####018003233####
WTPZ44 KNHC 310839

TCDEP4

 

Tropical Storm Pilar Discussion Number  11

NWS National Hurricane Center Miami FL       EP192023

400 AM CDT Tue Oct 31 2023



While deep convection has increased with Pilar overnight, the 

center of the storm remains mostly exposed on the southeastern 

side of a burst of deep convection.  It seems like moderate shear 

is preventing the system from strengthening, with basically no

thunderstorm activity southeast of the center.  The initial wind 

speed remains 45 kt based on a blend of the available intensity 

estimates.  

 

Pilar continues to creep east-northeastward, or 075/3 kt, a little 

slower than the previous advisory.  The steering flow is expected to 

collapse later today, with most of the guidance stalling Pilar just 

east of 90W, then accelerating the storm west-southwestward as a 

mid-level ridge builds by Thursday.  Generally, the model guidance 

stays a touch farther offshore than the last cycle, and the official 

forecast follows the trend.  Little change was made at long range, 

with the previous forecast coming in very close to the model 

consensus.  It is possible that later today the Tropical Storm Watch 

could be discontinued for portions of Central America, but there 

remains a significant heavy rain and flash flooding threat.



The storm still has a chance to intensify over the next day or so 

within moderate wind shear conditions but in a moist and unstable 

air mass along with warm ocean waters.  It seems like the chances of 

Pilar becoming a hurricane have decreased, and the peak NHC wind 

speed forecast is dropped 5 kt from the previous one, slightly above 

the model consensus.  It remains to be seen how Pilar maintains 

itself in a challenging environment after 60 hours, with dry air 

intrusions from a gap wind event and easterly wind shear.  The 

intensity forecast is maintained at 45 kt at long range, blending 

reliable guidance showing tropical depression to hurricane strength, 

and the uncertainty is high at long range.

 

Key Messages:

 

1. Heavy rains from Pilar will produce flash and urban flooding,

along with mudslides in areas of higher terrain of the Pacific coast

of Central America from El Salvador southward to Costa Rica through

Wednesday.

 

2. Tropical storm conditions are possible beginning later today

along portions of the Pacific coast of El Salvador, Honduras, and

Nicaragua, 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 few days.  These swells are

likely to cause life-threatening surf and rip current conditions.

 

 

FORECAST POSITIONS AND MAX WINDS

 

INIT  31/0900Z 11.4N  90.4W   45 KT  50 MPH

 12H  31/1800Z 11.6N  89.9W   50 KT  60 MPH

 24H  01/0600Z 11.8N  89.9W   55 KT  65 MPH

 36H  01/1800Z 11.7N  90.6W   55 KT  65 MPH

 48H  02/0600Z 11.3N  92.1W   50 KT  60 MPH

 60H  02/1800Z 10.7N  94.3W   45 KT  50 MPH

 72H  03/0600Z 10.1N  97.0W   45 KT  50 MPH

 96H  04/0600Z  9.2N 102.5W   45 KT  50 MPH

120H  05/0600Z  9.5N 108.0W   45 KT  50 MPH

 

$$

Forecaster Blake