Tropical Storm Isaias Forecast Discussion Number 6

What happened Source facts

Issued at 1000 PM CDT Wed Oct 07 2026 000 WTNT44 KNHC 080253 TCDAT4 Tropical Storm Isaias Discussion Number 6 NWS National Hurricane Center Miami FL AL092026 1000 PM CDT Wed Oct 07 2026 Aircraft data and satellite trends indicate Isaias has continued intensifying this evening. The center of the tropical cyclone is embedded underneath a small central dense overcast with very cold tops associated with deep convection. Upper-level outflow is observed in all quadrants, though it remains somewhat restricted to the southwest due to moderate vertical wind shear. Data from the Air Force Hurricane Hunters indicates the central pressure has fallen to 988 mb, and on the last fix they reported a circular eyewall open to the southwest. Based on these developments, the initial intensity is raised to 60 kt. Aircraft fixes indicate the center is still moving toward the east-northeast (070/8 kt). The system is expected to accelerate northeastward tomorrow and then northward on Friday within the flow between a deepening trough over the south-central United States and a strengthening subtropical ridge over the western Atlantic. This steering pattern is forecast to bring the center of Isaias to the northern Gulf Coast late Friday night into early Saturday. There were no major changes to the guidance suite, with the AI-based models generally faster and farther right than the physics-based models. The NHC forecast continues to lean more heavily on the better-performing corrected consensus (HCCA) and Google DeepMind (GDMI) aids, remaining on the faster and right side of the guidance envelope. The inland track at 60-72 h was shifted westward as more models now show Isaias becoming captured by the cutoff low over the southeastern United States. Continued strengthening is expected during the next day or so as Isaias moves over very warm waters in a moist environment with moderate vertical wind shear. Given its small size and formative inner core, rapid intensification is a distinct possibility, and the NHC forecast lies on the high end of the intensity guidance. The shear is predicted to markedly increase on Friday while Isaias approaches the northern Gulf Coast, but the system is expected to remain a dangerous hurricane through landfall. Gusty winds are expected well inland after landfall given the anticipated expansion of the wind field and fast forward speed of the storm. Hurricane, Storm Surge, and Tropical Storm Warnings have been issued with this advisory for portions of the northern Gulf Coast. Key Messages: 1. Isaias is expected to strengthen and be a strong hurricane when it approaches the northern Gulf Coast on Friday. A life-threatening storm surge is expected along a portion of the northern Gulf Coast, and a Storm Surge Warning is now in effect from the Mouth of the Mississippi River to Steinhatchee, Florida. Residents in the warning area should follow advice given by local officials and evacuate if told to do so. 2. Damaging hurricane force-winds are expected over portions of the Florida Panhandle, southern Alabama, and southern Mississippi, and a Hurricane Warning is now in effect from Ocean Springs, Mississippi to the Bay/Gulf County Line, Florida. Residents in these areas should prepare for the possibility of long-duration power outages. 3. Isaias will bring areas of heavy rainfall to the central U.S. Gulf coast and much of the Southeast Friday into the weekend. Flash and urban flooding, along with isolated river flooding, will be possible. 4. Isaias could bring gusty winds and areas of heavy rain to the western portion of the Yucatan Peninsula through Thursday. FORECAST POSITIONS AND MAX WINDS INIT 08/0300Z 22.9N 91.9W 60 KT 70 MPH 12H 08/1200Z 23.4N 90.7W 75 KT 85 MPH 24H 09/0000Z 24.7N 89.1W 85 KT 100 MPH 36H 09/1200Z 26.8N 87.9W 95 KT 110 MPH 48H 10/0000Z 29.6N 87.3W 90 KT 105 MPH 60H 10/1200Z 32.5N 87.5W 50 KT 60 MPH...INLAND 72H 11/0000Z 35.1N 88.0W 25 KT 30 MPH...POST-TROP/INLAND 96H 12/0000Z...DISSIPATED $$ Forecaster Reinhart

