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Hurricane DORA Forecast Discussion Number 7
2017-06-26 16:32:42| National Hurricane Center (East Pacific)
Issued at 900 AM MDT Mon Jun 26 2017 000 WTPZ44 KNHC 261432 TCDEP4 Hurricane Dora Discussion Number 7 NWS National Hurricane Center Miami FL EP042017 900 AM MDT Mon Jun 26 2017 Dora has continued to rapidly intensify with a 20-nmi-diameter, cloud-filled eye now evident in visible satellite imagery. The upper-level outflow pattern remains quite impressive and continues to expand in all quadrants. Satellite intensity estimates are a consensus T4.5/77 kt from TAFB and SAB, and T4.7/82 kt from CIMSS ADT, which supports an initial intensity of 75 kt. Dora could be a little stronger, but recent infrared imagery indicates that the inner-core convection has eroded significantly since the 1200 UTC fixes, so the initial intensity will remain on the low end of estimates for this advisory. Dora has been holding on a steady west-northwestward course or 295/11 kt for the past 12 hours. A strong deep-layer subtropical ridge entrenched to the north of the hurricane is expected to keep Dora moving in a general west-northwestward motion for the next 3 days or so. By 72 hours, the cyclone is expected to weaken significantly and become a more vertically shallow system, steered westward by the low-level trade wind flow until Dora dissipates by day 5. The new NHC track forecast is essentially just an update of the previous advisory track, and lies a little south of the consensus track model TVCE out of respect for the more southerly ECMWF solution. Dora has about another 12 hours or so to strengthen. However, the rapid intensification event that the hurricane has undergone for the past 30 hours has likely ended. The aforementioned erosion of the inner-core convection is possibly due to the entrainment of cooler and more stable air into the western semicircle now that Dora is beginning to encroach upon 26-deg C SSTs. The vertical wind shear is expected to remain low at less than 5 kt and the favorable upper-level outflow pattern is forecast to persist for the next few days as well. The only hindering factor will be the decreasing thermodynamics due to the hurricane moving over sub-26C SSTs within 12-18 hours. Steady weakening should begin by 24 h, but the rate of the weakening trend should be lessened due to proximity to warmer water just south of the path of Dora and the aforementioned favorable dynamic conditions. The NHC official intensity forecast is similar to the previous advisory, and closely follows the consensus model IVCN. Although the center of Dora is forecast to remain well offshore, the outer bands of the cyclone could bring brief locally heavy rainfall to portions of coastal southwestern Mexico into this evening. FORECAST POSITIONS AND MAX WINDS INIT 26/1500Z 17.3N 106.3W 75 KT 85 MPH 12H 27/0000Z 17.9N 107.7W 80 KT 90 MPH 24H 27/1200Z 18.6N 109.5W 70 KT 80 MPH 36H 28/0000Z 19.1N 111.1W 60 KT 70 MPH...NEAR SOCORRO ISLAND 48H 28/1200Z 19.5N 112.7W 50 KT 60 MPH 72H 29/1200Z 20.2N 115.7W 35 KT 40 MPH...POST-TROPICAL 96H 30/1200Z 20.4N 118.6W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 01/1200Z...DISSIPATED $$ Forecaster Stewart
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