000 WTPZ44 KNHC 270237 TCDEP4 Hurricane Hilary Discussion Number 23 NWS National Hurricane Center Miami FL EP092017 900 PM MDT Wed Jul 26 2017 Recent microwave images indicate that Hilary is vertically titled due to 15-20 kt of northwesterly shear. Although the low-level center of the hurricane is still located beneath very cold cloud tops, the overall cloud pattern appears more ragged than it was earlier today. The Dvorak classifications from TAFB and SAB have held steady at 5.0/90 kt, but based on the degraded appearance and structure, the initial wind speed is lowered a little to 85 kt. This intensity estimate is between the above mentioned subjective Dvorak estimates and the ADT values from CIMSS at the University of Wisconsin. The moderate shear currently affecting Hilary is expected to continue for about another day, which should cause some additional weakening. Even though the shear should lessen beyond 24 hours, Hilary will be moving over progressively cooler waters and it is forecast to cross the 26 degree C isotherm in about 2 days. These less favorable oceanic conditions and a progressively drier and more stable air mass should cause additional weakening, and Hilary is expected to become a post-tropical cyclone by the end of the forecast period. The NHC intensity forecast is a little lower than previous one, and it is close to the HFIP and IVCN consensus models. The hurricane is moving west-northwestward at 10 kt steered by a mid-level ridge to its northeast. The track forecast philosophy has not changed from the past few advisories. Although some interaction may take place with Irwin, currently located about 500 nmi to the west of Hilary, it is not expected to have much of an impact on the future path of Hilary. A general track to the west-northwest at a slightly slower pace is expected throughout the forecast period. The new NHC track forecast is similar to the previous one, and it is in best agreement with the various consensus aids. FORECAST POSITIONS AND MAX WINDS INIT 27/0300Z 17.1N 114.2W 85 KT 100 MPH 12H 27/1200Z 17.4N 115.6W 80 KT 90 MPH 24H 28/0000Z 17.9N 117.2W 75 KT 85 MPH 36H 28/1200Z 18.6N 118.8W 75 KT 85 MPH 48H 29/0000Z 19.3N 120.5W 70 KT 80 MPH 72H 30/0000Z 20.7N 124.3W 60 KT 70 MPH 96H 31/0000Z 21.8N 128.1W 45 KT 50 MPH 120H 01/0000Z 22.9N 131.2W 35 KT 40 MPH...POST-TROPICAL $$ Forecaster Cangialosi