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| #1280408 (Received by flhurricane at: 11:03 AM 28.Sep.2026) TCDAT3 Tropical Storm Hanna Discussion Number 1 NWS National Hurricane Center Miami FL AL082026 1100 AM AST Mon Sep 28 2026 Recent scatterometer data shows that the disturbance that NHC has been tracking over the central subtropical Atlantic has acquired a well-defined surface circulation and center. Despite significant westerly shear the system has maintained an area of deep convection to the east of the center, and the scatterometer data revealed peak winds of 35 to 40 kt to the southeast of the center. As a result of this data, the system is being upgraded to 40-kt tropical storm Hanna at this time. The shear over the tropical storm is expected to remain strong out of the west-northwest for the next several days, so little, if any, strengthening is anticipated. In a couple of days, the shear and dry mid-level air are likely to cause weakening. Simulated satellite imagery from the global models indicated the deep convection is likely to cease in about 60 hours, therefore the NHC forecast calls for it to become a remnant low at that time. Hanna is moving eastward at about 15 kt. An eastward to east-southeastward motion is forecast during the next 24 hours as the system is embedded along the southern side of the mid-latitude westerlies. After that time, the westerlies lift northward and the steering flow will weaken, causing the system to slow down and turn east-northeastward. The NHC track forecast is close to the HCCA and GDMI models which are along the southern side of the model envelope. FORECAST POSITIONS AND MAX WINDS INIT 28/1500Z 36.6N 50.4W 40 KT 45 MPH 12H 29/0000Z 36.1N 47.7W 40 KT 45 MPH 24H 29/1200Z 34.8N 45.1W 40 KT 45 MPH 36H 30/0000Z 33.9N 43.8W 40 KT 45 MPH 48H 30/1200Z 33.9N 43.3W 35 KT 40 MPH 60H 01/0000Z 34.4N 42.4W 30 KT 35 MPH...POST-TROP/REMNT LOW 72H 01/1200Z 35.3N 40.7W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 02/1200Z...DISSIPATED $$ Forecaster Brown |
| #1280406 (Received by flhurricane at: 10:42 AM 28.Sep.2026) TCDAT1 Tropical Depression Fay Discussion Number 34 NWS National Hurricane Center Miami FL AL062026 300 PM GMT Mon Sep 28 2026 Fay continues to produce bursts of deep convection, mainly to the south of the low-level center. A recent ASCAT-B scatterometer pass indicated the highest reliable satellite-derived surface winds were around 25-30 kt, which is in good agreement with the TAFB subjective Dvorak intensity estimate of T2.0/30 kt. Although some of the UW-CIMSS objective intensity estimates are higher, the initial intensity is held at 30 kt, leaning toward the scatterometer data. The initial motion is estimated to be south-southwestward, or 210/8 kt. Fay should continue to move south-southwestward to southwestward along the southern periphery of a subtropical ridge located over the central Atlantic. Track guidance is in fairly good agreement on this general motion, with the primary differences being in the along-track spread. The latest NHC track forecast is slightly faster than the previous advisory and lies near the HCCA corrected-consensus aid. Fay has maintained persistent convection near the low-level center within a favorable environment over warm sea surface temperatures, low vertical wind shear, and abundant mid-level moisture. It is possible Fay could regain tropical storm strength. However, this favorable environment is expected to be short-lived. Global models continue to show the system will struggle to produce deep convection in a day or so as it encounters a more stable air mass and convergence aloft. The latest NHC intensity forecast is similar to the previous one, showing the system dissipating late Tuesday and degenerating into a surface trough shortly thereafter. FORECAST POSITIONS AND MAX WINDS INIT 28/1500Z 27.1N 44.6W 30 KT 35 MPH 12H 29/0000Z 26.0N 45.5W 30 KT 35 MPH 24H 29/1200Z 24.6N 47.2W 30 KT 35 MPH 36H 30/0000Z 23.4N 48.9W 30 KT 35 MPH...POST-TROP/REMNT LOW 48H 30/1200Z 23.1N 50.9W 25 KT 30 MPH...POST-TROP/REMNT LOW 60H 01/0000Z...DISSIPATED $$ Forecaster Kelly |
| #1280384 (Received by flhurricane at: 4:51 AM 28.Sep.2026) TCDAT1 Tropical Depression Fay Discussion Number 33 NWS National Hurricane Center Miami FL AL062026 900 AM GMT Mon Sep 28 2026 Fay's convection has persisted a bit longer overnight than previously seen the last couple of days. Dvorak intensity estimates appear to have picked up on this, with TAFB providing a subjective estimate of T2.0/30 kt. Based primarily on Fay's satellite presentation since the last advisory, the initial intensity was raised slightly to 30 kt, but Fay remains a tropical depression. The forecast increase in forward speed, as well as a turn to the southwest, is becoming more evident on satellite imagery. For this advisory, the initial motion is set at 210/6 kt. Track guidance remains in fairly good agreement on Fay tracking to the southwest and then west-southwest as it is steered by the prevailing easterlies along the southern periphery of the Atlantic subtropical high. The greatest uncertainty across the guidance is the forward speed of the depression. The latest track forecast shows a faster forward speed over the next 48 h, in close agreement with the HCCA guidance. So long as organized deep convection persists and scatterometry data depicts a closed low, Fay will remain a tropical depression. Even as SHIPS guidance shows Fay entering a favorable environment in terms of SSTs, vertical wind shear, and mid-level moisture, the current forecast thinking is that Fay's presence under mid- to upper-level ridging will drive convergence aloft and weaken its circulation to the point of dissipation. Global models agree on this and have Fay ultimately dissipating during the day Wednesday, with the exception of the UKMET, which holds onto the cyclone through the end of the week. The latest intensity forecast shows Fay becoming post-tropical late Tuesday, with dissipation a day or two later. FORECAST POSITIONS AND MAX WINDS INIT 28/0900Z 27.9N 44.1W 30 KT 35 MPH 12H 28/1800Z 27.0N 44.8W 25 KT 30 MPH 24H 29/0600Z 25.5N 46.3W 25 KT 30 MPH 36H 29/1800Z 24.4N 47.9W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 30/0600Z 23.2N 49.3W 25 KT 30 MPH...POST-TROP/REMNT LOW 60H 30/1800Z...DISSIPATED $$ Forecaster Evans/Hagen/Mahoney |
