Issued at 900 PM CST Sun Jun 29 2025
001 WTPZ41 KNHC 300233 TCDEP1 Tropical Storm Flossie Discussion Number 4 NWS National Hurricane Center Miami FL EP062025 900 PM CST Sun Jun 29 2025 Flossie is holding steady as a broad tropical storm. New bursts of deep convection are forming in the southern semicircle with cloud top temperatures near -80 degrees C. Earlier microwave imagery showed the circulation open to the east, indicating a possible dry air intrusion. Subjective and objective satellite intensity estimates range between 31 to 45 kt, with the majority near 35 kt. Therefore, the intensity is held at 35 kt for this advisory. The tropical storm is expected to strengthen during the next couple of days. Warm waters, low vertical wind shear, and abundant mid-level moisture should allow for Flossie to strengthen. Rapid intensification indices are relatively high compared to climatology, and the official NHC forecast shows periods of steady-to-rapid intensification in the next two days. However, the forecast lies on the high end of the intensity guidance envelope. Beyond the peak at 48 h, Flossie should gradually encounter a dry and stable airmass and cross over cooling waters which will lead to steady weakening. The current motion is westward-northwestward at 295/7 kt. Flossie is forecast to move west-northwestward with a turn towards the northwest anticipated soon around the western edge of a subtropical ridge. The track guidance envelope shifted noticeably westward. The latest track forecast shifted to the left of the previous advisory, and lies on the right side of the envelope, closest to the HCCA corrected consensus aid. Residents of Mexico should stay updated on the latest forecast. A shift in track to the right of the official forecast could bring more significant impacts to the coast of southwestern Mexico. KEY MESSAGES: 1. The outer bands of Tropical Storm Flossie may bring locally heavy rainfall to the Mexican states of Oaxaca, Guerrero, Michoacán, Colima, and Jalisco through early this week. Life-threatening flooding and mudslides are possible, particularly in areas of steep terrain. 2. A tropical storm watch is in effect for southwestern Mexico, and tropical storm warnings could be required on Monday for a portion of the coast of southern Mexico. FORECAST POSITIONS AND MAX WINDS INIT 30/0300Z 14.0N 101.0W 35 KT 40 MPH 12H 30/1200Z 14.8N 102.0W 45 KT 50 MPH 24H 01/0000Z 16.0N 103.6W 60 KT 70 MPH 36H 01/1200Z 17.2N 105.4W 75 KT 85 MPH 48H 02/0000Z 18.1N 106.9W 85 KT 100 MPH 60H 02/1200Z 19.1N 108.2W 80 KT 90 MPH 72H 03/0000Z 20.0N 109.3W 70 KT 80 MPH 96H 04/0000Z 22.0N 111.3W 50 KT 60 MPH 120H 05/0000Z 24.0N 113.7W 30 KT 35 MPH...POST-TROP/REMNT LOW $$ Forecaster Bucci