected to affect the
western and northern portions of the Yucatan Peninsula beginning on
Thursday. These swells are likely to cause life-threatening surf and
rip current conditions.  Please consult products from your local
weather office.
 
A depiction of rip current risk for the United States can be found
at:
hurricanes.gov/graphics_at4.shtml?ripCurrents
 
 
NEXT ADVISORY
-------------
Next complete advisory at 1000 PM CDT.
 
$$
Forecaster Cangialosi
 

000
WTNT44 KNHC 062039
TCDAT4
 
Tropical Depression Nine Discussion Number   1
NWS National Hurricane Center Miami FL       AL092026
400 PM CDT Tue Oct 06 2026
 
Satellite imagery indicates that the area of low pressure located
over the southwestern Gulf of America has recently developed a
closed circulation, though it might still be elongated. Associated
showers and thunderstorms have also become better organized, and
this system now meets the criteria to be a tropical depression, the
ninth one of the season. The initial intensity is set at 30 kt based
on a Dvorak classification from TAFB.
 
The depression has barely moved over the past 6 to 12 hours, with 
the initial motion estimated to be 120/1 kt. The cyclone is expected 
to track slowly eastward or east-northeastward during the next 
couple of days while it moves in the flow near the base of a broad 
deep-layer trough, and could bring gusty winds and heavy rains to 
the western portions of the Yucatan Peninsula on Thursday. By 
Friday, a sharp turn to the northeast is expected when a shortwave 
trough forms over Texas and a ridge strengthens over the western 
Atlantic. This pattern change should cause the system to accelerate 
toward the northern Gulf Coast on Friday and into early Saturday. 
The NHC track forecast lies near the fast side of the guidance, in 
best agreement with the GDMI and ECAI aids. It should be noted that 
there is significant uncertainty in where the system makes the 
northeast turn and how fast it moves toward the coast. It appears 
that the stronger the system gets, the faster it will move toward 
the coast given the strength of the deep-layer flow. The NOAA G-IV 
jet is currently sampling the environment and special upper-air 
soundings are being deployed over the south-central U.S. The 
assimilation of these data into the dynamical models should improve 
their representation of the current environmental conditions, 
ideally yielding more reliable track and intensity guidance.
 
The environmental conditions appear generally conducive for
strengthening over the next few days, and given that the storm
appears compact, it will likely steadily strengthen during that
time. The NHC intensity forecast shows the system becoming a
tropical storm by early Wednesday and a hurricane on Thursday. Based
on the environmental conditions and the model guidance, the cyclone
will likely peak in strength before reaching the coast. Although not
seen in the forecast, some weakening seems likely when the storm
nears the Gulf Coast due to an increase in vertical wind shear, but
it is still expected to be a dangerous hurricane when it makes
landfall. This forecast is in fair agreement with the consensus
aids, but it should be noted that there are skillful models that are
higher than the current forecast.
 
Although the storm is expected to be compact for the next few days,
it will likely grow significantly in size, particularly on the
eastern side, when it reaches the northern Gulf Coast. Therefore,
based on the forecast uncertainty and expected larger size, users
are urged not to focus on the forecast points and stay tuned to
updates.
 
Key Messages:
 
1. There is an increasing risk of dangerous wind and storm surge 
impacts along portions of the northern Gulf Coast, and watches could 
be required on Wednesday. Residents from Louisiana to the Florida 
Panhandle should closely monitor the latest forecast updates and 
ensure they have their hurricane plan in place.
 
2. The system will bring areas of heavy rainfall to the central 
U.S. Gulf coast Friday into the weekend.  Flash and urban flooding, 
along with isolated river flooding, will be possible.
 
3. Yucatan Peninsula of Mexico: The depression is expected to
strengthen and could bring gusty winds and areas of heavy rain to
the western portion of the Yucatan Peninsula in a couple of days.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  06/2100Z 22.1N  95.6W   30 KT  35 MPH
 12H  07/0600Z 22.1N  95.0W   35 KT  40 MPH
 24H  07/1800Z 22.6N  93.4W   45 KT  50 MPH
 36H  08/0600Z 23.1N  91.8W   55 KT  65 MPH
 48H  08/1800Z 24.2N  90.1W   70 KT  80 MPH
 60H  09/0600Z 25.9N  88.8W   80 KT  90 MPH
 72H  09/1800Z 28.5N  88.3W   85 KT 100 MPH
 96H  10/1800Z 34.0N  88.7W   30 KT  35 MPH...INLAND
120H  11/1800Z 38.9N  86.5W   20 KT  25 MPH...POST-TROP/INLAND
 
$$
Forecaster Cangialosi