Recorded source facts

Issued at 1000 PM CDT Wed Oct 07 2026 000 WTNT44 KNHC 080253 TCDAT4 Tropical Storm Isaias Discussion Number 6 NWS National Hurricane Center Miami FL AL092026 1000 PM CDT Wed Oct 07 2026 Aircraft data and satellite trends indicate Isaias has continued intensifying this evening. The center of the tropical cyclone is embedded underneath a small central dense overcast with very cold tops associated with deep convection. Upper-level outflow is observed in all quadrants, though it remains somewhat restricted to the southwest due to moderate vertical wind shear. Data from the Air Force Hurricane Hunters indicates the central pressure has fallen to 988 mb, and on the last fix they reported a circular eyewall open to the southwest. Based on these developments, the initial intensity is raised to 60 kt. Aircraft fixes indicate the center is still moving toward the east-northeast (070/8 kt). The system is expected to accelerate northeastward tomorrow and then northward on Friday within the flow between a deepening trough over the south-central United States and a strengthening subtropical ridge over the western Atlantic. This steering pattern is forecast to bring the center of Isaias to the northern Gulf Coast late Friday night into early Saturday. There were no major changes to the guidance suite, with the AI-based models generally faster and farther right than the physics-based models. The NHC forecast continues to lean more heavily on the better-performing corrected consensus (HCCA) and Google DeepMind (GDMI) aids, remaining on the faster and right side of the guidance envelope. The inland track at 60-72 h was shifted westward as more models now show Isaias becoming captured by the cutoff low over the southeastern United States. Continued strengthening is expected during the next day or so as Isaias moves over very warm waters in a moist environment with moderate vertical wind shear. Given its small size and formative inner core, rapid intensification is a distinct possibility, and the NHC forecast lies on the high end of the intensity guidance. The shear is predicted to markedly increase on Friday while Isaias approaches the northern Gulf Coast, but the system is expected to remain a dangerous hurricane through landfall. Gusty winds are expected well inland after landfall given the anticipated expansion of the wind field and fast forward speed of the storm. Hurricane, Storm Surge, and Tropical Storm Warnings have been issued with this advisory for portions of the northern Gulf Coast. Key Messages: 1. Isaias is expected to strengthen and be a strong hurricane when it approaches the northern Gulf Coast on Friday. A life-threatening storm surge is expected along a portion of the northern Gulf Coast, and a Storm Surge Warning is now in effect from the Mouth of the Mississippi River to Steinhatchee, Florida. Residents in the warning area should follow advice given by local officials and evacuate if told to do so. 2. Damaging hurricane force-winds are expected over portions of the Florida Panhandle, southern Alabama, and southern Mississippi, and a Hurricane Warning is now in effect from Ocean Springs, Mississippi to the Bay/Gulf County Line, Florida. Residents in these areas should prepare for the possibility of long-duration power outages. 3. Isaias will bring areas of heavy rainfall to the central U.S. Gulf coast and much of the Southeast Friday into the weekend. Flash and urban flooding, along with isolated river flooding, will be possible. 4. Isaias could bring gusty winds and areas of heavy rain to the western portion of the Yucatan Peninsula through Thursday. FORECAST POSITIONS AND MAX WINDS INIT 08/0300Z 22.9N 91.9W 60 KT 70 MPH 12H 08/1200Z 23.4N 90.7W 75 KT 85 MPH 24H 09/0000Z 24.7N 89.1W 85 KT 100 MPH 36H 09/1200Z 26.8N 87.9W 95 KT 110 MPH 48H 10/0000Z 29.6N 87.3W 90 KT 105 MPH 60H 10/1200Z 32.5N 87.5W 50 KT 60 MPH...INLAND 72H 11/0000Z 35.1N 88.0W 25 KT 30 MPH...POST-TROP/INLAND 96H 12/0000Z...DISSIPATED $$ Forecaster Reinhart