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WTPZ44 KNHC 011446

TCDEP4

 

Tropical Storm Pilar Discussion Number  16

NWS National Hurricane Center Miami FL       EP192023

1000 AM CDT Wed Nov 01 2023

 

Deep convection has continued to burst over the western portion of 

Pilar's circulation this morning.  However, the cloud tops have been 

warming during the past couple of hours, and recent visible imagery 

still indicates that the low-level circulation is located near the 

eastern edge of the convection.  The initial intensity is again held 

at 50 kt, which is a blend of the latest subjective Dvorak T- and 

CI-numbers from TAFB and SAB.

 

Recent satellite fixes show that Pilar is now moving westward or

270 degrees at 6 kt. A much faster westward to west-southwestward

motion is expected during the next few days as a narrow mid-level

ridge builds across southern Mexico.  The dynamical model guidance

continues to trend toward a faster solution, and the NHC track

forecast has again been sped up from the previous advisory.  The

new forecast track lies between the previous interpolated forecast

and the latest HCCA and TVCE consensus aids.

 

The moderate shear that has been plaguing Pilar is expected to

continue for another day or so.  Although the shear may decrease

somewhat after that time, the storm is likely to encounter a drier

and more stable airmass from an ongoing Gulf of Tehuantepec gap wind

event.  In addition, Pilar is expected to pass over an area of

slightly cooler upwelled waters to the south and southwest of the

Gulf of Tehuantepec.  As a result of these unfavorable conditions,

most of the dynamical model guidance shows gradual weakening

during the next few days, and the NHC intensity forecast follows

suit.  It should be noted that simulated satellite imagery from the

GFS suggests that Pilar could struggle to maintain organized deep

convection by the weekend.  The NHC forecast maintains Pilar as a

tropical cyclone for the entire 5-day period, but it is possible

that the system degenerates into a remnant low or trough before the

end of the period.  There is still a fair amount of uncertainty in 

the longer range status and intensity of the system.

 

 

Key Messages:

 

1. Additional heavy rainfall from Pilar will produce flash and urban

flooding, along with mudslides in areas of higher terrain of the

Pacific coast of Central America from southern El Salvador, across

southern Honduras, western Nicaragua into northern Costa Rica

through today.

 

2. Tropical storm conditions are possible along portions of the

Pacific coast of El Salvador where a Tropical Storm Watch remains

in effect.

 

3. Swells generated by Pilar will continue to affect the Pacific

coast of Central America during the next day or two.  These

swells are likely to cause life-threatening surf and rip current

conditions.

 

 

FORECAST POSITIONS AND MAX WINDS

 

INIT  01/1500Z 12.5N  90.5W   50 KT  60 MPH

 12H  02/0000Z 12.2N  91.8W   45 KT  50 MPH

 24H  02/1200Z 11.6N  94.2W   45 KT  50 MPH

 36H  03/0000Z 10.6N  97.3W   45 KT  50 MPH

 48H  03/1200Z  9.9N 100.4W   40 KT  45 MPH

 60H  04/0000Z  9.4N 103.3W   40 KT  45 MPH

 72H  04/1200Z  9.3N 105.8W   35 KT  40 MPH

 96H  05/1200Z  9.6N 110.2W   35 KT  40 MPH

120H  06/1200Z 10.4N 113.7W   30 KT  35 MPH

 

$$

Forecaster Brown