000 WTPZ41 KNHC 280834 TCDEP1 TROPICAL STORM AMANDA DISCUSSION NUMBER 23 NWS NATIONAL HURRICANE CENTER MIAMI FL EP012014 200 AM PDT WED MAY 28 2014 A 0457 UTC AMSU pass confirmed that Amanda is a sheared tropical storm, with the low-level center displaced to the south of the deep convection due to about 15 kt of southerly shear. The convection itself increased beginning around 0100 UTC, and now the center is located beneath the cirrus canopy. The initial intensity is held at 60 kt based mainly on SAB's Dvorak classification of T3.5/4.0 using a shear pattern. Modest south to southwesterly shear is expected to continue affecting Amanda for the next 24-36 hours. The shear could relax somewhat after 36 hours, but Amanda will have moved into a less favorable thermodynamic environment by that time. Therefore, gradual weakening is expected, and Amanda is likely to degenerate to a remnant low in about 3 days. The NHC official forecast is unchanged from the previous advisory and is fairly close to the intensity consensus IVCN. Fixes based on microwave data indicate that Amanda's center began meandering and drifting eastward during the past 12 hours. The initial motion is 050/2 kt, but that estimate is highly uncertain. The steering pattern around Amanda is complicated at the moment. An elongated mid-level ridge extends from the Four Corners region of the U.S. southeastward along the length of Mexico, while a broad mid-level trough covers much of the area west of the Baja California peninsula. These features should push Amanda slowly northeastward during the next 48 hours while the cyclone still has some vertical coherency. Once it becomes a remnant low, Amanda will be located in very weak low-level flow and will likely meander or drift southwestward on days 3 through 5. The new NHC track forecast is farther east than the previous forecast due to the relocated initial position. It is not, however, quite as far east as the GFS, ECMWF, or multi-model consensus TVCE. FORECAST POSITIONS AND MAX WINDS INIT 28/0900Z 14.6N 112.4W 60 KT 70 MPH 12H 28/1800Z 15.0N 111.9W 50 KT 60 MPH 24H 29/0600Z 15.8N 110.9W 40 KT 45 MPH 36H 29/1800Z 16.6N 109.9W 35 KT 40 MPH 48H 30/0600Z 17.2N 109.0W 30 KT 35 MPH 72H 31/0600Z 17.5N 109.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 01/0600Z 17.0N 110.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 02/0600Z 16.0N 110.5W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ Forecaster Berg