Issued at 500 AM AST Sun Sep 24 2023
000 WTNT42 KNHC 240837 TCDAT2 Tropical Storm Philippe Discussion Number 4 NWS National Hurricane Center Miami FL AL172023 500 AM AST Sun Sep 24 2023 Philippe is still trying to become better organized this morning. There continues to be burst within the convection with very cold cloud tops to -80 degrees Celsius. However, the convection remains displaced to the northeast of the estimated low-level center. An ASCAT pass that arrived just after the previous advisory revealed winds on the northeast side of the system were near 40 kt. Subjective satellite Dvorak estimates for this cycle from TAFB and SAB were T3.0/T2.5, respectively. Using a blend of these estimates and the scatterometer satellite-derived winds, the intensity for this advisory is raised to 40 kt. The system is moving westward at an estimated motion of 280/8 kt. Philippe should continue westward fro the next couple of days, steered along the southern side of a mid-level ridge. In about 2 to 3 days, a weakness in the ridge will develop and the tropical storm should gradually turn west-northwest and then northwest. Models have continued to slow the forward motion of Philippe towards the end of the forecast period, and the NHC track forecast was adjusted accordingly. The NHC track forecast lies near the corrected consensus aids throughout the period, with a slight nudge to the left of the previous track. Models depict that Philippe will take some time to get organized due to mid-level vertical wind shear and some drier mid-level RH values. This will lead to only slow strengthening the next few days. In about 3 days, as Philippe approaches a mid-upper level trough, deep-layer vertical wind shear is forecast to increase but upper-level divergence should increase over the system as well. The guidance continues to favor some additional strengthen through the end of the forecast period. The NHC intensity forecast is similar to the previous advisory. FORECAST POSITIONS AND MAX WINDS INIT 24/0900Z 15.6N 41.4W 40 KT 45 MPH 12H 24/1800Z 15.9N 43.1W 40 KT 45 MPH 24H 25/0600Z 16.3N 45.3W 45 KT 50 MPH 36H 25/1800Z 16.7N 47.5W 45 KT 50 MPH 48H 26/0600Z 17.3N 49.2W 45 KT 50 MPH 60H 26/1800Z 18.1N 50.9W 50 KT 60 MPH 72H 27/0600Z 19.2N 52.4W 50 KT 60 MPH 96H 28/0600Z 22.4N 54.4W 55 KT 65 MPH 120H 29/0600Z 24.2N 55.4W 60 KT 70 MPH $$ Forecaster Kelly