000 WTNT41 KNHC 021453 TCDAT1 HURRICANE JOAQUIN DISCUSSION NUMBER 19 NWS NATIONAL HURRICANE CENTER MIAMI FL AL112015 1100 AM EDT FRI OCT 02 2015 An Air Force Reserve Hurricane Hunter aircraft has reported 700-mb flight-level winds of 124 kt in the southeastern eyewall, along with an eyewall dropsonde that supports surface winds of 110-115 kt. Based on these data, the intensity remains 115 kt. The latest central pressure indicated by the aircraft data is 939 mb. While the hurricane continues to produce cloud tops of -80C in the eyewall, the eye is ragged and poorly defined in satellite imagery. Joaquin has turned northward during the past few hours and the initial motion is now 360/3. Water vapor imagery shows a mid- to upper-level ridge to the north and northeast of the hurricane, while a deep-layer trough and associated surface front are located over the southeastern United States. This system is forecast to move slowly eastward with a non-tropical low forming along the front during the next couple of days. These developments should steer Joaquin northward to northeastward during the next 12 hours or so, followed by a faster motion toward the northeast. The GFS, UKMET, and ECMWF are now in better agreement that Joaquin will move generally northeastward through 48 hours, followed by a more northward turn between 48 and 72 hours. This is then followed by movement into the westerlies and acceleration toward the east- northeast after 72 hours. The new forecast track is adjusted to the east of the previous track after 24 hours, and it lies between the previous track and the model consensus. Some additional eastward adjustments to the track may occur on the next advisory based on the 1200 UTC model runs. Joaquin is forecast to remain in an environment of light vertical wind shear for another 24 hours or so, and during this time some fluctuations in intensity are possible due to eyewall replacement cycles. After 24 hours, the shear is forecast to increase, which should start a steady weakening. Extratropical transition is expected to begin after 96 hours, but the dynamical models suggest it may not be complete before 120 hours. Overall, the new intensity forecast is an update of the previous advisory and lies near the upper edge of the intensity guidance. KEY MESSAGES: 1. Hurricane conditions over portions of the Bahamas are likely to continue into this evening. 2. Swells from a hurricane moving even far offshore of the U.S. east coast can still cause life-threatening surf and rip-current conditions. Please see products from your local National Weather Service forecast office. For information on the heavy rains occurring along the U.S. Atlantic states that are mostly unrelated to Hurricane Joaquin, please see products from the NWS Weather Prediction Center and your local forecast office. 3. A Tropical Storm or Hurricane Watch could be required for Bermuda this afternoon. FORECAST POSITIONS AND MAX WINDS INIT 02/1500Z 23.5N 74.8W 115 KT 130 MPH 12H 03/0000Z 24.4N 74.4W 115 KT 130 MPH 24H 03/1200Z 26.1N 73.0W 115 KT 130 MPH 36H 04/0000Z 28.2N 71.2W 105 KT 120 MPH 48H 04/1200Z 30.6N 69.6W 95 KT 110 MPH 72H 05/1200Z 35.5N 67.5W 80 KT 90 MPH 96H 06/1200Z 39.5N 63.0W 65 KT 75 MPH 120H 07/1200Z 43.5N 49.0W 55 KT 65 MPH $$ Forecaster Beven