000 WTNT44 KNHC 192033 TCDAT4 Hurricane Humberto Discussion Number 29 NWS National Hurricane Center Miami FL AL092019 500 PM AST Thu Sep 19 2019 Humberto is almost a post-tropical cyclone. Satellite images show a well-defined cold and warm front, but they do not appear to be fully connected to the center of circulation yet. In addition, the cyclone is still producing an area of deep convection to the northwest of the exposed low-level center. ASCAT data from earlier today indicated that the wind field of Humberto is very large with tropical-storm-force winds extending up to 330 n mi from the center and hurricane-force winds extending out to 70 n mi from the center. The initial intensity is lowered a little to 90 kt for this advisory. The cyclone is anticipated to become fully extratropical soon, within the next 6 to 12 hours. Although weakening is forecast, Humberto is expected to be a large and powerful extratropical cyclone for a couple of days before it is absorbed by another extratropical low over the north Atlantic. The NHC intensity forecast generally follows the guidance of the GFS model, which typically handles extratropical lows better than the tropical cyclone intensity guidance. Humberto is moving northeastward at 21 kt. A slight turn to the left and a decrease in forward speed are expected during the next 12 to 24 hours as the cyclone rotates around the east and north sides of a mid- to upper-level low to its west. After that time, a faster east-northeast or east motion is expected when the cyclone becomes embedded in the mid-latitude westerlies. The NHC track forecast is largely an update of the previous one and near the various consensus aids. Key Messages: 1. Large swells will continue to affect Bermuda, the northwestern Bahamas, and the east coast of the United States from east-central Florida to the Mid-Atlantic States during the next couple of days. These swells could create life-threatening surf and rip current conditions. FORECAST POSITIONS AND MAX WINDS INIT 19/2100Z 38.5N 58.7W 90 KT 105 MPH 12H 20/0600Z 40.4N 57.5W 75 KT 85 MPH...POST-TROP/EXTRATROP 24H 20/1800Z 42.8N 55.5W 60 KT 70 MPH...POST-TROP/EXTRATROP 36H 21/0600Z 44.6N 51.2W 55 KT 65 MPH...POST-TROP/EXTRATROP 48H 21/1800Z 45.6N 44.6W 50 KT 60 MPH...POST-TROP/EXTRATROP 72H 22/1800Z...DISSIPATED $$ Forecaster Cangialosi