Tropical Storm Oscar Forecast Discussion

322 
WTNT41 KNHC 211445
TCDAT1

Tropical Storm Oscar Discussion Number  10
NWS National Hurricane Center Miami FL       AL162024
1100 AM EDT Mon Oct 21 2024

Surface observations and visible satellite imagery indicate that 
the center of Oscar, although not very easy to locate, is still 
moving over eastern Cuba this morning.  Radar observations from 
Guantanamo Bay show that the inner core of the tropical cyclone has 
become severely disrupted.  The system has continued to weaken while
interacting with the very mountainous terrain, and the initial wind 
speed is estimated to have decreased to near 35 kt, although this 
may be generous.

The initial motion is an uncertain 300/3 kt.  It is possible that 
the center of the system may re-form near the northern coast of 
Cuba later today.  In any event, Oscar is expected to turn 
northward and northeastward on the eastern side of a mid-level 
trough over the western Bahamas through tonight.  The system 
should then accelerate northeastward  over portions of 
the southeastern Bahamas and western Atlantic ahead of the 
aforementioned trough.  Global model predictions show the 
circulation of Oscar becoming absorbed by a larger, developing 
non-tropical low pressure area to the west of Bermuda by day 3.  
The NHC track forecast is similar to the previous one and is very 
close to the dynamical model consensus.

Some additional weakening is expected while Oscar continues 
to interact with the land mass of eastern Cuba today, and Oscar 
could weaken to a tropical depression before the circulation moves 
over water.  Thereafter, the system will be contending with 
increasing westerly vertical wind shear and drier air.  Therefore 
only slight restrengthening is anticipated within the next 
day or so, followed by little change in strength before Oscar 
becomes absorbed by the non-tropical low pressure system.

The primary hazard associated with Oscar will continue to be heavy 
rainfall and life-threatening flash flooding, particularly over the 
mountainous terrain of eastern Cuba. Preliminary reports in the 
Province of Guantanamo in eastern Cuba already indicate more than 
10 inches of rain have fallen in spots. 


Key Messages:

1. Through midweek, heavy rainfall from Oscar will lead to areas of 
significant, life-threatening flash flooding along with mudslides 
across portions of eastern Cuba, especially within the Sierra 
Maestra. In addition, localized flash flooding will be possible 
across the southeastern Bahamas.

2. Tropical storm conditions are expected to continue today across
portions of eastern Cuba. Tropical storm conditions are also
expected in portions of the southeastern Bahamas tonight and
Tuesday.


FORECAST POSITIONS AND MAX WINDS

INIT  21/1500Z 20.3N  75.4W   35 KT  40 MPH...INLAND
 12H  22/0000Z 21.0N  75.3W   35 KT  40 MPH...OVER WATER
 24H  22/1200Z 22.2N  74.7W   40 KT  45 MPH
 36H  23/0000Z 23.7N  73.2W   40 KT  45 MPH
 48H  23/1200Z 25.6N  71.2W   40 KT  45 MPH
 60H  24/0000Z 28.3N  68.3W   40 KT  45 MPH
 72H  24/1200Z...ABSORBED BY NON-TROPICAL LOW PRESSURE AREA

$$
Forecaster Pasch/Delgado