Tropical Storm Patty Forecast Discussion

539 
WTNT42 KNHC 040848
TCDAT2

Tropical Storm Patty Discussion Number   9
NWS National Hurricane Center Miami FL       AL172024
900 AM GMT Mon Nov 04 2024

This morning's METSAT-10 satellite imagery presentation consists of
a fragmented curved band with -30C to -40C cloud tops displaced to
the east of the exposed elongated surface center.  A blend of the 
TAFB and SAB subjective and UW-CIMSS objective technique satellite 
intensity estimates yields an initial intensity of 35 kt for this 
advisory.

Although Patty's cloud pattern is typical of a sheared tropical
cyclone, the FSU cyclone phase diagram based on the GFS and ECMWF 
models indicates an asymmetric deep cold core thermal structure.  
Despite the sub-23C oceanic sea surface temperatures, the very cold 
upper-tropospheric temperatures are more than likely supporting
sufficient thermodynamic instability to produce the remaining
convection associated with the cyclone.  The vertical tilt with
height is becoming more pronounced due to the strong westerly shear
and Patty should spin down while losing what remains of the
convection and become a post-tropical cyclone later today.  The
global models agree with Patty opening up into a trough by the 36
hr period and the official forecast follows suit.

Patty's initial motion is estimated to be eastward, or 070/17 kt.
A turn toward the east-northeast is expected today and this motion
should continue until it dissipates on Tuesday.  The NHC forecast
is similar to the previous one and closely follows the various
consensus aids.

Key messages:

1. Between late today and Tuesday, heavy rainfall across portions 
of Portugal and western Spain is possible from Patty or its 
remnants.


FORECAST POSITIONS AND MAX WINDS

INIT  04/0900Z 38.2N  18.0W   35 KT  40 MPH
 12H  04/1800Z 39.0N  14.9W   35 KT  40 MPH...POST-TROPICAL
 24H  05/0600Z 40.2N  11.5W   30 KT  35 MPH...POST-TROP/REMNT LOW
 36H  05/1800Z...DISSIPATED

$$
Forecaster Roberts