Official Discussion issued by the National Hurricane Center

Katia (AL122023) DATA RELEASED: 9/3/2023 9:00:00 PM UTC

Copy of official data

Tropical Storm Katia Discussion Number  10
NWS National Hurricane Center Miami FL       AL122023
900 PM GMT Sun Sep 03 2023

The center of Katia remains exposed on the latest satellite 
imagery, with a large convective burst in the northern semicircle 
noted this evening.  The intensity estimates are a split decision, 
with about half of data points suggesting tropical depression, and 
the other half still a tropical storm.  With the burst in 
convection, the initial wind speed is held at 35 kt, and there 
could be further clarity from partial scatterometer data this 
evening. A combination of southerly shear and very dry mid-level air 
should extinguish the thunderstorm activity early Monday and cause 
gradual weakening. The global models continue to show no organized 
thunderstorm activity by tomorrow, and Katia is likely to become a 
remnant low in 12-24 h.

The storm is holding steady on a northwest course at 6 kt. Katia 
is expected to be steered between a large middle- to upper- 
tropospheric cut-off low to the west over the central subtropical
Atlantic and a mid-level ridge to the east during the next 36 hours 
or so.  As Katia weakens, it should get trapped within the 
low-level subtropical ridge, causing little motion by Tuesday, and 
a southward drift by Wednesday. No significant changes were made to 
the NHC track or intensity forecasts.


INIT  03/2100Z 27.1N  32.9W   35 KT  40 MPH
12H  04/0600Z 27.5N  33.6W   30 KT  35 MPH
24H  04/1800Z 28.0N  34.2W   30 KT  35 MPH...POST-TROP/REMNT LOW
36H  05/0600Z 28.4N  34.4W   25 KT  30 MPH...POST-TROP/REMNT LOW
48H  05/1800Z 28.4N  34.1W   25 KT  30 MPH...POST-TROP/REMNT LOW
60H  06/0600Z 28.0N  33.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
72H  06/1800Z 27.5N  33.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
96H  07/1800Z...DISSIPATED

Forecaster Blake