000 WTPZ44 KNHC 260246 TCDEP4 Tropical Storm Dora Discussion Number 5 NWS National Hurricane Center Miami FL EP042017 1000 PM CDT Sun Jun 25 2017 Dora's cloud pattern has continued to quickly improve this evening. Several well-defined spiral bands wrap around the center and the CDO has become more symmetric and expanded since the previous advisory. Recent microwave imagery suggest that an eye feature has formed within the CDO. Subjective Dvorak intensity estimates from TAFB and objective estimates from UW/CIMSS supported an intensity of 55 kt at 0000 UTC, but with the continued improved structure, the initial intensity has been set to 60 kt for this advisory. Dora is forecast to move over warm water and remain within a low shear environment during the next 12 to 24 hours. These conditions should allow for additional intensification and Dora is likely to become a hurricane by early Monday. The tropical cyclone is forecast to reach cooler waters in about a day, which should begin the weakening process. A faster rate of spin down is expected by late Tuesday as Dora moves over even colder waters and into a more stable environment. The NHC intensity forecast is a little above the ICON consensus through 36 hours, and is in best agreement with the LGEM guidance later in the period. Dora is moving west-northwestward or 300/12 kt. A strong mid-level ridge to the north of Dora is expected to steer the tropical cyclone west-northwestward over the next couple of days. After that time, a weaker and more shallow Dora should turn westward. The updated NHC track forecast is similar to the previous advisory and lies a little south of the TVCN model consensus out of respect for the typically reliable ECMWF which is along the southern edge of the guidance envelope. Although Dora is forecast to remain offshore, the outer bands of the tropical cyclone could bring locally heavy rainfall to portions of coastal southwestern Mexico through Monday. FORECAST POSITIONS AND MAX WINDS INIT 26/0300Z 16.4N 104.3W 60 KT 70 MPH 12H 26/1200Z 17.2N 105.9W 70 KT 80 MPH 24H 27/0000Z 18.2N 107.9W 75 KT 85 MPH 36H 27/1200Z 19.0N 109.8W 65 KT 75 MPH 48H 28/0000Z 19.4N 111.7W 55 KT 65 MPH 72H 29/0000Z 19.8N 115.0W 40 KT 45 MPH 96H 30/0000Z 20.0N 118.2W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 01/0000Z 19.0N 121.5W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ Forecaster Brown