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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
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