ZCZC MIATCDEP1 ALL TTAA00 KNHC DDHHMM TROPICAL STORM AMANDA DISCUSSION NUMBER 6 NWS NATIONAL HURRICANE CENTER MIAMI FL EP012014 800 PM PDT FRI MAY 23 2014 Amanda has organized quickly over the past few hours. Deep convection now wraps more than halfway around the estimated center position, and an AMSR-2 microwave pass a few hours ago showed the development of a mid-level eye feature. Based on the latest ADT estimate from UW-CIMSS the initial intensity has been increased to 50 kt. Now that Amanda is developing inner-core structure, it seems likely that the cyclone will be able to take advantage of the favorable environment and intensify, possibly rapidly, during the next day or so. The SHIPS model shows the shear remaining 10 kt or less for the next 36 hours, and the SHIPS RI index shows a 58 percent probability of a 30-kt intensity increase in the next 24 hours. The official intensity forecast has been adjusted sharply upward and shows Amanda becoming a hurricane by 24 hours. A peak in intensity is shown at 48 hours, however, it is possible that Amanda could strengthen more than indicated here. After 48 hours, the shear will begin to increase ahead of an approaching trough and the cyclone will be moving over somewhat cooler waters, which should result in gradual weakening. The NHC forecast is a little above most of the guidance through 24 hours and is close to the IVCN intensity consensus after that time. The initial motion estimate is 290/04, as the cyclone continues to move slowly around the southwestern side of a weakening mid-level ridge centered over Mexico. This slow west-northwestward motion is expected to continue for the next 24 to 36 hours. A turn toward the northwest is shown around 48 hours, with a gradual northward acceleration expected late in the period as the ridge restrengthens to the east and a mid/upper-level trough approaches from the west. The track model guidance has trended somewhat faster this cycle, especially by day 5, and the official forecast has been adjusted in that direction. Otherwise, the new NHC track is largely an update of the previous advisory. FORECAST POSITIONS AND MAX WINDS INIT 24/0300Z 11.2N 109.1W 50 KT 60 MPH 12H 24/1200Z 11.4N 109.7W 60 KT 70 MPH 24H 25/0000Z 11.7N 110.6W 75 KT 85 MPH 36H 25/1200Z 11.9N 111.1W 80 KT 90 MPH 48H 26/0000Z 12.2N 111.4W 85 KT 100 MPH 72H 27/0000Z 13.2N 111.7W 75 KT 85 MPH 96H 28/0000Z 15.0N 112.0W 65 KT 75 MPH 120H 29/0000Z 17.0N 112.0W 55 KT 65 MPH $$ Forecaster Brennan NNNN