ZCZC MIATCDEP3 ALL TTAA00 KNHC DDHHMM Tropical Storm Carlotta Discussion Number 5 NWS National Hurricane Center Miami FL EP032024 800 AM MST Thu Aug 01 2024 After intensifying over the past 12 to 18 hours, Carlotta is taking a brief pause as the inner-core becomes better established, though the system is still quite healthy looking on satellite imagery with plenty of curved bands around a formative central dense overcast (CDO). A blend of the latest subjective Dvorak intensity estimates still support an intensity of 50-kt this advisory, which is also roughly in the middle of objective intensity guidance. Carlotta continues to move west-northwestward at 295/10-kt. This motion is caused by a prominent deep-layer ridge located over the southwestern United States, and Carlotta may turn more back westward over the next few days as this ridge continues to strengthen. However by day 3 and beyond, the tropical cyclone will begin to feel a weakness to the north, which will likely result in a gradual slowdown in its forward motion and another gentle shift more poleward in the track. The latest track guidance is ever so slightly further north and faster compared to the previous cycle. Thus, the NHC track forecast has been shifted a bit in that direction, roughly in between the prior track forecast, and the reliable consensus aids TVCE and HCCA. Environmental conditions still appear quite favorable for intensification, with warm 28-29 C sea-surface temperatures (SSTs), and low to moderate shear between 10-15 kt out of the northwest. The rate of intensification may be determined more by how Carlotta's inner-core evolves, and there have not been any recent microwave images to diagnose the current structure. The SHIPS rapid intensification index is a little lower than last night, though this could also be in response to the temporary pause in the intensification. However the last few GOES-18 images suggest the CDO is becoming better established though an eye has yet to fully appear on first-light visible imagery. Even though the intensity guidance has shifted a little lower than last night, I have elected to keep the same intensification rate in the NHC forecast from the last cycle over the next 24 hours. This forecast is in better agreement with the regional-hurricane models HAFS-A/B versus the lower consensus aids that have been influenced by the lower SHIPS and LGEM guidance. After 48-60 hours, SSTs begin to markedly decrease along the forecast track, dropping under 26 C in 96 hours. Thus, the NHC intensity forecast shows gradual weakening between days 3 to 5. FORECAST POSITIONS AND MAX WINDS INIT 01/1500Z 17.2N 111.0W 50 KT 60 MPH 12H 02/0000Z 17.9N 112.6W 65 KT 75 MPH 24H 02/1200Z 18.2N 114.8W 75 KT 85 MPH 36H 03/0000Z 18.3N 117.0W 85 KT 100 MPH 48H 03/1200Z 18.4N 119.2W 90 KT 105 MPH 60H 04/0000Z 18.6N 121.0W 85 KT 100 MPH 72H 04/1200Z 19.0N 122.7W 80 KT 90 MPH 96H 05/1200Z 19.5N 125.5W 65 KT 75 MPH 120H 06/1200Z 20.0N 128.0W 55 KT 65 MPH $$ Forecaster Papin NNNN