|
Show Selection: |
| #875801 (Received by flhurricane at: 10:40 AM 24.Sep.2016) TCDAT2 TROPICAL STORM KARL DISCUSSION NUMBER 41 NWS NATIONAL HURRICANE CENTER MIAMI FL AL122016 1100 AM AST SAT SEP 24 2016 Data from the last NOAA Hurricane Hunter aircraft mission into Karl earlier this morning found peak flight-level winds of 63 kt at 8,000 ft and a peak SFMR wind of 47 kt. Based on these data, the initial intensity is held at 55 kt for this advisory, but this could be a little generous. The latest minimum central pressure based on a dropsonde from the aircraft is 994 mb. Karl is still expected to strengthen, but it seems likely that this will be at least partly due to baroclinic effects, as the global models shows Karl intensifying while the shear increases to over 50 kt by 24 hours. The new NHC intensity forecast follows this trend, and keeps Karl as a 70-kt cyclone with a very large wind field when it becomes post-tropical in 36 hours. The circulation of Karl should be absorbed by a large extratropical cyclone over the north Atlantic by 48 hours, as shown in the global model solutions. The aircraft last fixed the center on the southeastern side of the deep convection, and the initial motion estimate is now 050/16. Karl should accelerate quickly northeastward ahead of a broad deep-layer trough moving into the Atlantic until it is absorbed, with the forward speed expected to reach 50 kt by 36 hours. The new NHC track forecast is an update of the previous one and remains near the middle of the tightly packed guidance envelope. The track, intensity, and wind radii forecast of Karl`s post- tropical phase has been coordinated with the Ocean Prediction Center. FORECAST POSITIONS AND MAX WINDS INIT 24/1500Z 32.8N 62.7W 55 KT 65 MPH 12H 25/0000Z 34.8N 58.8W 60 KT 70 MPH 24H 25/1200Z 38.9N 50.6W 70 KT 80 MPH 36H 26/0000Z 45.0N 39.9W 70 KT 80 MPH...POST-TROPICAL 48H 26/1200Z...ABSORBED $$ Forecaster Brennan |
