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Tropical Storm Pilar Discussion Number  13
NWS National Hurricane Center Miami FL       EP192023
400 PM CDT Tue Oct 31 2023
 
Satellite imagery shows that Pilar's center remains exposed on the 
southeast side of the main convective plume. Earlier AMSR2 and 
SSMI/S microwave imagery depicts some partial banding features 
within the northern semi-circle. Scatterometer ASCAT-B and -C passes 
this afternoon shows satellite derived winds are around 40 to 45 
knots. These values are in good agreement with the latest Dvorak 
satellite intensity estimates from both TAFB and SAB, T/3.0 or 45 
knots. Therefore, given the combination of data this the 
initial intensity remains at 45 kt for this advisory.
 
Pilar is moving slowly east-northeastward or 060/3 kt. The storm is 
forecast to move very little tonight as the steering currents over 
the far eastern Pacific collapse. A mid-level ridge is then forecast 
to build to the north and northeast of Pilar, which should cause the 
storm to begin moving west-southwestward. As the mid-level ridge 
continues to build westward, Pilar will be steered on a 
west-southwestward to westward motion along the southern side of the 
ridge. The latest NHC track forecast is similar to the previous 
advisory and lies near the latest consensus aids. The threat of 
tropical-storm-force winds should begin to diminish as Pilar starts 
moving westward, but the risk of heavy rain and flash-flooding is 
expected to continue over portions of Central America over the next 
couple of days.
 
Some slight strengthening is possible during the next day or so as 
the storm is located over warm sea surface temperatures and moderate 
vertical wind shear. In about 2 to 3 days vertical wind shear is 
forecast to weaken, but dry air from a gap wind event from the Gulf 
of Tehuantepec may limit intensification.  Towards the end of the 
period, the environmental conditions may become a little more 
conducive and the official forecast depicts strengthening once 
again. The NHC intensity forecast lies near the corrected HCCA 
consensus aids.
 
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 southern El Salvador, across southern 
Honduras, western Nicaragua into northern Costa Rica through 
Wednesday.
 
2. Tropical storm conditions are possible 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  31/2100Z 11.4N  89.5W   45 KT  50 MPH
 12H  01/0600Z 11.5N  89.7W   50 KT  60 MPH
 24H  01/1800Z 11.5N  90.5W   50 KT  60 MPH
 36H  02/0600Z 11.2N  92.2W   50 KT  60 MPH
 48H  02/1800Z 10.7N  94.5W   45 KT  50 MPH
 60H  03/0600Z 10.1N  97.2W   45 KT  50 MPH
 72H  03/1800Z  9.6N 100.0W   45 KT  50 MPH
 96H  04/1800Z  9.5N 105.3W   45 KT  50 MPH
120H  05/1800Z 10.1N 109.3W   50 KT  60 MPH
 
$$
Forecaster Kelly
 
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