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Tropical Storm Martin Forecast Discussion


000
WTNT41 KNHC 012055
TCDAT1

Tropical Storm Martin Discussion Number   2
NWS National Hurricane Center Miami FL       AL162022
500 PM AST Tue Nov 01 2022

Martin has a tight low-level center with a small central dense
overcast and some outer banding.  However, the deep convection
remains somewhat fragmentary, and the system may still have some
hybrid characteristics remaining. The subjective Dvorak estimates
from SAB and TAFB came in at a 3.0, or around 45 kt. Fortunately,
there's also some in-situ data from drifting buoy 44018, which just
reported a 993 mb surface pressure value close to the system's
center.  Based upon this, the central pressure is assessed at 991
mb and intensity is boosted slightly to 50 kt.

The tropical storm is moving a bit faster - 11 kt - toward the
east, as it is embedded in the mid-latitude westerlies in a split
in the jet stream with faster westerlies both poleward and
equatorward of the system.  Martin should turn toward the northeast
at an increasingly rapid forward speed during the next two days.
The official track forecast is based upon the consensus (TVCN and
HCCA) of the tightly clustered global and hurricane dynamical
models, and slightly to the right - eastward - of the previous
advisory at 60-72 hr. From days three to five, Martin should
decelerate as it interacts with a developing extratropical low to
its north.

For the intensity, the SSTs are a lukewarm 25-26C, which is a couple 
of degrees warmer than usual for this latitude.  This anomalous 
surface warmth along with quite cold upper-level temperatures should 
provide an unstable atmosphere. The mid-level moisture that Martin 
is currently embedded within is quite dry, but is expected to 
moisten up by tomorrow. The vertical shear is 20-25 kt out of the 
southwest, but the effects of this moderate shear are tempered by 
Martin moving in roughly the same direction as the shear vector. 
Within these generally conducive conditions, the system is expected 
to steadily intensify. The official intensity forecast is similar 
to that previously issued, and is based on a consensus of the 
statistical, global, and hurricane dynamical models.  Around 48 hr, 
Martin should transition into an extratropical low as a cold front 
reaches near the center of the system.  A significant change to the 
official forecast has Martin continuing now for five days as the 
new global models suggest that Martin will remain the dominant 
vortex and not be absorbed. It is expected that Martin will be a 
large and powerful extratropical system threatening the North 
Atlantic shipping lanes through days four and five.


FORECAST POSITIONS AND MAX WINDS

INIT  01/2100Z 35.4N  54.5W   50 KT  60 MPH
 12H  02/0600Z 35.5N  52.4W   60 KT  70 MPH
 24H  02/1800Z 37.3N  48.6W   70 KT  80 MPH
 36H  03/0600Z 41.0N  43.3W   80 KT  90 MPH
 48H  03/1800Z 47.9N  36.4W   80 KT  90 MPH...POST-TROP/EXTRATROP
 60H  04/0600Z 55.5N  31.2W   75 KT  85 MPH...POST-TROP/EXTRATROP
 72H  04/1800Z 59.0N  32.5W   70 KT  80 MPH...POST-TROP/EXTRATROP
 96H  05/1800Z 60.0N  34.0W   65 KT  75 MPH...POST-TROP/EXTRATROP
120H  06/1800Z 58.0N  35.0W   55 KT  65 MPH...POST-TROP/EXTRATROP

$$
Forecaster Landsea



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