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| #983542 (Received by flhurricane at: 11:12 AM 22.Sep.2019) TCDAT2 Tropical Storm Karen Discussion Number 2 NWS National Hurricane Center Miami FL AL122019 1100 AM AST Sun Sep 22 2019 Radar and satellite imagery shows that convection associated with Karen has lost some organization since advisories were initiated early this morning. However, surface observations and a very recently arriving ASCAT data show that the circulation is well-defined, and is currently passing through the southern Windward Islands. Given the current sprawling structure, nearby dry mid-level air, and moderate northwesterly shear, no significant strengthening is expected through 48 hours. In fact, the system may have trouble surviving over the eastern Caribbean Sea as the global models predict an increase in northeasterly upper-level winds over the system on Monday. Once the cyclone moves north of Puerto Rico, the shear is forecast to decrease, and some strengthening is indicated in the official forecast, but this will depend on the structure of the system at that time. At this time, the long range intensity forecast is quite uncertain. The initial motion estimate is 290/11 kt. The track guidance is in good agreement on Karen turning northwestward, and then northward around the southwestern portion of a deep-layer ridge during the next day or two. A northward motion should continue into mid-week as a weakness in the ridge remains over the western Atlantic. After that time, models suggest that another ridge will begin to build over the southeastern U.S. and far western Atlantic which may cause Karen to slow down by the end of the forecast period. The updated NHC track forecast is very close to the previous advisory and lies near the consensus models. A Tropical Storm Watch has been issued for Puerto Rico and the U.S. and British Virgin Islands. Key Messages: 1. Tropical-storm-force winds and heavy rainfall will continue to affect the southern Windward Islands through tonight. 2. Karen is forecast to approach Puerto Rico, and the U.S. and British Virgin Islands on Tuesday, and a tropical storm watch has been issued. Tropical-storm-force winds, heavy rainfall, and flash flooding is possible on these islands. FORECAST POSITIONS AND MAX WINDS INIT 22/1500Z 12.5N 61.7W 35 KT 40 MPH 12H 23/0000Z 13.1N 63.1W 35 KT 40 MPH 24H 23/1200Z 14.2N 64.1W 35 KT 40 MPH 36H 24/0000Z 15.4N 65.0W 35 KT 40 MPH 48H 24/1200Z 16.9N 65.6W 35 KT 40 MPH 72H 25/1200Z 20.7N 65.5W 45 KT 50 MPH 96H 26/1200Z 23.4N 65.3W 50 KT 60 MPH 120H 27/1200Z 25.3N 65.8W 55 KT 65 MPH $$ Forecaster Brown |