Tropical Storm MARTIN Advisory jue, 03-11

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Tropical Storm Martin Discussion Number   4
NWS National Hurricane Center Miami FL       AL162022
500 AM AST Wed Nov 02 2022

Deep convection has continued to increase in coverage and intensity
with Martin this morning, with occasional hints of a eye trying to
develop within the cyclonically rotating bands of cloud tops colder
than -60C. This improved core structure can also be seen on a recent
0732 UTC GMI microwave pass. Earlier scatterometer imagery mostly
missed the center, though the edge values of ASCAT-C in the
southwest quadrant did show a peak wind retrieval of 44 kt. While
earlier subjective satellite intensity estimates remained largely
unchanged, given the improvement in satellite imagery seen this
morning compared to last night, the initial intensity is being
nudged upward to 55 kt for this advisory.

Martin is starting to make the turn more northward as it accelerates
at 075/13 kt. The tropical cyclone should continue to turn more
northeastward and accelerate over the next 12 to 24 hours as it
becomes captured by pronounced deep-layer trough in Atlantic Canada
that is quickly amplifying towards the system. This same trough will
ultimately fully capture Martin, leading to its extratropical
transition. The merger of both systems is also forecast to lead to a
rapid expansion of both the 34- and 50-kt radii and these have been
increased significantly as Martin becomes extratropical. After this
trough-TC merger, the resulting extratropical cyclone will slow down
and then pivot eastward over the remainder of the forecast period.
The track guidance is tightly clustered early on, but is also
slightly east of the prior forecast track, so the latest track
forecast was shifted in that direction. Another eastward adjustment
was also made in days 4 and 5, in order to match closer with track
guidance this cycle.

Martin is having no issues maintaining moderate to deep convection
near its center, thanks in large part to very cold (-57 to -59
degree C) 200 mb temperatures over the cyclone maintaining
instability. Even though shear is forecast to increase over the next
24 hours, this negative factor will likely be offset by a pronounced
jet streak developing north of Martin, with the cyclone being
optimally placed for in its right entrance region, favoring
large-scale ascent. Thus, Martin is expected to intensify further
and is forecast to become a hurricane later today. The acceleration
in the cyclone's forward motion may also help to increase its
maximum sustained winds, and the latest NHC intensity forecast still
shows Martin peaking in intensity as it becomes a large and powerful
extratropical cyclone. This intensity forecast remains in good
agreement with the bulk of the intensity guidance.


FORECAST POSITIONS AND MAX WINDS

INIT  02/0900Z 35.3N  52.1W   55 KT  65 MPH
 12H  02/1800Z 36.6N  49.2W   65 KT  75 MPH
 24H  03/0600Z 40.6N  43.7W   75 KT  85 MPH
 36H  03/1800Z 47.4N  37.4W   80 KT  90 MPH...POST-TROP/EXTRATROP
 48H  04/0600Z 54.3N  34.0W   75 KT  85 MPH...POST-TROP/EXTRATROP
 60H  04/1800Z 57.0N  35.3W   65 KT  75 MPH...POST-TROP/EXTRATROP
 72H  05/0600Z 55.5N  34.4W   55 KT  65 MPH...POST-TROP/EXTRATROP
 96H  06/0600Z 54.4N  22.4W   45 KT  50 MPH...POST-TROP/EXTRATROP
120H  07/0600Z 57.7N  13.1W   40 KT  45 MPH...POST-TROP/EXTRATROP

$$
Forecaster Papin