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Tropical Storm Pilar Discussion Number 7
NWS National Hurricane Center Miami FL EP192023
400 AM CDT Mon Oct 30 2023
There has been little change with Pilar overnight. The storm is
still producing a concentrated area of deep convection, but
microwave data suggest that the low-level center is located near the
southeastern edge of the thunderstorms. The latest satellite
intensity estimates range from 35 to 45 kt, but an ASCAT pass from a
few hours ago showed maximum reliable winds closer to 30 kt. Based
on a blend of all of these data, the initial intensity is held at 35
kt.
Pilar is moving slowly to the east-northeast, and that motion should
continue for the next couple of days. Nearly all of the models
stall Pilar near the coast of Central America on Tuesday and Tuesday
night, but at this point the reliable models keep the core of the
storm offshore. On Wednesday, Pilar will likely turn southwestward
away from land as a mid-level ridge builds to the north of the
system. The cyclone will likely accelerate westward after that in
part due to an anticipated Gulf of Tehuantepec gap wind event. Only
small changes were made to the previous NHC track forecast and this
one lies fairly close to the consensus aids.
The storm will have an opportunity to strengthen during the next day
or so as it remains over warm SSTs and in relatively favorable
atmospheric conditions. Pilar is expected to be near hurricane
strength when it is close to the coast of Central America.
However, beyond that time, the slow motion of the system could
cause ocean upwelling and the Gulf of Tehuantepec gap wind event
will likely result in an increase in shear and intrusions of dry
and stable air. Therefore, a weakening trend is forecast beginning
late Tuesday or early Wednesday. The NHC intensity forecast lies
at the high end of the guidance in the short term, but falls closer
to the middle of the guidance envelope from 72-120 hours.
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 early Tuesday
along portions of the Pacific coast of El Salvador, Honduras, and
Nicaragua, where a Tropical Storm Watch remains in effect.
Interests elsewhere along the Pacific coast of Guatemala,
and Nicaragua should monitor the progress of this system as
additional watches or warnings could be needed later today.
3. Swells generated by Pilar will begin to affect portions
of the Pacific coast of Central America later today. These swells
are likely to cause life-threatening surf and rip current
conditions.
FORECAST POSITIONS AND MAX WINDS
INIT 30/0900Z 11.0N 91.8W 35 KT 40 MPH
12H 30/1800Z 11.1N 91.2W 45 KT 50 MPH
24H 31/0600Z 11.6N 90.1W 55 KT 65 MPH
36H 31/1800Z 12.0N 89.5W 60 KT 70 MPH
48H 01/0600Z 12.0N 89.2W 50 KT 60 MPH
60H 01/1800Z 11.7N 89.7W 40 KT 45 MPH
72H 02/0600Z 11.1N 91.2W 35 KT 40 MPH
96H 03/0600Z 9.8N 95.3W 35 KT 40 MPH
120H 04/0600Z 9.3N 100.8W 35 KT 40 MPH
$$
Forecaster Cangialosi
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