Issued at 900 AM CST Thu Aug 07 2025
000 WTPZ44 KNHC 071458 TCDEP4 Tropical Storm Ivo Discussion Number 4 NWS National Hurricane Center Miami FL EP092025 900 AM CST Thu Aug 07 2025 Finding the exact center of Ivo is tricky this morning, but my best guess is that its track has deviated rightward since the prior advisory. A pair of helpful microwave passes, an AMSR2 pass at 0850 UTC and a SSMIS pass at 1050 UTC, showed well-defined curved banding on the 37-GHz to 91-GHz channels respectively. More recently, a visible satellite animation of 1-min GOES-19 imagery shows bursting convection near the estimated center. Subjective Dvorak estimates by TAFB and SAB were T3.0/45 kt and T2.5/35 kt respectively, with the objective intensity estimates ranging from 34 to 51 kt. Thus, the initial intensity has been bumped up to 40 kt this morning. Ivo appears to be maintaining a brisk west-northwestward motion, estimated at 300/21 kt. This rapid forward motion is thanks in part to a strong and large mid-level ridge stretching across northern Mexico and southwestern United States. This ridge is forecast to move along with Ivo though it does gradually dampen out in magnitude. The net result of this pattern should keep Ivo on a general west-northwestward heading, with the cyclone turning more westward and slowing down towards the latter half of the forecast. The track guidance this cycle is a little farther north, largely a reflection of the farther north initial position. The latest NHC track forecast is also farther north roughly blending the simple and corrected consensus aids (TVCE and HCCA), but still remains offshore of Mexico, making its point of closest approach in the next 12-18 hours. The small core of Ivo likely could make it susceptible to rapid changes in intensity, either up or down. Because vertical wind shear is relatively low (10-15 kt), and sea surface temperatures remain above 27 C for the next 36 hours, the NHC intensity forecast continues to show significant intensification, making Ivo a hurricane. Thereafter, the storm will reach a sharp sea-surface temperature gradient, and should begin a gradual weakening trend. Towards the end of the forecast Ivo will likely lose its remaining deep convection over the sub 24 C waters west of Baja California, marking its transition to a post-tropical remnant low by 96 h. The NHC intensity forecast remains a bit on the high end of the overall model suite. Given the small radius of tropical-storm-force winds associated with Ivo, these winds are expected to remain offshore as it makes its closest approach to Mexico later today. However, heavy rain and rough surf are likely to occur along portions of the southwest coast of Mexico during the next day or so. Outer bands of Ivo are expected to produce locally heavy rainfall in portions of the Mexican states of Guerrero, Michoacan de Ocampo and Colima through Friday where Flash flooding is possible. FORECAST POSITIONS AND MAX WINDS INIT 07/1500Z 17.8N 104.4W 40 KT 45 MPH 12H 08/0000Z 19.5N 106.8W 50 KT 60 MPH 24H 08/1200Z 20.8N 109.6W 60 KT 70 MPH 36H 09/0000Z 21.5N 111.7W 65 KT 75 MPH 48H 09/1200Z 21.7N 113.5W 60 KT 70 MPH 60H 10/0000Z 21.8N 114.8W 45 KT 50 MPH 72H 10/1200Z 22.0N 116.3W 35 KT 40 MPH 96H 11/1200Z 22.5N 119.6W 30 KT 35 MPH...POST-TROP/REMNT LOW 120H 12/1200Z...DISSIPATED $$ Forecaster Papin
