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| #1139923 (Received by flhurricane at: 11:03 AM 19.Jun.2023) TCDAT3 Tropical Depression Three Discussion Number 1 NWS National Hurricane Center Miami FL AL032023 1100 AM AST Mon Jun 19 2023 Satellite images indicate that the tropical wave over the central Atlantic has become better organized this morning. GOES-16 1-min visible imagery shows that the center has become well defined near a developing central dense overcast with prominent convective banding in the northern semicircle. The initial intensity is set to 30 kt, based on Dvorak estimates from SAB and TAFB, and recent satellite trends indicate this system is close to tropical-storm status. The initial motion estimate is 275/18 kt, a bit uncertain because the center has just recently become trackable. A large ridge of high pressure over the central Atlantic Ocean is forecast to cause the depression to move westward over the next several days. As the system nears the Lesser Antilles late this week, the ridge should weaken, causing the system to move more toward the west-northwest. However, there is considerable uncertainty in how much of a right turn could occur because it is somewhat tied to the intensity of the cyclone. A stronger system would tend to move more to the right due to the upper-level flow, while a weaker system would continue more westward into the Caribbean. For now, this forecast lies near the model consensus, and adjustments are likely in future advisories. This should be considered a low confidence track forecast since this type of forecast situation can result in large errors. Environmental conditions appear conducive for strengthening over the next few days, with a much warmer than normal ocean in the depression`s path, along with plentiful mid-level moisture and light shear. This should promote strengthening through midweek. However, vertical wind shear is forecast to increase by most of the model guidance around day 3 in response to an upper-level trough. Thus the NHC forecast shows the intensity leveling off at the end of the forecast, consistent with the middle of the guidance envelope. This intensity forecast is also more uncertain than normal, due to the differences in the model suite, along with the aclimatological nature of this system. KEY MESSAGES: 1. The depression is forecast to strengthen and move across the Lesser Antilles as a hurricane on Thursday and Friday, bringing a risk of flooding from heavy rainfall, hurricane-force winds, and dangerous storm surge and waves. 2. Given the larger than usual uncertainty in the track forecast, it is too early to specify the location and magnitude of where these hazards could occur. However, everyone in the Lesser Antilles, Puerto Rico, and the Virgin Islands should closely monitor updates to the forecast for this system and have their hurricane plan in place. FORECAST POSITIONS AND MAX WINDS INIT 19/1500Z 11.0N 40.3W 30 KT 35 MPH 12H 20/0000Z 11.2N 42.9W 40 KT 45 MPH 24H 20/1200Z 11.7N 45.9W 45 KT 50 MPH 36H 21/0000Z 12.2N 48.6W 55 KT 65 MPH 48H 21/1200Z 12.8N 51.2W 60 KT 70 MPH 60H 22/0000Z 13.3N 53.9W 65 KT 75 MPH 72H 22/1200Z 13.8N 56.3W 70 KT 80 MPH 96H 23/1200Z 14.9N 61.5W 70 KT 80 MPH 120H 24/1200Z 16.5N 66.5W 65 KT 75 MPH $$ Forecaster Blake/Kelly |
