Zeta strengthened back to a hurricane on Tuesday night. At 8:00 a.m. EDT on Wednesday the center of Tropical Storm Zeta was located at latitude 26.0°N and longitude 91.7°W which put it about 295 miles (470 km) south-southwest of New Orleans, Louisiana. Zeta was moving toward the north at 17 m.p.h. (28 km/h). The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 110 m.p.h. (175 km/h). The minimum surface pressure was 978 mb.
A Hurricane Warning was in effect for the portion of the coast from Morgan City, Louisiana to the Mississippi/Alabama border. The Hurricane Warning included New Orleans, Lake Pontchartrain and Lake Maurepas. A Tropical Storm Warning was in effect for the portion of the coast from the Mississippi/Alabama border to the Walton/Bay County line in Florida. A Tropical Storm Watch was in effect for the portion of the coast from Intracoastal City to Morgan City, Louisiana.
After weakening to a tropical storm when it passed over the Yucatan Peninsula on Tuesday morning, Zeta intensified back to a hurricane over the Gulf of Mexico on Tuesday night. A circular eye with a diameter of 30 miles (50 km) developed at the center of the eye. The ring of thunderstorms around the eye strengthened during the night and the strongest winds were occurring in that ring of storms. Storms near the core of Hurricane Zeta generated upper level divergence which pumped mass away to the north of the hurricane. Winds to hurricane force were occurring mainly in the eastern side of Zeta. Winds in the western side of the circulation were blowing at less than hurricane force.
Winds to hurricane force extended out 35 miles (55 km) on the eastern side of Hurricane Zeta. Winds to tropical storm force extended out 150 miles (240 km) from the center. The Hurricane Intensity Index (HII) for Hurricane Zeta was 13.9. The Hurricane Size Index (HSI) was 8.7 and the Hurricane Wind Intensity Size Index (HWISI) was 22.6. Hurricane Zeta was capable of causing localized serious damage.
Hurricane Zeta will move through an environment favorable for intensification during the next few hours. Zeta will move over water where the Sea Surface Temperature is near 27°C when it reaches the Gulf. It will be under the western part of an upper level ridge where the upper level winds are weak and there will be little vertical wind shear. Zeta is likely to intensify further during the next few hours and it could strengthen to Category 2 on the Saffir-Simpson Scale. An upper level trough over the south central U.S. will produce southwesterly winds which will blow toward the top of Hurricane Zeta later today. Those winds will cause more vertical wind shear and Zeta could weaken when it moves over the northern Gulf of Mexico. However, Zeta will be moving more quickly at that time and it may not weaken much before it reaches the Gulf Coast.
The upper level trough is likely to steer Hurricane Zeta toward the northeast as it approaches the Gulf Coast. Zeta could approach the coast of southeast Louisiana on Wednesday afternoon. Hurricane Zeta is likely to make landfall near Grand Isle, Louisiana. The center of Hurricane Zeta will pass very close to New Orleans and that city could experience hurricane force winds. The strongest winds will be on the eastern side of Zeta, which could also bring hurricane force winds to the coast of Mississippi. Places west of Grand Isle will experience weaker winds. Winds blowing water toward the coast could cause a storm surge of up to 8 to 12 feet (2.5 to 4 meters) along the coast of Mississippi.
Hurricane Zeta will weaken when it moves inland. Zeta will be strong enough to cause widespread power outages in southeastern Louisiana, southern Mississippi, and central and southern Alabama. Zeta will also drop locally heavy rain over parts of the southeastern U.S. Flash Flood Watches extend from southeastern Louisiana to northern Georgia, western North Carolina and eastern Tennessee.