Official Discussion issued by the National Hurricane Center

Kirk (AL122024) DATA RELEASED: 10/1/2024 9:00:00 AM UTC

Copy of official data

Tropical Storm Kirk Discussion Number   7
NWS National Hurricane Center Miami FL       AL122024
500 AM AST Tue Oct 01 2024

Satellite imagery indicates that Kirk's structure hasn't changed 
very much over the past 6 h.  The infrared imagery consists of a 
large comma-shaped area of deep convection.  ASCAT data from Monday 
evening as well as a more recent 01/0416 AMSR2 image indicate that 
the center is near the northern edge of the convection.  The AMSR2 
image also indicates that the convective bands haven't become any 
better organized around the center over the past 6 h.  The latest 
subjective Dvorak intensity estimates range from 45 to 55 kt, and 
the latest objective intensity estimates from UW-CIMSS range from 49 
to 56 kt.  Given that the highest ASCAT vectors from around 0000 UTC 
were about 43 kt, and taking into account the recent intensity 
estimates, the initial intensity is set to 50 kt, which is unchanged 
from the previous NHC advisory.

Kirk is estimated to be moving west-northwestward, or 295/12 kt. 
This general motion should continue for the next day or so while 
Kirk moves around the southwestern periphery of a deep-layer 
subtropical ridge over the eastern Atlantic. A gradual turn toward 
the northwest is expected during the middle part of the week, 
followed by a recurvature to the north over the central Atlantic by 
the end of the forecast period.  The track guidance is in good 
agreement for the first couple days of the forecast, with a bit of 
spread noted thereafter.  The new NHC track forecast is similar to 
the previous official forecast through 72 h, and west of the 
previous forecast at days 4 and 5, close to the multi-model 
consensus aid TVCA.

Favorable environmental conditions are forecast to persist along 
Kirk's path through the next 4 days or so, with warm ocean waters, 
weak vertical wind shear and a relatively moist and unstable 
atmosphere.  Kirk has a broad structure with a large wind field.  
The tropical storm force radii are forecast to continue increasing 
through the forecast period.  This structure could limit Kirk's 
chances for rapid strengthening, despite the favorable environment. 
Little change has been made to the NHC intensity forecast, which 
calls for steady strengthening over the next 3 days.  The NHC 
intensity forecast is near the high end of the guidance envelope.  
Kirk is forecast to become a large, major hurricane over the open 
central Atlantic later this week.


FORECAST POSITIONS AND MAX WINDS

INIT  01/0900Z 14.9N  38.0W   50 KT  60 MPH
12H  01/1800Z 15.5N  39.6W   60 KT  70 MPH
24H  02/0600Z 16.5N  41.4W   75 KT  85 MPH
36H  02/1800Z 17.6N  43.1W   85 KT 100 MPH
48H  03/0600Z 18.7N  44.4W   95 KT 110 MPH
60H  03/1800Z 19.9N  45.8W  105 KT 120 MPH
72H  04/0600Z 21.1N  47.1W  110 KT 125 MPH
96H  05/0600Z 24.2N  49.7W  110 KT 125 MPH
120H  06/0600Z 29.0N  49.7W  100 KT 115 MPH

$$
Forecaster Hagen