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ZCZC MIATCDEP1 ALL TTAA00 KNHC DDHHMM HURRICANE VANCE DISCUSSION NUMBER 18 NWS NATIONAL HURRICANE CENTER MIAMI FL EP212014 700 AM PST MON NOV 03 2014 Recent microwave images show that the inner core of Vance remains vertically aligned, however, the outflow is becoming increasingly restricted over the southwestern portion of the circulation due to southwesterly shear. Vance has likely peaked in intensity and the initial wind speed is held at 90 kt for this advisory, which is in agreement with the latest Dvorak CI-numbers from both TAFB and SAB. The vertical shear over Vance is forecast to dramatically increase during the next 24 to 48 hours. In fact, the SHIPS model predicts shear to increase to 37 kt in 24 hours, and to 54 kt in 48 hours. These very hostile conditions should cause the hurricane to rapidly weaken during the next couple of days, and Vance is forecast to become a tropical depression in 48 hours. Although a 72-hour forecast as a remnant low is indicated, it is highly possible that this system will have dissipated by that time. The initial motion estimate is north-northwest or 345/10 kt. Vance has started its much anticipated northward turn ahead of an approaching mid-latitude trough. Vance should turn northward this afternoon, and then recurve north-northeastward ahead of the trough tomorrow. There continues to be some run-to-run inconsistencies in the model guidance as to how vertically coherent Vance will remain and how fast it will move north-northeastward. The GFS and ECMWF now bring a weakening cyclone to the coast, meanwhile the HWRF and UKMET show a much slower, and more erratic motion in a couple of days. The updated NHC track has trended faster than the previous advisory and is close to the multi-model consensus, however, the new forecast is slower than the GFS and ECMWF models. Moisture from Vance and its remnants are likely to spread northeastward across Mexico and into the south-central United States during the next several days. This is likely to produce heavy rains over portions of these areas through Thursday or Friday. FORECAST POSITIONS AND MAX WINDS INIT 03/1500Z 15.3N 110.6W 90 KT 105 MPH 12H 04/0000Z 16.7N 110.7W 80 KT 90 MPH 24H 04/1200Z 18.6N 110.1W 60 KT 70 MPH 36H 05/0000Z 20.6N 108.9W 45 KT 50 MPH 48H 05/1200Z 22.5N 107.7W 30 KT 35 MPH 72H 06/1200Z 24.0N 107.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 96H 07/1200Z...DISSIPATED $$ Forecaster Brown NNNN