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#1152690 (Received by flhurricane at: 4:53 PM 13.Sep.2023) TCDAT4 Hurricane Margot Discussion Number 26 NWS National Hurricane Center Miami FL AL142023 Issued by the NWS Weather Prediction Center College Park MD 900 PM GMT Wed Sep 13 2023 Very little change is noted with Margot's convective structure since the last advisory. The cyclone continues to exhibit a double eyewall structure based on a 1527Z AMSR-2 pass, and Margot's eye still occasionally appears in conventional GOES-16 IR and VIS imagery. Given the lack of change with the hurricane's internal structure and appearance, the intensity will be maintained at 80 kt for this advisory. The motion has bent just slightly to the right since this morning and is now moving due north at 6 kt. Margot continues to gradually slow down as it moves within the flow between a deep-layer ridge over the eastern Atlantic and a narrow upper trough to its west. A general northward motion should continue over the next day or so before the track forecast becomes very challenging. Margot will then become caught in weak steering currents, with the global models showing a blocking ridge developing to the north of the cyclone by late week into the weekend. There remain notable differences between the GFS and ECMWF with regards to the strength and position of this ridge, which has large implications in the longer-range track of Margot, but there has been some tightening of the model consensus since this morning. This supports the storm making a gradual clockwise loop between 36-72 hrs as the ridge initially builds north of the cyclone and then slides off to the east. By 120 hrs, the storm will likely begin accelerating off to the northeast as it gets picked up by the westerlies, but the overall track forecast confidence remains low given the model spread late in the forecast period. Increasing deep-layer shear during the next 24 to 36 hrs, entrainment of drier air, and a likelihood of Margot upwelling cooler waters should result in a steady weakening of the cyclone going through the end of the week and into the weekend. The NHC intensity forecast is close to the previous one and shows a gradual decrease in strength through 72 hrs, in good agreement with the consensus of the intensity aids. Although this forecast keeps Margot a tropical cyclone through day 5, simulated satellite imagery from the global models suggests these increasingly hostile environmental factors could cause the system to lose organized convection and become post-tropical by early next week as the storm lingers west of the Azores. FORECAST POSITIONS AND MAX WINDS INIT 13/2100Z 34.7N 40.6W 80 KT 90 MPH 12H 14/0600Z 35.5N 40.6W 75 KT 85 MPH 24H 14/1800Z 36.4N 40.0W 70 KT 80 MPH 36H 15/0600Z 36.7N 39.5W 65 KT 75 MPH 48H 15/1800Z 36.5N 39.4W 65 KT 75 MPH 60H 16/0600Z 36.0N 39.9W 60 KT 70 MPH 72H 16/1800Z 35.6N 41.0W 50 KT 60 MPH 96H 17/1800Z 36.5N 43.0W 45 KT 50 MPH 120H 18/1800Z 39.5N 41.5W 45 KT 50 MPH $$ Forecaster Orrison/Blake |