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| #984639 (Received by flhurricane at: 11:12 AM 30.Sep.2019) TCDAT3 Hurricane Lorenzo Discussion Number 33 NWS National Hurricane Center Miami FL AL132019 1100 AM AST Mon Sep 30 2019 Lorenzo continues to maintain its strength. A cloud filled eye is evident in infrared satellite imagery, while convection is attempting to wrap around a break in the southern portion of the hurricane. This is indicating that for the time being, the cyclone is fighting off some of the dry air entraining into it from the southwest. The subjective Dvorak intensity estimates from TAFB and SAB remain at 90 kt, which will be the initial intensity for this advisory. Lorenzo continues north-northeastward, now at 13 kt, around the northwestern periphery of a subtropical ridge. Over the next couple of days Lorenzo will be accelerated northeastward by increasing southwesterly flow ahead of a mid-latitude trough amplifying across the central Atlantic. This motion should take the core of Lorenzo near or just west of the western Azores late Tuesday and early Wednesday. The forecast track confidence is high through 72 hours, but decreases significantly thereafter, as forecast models continue to differ on their handling of the steering flow. By that time, the steering flow may break down as the trough to the west of Lorenzo de-amplifies, while an extratropical low quickly approaches from the west. Some of the forecast models turn Lorenzo north ahead of the approaching low as they begin to interact, other solutions turn Lorenzo or its remnants to the east in the westerlies, with limited interaction with this low. The official forecast track is very close to the previous one and to the consensus aids, which lies in between these two scenarios. Lorenzo should gradually weaken over the next couple of days while drier air continues to get pulled into the circulation and the system moves over progressively cooler waters. After 48 hours, the interaction with the approaching trough, an associated cold front, and very strong southwesterly shear will help transition Lorenzo into an extratropical low. This transition is expected to be complete by 72 hours. The low is then expected to either dissipate or become absorbed by another extratropical low by day 5. The official forecast intensity is very similar to the previous one, and is in good agreement with the consensus aids. Key Messages: 1. Lorenzo is expected to bring hurricane and tropical storm force winds to the Azores beginning Tuesday night, and these conditions will continue into Wednesday. Hurricane and Tropical Storm Warnings are now in effect for the Azores. 2. Large swells generated by Lorenzo will continue to spread across much of the north Atlantic basin during the next few days. These swells will produce life-threatening surf and rip currents. FORECAST POSITIONS AND MAX WINDS INIT 30/1500Z 30.0N 42.6W 90 KT 105 MPH 12H 01/0000Z 31.7N 41.5W 85 KT 100 MPH 24H 01/1200Z 34.5N 38.6W 80 KT 90 MPH 36H 02/0000Z 38.1N 34.3W 75 KT 85 MPH 48H 02/1200Z 43.3N 28.0W 70 KT 80 MPH 72H 03/1200Z 53.5N 17.8W 60 KT 70 MPH...POST-TROP/EXTRATROP 96H 04/1200Z 58.2N 11.4W 50 KT 60 MPH...POST-TROP/EXTRATROP 120H 05/1200Z...DISSIPATED $$ Forecaster Latto |
