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#940289 (Received by flhurricane at: 10:48 PM 14.Sep.2018) TCDAT5 Tropical Storm Joyce Discussion Number 10 NWS National Hurricane Center Miami FL AL102018 1100 PM AST Fri Sep 14 2018 Joyce continues to look better organized on GOES-16 satellite imagery and the convective canopy has expanded. However, recent microwave data reveals that the cyclone is still tilted to the northeast due to nearly strong southwesterly wind shear. The most recent TAFB and SAB Dvorak classifications support raising the initial intensity to 45 kt. Despite the shear, most of the intensity guidance shows very slight strengthening over the next 12 to 24 hours, and the NHC intensity forecast is a little higher than the previous advisory at most forecast times. Persistent shear and decreasing SSTs along the forecast track should cause Joyce to weaken beyond that time, likely dissipating entirely shortly after 72 h. A few models, most notably the HWRF and UKMET, persist the cyclone a little beyond that, but only as a remnant low. The storm has turned east as expected, and the initial motion is now 090/5 kt. As the larger Helene begins to accelerate away, a mid-latitude trough over the central Atlantic should cause Joyce to turn northeastward and speed up. A turn back toward the east, or possibly even east-southeast is possible by the end of the forecast period as Joyce weakens and follows the northern periphery of a subtropical high over eastern Atlantic. Very little change has been made to the track forecast through 48 h, but it has been adjusted to the south at 72 h, following the latest consensus guidance. FORECAST POSITIONS AND MAX WINDS INIT 15/0300Z 31.6N 43.6W 45 KT 50 MPH 12H 15/1200Z 32.2N 42.1W 50 KT 60 MPH 24H 16/0000Z 33.2N 39.8W 50 KT 60 MPH 36H 16/1200Z 34.4N 37.1W 45 KT 50 MPH 48H 17/0000Z 35.1N 33.6W 40 KT 45 MPH 72H 18/0000Z 34.0N 28.4W 35 KT 40 MPH 96H 19/0000Z...DISSIPATED $$ Forecaster Zelinsky |