WTPZ45 KNHC 280835
POST-TROPICAL CYCLONE SEYMOUR DISCUSSION NUMBER 21
NWS NATIONAL HURRICANE CENTER MIAMI FL EP202016
200 AM PDT FRI OCT 28 2016
The cyclone has lacked organized deep convection within 60-100 n mi of its center for over 12 hours, and no longer qualifies as a tropical cyclone. Since Seymour has become a post-tropical remnant low, advisories are being discontinued. Subjective Dvorak classifications from TAFB and SAB along with scatterometer data indicated an intensity of near 35 kt at 0600 UTC. Assuming some additional spindown of the cyclone since then, the advisory intensity is set at 30 kt. The low will be moving through an extremely hostile environment of southwesterly shear of 40-45 kt and SSTs cooler than 23 deg C during the next couple of days. These environmental factors should cause the remnant low to dissipate in a couple of days. This is also shown by the global model predictions.
The low has turned toward a slightly east of northward heading, and the initial motion is about 010/7 kt. A north-northeastward motion, ahead of an approaching frontal system, is expected over the next day or so. The official track forecast is adjusted a little to the left of the previous one, toward the latest model consensus.
For additional information on the remnant low please see High Seas Forecasts issued by the National Weather Service, under AWIPS header NFDHSFEPI, WMO header FZPN02 KWBC, and on the web at http://www.opc.ncep.noaa.gov/shtml/NFDHSFEPI.shtml.
FORECAST POSITIONS AND MAX WINDS
INIT 28/0900Z 22.4N 122.8W 30 KT 35 MPH...POST-TROP/REMNT LOW 12H 28/1800Z 23.3N 122.3W 25 KT 30 MPH...POST-TROP/REMNT LOW 24H 29/0600Z 24.5N 121.7W 20 KT 25 MPH...POST-TROP/REMNT LOW 36H 29/1800Z 25.8N 121.2W 15 KT 15 MPH...POST-TROP/REMNT LOW 48H 30/0600Z 27.5N 121.0W 15 KT 15 MPH...POST-TROP/REMNT LOW 72H 31/0600Z...DISSIPATED
$$ Forecaster Pasch