000 WTPZ44 KNHC 180239 TCDEP4 Tropical Storm Madeline Discussion Number 2 NWS National Hurricane Center Miami FL EP142022 900 PM MDT Sat Sep 17 2022 Madeline has changed little in appearance since earlier today. Moderate east-northeasterly vertical wind shear of 15-20 kt is keeping the center of circulation at the northeastern edge of the cyclone's deep convection. With the lack of any appreciable change to Madeline's structure, the initial advisory intensity is being kept at 40 kt for continuity. The storm has made its anticipated acceleration to the north and is now moving at about 8 kt. A mid-level ridge over the Atlantic should keep Madeline on a northward to northwestward track for the next day or so. By Tuesday, another ridge building over Texas should cause the cyclone to turn westward. There was very little change to the latest NHC track forecast from the previous one, which lies near the various multi-model consensus tracks. It should be noted that there is over 300 n mi north to south model spread by day 4. Therefore, the track forecast during days 4-5 is of lower confidence. Madeline's intensity forecast is fairly straightforward for the next few days, but is more complicated thereafter due to the uncertain track forecast. The moderate shear affecting the storm now is forecast to persist through early next week while the system remains embedded in a moist thermodynamic environment. The combination of these conditions should allow for some slight strengthening over the next couple of days. By 48 h, the SSTs beneath Madeline are expected to decrease to near 26 degrees Celsius, which in combination with the shear, should cause the system to begin weakening around that time. By late in the forecast period, the shear is forecast to decrease while warmer waters are present just to the south of the forecasted path of the cyclone. Therefore, a deviation to the left of the forecast track could put Madeline in a more favorable environment for strengthening. However, the models suggest that regardless of the water temperatures, Madeline is expected to encounter drier and more stable air later in the forecast period. Based on these conditions, the NHC intensity forecast was lowered slightly from the previous one, and is near the various consensus aids. The latter part of the current intensity forecast is also low confidence. FORECAST POSITIONS AND MAX WINDS INIT 18/0300Z 16.9N 106.8W 40 KT 45 MPH 12H 18/1200Z 18.0N 107.3W 40 KT 45 MPH 24H 19/0000Z 19.2N 108.2W 45 KT 50 MPH 36H 19/1200Z 20.0N 109.3W 45 KT 50 MPH 48H 20/0000Z 20.5N 110.6W 45 KT 50 MPH 60H 20/1200Z 20.6N 111.8W 40 KT 45 MPH 72H 21/0000Z 20.7N 113.0W 35 KT 40 MPH 96H 22/0000Z 20.7N 115.5W 35 KT 40 MPH 120H 23/0000Z 20.7N 118.4W 35 KT 40 MPH $$ Forecaster Latto