Hurricane Earl (1998)

Hurricane Earl was an atypical, disorganized, and short-lived Category 2 hurricane that caused moderate damage throughout the Southeast United States. It formed out of a poorly organized tropical disturbance over the southwest Gulf of Mexico late on August 31, 1998. Tracking towards the northeast, the storm quickly intensified into a hurricane on September 2 and made landfall early the next day near Panama City, Florida. Rapidly tracking towards Atlantic Canada, the extratropical remnants of Earl significantly intensified before passing over Newfoundland on September 6. The remnants were absorbed by former Hurricane Danielle two days later.

Moderate beach erosion occurred along the coasts of Louisiana, Mississippi, Alabama, and Florida as waves reached . Throughout Florida, nearly 2,000 homes were damaged and a few were destroyed. Severe flooding caused by storm surge and heavy rains was the main cause of damage in the state. Offshore, two men drowned after their boat capsized during the storm. A minor tornado outbreak took place in relation to Earl in Florida, Georgia, South Carolina, and North Carolina. A tornado in South Carolina killed one person after completely destroying the occupant's home. In all, three people were killed by Earl and damages were $79 million (1998 USD; $104.4 million 2009 USD).

Meteorological history

Hurricane Earl originated out of a strong tropical wave that moved off the west coast of Africa on August 17. By August 23, a weak area of low pressure developed within the wave and well-developed convective activity was present as it tracked through the Lesser Antilles. Once in the Caribbean, strong wind shear produced by the outflow of Hurricane Bonnie inhibited further development of the system. As it remained well-defined, satellites easily followed the low pressure into the Gulf of Mexico. By August 31, the storm had become sufficiently organized for the National Hurricane Center (NHC) to classify it as Tropical Depression Five. At this time, the depression was located roughly halfway between Mérida and Tampico, Mexico.

Operationally, the NHC immediately classified the system as Tropical Storm Earl based on a Hurricane Hunter Reconnaissance mission that found flight-level winds of , corresponding to surface winds of . Due to the existence of multiple circulation centers, the initial movement of the storm was uncertain, but forecasters anticipated a general northward movement. In post-season analysis, it was determined that the system intensified into Tropical Storm Earl while located about south-southwest of New Orleans. Initial advisories on Earl relocated the center of circulation several times before focusing on the true circulation center.

By September 1, the storm began to consolidate, with reconnaissance flights finding an elongated center and surface winds of . Moderate wind shear inhibited convective development in the western portion; however, outflow in other areas of the storm improved, leading to further development. A northwest track, fully identified by this time as a mid-tropospheric ridge located over Florida, strengthened. Remaining disorganized, Earl continued to intensify as the center of circulation was located close to deep convection. The NHC stated in their fifth advisory on the storm that Earl did not appear to be fully tropical due to the lack of organization. Around 1200 UTC on September 2, Earl intensified into a hurricane despite having an atypical structure; the wind field of the storm was asymmetric and the strongest winds were located well to the southeast of the center.

Several hours after becoming a hurricane, Earl further intensified into a Category 2 hurricane on the Saffir–Simpson Hurricane Scale; this observation was based on a flight-level winds of , which corresponded to surface winds of . The storm did not feature an eye or partial eyewall. The central barometric pressure continued to fall despite the fact that the storm was beginning to weaken. Around 0000 UTC on September 3, the central pressure decreased to ; however, winds also decreased to . As Earl neared landfall, cloud tops significantly warmed, indicating weakening, and the overall structure of the storm became less organized.

Around 0600 UTC (1:00 am EDT) on September 3, Hurricane Earl made landfall near Panama City, Florida with winds of . Shortly after landfall, the storm weakened to a tropical storm and rapidly accelerated as it quickly underwent an extratropical transition. By this time the NHC issued their final advisory on Earl. Several hours later, Earl finished its transition and continued to rapidly track through the Southeast United States. After entering the Atlantic Ocean, the remnants of Earl began re-intensify due to the effects of a baroclinic zone. Relatively cool sea surface temperatures near Atlantic Canada prevented tropical development; however, during a 36-hour span, Earl rapidly intensified, as the central barometric pressure decreased by 40 mbar (hPa; ) to 957 mbar (hPa; ). By the time the system made landfall over eastern Newfoundland, sustained winds had intensified to . On September 8, the remnants of Earl significantly weakened and were soon absorbed by a larger extratropical cyclone associated with the remnants of Hurricane Danielle.

Preparations

As Earl tracked towards the northeastern Gulf of Mexico on September 1, a hurricane warning was issued for coastal areas between Pascagoula, Mississippi and Cameron, Louisiana. Additionally, hurricane watches extended out to Destin, Florida and High Island, Texas from the edges of the warning respectively. Early the next day, a tropical storm warning was issued for areas between Pascagoula, Mississippi and Destin, Florida. In response to the eastward movement of the hurricane, the hurricane watch and warning was discontinued for areas west of Morgan City, Louisiana. Additionally, the hurricane warning was extended eastward to Destin, Florida, a tropical storm warning was issued east of Destin to Apalachicola, Florida, and a tropical storm watch was declared for areas between Morgan City and Cameron, Louisiana. Several hours later, the hurricane warning was again extended eastward to the mouth of the Suwannee River. All watches and warnings were discontinued for areas west of Pascagoula, Mississippi and due to the asymmetrical structure of Hurricane Earl, a tropical storm warning was issued as far south as the Florida Keys. Continuing uncertainty in the track of Earl prompted the issuance of a hurricane watch and tropical storm warning for areas between Pascagoula, Mississippi and Grand Isle, Louisiana, including the city of New Orleans. After Earl made landfall in Florida, all watches and warnings were discontinued in relation to the storm.

Offshore, several oil and natural gas rigs were evacuated due to the proximity of Earl. An estimated 10,000 workers were evacuated from both onshore and offshore rigs. The storm forced many Florida residences to evacuate, especially people living in the barrier islands along the Florida Gulf Coast. About 30 Air Force jets from Eglin Air Force Base were sent to Oklahoma to protect them from the storm. A mandatory evacuation was issued for 20,000 residents in Leon County as well as all barrier islands along the Florida coast due to the risk of substantial flooding. Franklin County was briefly under a mandatory evacuation order on September 2, the reasons for the lifting of the order are unknown. State parks along the Florida Panhandle were also closed and highways became congested with thousands of residents and tourists evacuating the barrier islands.

Along the Louisiana coastline, voluntary evacuation orders were given out. A state of emergency was declared for portions of southeast Louisiana as tides in relation to the storm were forecast to reach . Emergency shelters were opened throughout Plaquemines Parish, schools were closed in many areas, and the floodgates around New Orleans were shut. An estimated 5,000 people evacuated to inland areas throughout Louisiana. In Nueces County, Texas, work crews worked quickly to clear garbage along the streets and picked up trash cans to avoid possible problems with clogged drains. Throughout the Alabama and Mississippi coasts, schools were closed due to the storm.

Impact

Throughout the Southeast United States, Hurricane Earl killed three people and caused $79 million (1998 USD; $104.4 million 2009 USD) in damages.

Florida

Ahead of Hurricane Earl's landfall in Florida, several tornadoes were spawned along the outer bands