Official Discussion issued by the National Hurricane Center

Katia (AL122023) DATA RELEASED: 9/4/2023 9:00:00 AM UTC

Copy of official data

Tropical Depression Katia Discussion Number  12
NWS National Hurricane Center Miami FL       AL122023
900 AM GMT Mon Sep 04 2023

Katia barely qualifies as a tropical cyclone at this time.  The 
system is producing a few puffs of deep convection over the 
northern portion of its circulation.  Earlier scatterometer data 
indicated that the cyclone had weakened to a tropical depression 
and the current intensity estimate is kept at 30 kt.  This is in 
good agreement with various objective estimates from UW-CIMSS.

The depression is moving northwestward, or at about 310/6 kt.  
Katia's northwestward progress will soon be blocked by a high 
pressure area ahead of it.  Then, the flow on the southwestern side 
of a large cyclone over the eastern Atlantic is likely to cause the 
system to make a U-Turn and move slowly southeastward to 
south-southeastward in 24 to 72 hours.  The official forecast is a 
blend of the GFS and ECMWF solutions and is similar to the previous 
NHC track.

Katia should remain in an environment of very dry low- to mid-level 
air with moderate vertical shear.  Therefore, the cyclone is likely 
to degenerate into a remnant low by tonight, and dissipate in a few 
days.  This is also consistent with various global model 


INIT  04/0900Z 27.7N  33.7W   30 KT  35 MPH
12H  04/1800Z 28.0N  34.3W   30 KT  35 MPH
24H  05/0600Z 28.4N  34.6W   25 KT  30 MPH...POST-TROP/REMNT LOW
36H  05/1800Z 28.5N  34.4W   25 KT  30 MPH...POST-TROP/REMNT LOW
48H  06/0600Z 28.2N  33.9W   20 KT  25 MPH...POST-TROP/REMNT LOW
60H  06/1800Z 27.7N  33.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
72H  07/0600Z 26.7N  33.1W   20 KT  25 MPH...POST-TROP/REMNT LOW
96H  08/0600Z...DISSIPATED

Forecaster Pasch