####018003002####
WTPZ45 KNHC 040842

TCDEP5

 

Tropical Storm Lidia Discussion Number   5

NWS National Hurricane Center Miami FL       EP152023

300 AM MDT Wed Oct 04 2023

 

Earlier microwave imagery and recent geostationary satellite data

indicate that the low-level center of Lidia is located just beneath

the eastern edge of a large convective mass with cloud top

temperatures below -80 degrees C.  The most recent subjective Dvorak

intensity estimates from TAFB and SAB were T3.0 (45 kt) and T2.5 (35

kt), respectively.  Since the center appears to be slightly more

embedded within the deep convection, the initial intensity is raised

to 40 kt, using a blend of the subjective Dvorak estimates. A very

recently arriving GMI microwave overpass shows that there has been

some increase in organization, but the mid-level center is

displaced about 30-40 n mi west of the low-level center.

 

The initial motion estimate is north-northwestward or 330 degrees at

7 kt.  The track forecast reasoning is unchanged from before.  A

mid-level ridge over the northwestern Gulf of Mexico is expected to

steer the cyclone northwestward to north-northwestward during the

next 24 to 36 hours.  After that time, a narrow ridge is forecast to

build to the north of Lidia which should result in a slower westward

motion through much of the remainder of the forecast period.  There

is still a large amount of along-track spread in the guidance after

the westward turn, with the UKMET and ECMWF on the faster side of

the guidance envelope.  The GFS and HAFS-A/B models are much

slower.  It should also be noted that there is unusually large

spread between the HFIP corrected consensus model and the various

multi-model consensus aids.  This results in lower-than-normal

confidence in Lidia's long range track forecast.  The NHC track

forecast is close to a blend of the GFS, ECMWF, and regional

hurricane models.

 

The SHIPS guidance indicates that moderate-to-strong easterly

vertical wind shear will persist over Lidia during the next several

days.  However, other environmental conditions consisting of warm

sea surface temperatures and a moist environment favor some

strengthening.  As a result, the NHC intensity forecast calls from

slow intensification during the next several days, but it is a

little lower than the previous forecast at the long range. The

updated NHC wind speed forecast is a little above the latest HCCA

and IVCN consensus models.

 

 

FORECAST POSITIONS AND MAX WINDS

 

INIT  04/0900Z 14.0N 108.3W   40 KT  45 MPH

 12H  04/1800Z 14.8N 108.7W   45 KT  50 MPH

 24H  05/0600Z 15.3N 109.1W   45 KT  50 MPH

 36H  05/1800Z 15.7N 109.5W   45 KT  50 MPH

 48H  06/0600Z 15.8N 110.1W   50 KT  60 MPH

 60H  06/1800Z 15.7N 110.9W   50 KT  60 MPH

 72H  07/0600Z 15.6N 111.8W   55 KT  65 MPH

 96H  08/0600Z 15.5N 113.4W   60 KT  70 MPH

120H  09/0600Z 15.9N 114.3W   60 KT  70 MPH

 

$$

Forecaster Brown