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| #1114424 (Received by flhurricane at: 4:54 AM 02.Nov.2022) TCDAT1 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 |
