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#724127 (Received by flhurricane at: 10:48 PM 13.Oct.2014) TCDAT3 HURRICANE GONZALO DISCUSSION NUMBER 7 NWS NATIONAL HURRICANE CENTER MIAMI FL AL082014 1100 PM AST MON OCT 13 2014 The eye of Gonzalo moved just north of St. Maarten and over Anguilla earlier this evening. St. Maarten reported a peak 2-minute wind of 55 kt and a gust of 65 kt with a minimum pressure of 994 mb. Data from the Hurricane Hunter aircraft earlier indicated peak 700-mb flight-level winds of around 85 kt, which support an intensity of 75 kt for this advisory. This intensity is also supported by the latest Dvorak classification of T4.5 from TAFB. The next Hurricane Hunter aircraft will be investigating Gonzalo around 0600 UTC. Gonzalo appears to be poised to intensify, perhaps rapidly, in the next day or so. The inner-core features are quite distinct in recent microwave imagery and a warm spot has recently developed in infrared imagery with a more symmetric cloud pattern. Given these trends and the overall favorable environment, the intensity forecast has been adjusted upward and is close to the the SHIPS model on the high end of the intensity guidance through the first 48 hours, showing Gonzalo becoming a major hurricane in about 36 hours. As Gonzalo gains latitude later in the period, southwesterly shear ahead of a mid-latitude trough and cooler SSTs should result in gradual weakening. The eye of Gonzalo is now evident in WSR-88D imagery from San Juan, and the initial motion estimate is 315/10. Overall, the track forecast reasoning remains unchanged, as the hurricane will move northwestward into a weakness in the subtropical ridge and then accelerate northward and northeastward ahead of a mid-latitude trough moving off the east coast of the United States. The new NHC track forecast has been shifted a little to the right in the first 48 hours due to the initial position and motion and an adjustment and toward the latest multi-model consensus. Beyond that time, the new NHC forecast is largely and update of the previous one and is close to but a bit slower than a blend of the GFS and ECMWF models, especially by day 5. FORECAST POSITIONS AND MAX WINDS INIT 14/0300Z 18.7N 63.4W 75 KT 85 MPH 12H 14/1200Z 19.8N 64.7W 85 KT 100 MPH 24H 15/0000Z 21.5N 66.1W 95 KT 110 MPH 36H 15/1200Z 23.1N 67.4W 100 KT 115 MPH 48H 16/0000Z 24.5N 68.1W 105 KT 120 MPH 72H 17/0000Z 27.3N 67.9W 100 KT 115 MPH 96H 18/0000Z 31.5N 65.5W 95 KT 110 MPH 120H 19/0000Z 37.0N 61.0W 85 KT 100 MPH $$ Forecaster Brennan |