je.st
news
Tropical Storm Karen Forecast Discussion Number 6
2019-09-23 16:41:54| National Hurricane Center (Atlantic)
Issued at 1100 AM AST Mon Sep 23 2019 000 WTNT42 KNHC 231441 TCDAT2 Tropical Storm Karen Discussion Number 6 NWS National Hurricane Center Miami FL AL122019 1100 AM AST Mon Sep 23 2019 Although deep convection has recently developed near the low-level swirl seen in early morning visible satellite imagery, the Air Force Reserve reconnaissance aircraft that has been investigating Karen has had difficultly finding a closed surface circulation. It is possible that a center reformation will occur near the new convection, so the system is still being classified as a tropical cyclone for now. The aircraft has found believable SFMR winds of 30-35 kt over the eastern portion of the system, which still supports an initial intensity of 35 kt. Given the current structure of Karen and moderate to strong northeasterly shear that should remain over the storm for the next 24 hours, no change in strength is anticipated during that time. It is also possible that Karen could degenerate into an open wave, if it has not done so already. Regardless of whether or not Karen is a tropical cyclone when it passes near Puerto Rico and the Virgin Islands, the system is likely to produce tropical-storm-force winds in squalls and heavy rainfall over those areas. After that time, upper-level winds are forecast to become more conducive for intensification, and the NHC forecast calls for gradual strengthening like most of the typically reliable intensity guidance, however, the confidence in this portion of the intensity forecast is low. The initial motion estimate is 335/10 kt. Despite the overall lack of organization of the system, the track guidance is still in good agreement on Karen turning northward tonight or early Tuesday into a weakness in the ridge over the western Atlantic caused by Tropical Storm Jerry to its north. After 72 hours, a deep-layer ridge is forecast to build over the southeastern United States and western Atlantic which should slow Karen's northward progress and could cause the system to essentially stall over the western Atlantic by the end of the period. The new NHC track forecast is again close to the previous advisory, and is near the consensus aids through 96 h. At 120 h, the NHC forecast is south of the consensus models in deference to the more equatorward position shown by the ECMWF, but the spread of the guidance by that time is quite large, and confidence in the track forecast at days 4 and 5 is quite low. Key Messages: 1. Regardless of Karen's status as a tropical cyclone, this system is expected to bring tropical-storm-force winds, heavy rainfall, flash floods and mudslides to Puerto Rico and the U.S. and British Virgin Islands on Tuesday, where a tropical storm warning is in effect. FORECAST POSITIONS AND MAX WINDS INIT 23/1500Z 14.9N 64.8W 35 KT 40 MPH 12H 24/0000Z 16.0N 65.3W 35 KT 40 MPH 24H 24/1200Z 17.7N 65.8W 35 KT 40 MPH 36H 25/0000Z 19.6N 65.9W 35 KT 40 MPH 48H 25/1200Z 21.9N 65.7W 40 KT 45 MPH 72H 26/1200Z 25.6N 65.3W 45 KT 50 MPH 96H 27/1200Z 27.0N 65.8W 50 KT 60 MPH 120H 28/1200Z 27.0N 67.0W 60 KT 70 MPH $$ Forecaster Brown
Tags: number
discussion
storm
karen
Category:Transportation and Logistics
Latest from this category |
All news |
||||||||||||||||||
|
|||||||||||||||||||