ZCZC MIATCDEP1 ALL TTAA00 KNHC DDHHMM Hurricane Jova Discussion Number 13 NWS National Hurricane Center Miami FL EP112023 200 PM PDT Thu Sep 07 2023 Visible satellite imagery this afternoon shows Jova is gradually weakening. The eye has been cloud-filled for much of the day, with dry air trying to wrap into the southern and eastern side of the system. SSMIS microwave imagery depicts the earlier thick concentric eyewall is starting to thin, with the inner core becoming less pronounced. Infrared imagery shows this as well with the infrared cloud tops warming throughout the day as well. Subjective satellite estimates were lower this advisory, with Dvorak final-T numbers of 6.0 and CI numbers of 7.0 from both TAFB and SAB. Given the structural changes depicted in microwave and visible imagery, the initial intensity for this advisory is lowered to 125 kt, which falls between the latest Dvorak estimates. Jova may continue to experience some short-term intensity fluctuations as it undergoes structural changes and moves into a less favorable environment. In about 24 h, Jova will cross a sharp sea surface temperature gradient into cooler waters, while it moves into a drier, more stable airmass. This will induce a steady weakening trend over the next few days. By the end of the forecast period, simulated satellite imagery from the GFS and ECMWF models suggests the cyclone will be devoid of convection, and the official forecast shows Jova becoming a post-tropical remnant low by 96 h. The hurricane continues to move west-northwestward at 15 kt around a mid-level ridge centered over northern Mexico. Jova should generally follow this motion for the next several days. As the system weakens and becomes a shallow vortex, a turn toward the west and southwest within the low-level flow is anticipated. The guidance envelope remains in good agreement, and the track forecast is similar to the previous advisory. FORECAST POSITIONS AND MAX WINDS INIT 07/2100Z 17.7N 117.3W 125 KT 145 MPH 12H 08/0600Z 18.6N 119.4W 110 KT 125 MPH 24H 08/1800Z 19.8N 122.0W 95 KT 110 MPH 36H 09/0600Z 21.0N 124.4W 80 KT 90 MPH 48H 09/1800Z 22.4N 126.4W 60 KT 70 MPH 60H 10/0600Z 23.6N 127.8W 50 KT 60 MPH 72H 10/1800Z 24.5N 129.1W 40 KT 45 MPH 96H 11/1800Z 25.0N 131.1W 30 KT 35 MPH...POST-TROP/REMNT LOW 120H 12/1800Z 24.2N 133.2W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Kelly NNNN