Tag Archives: Grand Isle

Zeta Strengthens Back to a Hurricane

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.

Tropical Storm Cristobal Causes Storm Surge on Gulf Coast

Tropical Storm Cristobal caused a storm surge on the Gulf Coast on Sunday.  At 11:00 p.m. EDT on Sunday the center of Tropical Storm Cristobal was located at latitude 30.3°N and longitude 90.2°W which put it about 20 miles (30 km) north-northwest of New Orleans, Louisiana.  Cristobal was moving toward the north-northwest at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 993 mb.

A Tropical Storm Warning remained in effect for the portion of the coast from Morgan City, Louisiana to the Okaloosa/Walton County Line in Florida.

The large circulation around Tropical Storm Cristobal blew water toward the northern coast of the Gulf of Mexico on Sunday.  The wind produced a rise in the water level from northwest Florida to southeast Louisiana.  The highest storm surges occurred along the coast of Mississippi and southeast Louisiana.  The water level reached 7.47 feet (2.28 m) at the Waveland Yacht Club in Mississippi.  The storm surge was 7.62 feet (2.32 m) at Shell Beach in Louisiana.  The storm surge covered coastal roads in Grand Isle, Louisiana and Biloxi, Mississippi.

The broad center of Tropical Storm Cristobal passed across the Lower Mississippi River delta on Sunday afternoon before it moved over New Orleans.  Cristobal began to weaken slowly as it moved inland.  Winds to tropical storm force were still occurring in the southeastern part of the circulation which was still over the Gulf of Mexico.  Most of the rain was falling in bands on the northern side of Tropical Storm Cristobal.  Locally heavy rain fell over Northwest Florida, Southwest Alabama, Southern Mississippi and Southeastern Louisiana.

Tropical Storm Cristobal will move around the western end of a subtropical high pressure system over the western Atlantic Ocean.  The high will steer Cristobal toward the north during the next several days.  On its anticipated track Tropical Storm Cristobal will move over Louisiana and Arkansas on Monday.  Cristobal will continue to weaken slowly as it moves farther inland.  Tropical Storm Cristobal will drop locally heavy rain over parts of Mississippi, eastern Louisiana, Arkansas and Missouri.  Flood Watches have been issued for some of those areas.

Large Tropical Storm Cristobal Churns Toward Louisiana

Large Tropical Storm Cristobal churned toward the coast of Louisiana on Saturday night.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Cristobal was located at latitude 26.2°N and longitude 90.2°W which put it about 200 miles (320 km) south of Grand Isle, Louisiana.  Cristobal was moving toward the north at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 993 mb.

A Tropical Storm Warning was in effect for the portion of the coast from Intracoastal City, Louisiana to the Okaloosa/Walton County Line in Florida including Lake Pontchartrain and Lake Maurepas.

The circulation around Tropical Storm Cristobal continued to be very large.  Winds to tropical storm force extended out 250 miles (400 km) to the east of the center of Cristobal.  A thunderstorm in a rainband on the eastern periphery of the circulation around Tropical Storm Cristobal produced a tornado near Orlando, Florida.  Winds to tropical storm force extended out 160 miles (260 km) in the western half of the circulation.  The winds were blowing at less than tropical storm force near the center of circulation.  The center passed just to the west of NOAA buoy 42001 on Saturday evening.  The buoy measured a surface pressure of 29.34 inches (993.8 mb).  More thunderstorms appeared to be forming north and south of the center of circulation on Saturday night.

Tropical Storm Cristobal will move through an environment favorable for intensification during the next 12 to 18 hours.  Cristobal will move over water where the Sea Surface Temperature is near 27°C.  It will move under the western side of an upper level ridge.  The ridge will produce southerly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear but the the shear will not be great enough to prevent intensification.  Tropical Storm Cristobal will strengthen on Sunday.  If thunderstorms consolidate around the center of circulation, then there is a chance that Cristobal could strengthen into a hurricane.

Tropical Storm Cristobal will move around the western end of a subtropical high pressure system on Sunday.  The high will steer Cristobal toward the north.  A ridge in the middle troposphere will move north of Tropical Storm Cristobal later on Sunday.  The ridge will turn Cristobal toward the north-northwest.  On its anticipated track Tropical Storm Cristobal will approach the coast of Louisiana on Sunday afternoon.  The center of Cristobal could make landfall between Grand Isle and Morgan City.

Tropical Storm Cristobal will bring gusty winds to Northwest Florida, Southwest Alabama, Southern Mississippi and Southeastern Louisiana.  Those winds will push water toward the coast.  A storm surge of 1 to 4 feet (0.3 to 1.3 meters) will be possible.  The water level could rise 3 to 6 feet (1 to 2 meters) in parts of southeastern Louisiana.  Areas outside of levee protection systems could go under water.  Tropical Storm Cristobal will drop heavy rain over parts of southern Mississippi and Southeastern Louisiana.  Flash Flood Watches have been issued for those regions.